CHAPTER-4 PLANT PROFILE AND EVALUATION OF ANTIEPILEPTIC ACTIVITY OF ACALYPHA FRUTICOSA

Transcription

1 43 CHAPTER-4 PLANT PROFILE AND EVALUATION OF ANTIEPILEPTIC ACTIVITY OF ACALYPHA FRUTICOSA S. No Name of the Sub-Title Page No 4.1 Taxonomy Distribution Description Chemical constituents Traditional uses Previous Investigations Reason for selection Materials and methods Results Discussion 84-88

2 44 Fig: 4.1. Acalypha fruticosa Fig: 4.2. Acalypha fruticosa

3 Taxonomy Kingdom Phylum Class Order Family Genus Species Synonyms : Plantae : Magnoliophyta : Magnoliopsida : Euphorbiales : Euphorbiaceae : Acalypha : fruticosa : Ricinocarpus fruticosus, Acalypha betulina Common name: Birched-leaved Acalypha. Vernacular Names Telugu Kannada Malayalam Tamil : cinnaku, chinni, cinni, tsinnie, chinnaaku, mabbaku : chinee mara, chinni, chinnimara, cinni. : perim-munja : siru sinni, cinni, kittik-kilanku, sinni, cinniver, perun cinni, chinni Distribution Acalypha fruticosa (Euphorbiaceae) commonly known as Chinnichedi and Birch-leaved Acalypha is a strong smelling pubescent and bushy shrub found in India from Orissa to Karnataka, Tamil Nadu and Kerala Description Monoecious, much-branched, aromatic shrub upto 4 m tall. Stems hairy and green first, later almost glabrous and reddish brown. Leaves are simple and arranged spirally. Stipules are brown, 3-4 mm long

4 46 and narrowly lanceolate; petiole cm long; blade broadly ovate to rhombic ovate, 1-9 cm X 1-5 cm, base cuneate to rounded, apex is acuminate with toothed margins, sparingly to evenly yellowish glanddotted beneath and membranous, 5-7 veined at base and with 2-5 pairs of lateral veins. Inflorescence an axillary, solitary spike upto 5 cm long, the lower part interrupted, with 1-7 female flowers, the upper part consists of densely congested male flowers, ending with a female flower; peduncle hairy; bracts in female flowers broadly ovate to kidney shaped, 1 cm X cm, toothed, sparingly yellow gland-dotted and prominently ribbed. Flowers are unisexual, sessile and petals are absent; male flowers consist of 4-lobes with minute, densely white hairy calyx and 8 stamens; female flowers consist of 3 ovate-lanceolate, 1 mm long, ciliate sepals, ovary superior, 0.5 mm in diameter, 3-celled, 3-lobed to almost globose, densely shortly hairy, styles 3, free, 4 mm long, fringed, pink or red. Fruit a 3-lobed capsule 2 mm X 3 mm, yellow gland-dotted, densely shortly hairy. Fruit is splitted into 3 cocci with 2-valves and 1-seed each. Seeds ellipsoid-ovoid, mm X mm, smooth, brown, caruncle elliptical Chemical Constituents Alkaloids, anthraquinones, coumarins, flavonoids, phenols, quinones, tannins, terpenoids, saponins and steroids [102].

5 Traditional uses In traditional system of medicine the young twigs and leaves of the plant are prescribed in the treatment of dyspepsia, colic, diarrhoea and in cholera. The Paliyar and Irula tribes in Western Ghats of South India use leaves and roots of Acalypha fruticosa to treat stomachache, skin diseases, wounds and poisonous bites [103]. In Siddha Materia Medica it is used to treat poisonous bites. Medicinally the leaves are used as stomachic in dyspepsia, attenuant, alterative and vulnerary [104]. In Yemen, leaf and stem have been used to treat skin diseases, malaria and wounds [105]. In Tanzania, a leaf decoction is drunk to treat epilepsy. Leaf maceration is used to treat eye infections. A leaf infusion is used to treat stomach problems and swellings of the body. Leaf sap is used as nose drops to treat cough and chest problems. Leaf paste is applied to scabies and sores. Stems ground in water are applied to wounds of animals. The Suiei hunter-gatherers of northern Kenya used root decoction to treat convulsions, colds, fever and swellings of the scrotum. They used root infusion to treat whooping cough. They chewed stem and root to relieve toothache. In southern Africa a root decoction is taken to treat snakebites, fever and ulcers of venereal origin. Ground fresh leaves mixed with water are rubbed in and inhaled as a sedative [21] Previous Investigations Mathad et al., evaluated the antidiarrhoeal activity of methanol and aqueous extracts of Acalypha fruticosa leaves by using

6 48 castor oil-induced diarrhoea model in rats. They reported that methanol and aqueous extracts decreased propulsion of the charcoal meal (p<0.001) through the gastrointestinal tract at the oral dose of 200mg/kg as compared with control group [106]. Gupta et al., reported the antioxidant and anti-inflammatory activities of the methanol extract of the leaves of Acalypha fruticosa by DPPH radical scavenging assay and in vitro lipid perioxdation induced by Fe 2+ -ascorbate system in the rat liver homogenate, carrageenan induced paw oedema and cotton pellet induced granuloma in rats. They reported that the extract showed marked free radical scavenging activities in DPPH radical scavenging assay, in vitro lipid perioxidation induced by Fe 2+ -ascorbate system in the rat liver homogenate and significant anti-inflammatory activity in carrageenan-induced paw oedema in rats [107]. Duraipandiyan and coworkers reported the antimicrobial activity of the hexane and methanol extracts of Acalypha fruticosa against some bacterial strains. They reported that the methanol extract showed significant activity against tested organisms when compared to hexane extract [108]. Alshawsh and coworkers reported the antimalarial activity of the methanol and aqueous extracts of Acalypha fruticosa leaves against Plasmodium falciparum. They found that the extract have significant antiplasmodial activity with IC 50 values less than 4µg/ml [109].

