Analgesic and anti-inflammatory activities of Annona squamosa Linn bark

Similar documents
Journal of Chemical and Pharmaceutical Research

Scholars Research Library

South Asian Journal of Biological Sciences Vo.1. No.1 (September 2011)

Pharmacologyonline 3: (2008)

Evaluation of anti-inflammatory potential of Kigelia pinnata leaf extract in wistar rats Parmar Namita 1, Rawat Mukesh 2, Kumar Tirath 1

EVALUATION OF ANTI-INFLAMMATORY ACTIVITY OF ROOTS OF ATALANTIA MONOPHYLLA

Journal of Chemical and Pharmaceutical Research

Antinociceptive and Anti-Inflammatory Effects of Solvent Extracts of Tagetes erectus Linn (Asteraceae)

Analgesic Activity of Sathikkai Podi- a Siddha Drug

Antimalarial alkaloids isolated from Annona squamosa

International Journal of Current Pharmaceutical Research Vol 1 Issue 1, 2009

Anti-inflammatory Activity of Trichosanthes cucumerina L. var. cucumerina seeds.

Research Journal of Pharmaceutical, Biological and Chemical Sciences

Journal of Chemical and Pharmaceutical Research

Analgesic and antipyretic activity of ethanolic extract of leaves of Catharanthus Roseus

EVALUATION OF ANTI-INFLAMMATORY ACTIVITY OF THE LEAF EXTRACTS OF SOLANUM TRILOBATUM LINN

Evaluation of anti-inflammatory activity of Nigella sativa: An experimental study

Pharmacological Screening of Ethanolic Extracts of Emblica Officinalis Gearth Plant on Animals

Evaluation of Analgesic Activity of Hydroalcoholic Extract of Curcuma longa Rhizomes in Albino Rats

Vol-3, Issue-3, July-2012 ISSN: Panda et al

Anti-inflammatory activity of Aponogeton natans (Linn.) Engl. & Krause in different experimental animal models

Evaluation of Analgesic Activity of Hydroalcoholic Extract of Cinnamomum zeylanicum Bark in Albino Rats

Received: 08 th Nov-2012 Revised: 14 th Nov-2012 Accepted: 14 th Nov-2012 Research article

ANTI-INFLAMMATORY ACTIVITY OF ALSTONIA SCHOLARIS IN ALBINO RATS

International Journal of Research and Development in Pharmacy and Life Sciences. Research Article

Research Article. In vivo evaluation of analgesic activity of methanolic extract of Laportea interrupea (L.) leaves

Research Article Anti Inflammatory and Analgesic Activities of Methanol Extract of Terminalia chebula Fruits

Pharmacologyonline 3: (2011) Newsletter Patil et al.

IJBCP International Journal of Basic & Clinical Pharmacology

Journal of Chemical and Pharmaceutical Research

ANTI-INFLAMMATORY EVALUATION OF METHANOL EXTRACT AND AQUEOUS FRACTION OF THE BARK OF BAUHINIA VARIEGATA (LEGUMINOSAE)

Evaluation of Anti-inflammatory and Analgesic Activities of Tamarindus indica Seeds

EVALUATION OF ANALGESIC AND ANTI-INFLAMMATORY ACTIVITIES OF TINOSPORA CORDIFOLIA IN RODENTS

Pelagia Research Library. Anti-inflammatory and acute toxicity studies of the extracts from the rhizomes of Alpinia galanga Willd.

Scholars Research Library

PHARMACOGNOSTIC, PHYTOCHEMICAL, AND PHARMACOLOGICAL INVESTIGATION ON BARK OF THUJA ORIENTALIS LINN (CUPRESSACEAE)

ANALGESIC ACTIVITY OF THE FRUIT EXTRACT OF AVERRHOA CARAMBOLA

Anti-ulcer effect of Cordia dichotoma Forst.f. fruits against gastric ulcers in rats. I Kuppast, P Vasudeva Nayak, K Chandra Prakash, K Satsh Kumar

TOPICAL ANTI-INFLAMMATORY ACTIVITY OF PINDA THAILAM, A HERBAL GEL FORMULATION

siamensis AND ITS ANTI-INFLAMMATORY STUDIES

Scholars Research Library

International Journal of Research in Pharmacology & Pharmacotherapeutics

This PDF is available for free download from a site hosted by Medknow Publications

