Antidiabetic activity of a polyherbal formulation (DRF/AY/5001)

Transcription

1 Indian Journal of Experimental Biology Vol. 46, August 2008, pp Antidiabetic activity of a polyherbal formulation (DRF/AY/5001) Rahul V Mandlik, Sandya K Desai & Suresh R Naik* Principal, K M Kundnani College of Pharmacy, Colaba, Mumbai, , India and Gaurav Sharma & R K Kohli Dabur Research Foundation, Gaziabad, India Received 28 December 2007; revised 16 June 2008 The herbal formulation, DRF/AY/5001, elicits hypoglycemic/antidiabetic effects in both normal and experimentally induced hyperglycemic (epinephrine and alloxan) rats. Further, herbal formulation treatment can significantly alter the pattern of glucose tolerance in normal and diabetic rats. It is possible that the herbal formulation may act through both, pancreatic and extra-pancreatic mechanism(s). The DRF/AY/5001 also elicited a significant antioxidant effect in alloxan diabetic rats as reflected by its ability to inhibit lipid peroxidation and to elevate the enzymatic antioxidants in pancreatic tissue. The histopathological studies during the long term treatment have shown to ameliorate the alloxan induced histological damage of islets of Langerhans. The inhibitory effects on biochemical and histological parameters induced by herbal formulation at a dose of 600 mg/kg were almost comparable to that of standard drug, glibenclamide (4 mg/kg). The present study demonstrates that herbal formulation exhibits promisisng antidiabetic activity and helps to maintain good glycemic and metabolic control. Keywords: Alloxan, Antidiabetic activity, Antioxidant activity, Herbal formulation Diabetes mellitus is caused due to deficiency in production of insulin by the pancreas, or by the ineffectiveness of the insulin produced. It is a global problem and number of those affected is increasing day by day 1. Oral hypoglycemic agents are useful in the treatment of diabetes mellitus but their use is restricted by their pharmacokinetic properties, secondary failure rates, and accompanying side effects and the World Health Organization expert committee on diabetes has listed as one of its recommendations that traditional methods of treatment for diabetes should be further investigated 2. Traditional medicines all over the world have advocated the use of herbs to treat diabetes since time immemorial. Many Indian plants have been investigated for their beneficial use in different types of diabetes and reports occur in numerous scientific journals 1. In the Ayurvedic system of medicine, as mentioned in ancient Indian books like Charak *Present address of correspondent author: Sinhgad Institute of Pharmaceutical Sciences S.No. 309/310, Kusgaon (Bk.) Off Mumbai-Pune Expressway Lonavala, Pune , India Telephone: Fax: srnaik5@rediffmail.com Samhita, Madhav Nidan and Astang Sanghra, there are about 600 plants, which are stated to have antidiabetic property 3. Wide arrays of plant derived active principles representing numerous phytochemicals have demonstrated consistent hypoglycemic activity and their possible use in the treatment of diabetes mellitus. Indian plants which are most effective and commonly studied in relation to diabetes and its associated complications are: Allium cepa, Allium sativum, Aloe vera, Cajanus cajan, Coccinia indica, Caesalpinia bonducella, Ficus bengalenesis, Gymnema sylvestre, Momordica charantia, Ocimum sanctum, Pterocarpus marsupium, Swertia chirayita, Syzigium cumini, Tinospora cordifolia and Trigonella foenum graecum 4,5. Keeping the above information in view DRF/AY/5001, an indigenous polyherbal formulation (containing medicinal plants shown in Table 1) was developed by Dabur Research Foundation, Ghaziabad, India. This formulation has been selected to evaluate its antidiabetic activity and probable underlying mechanism(s) of action. Materials and Methods Animals Albino mice of Haffkine strain (15-25g body weight) and albino rats of Wistar strain ( g body weight) of either sex, obtained from