7 49 Mothana et al., investigated the antimicrobial activity of the methanolic and aqueous extracts of Acalypha fruticosa using agar diffusion method. They also studied the antioxidant activity using scavenging activity of DPPH radical method and cytotoxic activity using the neutral red uptake assay. They reported that the methanol extract showed antibacterial activity only against Gram-positive bacteria, high free radical scavenging activity and remarkable cytotoxic activity against FL-cells [110]. Lingathurai and coworkers proved the antifeedant and larvicidal activities of the n-hexane, chloroform and ethylacetate extracts of Acalypha fruticosa leaves against Plutella xylostella larvae using leaf disc no-choice method. They reported that the chloroform extract showed maximum antifeedant activity [111]. Gopalakrishnan and coworkers investigated the wound healing activity of the ethanol extract of the aerial parts of Acalypha fruticosa by excision and dead space wound models in rats and reported that the extract showed significant wound healing activity [112]. Sivakumar et al., reported the anti-tumor activity of the methanol extract of the leaves of Acalypha fruticosa against Ehrlich s Ascites Carcinoma (EAC) bearing Swiss albino mice. They proved that the extract showed remarkable decrease in tumor volume and viable cell count and prolonged the life span of EAC tumor bearing mice and also significantly decreased the lipid peroxidation while it increased the glutathione content and

8 50 superoxide dismutase level as compared to that of EAC control group [113]. Ireri and coworkers reported the insecticidal activity of the methanol and ethyl acetate extracts of aerial parts of Acalypha fruticosa against sandflies (Phlebotomus duboiscqi). They reported that the extracts were found to be insecticidal to adult sandflies [114]. Rajkumar et al., reported the antioxidant activity of Acalypha fruticosa by Ferric reducing antioxidant property (FRAP) assay, radical scavenging assays (DPPH and hydroxyl) and thiobarbituric acid (TBA) assay. They assessed the cytotoxicity by XTT assay in MDA-MB-435S (human breast carcinoma cell line) and Hep3B (human hepatocellular carcinoma) and DNA protective efficiency using UV-photolysed H2O2-driven oxidative damage to pbr322. They reported that both the extracts exhibited promising antioxidant potentials and marginal cytotoxicity to the tested cell lines [115]. Sripathi and Sankari evaluated the antibacterial activity of the ethanol extract of Acalypha fruticosa against Streptococci sp, Escherichia coli and Proteus sp. and reported that the extract showed moderate activity against chosen strains [116]. Gopalakrishnan et al., identified 1, 2-Benzene dicarboxylic acid di isooctyl ester, n-hexadecanoic acid, 9,12-octadecadienoic acid (Z, Z), α-d-glucopyranoside and eicosyl trichlorosilane from

9 51 the aerial parts of Acalypha fruticosa by GC-MS analysis of the ethanol extract [102]. Deepa et al., isolated β caryophyllene, α-humulene, isocaryophyllene, caryophyllene oxide and tans-phytol from the essential oil of Acalypha fruticosa leaves [117] Reason for selection Aerial parts of Acalypha fruticosa were traditionally used to treat epilepsy [21]. But till today, there were no reports to justify its claim. Hence the present work was designed to prepare petroleum ether, chloroform, ethanol, aqueous extracts of Acalypha fruticosa and evaluate the antiepileptic activity by using three models namely MES, PTZ and INH-induced convulsions in mice Materials and methods Drugs and Chemicals Isoniazid (S.D. Fine-Chem. Ltd), Diazepam (Ranbaxy), Phenobarbitone sodium (Bayer AG) and Pentylenetetrazole (Sigma Aldrich Chemical Co.). All other chemicals used are of Merck, India (LR grade) Plant collection The aerial parts of Acalypha fruticosa were collected from Tirupati, Andhra Pradesh, India. The aerial parts of the plant were identified and authenticated by Botanist, Dr. K. Madhava Chetty, Assistant Professor, Department of Botany, Sri Venkateswara University, Tirupati. The plant specimen was deposited at Sri Venkateswara University Herbarium, Tirupati with voucher number 1252.

10 Preparation of the extracts The fresh aerial parts of Acalypha fruticosa were collected, shade dried and was made in to coarse powder. Then petroleum ether, chloroform, ethanol and aqueous extracts were prepared by following maceration method [118] Preliminary Phytochemical Studies Different extracts of plant were subjected to qualitative chemical tests for various phytoconstituents like alkaloids, carbohydrates, flavonoids, lipids, proteins, saponins, steroids and tannins. The various tests and reagents used are given below [119]. Table 4.1. Preliminary Phytochemical studies Phytoconstituents Chemical test Alkaloids Dragendorff s test Carbohydrates Molisch test Flavonoids Shinoda test Lipids Filter paper test Proteins Biuret test Saponins Foam test Steroids Liebermann-Burchard test Tannins Ferric chloride test Pharmacological Investigations Animals Young adult Swiss albino rats of either sex weighing ( g) and Swiss albino mice of either sex, weighing (25 30 g) were procured from M/s Mahavir Enterprises, Hyderabad. They were housed in standard polypropylene cages and kept under controlled room

11 53 temperature (24±2 0 C; relative humidity 60-70%) in a 12h light dark cycle. The rats and mice were given a standard laboratory diet and water ad libitum. The animals were acclimatizated before the study. The experimental protocol was approved by the Institutional Animals Ethics Committee (IAEC) of Talla Padmavathi College of Pharmacy, Warangal, Andhra Pradesh (CPCSEA no. 1505/PO/a/11/CPCSEA) Acute toxicity studies Acute toxicity study was performed for the extracts to ascertain safe dose by acute oral toxic class method of Organization of Economic Co-operation and Development, as per 420 guidelines (OECD). Young adult Swiss albino rats and Swiss albino mice of either sex were used for the study. Each extract of plant was tested in both the species upto a dose of 2000 mg/kg, body weight [120] Evaluation of Anti-epileptic activity Maximum Electroshock (MES) in mice Five groups of six Swiss albino mice (25 30 g) of either sex were used. Mice belonging to Group I were treated with the vehicle, Group II, III and IV were treated with different doses (30, 100 and 300 mg/kg, p.o.) of Acalypha fruticosa respectively. Mice belonging to Group V received diazepam (standard) at the dose of 3 mg/kg, p.o. The test was started one hour after oral treatment with the extract or the vehicle or the standard. Tonic hind limb extensions were induced by an apparatus with corneal electrodes. The intensity of the stimulus was dependent on the apparatus, eg: 45 ma, 50Hz for 0.2 sec has