International Journal of Pharma and Bio Sciences

Screening the Anti-ulcer Activity of Polyherbal Extract of Selected Medicinal Herbs Against Albino Wistar Rats

Biology and Medicine

Evaluation of Diuretic Activity of Jussiaea Suffruticosa Linn.

creening of Natural/Synthetic Compounds for Antimalarial Activity

ANTI-INFLAMMATORY AND HYPOGLYCEMIC EFFECTS OF HELIOTROPIUM KERALENSE IN ALBINO RATS

Priyanka Vijay et al, /J. Pharm. Sci. & Res. Vol.2(1), 2010, 64-71

In vitro study of antibacterial activity of Carissa carandas leaf extracts

Evaluation of the Anti-Inflammatory Activity of Desmodium Triangulare (Retz.) Merr. Root

Anti- inflammatory, analgesic and diuretic activity of Ludwigia hyssopifolia Linn

Pharmacologyonline 1: (2011) ewsletter Tarafdar et al.

Mechanism of action of antiinflammatory effect of fixed oil of Ocimum basilicum Linn.

International Journal of Pharmacy and Pharmaceutical Sciences Vol 2, Issue 1, 2010

Abdul Bakrudeen Ali Ahmed* et al. / Int. Journal Of Pharmacy & Technology

Pelagia Research Library

Anti-inflammatory and Neuropharmacological activities of the seed extract of Setaria italica

ANTI-DIABETIC ACTIVITY OF HELICTERES ISORA ROOT

COMPARATIVE ANALGESIC AND ANTI-INFLAMMATORY EFFECT OF ANGELICA SINENSIS PIECES AND ITS PRODUCTS IN MICE

In-Vitro and In-Vivo Anti-Inflammatory and Analgesic Activity of Bixa orellana Linn Leaf Extracts

ANTI-TERMITE ACTIVITY OF HEARTWOOD OF DALBERGIA SISSO ROXB. EX. DC.

Anxiolytic effects of Elaeocarpus sphaericus fruits on the elevated plus-maze model of anxiety in mice

International Journal of Pharma and Bio Sciences

In Vivo Evaluation of Anti-inflammatory Activity of Topical Preparations from Fenugreek (Trigonella foenum-graecum L.) Seeds in a Cream Base

Evaluation of Synergistic Activity of Hemidesmus indicus and Terminalia catappa on Rheumatoid Arthritis in Rats

Anti-inflammatory evaluation of methanol extract and aqueous fraction of the leaves of Anthocleista djalonensis A. Chev (Gentianaceae).

EVALUATION OF ANTI-INFLAMMATORY, ANALGESIC AND ANTIPYRETIC ACTIVITIES OF THYMUS SERPHYLLUM LINN. IN MICE

IMMUNO MODULATORY ACTIVITY OF THE ALCOHOLIC EXTRACTS OF MIMOSA PUDICA (LINN) IN MALE WISTAR RATS

Impact factor: 3.958/ICV: 4.10 ISSN:

PHARMACOGNOSTIC, PHYTOCHEMICAL STUDIES ON THE ROOT OF CLERODENDRON INFORTUNATUM LINN ROOT

* a Onasanwo SA and a Elegbe RA a Department of Physiology, College of Medicine,

Anti-inflammatory, analgesic and anti-lipid peroxidation studies on leaves of Commiphora caudata (Wight & Arn.) Engl.

K. Vennila* and R. Pattarayan 2 *Lecturer, 2 Former Head of the Paediatrics Department, National institute of Siddha, Chennai, (TN) - India.

Prevention of Development of Tolerance and Dependence to Opiate in Mice by BR-16A (Mentat) A Herbal Psychotropic Preparation

Pharmacologyonline 3: (2009)

International Journal of Pharma Research & Review, May 2013; 2(5):13-17

CHEMICAL STANDARDIZATION AND QUANTIFICATION OF PIPERIN FROM METHANOLIC EXTRACT OF PIPER NIGRUM BY HPLC METHOD ON THE BASIS OF ISOLATED MARKERS

PRESENTER: DR. DEEPA JJM MEDICAL COLLEGE DAVANGERE

A comparative study of nicardipine with diclofenac sodium in chemically induced inflammatory models in rats and mice

Wound healing activity of Kaempferia rotunda Linn leaf extract

Volume: 2; Issue: 11; November-2016; pp ISSN: Antipyretic and Analgesic effects of Aristolochia tagala