2 600 INDIAN J EXP BIOL, AUGUST 2008 Bharat Serum and Vaccines, Thane, India were housed under standard conditions of temperature C, 65+10% RH, 10:14 hr L:D cycle and fed with standard pellet diet (Chakan Mill Ltd, Pune, India) and water ad libitum. Experimental protocols were approved by Institutional Ethics Committee. Drugs, chemicals and reagents The polyherbal formulation DRF/AY/5001 was obtained as a gift sample from Dabur Research Foundation, Ghaziabad India. Glibenclamide was obtained as a gift sample from USV Ltd, Mumbai, India. Alloxan monohydrate and epinephrine tartarate injection I.P were obtained from Loba Chemie, Mumbai, India and H. Jules & Co Ltd, Nagpur, India respectively. All other reagents and chemicals used were of analytical grade and procured locally. Treatment The various constituents of DRF/AY/5001 are outlined in Table 1. Suspensions of finely powdered DRF/AY/5001 and glibenclamide were prepared in 1% (w/v) sodium carboxymethyl cellulose (CMC) solution and administered orally. Alloxan solution was prepared in ice cold normal saline. The control animals received vehicle. Acute toxicity studies Different doses (1-8 g/kg) of DRF/AY/5001 were administered orally to the different groups of mice (10 mice/group), while one group with same number of mice served as control. The animals were observed for various clinical symptoms and mortality up to 72 hr. Hypoglycemic activity screening in normal rats Normal fasted rats 6,7 Normal albino rats were first used for the screening of the herbal formulation for hypoglycemic activity. Overnight fasted normal rats were randomly divided into 5 groups, of 6 rats each. The group I served as control, which received vehicle i.e. 1% CMC solution (1ml/kg, orally). Group II, III and IV were treated orally with DRF/AY/ , 300 and 600 mg/kg, respectively. Group V received glibenclamide 4 mg/kg orally. Blood samples were collected from tail vein prior and 1, 2, 4 and 6 hr after treatment. Fasting blood glucose (FBG) was determined by the glucose oxidase method using Hypogaurd s advanced Microdraw test strips. The % fall in blood glucose level was also calculated at peak hour of effect. Glucose tolerance test (GTT) in normal rats 8 Prior to GTT, rats were fasted for 15 hr. Vehicle, DRF/AY/5001 and glibenclamide were then orally administered to groups of 6 rats each (as mentioned above). After 30 min glucose (1 g/kg) was orally administered to each rat. Blood samples were taken from tail vein just before drug administration and at 0.5, 1 and 2hr (after glucose administration) for determination of glucose. Epinephrine induced hyperglycemic rats 9 Overnight fasted normal rats were randomly divided into following 5 groups of 6 each after determining their fasting blood glucose (FBG). The groups I and II served as normal and hyperglycemic control respectively and received vehicle (1 ml/kg, po). Groups III and IV were treated orally with DRF/AY/5001 (300 and 600 mg/kg, respectively). Group V received glibenclamide (4 mg/kg, orally). Epinephrine hydrochloride (0.8 mg/kg) was administered intraperitoneally (ip) to all the animals (except group I) 2 hr after the DRF/AY/5001 and glibenclamide administration. FBG was determined 30, 60 and 120 min after epinephrine treatment. Induction of experimental diabetes Overnight fasted albino rats were made diabetic by injecting alloxan monohydrate (in the ice cold normal saline) intraperitoneally at a dose of 150 mg/kg body weight 10. Diabetes was confirmed in alloxan injected rats by measuring the fasting blood glucose concentration, 72 hr after the alloxanization. Rats with blood glucose level above 250 mg/dl were considered to be diabetic and were used in this study. Antidiabetic activity screening in experimentally induced diabetic rats The diabetic rats were divided Herbs Gymnema sylvestre- Periploca of the woods (Hindi Gurmar leaves) Syzygium cuimini- Black berry (Hindi Jamun guthli) Pterocarpus marsupium- Indian malabar (Hindi Vijay saar) Momordica charantia- Bitter gourd powder (Hindi Karela powder) Emblica officinalis- Indian gooseberry (Hindi Amlaki) Terminalia belirica- Beliric myrobalan (Hindi Bibhitaki) Terminalia chebula- Chebulic myrobalan (Hindi Haritaki) Shudh Shilajit (Asphaltum) Table 1 Composition of polyherbal formulation (DRF/AY/5001) Quantity (g/100g of formulation)