12 54 been used. Percentage of inhibition of convulsions relative to control was calculated [40]. Control - Treated Percentage of Inhibition = X 100 Control Same treatment schedule was followed for chloroform, ethanol and aqueous extracts Pentylenetetrazole (PTZ)-induced convulsions Mice of either sex were randomly allotted to five different groups of six mice each. Mice belonging to Group I received the vehicle, Group II, III and IV received Acalypha fruticosa at the doses of 30, 100 and 300 mg/kg, p.o. respectively. Mice belonging to Group V received phenobarbitone sodium (standard) at the dose of 40 mg/kg, i.p. Mice belonging to Group I were administered with pentylenetetrazole (PTZ) (75 mg/kg, i.p.) one hour after vehicle. Mice belonging to Group V received PTZ, 15 min after phenobarbitone sodium (40 mg/kg, i.p.). Mice belonging to Group II, III and IV mice received different doses of plant extracts, p.o. one hour before PTZ. Onset time as well as duration of convulsions were recorded [85]. Same treatment schedule was followed for chloroform, ethanol and aqueous extracts Isoniazid (INH)-induced convulsions Five Groups of six Swiss albino mice (25 30 g) of either sex were used. Mice belonging to Group I were treated with the vehicle, Group II, III and IV were treated with different extracts of Acalypha fruticosa

13 55 at the doses of 30, 100 and 300 mg/kg, p.o. Mice belonging to Group V received the standard drug, diazepam at the dose of 4 mg/kg, i.p. One hour after the administration of vehicle or different extracts of Acalypha fruticosa, isoniazid at a dose of 300mg/kg, s.c. was administered to mice belonging to Group I, II, III, IV and 15 min after administration of diazepam to mice belonging to Group V. The mice were placed in isolated perplex chamber and the latency of convulsions was recorded [121]. Same treatment schedule was followed for chloroform, ethanol and aqueous extracts Statistical analysis: The data was analyzed using one-way analysis of variance (ANOVA), followed by Dunnett s test and p<0.05 was considered as statistically significant. The data was expressed as mean ± Standard deviation (SD) Results Percentage yield of different extracts of Acalypha fruticosa After extraction with different solvents by maceration method, the percentage yield was calculated. The percentage yield obtained for petroleum ether extract-12.74, chloroform extract-14.55, ethanol extract and aqueous extract Preliminary Phytochemical Studies Preliminary phytochemical studies gave positive tests for alkaloids, steroids, carbohydrates, tannins, flavanoids, saponins, lipids and proteins in various extracts of the plants.

14 56 Table 4.2. Preliminary Phytochemical studies of Acalypha fruticosa Phytoconstituents PAF CAF EAF AAF Alkaloids -ve - ve + ve + ve Steroids + ve + ve + ve - ve Carbohydrates - ve - ve - ve + ve Tannins - ve - ve + ve + ve Flavonoids - ve + ve + ve - ve Saponins - ve - ve + ve + ve Lipids + ve + ve + ve - ve Proteins - ve - ve - ve + ve Pharmacological Investigations Acute toxicity studies In the acute toxicity studies, mortality was found at 2000mg/kg, p.o. for all the extracts. All the four extracts were found to be safe upto 1000 mg/kg, p.o. Based on the results of the study, three doses of different extracts i.e., 30, 100 and 300 mg/kg, p.o. were selected for the evaluation of anti-epileptic activity Evaluation of Antiepileptic activity Antiepileptic activity of Petroleum ether extract of Acalypha fruticosa (PAF) Maximal electroshock-induced convulsions in mice The average time of onset, duration of tonic hind limb extension (THLE) and percentages of inhibition of convulsions were presented in Table 4.3.

15 57 Effect on onset time of convulsions The onset time of THLE in control group animals was found to be 1.34±0.04 sec. PAF treated mice showed the onset time as 1.89±0.05, 2.25±0.05 and 3.04±0.08 sec (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. Animals treated with diazepam (3 mg/kg, p.o.) showed onset time as 2.48±0.05 sec (p<0.01). Effect on duration of convulsions The duration of THLE in control group animals was ±0.22 sec. Albino mice pretreated with PAF at the doses of 30, 100 and 300 mg/kg, p.o. showed the duration of 67.33±0.08, 58.66±0.06 and 44.79±0.14 sec (p<0.01) respectively. The standard group animals (diazepam 3 mg/kg, p.o.) showed 49.36±0.06 sec (p<0.01). It has been found that the time of onset of THLE in control group animals was very less when compared to that of animals which received extract and standard. Duration of THLE in control group animals was greater when compared to that of animals which received extract and standard. Albino mice pretreated with PAF at the doses of 30, 100 and 300 mg/kg were provided significant protection from convulsions induced by electroshock method. Percentage inhibition of convulsions The percentage of inhibition achieved in mice pretreated with PAF at the doses of 30, 100 and 300 mg/kg were 43.38%, 50.67% and 62.33% (p<0.01) respectively when compared to control group animals. Animals treated with PAF exhibited significant antiepileptic

16 58 activity and more percentage of inhibition of convulsions at the dose of 300 mg/kg when compared to diazepam treated animals (58.49%). Table 4.3. Effect of PAF on maximal electroshock-induced convulsions in mice Group Percentage Onset of Duration of (n=6)= Treatment inhibition of THLE (sec) THLE (sec) 6) convulsions I PAM DMSO 1.34± ± II PAM PAF (30 mg/kg) 1.89±0.05** 67.33±0.08** 43.38** IIIPAM PAF (100 mg/kg) 2.25±0.05** 58.66±0.06** 50.67** IV PAM PAF (300 mg/kg) 3.04±0.08** 44.79±0.14** 62.33** V PAM Diazepam (3 mg/kg) 2.48±0.05** 49.36±0.06** 58.49** PAF: Petroleum ether extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01when compared to Group IPAM (control) Pentylenetetrazole (PTZ)-induced convulsions in mice The average time of onset, duration of convulsions and percentages of inhibition of convulsions were presented in Table 4.4. Effect on onset time of convulsions The onset time of convulsions in control group animals was 3.11±0.04 min. PAF treated mice exhibited the onset time as 3.48±0.05, 3.58±0.01 and 4.24±0.03 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (Phenobarbitone sodium, 40 mg/kg, i.p.) showed 6.36±0.03 min (p<0.01).