ANTI-OXIDANT ACTIVITY OF MORINDA CITRIFOLIA ON LYMPHOMA-BEARING MICE

Antihyperglycemic Activity of Trianthema Portulacastrum Plant in Streptozotocin Induced Diabetic Rats

International Journal of Pharma and Bio Sciences

International Journal of Pharmaceutical and Phytopharmacological Research (eijppr) [Impact Factor ]

Synthesis and Blastocyst Implantation Inhibition Potential of Lupeol Derivatives in Female Mice

Available online through ISSN

Pharmacologyonline 3: (2011) ewsletter Verma et al.

Journal of Biological and Chemical Research An International Peer reviewed Journal of Life Sciences and Chemistry

Pharmacology AHMAD BILAL** NAEEM A. KHAN** A. GHUFRAN** INAMUDDIN***

Evaluation of in-vivo Activity of Clerodendrum serratum L. against Rheumatism

ISSN: Available online Journal of Global Trends in Pharmaceutical Sciences Vol.2, Issue 2, pp , April-June 2011

ANTIBACTERIAL EFFECTS OF CRUDE EXTRACT OF Azadirachta indica AGAINST Escherichia coli and Staphylococcus aureus

Dose-dependent effect of Coriandrum sativum Linn. seeds on thermal pain stimulus

Pharmacologyonline 3: (2009) I VESTIGATIO OF A TIHYPERGLYCEMIC EFFECT OF MORUS IGRA O BLOOD GLUCOSE LEVEL I STREPTOZOTOCI DIABETIC RATS

IJPRD, 2011; Vol 4(03): May-2012 ( ) International Standard Serial Number

INTRODUCTION MATERIALS AND METHODS

QUANTITATIVE ESTIMATION OF PHYTOSTEROL FROM TWO MEDICINALLY IMPORTANT PLANTS OF CUCURBITACEAE

Transcription:

2014; 3 (1): 60-64 Available online at: www.jsirjournal.com Research Article ISSN 2320-4818 JSIR 2014; 3(1): 60-64 2014, All rights reserved Received: 24-11-2013 Accepted: 26-01-2014 Tej Pratap Singh Rakesh Kumar Singh Paras Malik Venkateshwara School of Pharmacy. Meerut, Uttar Pradesh, India Analgesic and anti-inflammatory activities of Annona squamosa Linn bark Tej Pratap Singh*, Rakesh Kumar Singh, Paras Malik Abstract was isolated from a methanolic extract of the bark of Annona squamosa and studied for its analgesic and anti-inflammatory activity. at the doses of 12.5 and 25 mg/kg body wt. and methanol extract at a dose of 50 mg/kg body wt. showed significant central as we as peripheral analgesic along with anti-inflammatory activity. These activities of caryophyllene oxide were comparable with the standard drug Pentazocin (50 mg/kg body wt.) for Anti-inflammatory activities and Aspirin (100 mg/kg body wt.) for Analgesic activity used in the respective experiments. Keywords: Annona squamosa, Methanolic extract,, Analgesic, Anti-inflammatory. Introduction Annona squamosa L. (Annonaceae) is a tree occurs wild and is also cultivated throughout India. Its leaves are used as insecticidal and antispasmodic agents and are used in the treatment of rheumatism and painful spleen. The plant is reported to possess analgesic, anti-inflammatory 1, antipyretic, antiulcer, and antiseptic and abortifacient activities 2. Its use as an insecticidal agent has been investigated by several workers 3 and various phytochemical, pharmacological, antibacterial and antiovulatory studies have already been carried out with the seed extracts 4. Post-cortical antifertility activity of A. squamosa has also been reported from studies with the seed extract. 5 A tetrahydroisoquinoline alkaloid with cardiotonic activity has been isolated from the leaves of Annona squamosa1 1 along with a bioactive acetogenin from its bark 6. A novel diazepine, squamolone was also isolated from this plant. 7 The purpose of the study reported here was to isolate the pure constituent responsible for analgesic and antiinflammatory activity from the bark of the plant. Materials and Methods Plant material Correspondence: Tej Pratap Singh Tel: +91-8957553306 E-mail: tej.ptp@gmail.com Bark of Annona squamosa L. was collected from Banglore district, Karnatka, in August 2008. Extraction and isolation Shade dried powdered material weighing 1kg was extracted by soxhlet using methanol. 60

