Introduction

rats Diabetes mellitus, often simply referred as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced. Diabetes mellitus is one of the common metabolic disorders, and 2.8% of the population suffer from this disease throughout the world and it may cross 5.4% by the year 2025. diabetes mellitus is group of many different disease because, hyperglycemia causes damage to eyes, kidneys, nerves, heart and blood vessels. Diabetes is one of the causes of renal end- stage disease. It is caused by inherited and/or acquired deficiency in production of insulin by the pancreas or by the effectiveness, uncontrolled high blood sugar leads to the development of kidney damage especially high blood pressure is also present. Hyperglycemia generates more reactive oxygen species and attenuates anti-oxidative mechanism through glycation of the scavenging enzymes. Therefore, oxidative stress has been considered to be a common pathogenic factor of the diabetic. Traditionally herbal folk, medicine is most popular, which have antioxidant property, and 1000 side effects. Due to antioxidant property and these drugs give good results and reduce the blood glucose level, therefore, some herbal folk medicinal plant have been reported which are useful in diabetes treatment. Now days more than 400 plants are being used in different forms for hypoglycemic effects all the claims practitioners or users therefore a proper scientific evaluation & Screening of plant by Pharmacological tests followed by chemical investigation is necessary (Shukla et al., 2011; Dixit et al., 2006; Patil et al., 2011). Various studies have shown that of free radicals and decrease in antioxidant potential due to persistent hyperglycemia. This leads to oxidative damage of cell components such as proteins, lipids and nucleic acids (Rolo and Palmeira, 2006). diabetes mellitus is associated with increased formation Besides, drugs classically used for the treatment of diabetes include, insulin, sulphonylureas, biguanides and thiazolidinediones. Recently, many investigations indicated that supplementation with nature antioxidants may alleviate the oxidative damage in diabetes (Naziroglu and Butterworth, 2005; Kamalakkannan and Prince, 2006). In particular, it is recognized that consumption of natural antioxidants of fruits, vegetables and grains are important for the prevention of chronic illnesses in diabetes patients (Dixit and Kar, 2010; Singh et al., 2005). A considerable interest has grown in finding both hypoglycemic and antioxidative properties of natural antioxidants for the treatment of diabetes (Rajkumar et al., 1991). Hence, this paper was designed to investigate antidiabetic activity of burdock extract in alloxan diabetic rats.

Preparation of burdock ethanolic extracts (BRE)

Fresh roots of burdock were cleaned, dried in shade and finelypowdered. The powder was defatted with petroleum ether and thenextracted with 70% ethanol (1:10, w/v) for 72 h at roomtemperature. Filtered with Whatman paper No.1 and the residuewas re-extracted twice till exhaustion, the combined filtrates wasconcentrated under vacuum at 50°C and the resulting filtrate were freeze-dried (Boyikang Refrigerated Vapor Trap, SD-1A-50). Theextract yield was 16.5% (w/w); the obtained extract was stored at -20°C until use.

Induction of Diabetes Mellitus in rats

Diabetes is induced by injecting Alloxanhydrate(C4H2N2O4.H2O (LOBA CHEMIE PVT LTD, Mumbai)80mg / kg body weight, subcutaneously in albino rats after 12 h of continuous fasting.[80]Fasting blood sugar wasevaluated by using Glucometer (SD Fine chemicals) after 72h. Rats whose blood glucose levels remained <300 mg/dl fomore than one week following the initial injection of alloxan received a second dose of alloxan to maintain a bloodglucose level >300 mg/dl for the duration of the study (Oi et al., 1997).

Experimental design and treatment schedule

24 diabetic rats and six normal rats were randomly divided into five groups (n = 6). The extract was administered for 21 days. They included: group I: normal control rats administered saline (0.9%, w/v); group II: diabetic control rats administered saline (0.9%, w/v); group III: diabetic rats administered glibenclamide (100 mg/kg b.w.) daily for 14 days; group IV: diabetic rats administered BRE (200 mg/kg b.w.); and group V: diabetic rats administered BRE (300 mg/kg b.w.). The effects of administration of BRE in diabetic rats were observed by measuring fasting blood glucose and changes in body weight. Fasting blood glucose was estimated on day 7,14 and 21 of BRE administration. Serum insulin level was estimated by using a commercial diagnostic radio immunoassay kit (Beijing North Institute of Biological Technology, China).

Statistical analysis

Data were statistically evaluated using one-way analysis of variance followed by Duncan’s test as a post-analysis of variance test. The values were considered significant when p<0.05.

Results

In table 1 all of the data were expressed in SI units and analyzed by repeated measurements ANOVA, LSD and T-test using SPSS/PC software (Norusis, 1993). All values were expressed as mean and standard error of mean (SEM), and P<0.05 was seen as statistically significant., Also as is indicated in Table 1 mean of Blood glucose are studied between different groups in rats. According to this study on day 7, 14 and 21 the average amount of blood glucose in group 3 which received insulin compared to the control group(2) was significantly decreased (p≤0.05) but on day 21 not only The average amount of blood glucose in group 3, but also The average amount of blood glucose in group 4,5 and 6 compared to the control group(2) was significantly decreased. (p≤0.05)

This data showed that after 21 day , the level of blood glucose in group which received extract in dose of 100, 200 and 300 mg/kg was significantly decreased and this extract can act like insulin.