17 59 Effect on duration of convulsions The duration of convulsions in control group animals was 22.14±0.05 min. Animals pretreated with PAF at the doses of 30, 100 and 300 mg/kg, p.o. exhibited the duration as 10.43±0.08, 8.59±0.22 and 7.42±0.10 min (p<0.01) respectively. The standard group mice (Phenobarbitone sodium 40 mg/kg, i.p.) showed 11.13±0.05 min (p<0.01). The time of onset of convulsions in control group animals was very less when compared to the animals treated with extract and standard. Duration of convulsions in control group animals was greater when compared to the extract and standard treated animals. It has been found that animals pretreated with PAF were significantly protected from convulsions induced by PTZ in a dose-dependent manner. Percentage inhibition of convulsions The percentage of inhibition achieved in PAF treated mice were 52.89%, 61.20% and 66.49% (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg when compared to control group animals. Animals which were treated with PAF exhibited significant antiepileptic activity and more percentage inhibition of convulsions when compared to Phenobarbitone sodium treated mice (49.73%, p<0.01).

18 60 Table 4.4. Effect of PAF on Pentylenetetrazole (PTZ)-induced convulsions in mice Group Onset of Duration of Percentage (n=6)= 6) Treatment convulsions (min) convulsions (min) inhibition of convulsions IPAP DMSO 3.11± ± II PAP PAF (30 mg/kg) 3.48±0.05** 10.43±0.08** 52.89** IIIPAP PAF (100 mg/kg) 3.58±0.01** 8.59±0.22** 61.20** IV PAP PAF (300 mg/kg) 4.24±0.03** 7.42±0.10** 66.49** V PAP Phenobarbitone sodium 6.36±0.03** 11.13±0.05** 49.73** (40 mg/kg, i.p.) PAF: Petroleum ether extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I PAP (control) Isoniazid (INH)-induced convulsions in mice The average latency of convulsions were presented in Table 4.5. Effect on latency of convulsions The latency of convulsions in control group animals was 25.33±0.03 min. Albino mice pretreated with PAF showed the latency of convulsions of 29.18±0.09, 31.02±0.41 and 34.12±0.06 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (diazepam 4 mg/kg, i.p.) exhibited 63.27±0.04 min (p<0.01). The latency of convulsions in control group animals was very less when compared to that of animals pretreated with extract and standard. Animals treated with PAF showed the latency time more than that of control group animals and less than that of standard

19 61 group animals. Although all the three doses of PAF significantly delayed the latency of convulsions in a dose-dependent manner but failed to protect mice against mortality. Table 4.5. Effect of PAF on Isoniazid (INH)-induced convulsions in mice Group (n=6) Treatment Latency of convulsions (min) I PAI DMSO 25.33±0.03 IIPAI PAF (30 mg/kg) 29.18±0.09** III PAI PAF (100 mg/kg) 31.02±0.41** IV PAI PAF (300 mg/kg) 34.12±0.06** V PAI Diazepam (4 mg/kg, i.p.) 63.27±0.04** PAF: Petroleum ether extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I PAI (control) Anti-epileptic activity of Chloroform extract of Acalypha fruticosa (CAF) Maximal electroshock-induced convulsions in mice The average time of onset, duration of THLE and percentages of inhibition of convulsions were presented in Table 4.6. Effect on onset time of convulsions The onset time of THLE in control group animals was 1.34±0.04 sec. CAF treated mice showed the onset time as 1.97±0.05, 2.57±0.06 and 3.16±0.10 sec (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. Animals which received standard i.e., diazepam (3 mg/kg, p.o.) showed 2.48±0.05 sec (p<0.01).

20 62 Effect on duration of convulsions The duration of THLE in control group animals was ±0.22 sec. Mice pretreated with CAF at the doses of 30, 100 and 300 mg/kg, p.o. showed the duration of 62.07±0.13, 51.96±0.11 and 40.04±0.07 sec (p<0.01) respectively. The standard group mice (diazepam 3 mg/kg, p.o.) showed 49.36±0.06 sec (p<0.01). The time of onset of THLE in control group animals was very less when compared to the extract and standard group animals. Duration of THLE in control group animals was greater when compared to the extract and standard group animals. Albino mice pretreated with CAF at doses 30, 100 and 300 mg/kg provided significant protection from convulsions induced by electroshock method. Percentage inhibition of convulsions The percentage inhibition achieved in CAF treated animals were 47.80% (30 mg/kg), 56.30% (100 mg/kg) and 66.33% (300 mg/kg) (p<0.01) respectively when compared to control group animals. Animals pretreated with CAF exhibited significant antiepileptic activity and more percentage inhibition of convulsions at the dose of 300 mg/kg when compared to diazepam treated animals (58.49%, p<0.01).

21 63 Table 4.6. Effect of CAF on maximal electroshock-induced convulsions in mice Group Percentage Onset of Duration of (n=6)= Treatment inhibition of THLE (sec) THLE (sec) 6) convulsions ICAM DMSO 1.34± ± II CAM CAF (30 mg/kg) 1.97±0.05** 62.07±0.13** 47.80** IIICAM CAF (100 mg/kg) 2.57±0.06** 51.96±0.11** 56.30** IV CAM CAF (300 mg/kg) 3.16±0.10** 40.04±0.07** 66.33** V CAM Diazepam (3 mg/kg) 2.48±0.05** 49.36±0.06** 58.49** CAF: Chloroform extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I CAM (control) Pentylenetetrazole (PTZ)-induced convulsions in mice The average time of onset, duration of convulsions and percentages of inhibition of convulsions were presented in Table 4.7. Effect on onset time of convulsions The onset time of convulsions in control group animals was found to be 3.11±0.04 min. Animals which received CAF at the doses of 30, 100 and 300 mg/kg, p.o. exhibited the onset time as 3.57±0.03, 4.22±0.05 and 4.42±0.05 min (p<0.01) respectively. Animals belonging to standard group (Phenobarbitone sodium, 40 mg/kg, i.p.) showed 6.36±0.03 min (p<0.01). Effect on duration of convulsions The duration of convulsions in control group animals was 22.14±0.05 min. CAF treated mice exhibited the duration as