The solvent was evaporated in vacuum to obtain the crude methanol extract. The methanolic extract (ME) (10 g) obtained was applied to a column of Silica gel 60 (60-120 mesh) packed in benzene slurry and the column was developed with benzene, from which were collected 14 fractions of 300-400 ml each. Fractions 6-10 were combined on the basis of similar TLC pattern (Si gel plates, benzene, vanilline-sulphuric acid spray). These fractions were further resolved by preparative TLC on silica gel using benzene as a mobile phase, resulting in isolation of two minor compounds along with caryophyllene oxide (32 mg). : white amorphous powder, m.p. 60-61 ºC. NMR and mass spectra of the compound were matched with those reported in the literature. 2 Animals All the experiments were carried out using male Swiss albino mice (20-25 g each) and Wistar rats (150-200 g each). The animals had free access to food and water and they were housed under a natural (12 h each) light-dark cycle with access to standard pellet chow and water ad libitum. The animals were acclimatized for at least 5 days to the laboratory conditions before performing the experiments. The experimental protocol was approved by the Institutional Animal Ethics Committee (Registration No. 372/01/a/ CPCSEA). In all experimental models, six animals were used in each group. Analgesic activity The central analgesic activity of the test drug was studied against thermal stimuli using the hot plate test 8, while peripheral analgesic activity of the test drug was evaluated using the acetic acid-induced writhing test 9. Eddy's hot plate test The initial reaction times of all the animals of control and test groups were recorded by putting them on the hot plate maintained at 55 ± 0.5ºC. Licking of paw or jumping was taken as the index of reaction to heat. The albino mice were divided into five groups. ME (50 mg/kg body wt.), (12.5 and 25 mg/kg body wt.), or pentazocin lactate injection (50 mg/kg body wt.) were administered by intra peritoneal route. The first group served as control and received vehicle only (1% dimethyl formamide in water for injection). The post-treatment reaction time of each animal was recorded at 30, 60, 90, 120 and 180 min. Acetic acid induced writhing The albino mice were divided into five groups. ME (50 mg/kg body wt.), (12.5 and 25 mg/kg body wt.) or aspirin (100 mg/kg body wt.) were administered one hour prior to intra peritoneal injection of 0.6% v/v acetic acid. Five minutes after the intra peritoneal injection of acetic acid, the number of writhings during the following 20 min was counted. Control mice received vehicle only (1% dimethyl formamide in water for injection). Anti-inflammatory activity Albino rats of Wistar strain of either sex were divided into five groups. Acute inflammation was produced by sub plantar injection of 0.1 ml of 1% suspension of carrageenan with 2% gum acacia in normal saline, in the right hind paw of rats, one hour after oral administration of ME (50 mg/kg body wt.), (12.5 and 25 mg/kg body wt.) or aspirin (100 mg/kg body wt.). Control rats were received vehicle only (1% dimethyl formamide in water for injection). The paw volume was measured plethysmometrically (Ego Basil, Italy) at 0, 1, 2, and 3 h after the carrageenan injection. The difference between '0' readings and readings after 1, 2, and 3 h, respectively, was taken as the volume of edema. 10 Statistical Analysis All the results were statistically analyzed by student's t-test and expressed as mean ± S.E.M. Results were regarded as significant when p<0.05. Results The effect of Methanolic extract and pure caryophyllene oxide were evaluated for central as well as peripheral analgesic, along with anti-inflammatory, activity. Table 1 shows the results on thermic stimulus induced pain (Eddy's hot plate test) in mice. Pretreatment with pentazocin or ME or caryophyllene oxide did not produce any significant changes of paw licking time in the early phase of pain. However, in the late phase, a dose-dependent and significant (p<0.05) increase in licking time was observed in mice treated with caryophyllene oxide as well as with ME and pentazocin. The maximum activity was observed with caryophyllene oxide (25 mg/kg body wt., i.p.) at the 120 min time interval, which is comparable to the standard pentazocin. The maximum analgesia induced by ME (50 mg/kg body wt., i.p.) was at the 60 min time interval and persisted up to 120 min. 61