3 MANDLIK et al.: ANTIDIABETIC ACTIVITY OF POLYHERBAL FORMULATION 601 into 5 groups of 6 rats each. Group I and II served as normal and diabetic control respectively and received vehicle (1 ml/kg, po). Group III and IV were treated orally with DRF/AY/ and 600 mg/kg, respectively. Group V received glibenclamide 4 mg/kg, orally on 3 rd day after alloxanization (i.e. 1 st day of treatment). In single-dose, short term study, FBG was estimated from the tail vein prior and 1, 3 and 6 hr after administration of test drugs and vehicle. In multi-dose long term study, the same animals were continued with the same dose of vehicle, DRF/AY/5001 and glibenclamide once daily for 15 days. FBG in the blood was collected at and measured 24 hr after the previous dose on 3, 6, 9, 12 and 16 th day. Biochemical determinations After 15 days of treatment, overnight fasted rats were sacrificed and blood was collected. Glycosylated hemoglobin (HbA1c) was determined in heparinized whole blood by ion exchange method 11,12 using commercial kit from Eagle Diagnostics, USA. The serum was separated and analyzed for lysosomal enzymes such as transaminases 13 (serum glutamate oxaloacetate transaminase, SGOT and serum glutamate pyruvate transaminase, SGPT) and alkaline phosphatase (ALP) 14, by colorimetric method. The liver, diaphragm and pancreas were dissected out and washed with ice-cold saline immediately. Liver glycogen was estimated by the method of Caroll et al 15. A portion of pancreatic tissue was homogenized and the extract was used for the estimation of enzymatic antioxidants (catalase, CAT and glutathione peroxidase, GPx) activities including also lipid peroxidation process to see the effect of 15 days treatment with DRF/AY/5001. Effect on glucose uptake by hemidiaphragm (in vitro) Isolated diaphragm was divided into approximately 2 equal halves. The hemidiaphragms were rinsed with cold Tyrode solution, to remove blood clots. The hemidiaphragms were placed in 2 small tubes containing 2 ml of Tyrode solution with 2% glucose and incubated for 30 min at 37 ± 0.2 C with appropriate aeration to enable stirring and also to provide oxygen. Following 30 min of incubation, the hemidiaphragms were taken out, dried at 60 C till constant weight was obtained. The glucose content of the incubated medium was measured 16. Glucose uptake by the hemidiaphragm was calculated as the difference between the initial and final glucose content in the incubation medium 17. Histopathological study of pancreas Pancreas were isolated and preserved in 10% formalin. Histopathological observation of the tissues was carried out at the Unique Bio-Diagnostic Enterprises Veterinary Pathology Laboratory, Parel (Mumbai, India). Statistical analysis The results are expressed as the mean ± SE. Statistical evaluation was carried out using the ANOVA followed by Dunnett s test. The herbal formulation and Glibenclamide treated groups were compared with the corresponding normal or diabetic control. A P value <0.05 was considered to be significant. Results Acute toxicity studies All DRF/AY/5001 treated mice showed no discernible behavioral changes up to 8 g/kg by oral route. No mortality was observed at any of the doses used during 72 hr observation period (results not shown). Hypoglycemic activity screening in normal rats Normal fasted rats The onset of hypoglycemic activity of DRF/AY/5001 at 150 and 300 mg/kg was evident between 1-2 hr, the peak was found to be at 4 hr. The rats receiving 600 mg/kg of DRF/AY/5001 showed the onset of effect at 1hr with a peak effect at 4 hr. The hypoglycemic effect of DRF/AY/5001 at 600 mg/kg (25.9 % fall) was found to be nearly comparable to that of glibenclamide (4 mg/kg) (30.1 % fall) (Table 2). Glucose tolerance test (GTT) in normal rats The plasma glucose levels of the normal rats reached a peak at 30 min after the oral administration of glucose (1 g/kg) and gradually decreased to 75 mg/dl in 2 hr. The pretreatment with DRF/AY/5001 (150, 300 and 600 mg/kg) and glibenclamide (4 mg/kg) elicited decreased plasma glucose level significantly (P<0.01) as compared to the normal control group. Maximum reduction to 55.7 mg/dl at 2h was seen with 300 mg/kg (Table 3). Epinephrine induced hyperglycemic rats The intraperitoneal administration of epinephrine elicited significant (P<0.01) hyperglycemia in rats. Rats pretreated with the DRF/AY/5001 (300 and 600 mg/kg) elicited significant (P<0.01) inhibition of epinephrine induced hyperglycemia. Almost similar and significant (P<0.01) inhibitory effect was observed at 2 hr for DRF/AY/5001 (600 mg/kg) and glibenclamide (4 mg/kg) (Table 4).