22 ±0.35, 8.02±0.22 and 7.04±0.24 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (Phenobarbitone sodium 40 mg/kg, i.p.) showed 11.13±0.05 min (p<0.01). The time of onset of convulsions in control group animals was very less when compared to the extract and standard treated animals. Duration of convulsions in control group animals was greater when compared to the extract and standard treated animals. All the three doses of CAF afforded significant protection in dose-dependent manner against convulsions induced by PTZ. Percentage inhibition of convulsions The percentage of inhibition achieved in CAF treated mice were 54.79%, 63.78% and 68.20% (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg when compared to control group animals. Animals pretreated with CAF exhibited significant anti-epileptic activity and more percentage of inhibition of convulsions when compared to Phenobarbitone sodium treated animals (49.73%, p<0.01).

23 65 Table 4.7. Effect of CAF on Pentylenetetrazole (PTZ)-induced convulsions in mice Group (n=6)= 6) Treatment Onset of convulsions (min) Duration of convulsions (min) Percentage inhibition of convulsions I CAP D DMSO MSO 3.11± ± II CAP CAF (30 mg/kg) 3.57±0.03** 10.01±0.35** 54.79** III CAP CAF (100 mg/kg) 4.22±0.05** 8.02±0.22** 63.78** IV CAP CAF (300 mg/kg) 4.42±0.05** 7.04±0.24** 68.20** V CAP Phenobarbitone sodium (40 mg/kg, i.p.) 6.36±0.03** 11.13±0.05** 49.73** CAF: Chloroform extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I CAP (control) Isoniazid (INH)-induced convulsions in mice The average latency of convulsions were presented in Table 4.8. Effect on latency of convulsions The latency of convulsions in control group animals was 25.33±0.03 min. Albino mice pretreated with CAF showed the latency of convulsions of 29.47±0.06, 31.49±0.06 and 35.01±0.22 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. Animals belonging to standard group (diazepam 4 mg/kg, i.p.) showed 63.27±0.04 min (p<0.01). The latency of convulsions in control group animals was very less when compared to the extract and standard group animals. All the three doses of CAF showed the latency of convulsions more than that of control and less than that of standard i.e., diazepam. Although CAF delayed the latency of convulsions in a

24 66 dose-dependent manner, but failed to protect the mice against mortality. Table 4.8. Effect of CAF on Isoniazid (INH)-induced convulsions in mice Group (n=6) Treatment Latency of convulsions (min) I CAI DMSO 25.33±0.03 II CAI CAF (30 mg/kg) 29.47±0.06** III CAI CAF (100 mg/kg) 31.49±0.06** IVCAI CAF (300 mg/kg) 35.01±0.22** V CAI Diazepam (4 mg/kg, i.p.) 63.27±0.04** CAF: Chloroform extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I CAI (control). Duration of THLE (sec) DMSO PAF 30 mg/kg PAF 100 mg/kg PAF 300 mg/kg CAF 30 mg/kg CAF 100 mg/kg CAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: 4.3. Effect of PAF and CAF on duration of maximal electroshockinduced convulsions in mice. Values were mean±s.d (n=6).

25 67 Percentage inhibition of convulsions PAF 30 mg/kg PAF 100 mg/kg PAF 300 mg/kg CAF 30 mg/kg CAF 100 mg/kg CAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: 4.4. Effect of PAF and CAF on maximal electroshock-induced convulsions in mice. Duration of convulsions (min) Treatment DMSO PAF 30 mg/kg PAF 100 mg/kg PAF 300 mg/kg CAF 30 mg/kg CAF 100 mg/kg Fig: 4.5. Effect of PAF and CAF on duration of pentylenetetrazoleinduced convulsions in mice. Values were mean±s.d (n=6).

26 68 Percentage inhibition of convulsions PAF 30 mg/kg PAF 100 mg/kg PAF 300 mg/kg CAF 30 mg/kg CAF 100 mg/kg Treatment CAF 300 mg/kg Fig: 4.6. Effect of PAF and CAF on pentylenetetrazole-induced convulsions in mice. Latency of convulsions (min) DMSO PAF 30 mg/kg PAF 100 mg/kg PAF 300 mg/kg CAF 30 mg/kg CAF 100 mg/kg CAF 300 mg/kg Diazepam 4 mg/kg Treatment Fig: 4.7. Effect of PAF and CAF on isoniazid-induced convulsions in mice. Values were mean±s.d (n=6).

27 Antiepileptic activity of Ethanol extract of Acalypha fruticosa (EAF) Maximal electroshock-induced convulsions in mice The average time of onset, duration of THLE and percentages of inhibition of convulsions were presented in Table 4.9. Effect on onset time of convulsions The onset time of THLE for control group animals was found to be 1.03±0.01 sec. EAF treated mice showed the onset time as 1.47±0.02, 2.59±0.02 and 3.76±0.04 sec (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. Animals treated with diazepam (3 mg/kg, p.o.) showed onset time as 2.85±0.02 sec (p<0.01). Effect on duration of convulsions The duration of THLE in control group animals was ±2.92 sec. Albino mice pretreated with EAF at the doses of 30, 100 and 300 mg/kg, p.o. showed the duration of 55.33±1.21, 46.58±0.92 and 36.09±1.84 sec (p<0.01) respectively. The standard group animals (diazepam 3 mg/kg, p.o.) showed 50.33±1.86 sec (p<0.01). It has been found that the time of onset of THLE in control group animals was very less when compared to that of animals which received extract and standard. Duration of THLE in control group animals was greater when compared to that of animals which received extract and standard. Albino mice pretreated with EAF at the doses of 30, 100 and 300 mg/kg were provided significant protection from convulsions induced by electroshock method.