Table 2 shows the response of mice to acetic acid-induced writhing. Treatment of M E, caryophyllene oxide and standard aspirin significantly (p<0.05) reduce the number of writhes. The inhibitions were 64.89%, 57.87% and 75.19% for ME and two doses of pure caryophyllene oxide, respectively. At the dose of 25 mg/kg body wt., caryophyllene oxide inhibited the writhing response almost to the same degree as aspirin (74.41%). Table 3 shows the response of rats to the carrageenan induced paw edema. The results obtained with ME, caryophyllene oxide and standard aspirin show significant (p<0.05) inhibition of inflammatory edema at the first and second hours after the carrageenan treatment. The effect of caryophyllene oxide at a dose of 25 mg/kg body wt. p.o. was comparable to standard aspirin. The dose-dependent inhibition of edema was observed with caryophyllene oxide treatment. Table 1: Effect of on thermic stimulus-induced pain in mice (hot plate test) Treatment Pre drug 30 min 60 min 90 min 120 min 180 min reaction time Control 12.45 ± 0.50 8.50 ± 0.92 9.00 ± 1.15 8.83 ± 0.54 8.16 ± 1.10 8.00 ± 0.89 Pentazocin 8.83 ± 0.87 16.16 ± 1.24 8.83 ± 0.87 16.16 ± 1.24 * 17.50 ± 0.95 * 7.08 ± 0.58 (50 mg/kg body wt.) * ME (50 mg/kg body wt.) 20 ± 0.18 * 20 ± 0.94 * 20 ± 0.18 * 20 ± 0.94 * 20 ± 0.26 * 10.74 ± 0.20 8.92 ± 1.2 6.66 ± 0.88 10.33 ± 12.33 ± 1.20 * 14.5 ± 1.02 * 8.00 ± 0.68 0.95* 9.45 ± 0.94 5.50 ± 0.76 8.33 ± 0.91 12.66 ± 0.98 * 17.0 ± 0.96 * 9.33 ± 0.80 Values are mean ± S.E.M., n= 6, * p<0.05, significant* compared to control. ME- Methanolic Extract Table 2: Effect of Caryolphyllene oxide on acetic acid-induced writhing test in mice Treatment No. of writhing Inhibition (%) Control 42.33 ± 1.62 - Aspirin (100 mg/kg body wt.) 10.83 ± 0.65 * 74.41 ME (50 mg/kg body wt.) 14.86 ± 1.21 * 64.89 17.83 ± 1.10 * 57.87 10.50 ± 1.05 * 75.19 Values are mean ± S.E.M., n = 6. * p<0.05, significant * compared to control. ME- Methanolic extract Table 3: Effect of on carrageenan-induced paw edema in rats Treatment Increase in paw volume in ml for 1 Hour 2 Hours 3 Hours Control 0.56 ± 0.036 0.55 ± 0.029 0.65 ± 0.064 Aspirin (100 mg/kg body wt.) 0.23 ± 0.017 * 0.20 ± 0.011 * 0.66 ± 0.036 ME (50 mg/kg body wt.) 0.26 ± 0.016 * 0.29 ± 0.024 * 0.61 ± 0.028 0.25 ± 0.016 * 0.30 ± 0.021 * 0,45 ± 0.028 * 0.23 ± 0.015 * 0.27 ± 0.013 * 0.66 ± 0.036 Values are mean ± S.E.M., n=6, * <0.05, significant * compared to control. ME-Metrhanolic Extract 62