4 602 INDIAN J EXP BIOL, AUGUST 2008 Antidiabetic activity screening in experimentally induced diabetic rats A single-dose administration of DRF/AY/5001 (300 and 600 mg/kg, po) on 3 rd day after alloxanization, showed a significant (P<0.01) reduction in blood glucose level (BGL) after 1 and 3 hr interval. Maximum reduction in BGL to mg/dl was seen at 3hr after administration of 600 mg/kg of DRF/AY/5001. Glibenclamide (4 mg/kg, po) also showed maximum reduction to 122.8±2.77 mg/dl at 3 hr. At 6 hr the BGL slightly increased as compared to 3 hr values (Table 5). On repeated administration of either vehicle, DRF/AY/5001 or glibenclamide for 15 days, a sustained and significant (P<0.01) decrease in the blood glucose of the diabetic rats was observed at a dose of 300 (38.0 % fall) and 600 mg/kg (40.4 % fall) (po), in a dose dependent manner as compared to the vehicle treated group. Glibenclamide also showed a Table 2 Effect of DRF/AY/5001 on blood glucose level in normal fasted rats [Values are mean ± SE from 6 animals in each group.figure in parenthesis indicates % fall in BGL as compared to 0 hr.] Group Treatment (dose mg/kg, po) 0 hr 1 hr 2 hr 4 hr 6 hr Normal Control 61.3 ± ± ± ± ± 1.08 DRF/AY/5001 (150) 61.7 ± ± ± ± ± 0.88 a (1.6) (9.7) (15.2) (12.0) DRF/AY/5001 (300) 60.3 ± ± ± 1.30 a 48.5 ± 1.33 b 51.7 ± 0.88 b (2.1) (12.6) (19.6) (14.2) DRF/AY/5001 (600) 58.7 ± ± 1.11 a 48.5 ± 1.33 b 43.5 ± 1.11 b 47.3 ± 1.40 b (5.1) (14.3) (25.9) (19.5) Glibenclamide (4) 60.8 ± ± ± 1.23 b 42.5 ± 1.11 b 46.8 ± 0.98 b (7.0) (20.2) (30.1) (23.0) P value: a < 0.05; b P< 0.01 Table 3 Effect of DRF/AY/5001 on blood glucose level in normal glucose loaded rats [Values are mean ± SE from 6 animals in each group. Figure in parenthesis indicates % fall in BGL as compared to +0.5 hr.] GroupTreatment (dose mg/kg, po) -0.5 hr hr +1.0 hr +2.0 hr Normal Control 62.3 ± ± ± ± 1.61 DRF/AY/5001 (150) 61.7 ± ± 1.13 a 75.3 ± 0.94 a (5.6) 67.2 ± 1.22 b (15.8) DRF/AY/5001 (300) 60.0 ± ± 0.94 b 65.7 ± 1.80 b (5.8) 55.7 ± 2.27 b (20.2) DRF/AY/5001 (600) 59.3 ± ± ± 0.94 b (5.8) 57.3 ± 1.45 b (11.8) Glibenclamide (4) 61.8 ± ± 1.48 b 52.3 ± 1.08 b ((12.8) 50.0 ± 1.12 b (16.7) P a < 0.05; b P< 0.01 Table 4 Effect of DRF/AY/5001 on blood glucose level in epinephrine-induced hyperglycemic rats [Values are mean ± SE from 6 animals in each group. Figure in parenthesis indicates % fall in BGL as compared to +0.5 hr.] Group Treatment (dose mg/kg, po) -3.0 hr hr +1.0 hr +2.0 hr Normal Control 62.3 ± ± ± ± 1.64 Hyperglycemic control 63.2 ± ± 1.32 a ± 2.33 a (-10.3) ± 3.02 a (-0.5) DRF/AY/5001 (300) 63.8 ± ± 2.87 b ± 2.51 b (14.5) ± 3.78 b (27.1) DRF/AY/5001 (600) 59.3 ± ± 2.81 b ± 1.89 b (12.6) 87.8 ± 1.47 b (31.8) Glibenclamide (4) 60.7 ± ± 2.57 b ± 3.93 b (10.9) 82.0 ± 2.28 b (34.5) P values: <0.01; comound to a normal; group b epinephrinc control group

5 MANDLIK et al.: ANTIDIABETIC ACTIVITY OF POLYHERBAL FORMULATION 603 significant (P<0.01) decrease in blood glucose (41.4 % fall) at a dose of 4 mg/kg (po), as compared with vehicle treated group (Table 6). Biochemical Parameters (Table 7) There was a significant (P<0.01) elevation in the blood glycosylated hemoglobin and a decrease in liver glycogen levels in alloxan induced diabetic rats as compared to normal rats. Administration of the DRF/AY/5001 (300 and 600 mg/kg) and glibenclamide (4 mg/kg) restored the increased glycosylated hemoglobin