Discussion

The study results showed that BRE had a marked hypoglycemic activity by lowering the blood glucose levels in STZ-induced diabetic rats, and by the improvement of the glucose tolerance but not fasting blood glucose in normoglycemic rats. STZ is an antibiotic that can cause pancreatic β-cell destruction. STZ-induced diabetic rat is one of the animal models of insulin dependent diabetes mellitus or type I diabetes mellitus. In this model, STZ significantly induced hyperglycemia accompanied by hypoinsulinemia, which arises from irreversible destruction of the β-islet cells of the pancreas through its generation of cytotoxic oxygen free radicals (Szkudelski, 2001). In this study, oral administration of BRE 14 days produced a significant increase in insulin levels along with a decrease in blood glucose levels in STZ-induced diabetic rats, exhibiting its protective potential for regulating diabetes mellitus. The elevation in serum insulin levels may be due to substances present in BRE which promote insulin secretion by the stimulation of a regeneration process and protect the remaining beta cells from further deterioration. Under normal conditions, insulin promotes intracellular glycogen deposition by stimulating glycogen synthase (Eliza et al., 2009) in the diabetic state due tolack of insulin which results in the inactivation of glycogensynthase system as well as reduced insulin-inducedglucose utilization by the tissues (Munoz et al., 1996). Inthis study, it was shown that hepatic and skeletal muscleglycogen content reduced drastically in STZ-diabetic ratsTreatment of BRE to diabetic rats significantly improvedglycogen content of liver and muscles. Induction of diabetes with STZ also leads to loss of body weightwhich may be due to increased catabolism of glycogen inmuscle, liver and loss of tissue proteins (Rajkumar et al., 1991). After 14 days of BRE treatment, body weight oSTZ-diabetic rats was improved. An increase in glycogencontent and body weight of diabetic rats might be due to an improvement in insulin secretion and glycemic control.

References (10)(Add 4)

1. Shukla, A., V. Bukhariya, J. Mehta, J. Bajaj, R. Charde, M. Charde and B. Gandhare, 2011. Herbal remedies for diabetes: An overview. Int. J. Biomed Adv. Res., 2: 57-58.1137461ja
2. Dixit, P.P., J.S. Londhe, S.S. Ghaskadbi and T.P.A. Devasagayam, 2006.Antidiabetic and related beneficial properties of Indian medicinal plants. In: Sharma RK, Arora R. Herbal Drug Research-A twenty first century perspective. New Delhi: Jaypee brothers medical publishers Limited; 2006, p. 377-386.20981bc
3. Patil, R.N., R.Y. Patil, A. Ahirwar and D. Ahirwar, 2011. Evaluation of antidiabetic and related actions of some Indian medicinal plants in diabetic rats. Asian Pac. J. Trop. Med., 4: 20-23. 1137464ja
4. Rolo, A.P. and C.M. Palmeira, 2006. Diabetes and mitochondrial function: role of hyperglycemia and oxidative stress. Toxicol. Appl. Pharmacol 2006; 212: 167-178. 100104ja
5. Naziroglu, M. and P.J. Butterworth, 2005. Protective effects of moderate exercise with dietary vitamin C and E on blood antioxidative defense mechanism in rats with streptozotocin- induced diabetes. Can J. Appl. Physiol 2005; 30: 172-185. 381144ja
6. Kamalakkannan, N. and P.S. Prince, 2006.Antihyperglycaemic and antioxidant effect of rutin, a polyphenolic flavonoid, in streptozotocin-induced diabetic Wistar rats. Basic Clin. Pharmacol. Toxicol 2006; 98: 97-103. 96506ja
7. Dixit, Y. and A. Kar, 2010. Protective role of three vegetable peels in alloxan induced diabetes mellitus in male mice. Plant Foods Human Nutr., 65: 284-289. 1137469ja
8. Singh, N., V. Kamath and P.S. Rajini, 2005. Protective effect of potato peel powder in ameliorating oxidative stress in streptozotocin diabetic rats. Plant Foods Hum. Nutr 2005; 60:49-54. 149676ja
9. Rajkumar, L., P. Govidarajula, N. Srinivasan and K. Balasubramanian, 1991. Increased degradation of dermal collagen in diabetic rats. Indian J. Exp 1991; Biol. 29: 1081-1083. 381222ja
10. Oi, K., H. Komori and H. Kajinuma, 1997.Changes in plasma glucose, insulin, glucagon, cathecolmine, and glicogencontentes in tissue during development of alloxan diabetes in rats. BiochemMol Med 1997; 62: 70-5. 936615ja
11. Norusis, M.Y., 1993. SPSS for Windows Base System User’s Guide Release 6.0.1st edn, (SPSS Inc Michigan)2001; pp. 281-290. 4532b
12. Szkudelski, T., 2001. The mechanism of alloxan and streptozotocin action in B cells of the rat pancreas. Physiol. Res 2001; 50: 537-546. 100477ja
13. Eliza J., P. Daisy, S. Ignacimuth and V Duraipandiyan, 2009. Antidiabetic and antilipidemic effect of elemantrin from Costusspeciosus (Koen.) Sm. in STZ-induced diabetic rats. Chemicobiol. Int., 179: 329-334. 930884ja
14. Munoz, P., J. Chillaron, M. Camps, A. Castello, M. Furriols,<i>et al</i>., 1996. Evidence for posttranscriptional regulation of GLUT4 expression in muscle and adipose tissue from streptozotocin-induced diabetic and benfluorex-treated rats. Biochem. Pharmacol., 52: 1665-1673. 1137477ja