28 70 Percentage inhibition of convulsions The percentage inhibition achieved in mice pretreated with EAF at the doses of 30, 100 and 300 mg/kg were 52.52%, 60.03% and 69.03% (p<0.01) respectively when compared to control group animals. Animals treated with EAF exhibited significant antiepileptic activity and more percentage of inhibition of convulsions at the doses of both 100 and 300 mg/kg when compared to diazepam treated animals (56.81%). Table 4.9. Effect of EAF on maximal electroshock-induced convulsions in mice Group (n=6)= 6) Treatment Onset of THLE (sec) Duration of THLE (sec) Percentage inhibition of convulsions IEAM Gum acacia 1.03± ± II EAM EAF (30 mg/kg) 1.47±0.02** 55.33±1.21** 52.52** III EAM EAF (100 mg/kg) 2.59±0.02** 46.58±0.92** 60.03** IV EAM EAF (300 mg/kg) 3.76±0.04** 36.09±1. 84** 69.03** V EAM Diazepam (3 mg/kg) 2.85±0.02** 50.33±1.86** 56.81** EAF: Ethanol extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group IEAM (control).

29 71 Duration of THLE (sec) Gum acacia EAF 30 mg/kg EAF 100 mg/kg EAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: 4.8. Effect of EAF on duration of maximal electroshock-induced convulsions in mice. Values were mean±s.d (n=6). Percentage inhibition of convulsions EAF 30 mg/kg EAF 100 mg/kg EAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: 4.9. Effect of EAF on maximal electroshock-induced convulsions in mice.

30 Pentylenetetrazole (PTZ)-induced convulsions in mice The average time of onset, duration of convulsions and percentages of inhibition of convulsions were presented in Table Effect on onset time of convulsions The onset time of convulsions in control group animals was 3.43±0.04 min. EAF treated mice exhibited the onset time as 4.38±0.05, 4.54±0.02 and 5.14±0.03 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (Phenobarbitone sodium, 40 mg/kg, i.p.) showed 6.46 ±0.02 min (p<0.01). Effect on duration of convulsions The duration of convulsions in control group animals was 22.54±0.02 min. Animals pretreated with EAF at the doses of 30, 100 and 300 mg/kg, p.o. exhibited the duration as 9.55±0.02, 7.52±0.05 and 6.58±0.01 min (p<0.01) respectively. The standard group mice (Phenobarbitone sodium 40 mg/kg, i.p.) showed 11.09±0.03 min (p<0.01). The time of onset of convulsions in control group animals was very less when compared to the animals treated with extract and standard. Duration of convulsions in control group animals was greater when compared to the extract and standard treated animals. It has been found that animals pretreated with EAF were significantly protected from convulsions induced by PTZ in a dose-dependent manner.

31 73 Percentage inhibition of convulsions The percentage of inhibition achieved in EAF treated mice were 57.62%, 66.63% and 70.82% (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg when compared to control group animals. Animals which were treated with EAF exhibited significant and dosedependent antiepileptic activity and more percentage inhibition of convulsions when compared to Phenobarbitone sodium treated mice (50.82%, p<0.01). Table Effect of EAF on Pentylenetetrazole (PTZ)-induced convulsions in mice Group (n=6)= 6) Treatment Onset of convulsions (min) Duration of convulsions (min) Percentage inhibition of convulsions I EAP Gum acacia 3.43± ± II EAP EAF (30 mg/kg) 4.38±0.05** 9.55±0.02** 57.62** III EAP EAF (100 mg/kg) 4.54±0.02** 7.52±0.05** 66.63** IV EAP EAF (300 mg/kg) 5.14±0.03** 6.58±0.01** 70.82** V EAP Phenobarbitone sodium 6.46±0.02** 11.09±0.03** 50.82** (40 mg/kg, i.p.) EAF: Ethanol extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I EAP (control).

32 74 Duration of convulsions (min) Gum acacia EAF 30 mg/kg EAF 100 mg/kg EAF 300 mg/kg Phenobarbitone sodium 40 mg/kg Treatment Fig: Effect of EAF on duration of pentylenetetrazole-induced convulsions in mice. Values were mean±s.d (n=6). Percentage inhibition of convulsions EAF 30 mg/kg EAF 100 mg/kg EAF 300 mg/kg Phenobarbitone sodium 40 mg/kg Treatment Fig: Effect of EAF on pentylenetetrazole-induced convulsions in mice.

33 Isoniazid (INH)-induced convulsions in mice The average latency of convulsions were presented in Table Effect on latency of convulsions The latency of convulsions in control group animals was 25.15±0.28 min. Albino mice pretreated with EAF showed the latency of convulsions of 30.08±0.05, 32.52±0.06 and 36.06±0.04 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (diazepam 4 mg/kg, i.p.) showed 63.27±0.04 min (p<0.01). The latency of convulsions in control group animals was very less when compared to that of animals pretreated with extract and standard. EAF treated animals showed the latency time more than that of control group animals and less than that of standard group animals. Although all the three doses of EAF significantly delayed the latency of convulsions in a dose-dependent manner but failed to protect mice against mortality. Table Effect of EAF on Isoniazid (INH)-induced convulsions in mice Latency of Group (n=6) Treatment convulsions (min) I EAI Gum acacia 25.15±0.28 II EAI EAF (30 mg/kg) 30.08±0.05** IIIEAI EAF (100 mg/kg) 32.52±0.06** IV EAI EAF (300 mg/kg) 36.06±0.04** V EAI Diazepam (4 mg/kg, i.p.) 63.27±0.04** EAF: Ethanol extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I EAI (control).