and decreased liver glycogen significantly (P<0.01) and the values were close to normal levels. Serum SGOT and SGPT levels were elevated significantly (P<0.01) in alloxan induced diabetic rats as compared to normal rats. In alloxan diabetic rats when treated with the DRF/AY/5001/glibenclamide there was a significant (P<0.01) reduction in the elevated levels of SGOT and SGPT. Similarly, elevated ALP levels in serum during alloxan induced diabetes were found to be significantly (P<0.01) lowered by DRF/AY/5001 and glibenclamide treatment. There was a significant (P<0.01) reduction in the activities of antioxidant enzymes like CAT, GPx and an increase in % lipid peroxidation in the pancreas of alloxan diabetic rats. Administration of DRF/AY/5001 (300 and 600 mg/kg) /glibenclamide (4 mg//kg) elevated CAT and GPx level and decreased lipid peroxidation. Effect on glucose uptake by hemidiaphragm The hemidiaphragms taken from rats treated with the DRF/AY/5001 and glibenclamide showed a significant (P<0.01) enhancement in the glucose uptake process as compared to diabetic untreated rats (Table 7). Histopathological studies The photomicrograph of vehicle treated normal rats showed normal acini and normal cellular population in the pancreatic islets of Langerhans (Fig. 1). The islets of alloxan diabetic rats showed extensive necrotic changes followed by fibrosis and atrophy (Fig. 2). The rats treated with DRF/AY/5001 (300 mg/kg) showed minimal to moderate degree of necrotic and fibrotic changes and atrophy of islets of Langerhans (Fig. 3). The fibrotic and necrotic changes were not detected in the islets of the rats treated with DRF/AY/5001 (600 mg/kg). But, atrophy was evident at mild to moderate degree (Fig. 4). The necrotic changes were also found to be minimal in the pancreatic islets of glibenclamide (4 mg/kg) treated rats. But, islets showed fibrosis and atrophy of minimal to moderate degree (Fig. 5). Table 5 Effect of DRF/AY/5001 on blood glucose level in alloxan-induced diabetic rats (Single-dose short term study) [Values are mean ± SE from 6 animals in each group. Figure in parenthesis indicates % fall in BGL as compared to 0 hr. ] Group Treatment (dose mg/kg, po) 0 hr 1 hr 3 hr 6 hr Normal Control 65.2 ± ± ± ± 1.40 Diabetic Control ± 2.86 a ± 3.99 a (0.7) ± 4.06 a (0.1) ± 2.67 a (-0.9) DRF/AY/5001 (300) ± ± 5.46 b (26.8) ± 5.77 b (40.2) ± 5.44 b (31.3) DRF/AY/5001 (600) ± ± 7.70 b (31.7) ± 8.13 b (52.4) ± 8.57 b (34.5) Glibenclamide (4) ± ± 1.99 b (32.3) ± 2.77 b (58.2) ± 2. (44.1)89 b P values: <01; compound to a normal group, b diabetic group Table 6 Effect of multi dose administration of DRF/AY/5001on blood glucose level in alloxan-induced diabetic rats (long term study of 15 days daily once) [Values are mean ± SE from 6 animals in each group. Figure in parenthesis indicates % fall in BGL as compared to Day 3.] Group Treatment (dose mg/kg, po) Day 3 Day 6 Day 9 Day 12 Day 16 Normal Control 59.3 ± ± ± ± ± 1.11 Diabetic Control ± 1.97 a ± ± 1.35 a (3.4) ± 2.46 a (12.4) ± 2.51 a (15.9) a (2.2) DRF/AY/5001 (300) ± 3.85 b ± ± 5.44 c (19.5) ± 6.07 c (34.4) ± 5.85 c (38.0) c (6.6) DRF/AY/5001 (600) ± 8.03 c ± ± 5.67 c (22.4) ± 5.60 c (37.1) ± 5.44 c (40.4) c (8.8) Glibenclamide (4) ± 5.54 c ± 5.51 (9.1) ± 5.19 c (20.6) ± 4.50 c (33.2) ± 4.54 c (41.4) P values: <0.01; compound to a normal group; c diabetic group b <0.05 compound to diabetic group.