Discussion The results of the present study show that the methanolic extract and caryophyllene oxide isolated from this extract of Annona squamosa bark exhibit significant analgesic and anti-inflammatory activities. The results obtained in the analgesic test experiments appear to suggest that ME and pure caryophyllene oxide isolated from this extract possess centrally and peripherally mediated analgesic properties. The central analgesic action may be mediated via inhibition of central pain receptors, while the peripheral analgesic effect may be mediated through inhibition of cyclooxygenase and/or lipoxygenase (and other inflammatory mediators). This hypothesis is in consonance with those of Eddy et al 8, Koster et al 9 and Wagner et al 11 who postulated that acetic acid writhing and hot plate test methods are useful techniques for the evaluation of centrally and peripherally acting analgesic drugs, respectively. produced an analgesic effect against thermal induced pain stimuli in mice at various time points post-treatment. The effect observed was dose-dependent and statistically significant. The hot plate test is considered to be selective for opioid-like compounds, which are centrally acting analgesics in several animal species. 12 Furthermore, the effect of ME was initiated first and appears for long duration when compared with different doses of caryophyllene oxide in the hot plate test. This might be due to the other constituents present in the ME, such as the kaurane-type diterpenes, which might contribute to the central analgesic activity. 6 The carrageenan-induced rat paw edema is a suitable test for evaluating anti-inflammatory drugs that has frequently been used to assess the anti-edematous effect of natural products. 5 Development of the edema in the paw of the rat after injection of carrageenan is a biphasic event. The initial phase observed during the first hour is attributed to the release of histamine and serotonin. The second phase of edema is due to the release of prostaglandins, protease and lysosomes. 13, 14 The ME at 50 mg/kg body wt. and caryophyllene oxide at doses of 12.5 and 25 mg/kg body wt. shows significant activity in the first and second hours. This might be due to the inhibition of the biphasic response induced by the carrageenan. Conclusion administered intra peritoneally exhibits antinociceptive activity and might exert its effect through diverse mechanisms that may involve both central and peripheral pathways. Further pharmacodyanamic investigations are required to understand the analgesic and anti-inflammatory activity exhibited by caryophyllene oxide. References 1. Dash, G.K., Ganapathy, S., Suresh, P., Panda, S.K., Sahu, S.K.. Analgesic and anti-inflammatory activity of Annona squamosa leaves. Ind. J. Nat. Prod. 2001; 17: 32-35. 2. Ahmed, R.G., Abbas, H., Seyed, E.S., Soodabeh. S., Abbas, S. Cytotoxic triterpenoids from Sutureja macrantha C.A. Mey. DARU 2005; 13: 177. 3. Akolkar, L.V., Kakkar, K.K., Chakre, O.J. Second Supplement to Glossary of Indian Medicinal Plants with Active Principles. Part 1. CSIR, New Delhi, 1992, p. 72. 4. Vohra. S.B.. Ishwar, K., Naqvi, S.A.H. Phytochemical, pharmacological, antibacterial and anti-ovulatory studies on Annona squamosa. Planta Med. 1975; 28: 97-100. 5. Panthong, A., Kanjanapothi, D., Taesotikul, T., Wongcome, T., Reutrakul, V. Anti-inflammatory and antipyretic properties of Clerodendrum petasites. S. Moore. J. Ethnopharmacol. 2003; 85: 151-156. 6. Li, X.H., Hui, Y.H., Rupprecht, J.K., Liu, Y.M., Wood, K.V., Smith, D.L., Chang, C.J., Mclaughlin, J.L. Bullatacin, bullatacinone and squamone, a new bioactive acetogenins from bark of Annona Squamosa. J. Nat. Prod. 1990; 53: 81-86. 7. Yang, T.H., Chi-Ming, C. Structure of squamolone, a novel diazepine from Annona squamosa L. J.Chin. Chem. Soc. 1972; 19: 149-151. 8. Eddy, N.D., Leimback, D. Synthetic analgesics: 11. Dithyienylbutenyl-amines and dithyienylbulylamines. J. Pharmacol. Exp. Ther. 1953; 3: 554-557. 9. Koster, R.M., Anderson, M., De-Beer, E.J. Acetic acid for, analgesic screening. Fed. Proc. 1959; 18: 412-418. 10. Winter, CA., Risley, E.A., Nuss, G.W. Carrageenan induced edema in hind paw of the rats as an assay for inflammatory drugs. Proc. Soc. Exp. Biol. Med. 1962; 1ll: 544-547. 11. Wagner, H., Reiter, M., Frest, W. Neue herzwirksame Drrogen L: Zur chemie und pharmacologie des herzwirksame prinzips von Annona squamosa. Planta Med. 1980; 40: 77-85. 12. Janseen, P.A.J., Niememegeers, C.J., Dony, G.H. The inhibitory effect of fentanyl and other morphine like analgesics on warm water induced tail withdrawal reflex in rats. Arzneimittelforschung 1963; 13: 502-507. 63

13. Vinegar, R., Schreiber, W., Hugo, R. Biphasic development of carrageenan edema in rats. J. Pharmacol. Exp. Ther. 1969; 166: 96-103. 14. Crunkhon, P., Meacock, S.G.R. Mediators of the inflammation induced in the rat paw by carrageenan. Br. J. Pharmacol. 1971; 42: 392-402. 64