34 76 Latency of convusions (min) Gum acacia EAF 30 mg/kg EAF 100 mg/kg EAF 300 mg/kg Diazepam 4 mg/kg Treatment Fig: Effect of EAF on isoniazid-induced convulsions in mice. Values were mean±s.d (n=6) Anti-epileptic activity of Aqueous extract of Acalypha fruticosa (AAF) Maximal electroshock-induced convulsions in mice The average time of onset, duration of THLE and percentages of inhibition of convulsions were presented in Table Effect on onset time of convulsions The onset time of THLE in control group animals was 1.52±0.05 sec. Animals which received AAF at the doses of 30, 100 and 300 mg/kg, p.o. showed the onset time as 2.29±0.14, 2.51±0.32 and 2.88±0.04 sec (p<0.01) respectively. The standard group animals (diazepam 3 mg/kg, p.o.) showed 3.53±0.25 sec (p<0.01). Effect on duration of convulsions The duration of THLE in control group animals was ±0.33 sec. Albino mice pretreated with AAF showed the duration of

35 ±0.40, 51.59±0.35 and 42.22±0.22 sec (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (diazepam 3 mg/kg, p.o.) showed 39.59±0.35 sec (p<0.01). The time of onset of THLE in control group animals was very less when compared to the extract and standard treated animals. Duration of THLE in control group animals was greater when compared to the extract and standard treated animals. AAF significantly protected the mice from convulsions induced by electroshock method in a dosedependent manner. Percentage inhibition of convulsions The percentage inhibition achieved in AAF treated mice were 35.57% (30 mg/kg), 44.85% (100 mg/kg) and 54.87% (300 mg/kg) (p<0.01) respectively when compared to control group animals. Animals pretreated with AAF exhibited significant antiepileptic activity and less percentage of inhibition of convulsions when compared to diazepam treated animals (57.69%, p<0.01).

36 78 Table Effect of AAF on maximal electroshock-induced convulsions in mice Percentage Group Onset of Duration of Treatment inhibition of (n=6) THLE (sec) THLE (sec) convulsions IAAM Distilled water 1.52± ± II AAM AAF (30 mg/kg) 2.29±0.14** 60.28±0.40** 35.57** IIIAAM AAF (100 mg/kg) 2.51±0.32** 51.59±0.35** 44.85** IV AAM AAF (300 mg/kg) 2.88±0.04** 42.22±0.22** 54.87** V AAM Diazepam (3 mg/kg) 3.53±0.25** 39.59±0.35** 57.69** AAF: Aqueous extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I AAM (control). Duration of THLE (sec) Distilled water AAF 30 mg/kg AAF 100 mg/kg AAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: Effect of AAF on duration of maximal electroshock-induced convulsions in mice. Values were mean±s.d (n=6).

37 79 Percentage inhibition of convulsions AAF 30 mg/kg AAF 100 mg/kg AAF 300 mg/kg Diazepam 3 mg/kg Treatment Fig: Effect of AAF on maximal electroshock-induced convulsions in mice Pentylenetetrazole (PTZ)-induced convulsions in mice The average time of onset, duration of convulsions and percentages of inhibition of convulsions were presented in Table Effect on onset time of convulsions The onset time of convulsions in control group animals was 3.06±0.02 min. AAF treated mice exhibited the onset time as 3.11±0.04, 3.53±0.04 and 4.05±0.03 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. The standard group mice (Phenobarbitone sodium, 40 mg/kg, i.p.) showed 6.46 ±0.02 min (p<0.01). Effect on duration of convulsions The duration of convulsions in control group animals was 22.54±0.02 min. AAF treated mice exhibited the duration as 11.23±0.03, 9.43±0.03 and 8.02±0.21 min (p<0.01) respectively at the

38 80 doses of 30, 100 and 300 mg/kg, p.o. Albino mice pretreated with Phenobarbitone sodium, 40 mg/kg, i.p. showed 11.09±0.03 min (p<0.01). The time of onset of convulsions in control group animals was very less when compared to the extract and standard group animals. Duration of convulsions in control group animals was greater when compared to the extract and standard group animals. Albino mice pretreated with AAF at the doses of 30, 100 and 300 mg/kg were provided significant protection from convulsions induced by PTZ. Percentage inhibition of convulsions The percentage inhibition achieved in mice which received AAF were 50.19% (30 mg/kg), 58.16% (100 mg/kg) and 64.44% (300 mg/kg) (p<0.01) respectively when compared to control group animals. AAF treated mice exhibited significant antiepileptic activity and more percentage of inhibition of convulsions at both 100 and 300 mg/kg when compared to Phenobarbitone sodium 40 mg/kg, i.p. (50.82%, p<0.01).

39 81 Table Effect of AAF on Pentylenetetrazole (PTZ)-induced convulsions in mice Group (n=6)= 6) Treatment Onset of convulsions (min) Duration of convulsions (min) Percentage inhibition of convulsions IAAP Distilled water 3.06± ± II AAP AAF (30 mg/kg) 3.11±0.04** 11.23±0.03** 50.19** IIIAAP AAF (100 mg/kg) 3.53±0.04** 9.43±0.03** 58.16** IV AAP AAF (300 mg/kg) 4.05±0.03** 8.02±0.21** 64.44** V AAP Phenobarbitone sodium 6.46 ±0.02** 11.09±0.03** 50.82** (40 mg/kg, i.p.) AAF: Aqueous extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group IAAP (control). Duration of convulsions (min) Distilled water AAF 30 mg/kg AAF 100 mg/kg AAF 300 mg/kg Treatment Phenobarbitone sodium 40 mg/kg Fig: Effect of AAF on duration of pentylenetetrazole-induced convulsions in mice. Values were mean±s.d (n=6).

40 82 Percentage inhibition of convulsions AAF 30 mg/kg AAF 100 mg/kg AAF 300 mg/kg Phenobarbitone sodium 40 mg/kg Treatment Fig: Effect of AAF on pentylenetetrazole-induced convulsions in mice Isoniazid (INH)-induced convulsions in mice The average latency of onset of convulsions were presented in Table Effect on latency of convulsions In control group animals, the latency of convulsions was 25.15±0.28 min. Albino mice pretreated with AAF showed the latency of convulsions of 28.58±0.22, 30.33±0.03 and 33.59±0.22 min (p<0.01) respectively at the doses of 30, 100 and 300 mg/kg, p.o. Animals belonging to standard group (diazepam 4 mg/kg, i.p.) showed 63.27±0.04 min (p<0.01). The latency of convulsions in control group animals was very less when compared to the extract and standard. All the three doses of AAF showed the latency time more than that of control group animals and less than that of standard group animals i.e., diazepam. Although

41 83 AAF exhibited dose-dependent delay in the latency of convulsions but failed to protect the animals from mortality. Table Effect of AAF on Isoniazid (INH)-induced convulsions in mice Group (n=6) Treatment Latency of convulsions (min) I AAI Distilled water 25.15±0.28 II AAI AAF (30 mg/kg) 28.58±0.22** III AAI AAF (100 mg/kg) 30.33±0.03** IV AAI AAF (300 mg/kg) 33.59±0.22** VAAI Diazepam (4 mg/kg, i.p.) 63.27±0.04** AAF: Aqueous extract of Acalypha fruticosa; Values were mean±sd (n=6). Statistical significance was determined by ANOVA, followed by Dunnett s t test (n=6); ** p < 0.01 when compared to Group I AAI (control). Latency of convulsions (min) Distilled water AAF 30 mg/kg AAF 100 mg/kg AAF 300 mg/kg Diazepam 4 mg/kg Treatment Fig: Effect of AAF on isoniazid-induced convulsions in mice. Values were mean±s.d (n=6).