6 604 INDIAN J EXP BIOL, AUGUST 2008 Group Treatment (dose mg/kg, po) Table 7 Effect of DRF/AY/5001 on biochemical parameters in alloxan induced diabetic rats [Values are mean ± S.E.M. from 6 animals in each group.] Liver Glycogen (g/100g) Normal control ± % GHbA1c Glucose uptake by hemidiaphragm(mg/g) 4.61 ± ± SGPT (IU/L) ± SGOT (IU/L) ± Alkaline phosphatase (IU/L) ± % Lipid Peroxidation CAT (U/mg protein) ± GPx (U/mg protein) ± Diabetic control ± 7.14 ± ± ± ± ± ± ± a a a a a a a a DRF/AY/5001 (300) ± 6.09 ± ± ± ± ± ± ± ± b b b b b b b b b DRF/AY/5001 (600) ± 5.70 ± ± ± ± ± ± ± ± b b b b b b b b Glibenclamide (4) ± 5.41 ± ± ± ± ± ± ± ± b b b b b b b b b P values: <0.01; compound to a normal group b diabetic Discussion The herbal formulation (DRF/AY/5001) seems to be safe upto 8 g/kg because even at this high dose no toxic or deleterious effects were seen immediately or during 3 days of observation period. In the present experiments, the herbal formulation, like glibenclamide, showed hypoglycemic effect at 300 and 600 mg/kg in dose related manner both in normal (Table 2) as well as glucose loaded normal fasted rats (Table 3). It is to be studied whether DRF/AY/5001 brought about these changes by acting through pancreatic mechanism similar to that of glibenclamide 18, or by inhibition of glucose absorption through gastrointestinal tract like other herbs (P. marsupium and M. charantia) 19,20. DRF/AY/5001 inhibited significantly the hyperglycemia induced by epinephrine (Table 4). The epinephrine induced hyperglycemia is largely mediated through the release of glucocorticoids which in turn affect glucose metabolism in liver and are also known to inhibit insulin release by pancreas. It is therefore necessary to investigate whether both DRF/AY/5001 and glibenclamide antagonize the epinephrine action either at the release of glucocorticoids stage or its action on glucose utilization in liver through hexokinase or they act by release of insulin from pancreas in normal rats. DRF/AY/5001 showed significant reduction in BGL at 1-3 hr with single dose treatment in alloxan diabetic rats (Table 5). But 15 days treatment of alloxan diabetic rats with 600 mg/kg of DRF/AY/5001 was similar to that of glibenclamide and both the drugs brought about significant reduction in blood glucose (as observed on different days) (Table 6) and glycosylated hemoglobin (HbA1c) levels (Table 7). Since DRF/AY/5001 showed reasonably good antihyperglycemic effect, its mechanism of action was studied. Biochemical parameters have given some idea about its mechanism of action. This action could be by increase in liver glycogen content (decrease seen in untreated diabetic animals) after DRF/AY/5001 which can be by increase in glycogenesis and/or a decrease in glycogenolysis. The DRF/AY/5001 (at the dose of 600 mg/kg) enhanced the uptake of glucose by hemidiaphragm as indicated by the studies with isolated rat hemidiaphragm. Increrased lipid peroxidation seen in diabetic conditions is attributed to increased oxidative stress in the cells as a result of the depletion of antioxidant systems. In support to this view levels of both enzymatic antioxidants (GPx and CAT) decreased and lysosomal enzymes increased in diabetic rats. It is interesting that in DRF/AY/5001 treated rats there was decrease in lipid peroxidation, increaesed levels of the antioxidant enzymes (GPx and CAT) and decrease in lysosomal enzymes. This shows that DRF/AY/5001 can reverse all these abnormalities either by pancreatic or hepatic mechanism. Histopathological findings of pancreas of the diabetic rats showed necrosis, atrophy and fibrotic changes. But, the pancreas of the rats treated with DRF/AY/5001 and glibenclamide showed minimal necrosis and mild to moderate atrophy and fibrotic changes.

7 MANDLIK et al.: ANTIDIABETIC ACTIVITY OF POLYHERBAL FORMULATION 605 Figs 1 5 Section of the pancreatic tissue of (1) normal rats, (2) diabetic control rats, (3) DRF/AY/ mg/kg; treated rats, (4) DRF/ AY/ mg/kg treated rats, and (5) glibenclamide 4 mg/kg treated rats

8 606 INDIAN J EXP BIOL, AUGUST 2008 In conclusion, it can be stated that, DRF/AY/5001 is a potential antidiabetic herbal formulation and hence it is interesting to investigate its underlying molecular mechanism(s) of action and also long term toxicity studies in different animal species. After completing the preclinical studies the herbal product needs to be tried on human diabetic patients to ascertain its therapeutic efficacy and safety. References 1 Mukherjee P K, Maiti K, Mukherjee K, Houghton P J, Leads from Indian medicinal plants with hypoglycemic potentials, J Ethnopharmacol, 106 (2006) 1. 2 Naggar E M, Antidiabetic effect of Cleome droserifolia Areial parts: Lipid peroxidation-induced oxidative stress in diabetic rats, Acta Vet. Brno, 74 (2005) Murray, M.T.; (1995). Healing Power of Herbs. 2 nd edition, Gramercy Books NY, pp: Grover J K, Yadav S, Vats V, Medicinal plants of India with anti-diabetic potential, J Ethnopharmacol, 81 (2002) Shukla R, Sharma S B, Puri D, Prabhu K M & Murthy P S, Medicinal plants for treatment of diabetes mellitus, Indian Journal of Clinical Biochemistry, 15 (Suppl.) (2000) Skim F, Kaaya A, Jaouhari J T, Lazrek H B, Jana M & Amri H E, Hypoglycemic activity of Globularia alypum leaves in rats, Fitoterapia, 70 (1999) Sabu M C, Kuttan R, Anti-diabetic activity of medicinal plants and its relationship with their antioxidant property, J Ethnopharmacol, 81 (2002) Williamson E M, Okpako D T & Evans F J, Diabetes mellitus, in Pharmacological methods in phytotherapy research (Wiley and Sons Publication, England) 1996, Naik S R, Filho J M B, Dhuley J N & Deshmukh V K, Probable mechanism of hypoglycemic activity of Bassic acid, J Ethnopharmacol, 33 (1991) Antia B S, Okokon J E & Okon P A, Hypoglycemic activity of aqueous leaf extract of Persea Americana Mill, Indian J Pharmaco, 37(2005) Trivelli L A, Ranney H M & Lai H T, Hemoglobin components in patients with diabetes mellitus, New England J Med, 284 (1971) Goen B & Rubenstein A H, Hemoglobin A1 and diabetes mellitus, Diabetologia, 15 (1978) Bergmeyer H U, Horder H & Rej R, Approved recommendation on IFCC method for the measurement of catalytic concentration of enzymes. Part 3. IFCC method for L-Aspartate aminotransferase. J Clin Chem Clin Biochem, 24 (1986) Henry R J, Cannon D C & Winkelman D C, Enzymes, in Clinical chemistry: principles and techniques (Harper & Row, N.Y.) 1974, Carroll V V, Longly R & Joseph H R, Determination of glycogen in liver and muscle by use of anthrone reagent, J Biol Chem, 220 (1956) Trinder P, Determination of glucose in blood using glucose oxidase with an alternative oxygen acceptor, Ann Clin Biochem, 6 (1969) Chattopadhyay R R, Sarkar S K, Ganguly S, Banerji R N & Basu T K, Effect of extract of leaves of Vinca rosea Linn. on glucose utilization and glycogen deposition by isolated rat hemidiaphragm, Indian J Physiol Pharmacol, 36 (1992) Best C H & Tayler N B, Physiological basis of medical practice, 6 th ed. (Williams & Williams Cpy. Baltimore) 1959, Mukhtar H M, Ansari S H, Ali M, Bhat Z A & Naved T, Effect of aqueous extract of Pterocarpus marsupium wood on alloxan- induced diabetic rats, Pharmazie, 60 (2005) Meir P & Yaniv Z, An in vitro study of Momordica charantia on glucose uptake and glucose metabolism in rats, Planta Medica, 1 (1985) 12.