42 Discussion Epilepsy is one of the major neurological disorders characterized by sporadic episodes of abnormal behavior, convulsive seizures, sensory disturbance and loss of consciousness or all of these symptoms resulting from a brain dysfunction or an abnormal discharge of cerebral neurons [35]. Higher prevalence, cultural and social stigma, lack of awareness and non-availability of proper diagnostic and treatment facilities are some of the major reasons for the increasing number of people with epilepsy in the developing countries. All the currently available AEDs are associated with side-effects, long-term toxicity, teratogenic effects and about 40% patients are refractory to therapeutic intervention and thus its effective and safe therapy still remains a challenge [44-46]. Hence there is a mere need to search for AEDs from alternative sources i.e., exploitation of medicinal plants. Medicinal plants in traditional medicine can become an invaluable source for search of new antiepileptic compounds. Literature survey revealed that many plants like Aegle marmelos, Asparagus racemosus, Carissa edulis, Cyperus articulatus, Delphinium denudatum, Hibiscus rosa and Jasminum grandflorum acclaim to possess antiepileptic activity [57, 58, 96, ]. Acalypha fruticosa is a shrub belonging to the family of Euphorbiaceae. Aerial parts of Acalypha fruticosa were traditionally used to treat epilepsy [21]. But till today there were no reports to

43 85 justify its claim. Hence the present work was designed to evaluate the antiepileptic activity of Acalypha fruticosa. In the present study, four different extracts were prepared by using solvents of increasing polarity like petroleum ether, chloroform, ethanol and water. Non-polar solvents have low dielectric constants and dissolve non-polar solutes with similar internal pressures through induced dipole interactions. Petroleum ether is a non-polar solvent which solubilises non-polar compounds like steroids and triterpenoids. Chloroform extracts non-polar to intermediately polar compounds such as steroids, triterpenoids, flavonoids. Ethanol dissolves most of the secondary metabolites such as steroids, triterpenoids, flavonoids, tannins, saponins and enhance their release from cellular matrix/cell surface. The polar components like polysaccharides, phenols, aldehydes, ketones, amines, saponins and other oxygen containing compounds dissolve in water due to formation of hydrogen bonding [124]. Thus petroleum ether, chloroform, ethanol and aqueous extracts of Acalypha fruticosa were prepared to predict which phytoconstituents are responsible for the remarkable antiepileptic activity. In preliminary phytochemical studies, the chief phytoconstituents present in the different extracts of Acalypha fruticosa were alkaloids, steroids, carbohydrates, tannins, flavanoids, saponins, lipids and proteins.

44 86 In acute toxicity studies, petroleum ether, chloroform, ethanol and aqueous extracts of Acalypha fruticosa were found to be safe upto 1000 mg/kg, (p.o.) body weight. Hence three doses i.e., 30, 100 and 300 mg/kg, p.o. were selected for all the extracts to evaluate antiepileptic activity. To screen the antiepileptic activity, most extensively studied, well established and simple animal seizure models viz. maximal electroshock, pentylenetetrazole and isoniazid-induced seizures in mice were selected. Another advantage of using the above models is the pharmacological profiles were comparable to the human condition [33-34]. The MES test identifies compounds/extracts which prevent seizure spread [29-30]. In this model, all the extracts of Acalypha fruticosa significantly and dose dependently increased the onset time of THLE and decreased the duration of THLE. But ethanol extract exhibited maximum significant antiepileptic activity at 300 mg/kg (69.03%). The order of antiepileptic activity for various extracts in MES model was ethanol>chloroform>petroleum ether>aqueous (chloroform extract %, petroleum ether extract-62.33% and aqueous extract %). All the extracts of Acalypha fruticosa might prevent the seizure spread and contribute to the activity. But the maximum antiepileptic activity of the ethanol extract may be due to the presence of phytoconstituents such as tannins and flavonoids. PTZ test identifies compounds/extracts which primarily raise seizure threshold [29-30]. In this model, all the extracts of Acalypha

45 87 fruticosa significantly increased the onset time of convulsions and decreased the duration of convulsions in a dose-dependent manner. But ethanol extract showed maximum antiepileptic activity at 300 mg/kg (70.82%) followed by chloroform extract (68.20%), petroleum ether extract (66.49%) and aqueous extract (64.44%). In this model, seizure threshold may be raised by all the extracts of Acalypha fruticosa but the potent activity of ethanol extract may be because of phytoconstituents like tannins and flavonoids present in the extract. Isoniazid is an antitubercular drug which was shown to lower the content of brain GABA in humans to approximately the same extent in rats and mice [32]. In this model, all the four extracts of aerial parts of Acalypha fruticosa delayed the latency of convulsions but could not protect the mice from mortality. At 300 mg/kg dose, ethanol extract possessed maximum delay in latency of convulsions. In this model, the extracts act as GABA agonists but unable to increase GABA levels in brain. All the extracts exhibited significant antiepileptic activity in all three tested models. The order of activity is AAF<PAF<CAF<EAF. The observed antiepileptic activity of AAF in all models could be due to the presence of tannins. Presence of steroids may attribute to the potent antiepileptic activity of PAF than AAF because steroids are involved in neuromodulatory effects [125]. Antiepileptic activity of CAF may be due to the presence of steroids and flavonoids because flavonoids and sterols have been involved in central inhibitory and neuromodulatory effects [126]. Maximum activity of EAF may be because of combined