streptozotocin

This study explored the effect of bark of Holarrhena antidysenterica Linn in management of diabetic neuropathy in experimental animals. Adult Wistar rats (either sex; 250-275 g) were injected with streptozotocin (50 mg/kg; i.p.) to induce diabetes. Methanol extract of bark of Holarrhena antidysenterica was administered in 3 doses (200, 400 and 600 mg/kg; p.o.) to rats for 28 successive days daily after 4 weeks of STZ administration. After 8 weeks, the neuropathic activity was evaluated using Open field test, Tail Flick test, Cold Allodynia and Formalin test. Afterwards, sciatic nerve was used for TBARS, GSH, Nitrite, Catalase and protein estimations. STZ induced diabetic neuropathy caused decrease in tail-flick latency time in radiant heat test and decreased allodynic response in tail-immersion (cold water) test. STZ caused increase in blood glucose, Glycosylated Haemoglobin and blood Cholesterol levels. Furthermore, activity of endogenous antioxidants like GSH and catalase significantly decreased; however, TBARS and nitrite levels were increased. Administration of MEHA for 28 days prevented the development of diabetic neuropathy as evident from reversed (p< 0.05) cold allodynia and tail flick latency (p< 0.05) as compared to diabetic control group. Glycosylated haemoglobin and cholesterol levels were significantly decreased (p< 0.05) in rats as compared to diabetic control group. MEHA treated rats showed significant decreased TBARS and nitrite levels and increased GSH and Catalase level. Thus, Holarrhena antidysenterica not only improved the diabetic condition but also reversed neuropathic pain through modulation of oxidative–nitrosative stress.

In the present study, the polyherbal antidiabetic nutraceutical formulation was screened for its safety and efficacy using albino wistar rats (130-150gm). The formulation consists of Gymnema sylvestre, Trigonella foenum-graecum, Allium cepa, Curcuma longa, Phyllanthus amarus, Tinospora cordifolia, Eugenia jambolana, Cinnamomum zeylanicum. The safety of the formulation was studied by acute toxicity studies according to Organisation for Economic Co-operation and Development (OECD) guidelines and efficacy was studied by using streptozotocin induced diabetes model at 45 mg/kg b.w. The test drug did not show any signs of toxic­ity or mortality up to 5000 mg/kg which was fixed as the cut off point for the maximum tolerated dose.  Antidiabetic activity was screened in streptozotocin induced diabetic rat model for 21 days using glibenclamide 1.5 mg/kg as standard and parameters like blood glucose level and weight variation were studied. After 21 days treatment the mean blood glucose level of the formulation, dose 1 (500mg/kg) treated group showed 142.50±1.11mg/dl, the formulation, dose 2 (250mg/kg) treated group showed 210.66±2.96 mg/dl, the standard group showed 137.66±2.10 mg/dl, Control group 433.33±9.89mg/dl, Normal group 94.83±0.30 mg/dl respectively and at a dose of 500mg/kg body weight. The formulation showed significant increase in the body weight. Therefore, the results indicated that the polyherbal neutraceuticals formulation is an efficacious and safer antidiabetic/ oral hypoglycemic formulation in Type II diabetes.

To study the effects of ethanolic extracts of Vernonia amygdalina(VA) and Ocimum gratissimum (OG)on the testes of diabetic rats, thirty-two male rats were used. Control consisted of eight (8) rats which served as non- diabetic control, receiving sodium citrate daily. The remaining rats were injected intraperitoneally with streptozotocin(65mg/kg) to induce diabetes. The rats confirmed diabetic were randomly divided into three experimental groups (1, 2 and 3) made up of eight rats each. Group 1 received 6IU/kg of insulin. Group 2 was given 100mg/kg body weight of Vernonia amygdalina and 200mg/kg body weight of Ocimum gratissimum combined daily. Group 3 served as the diabetic control and was given distilled water. The entire investigation lasted for 6 weeks. Results revealed typical testicular architecture in the normal control. Diabetic control exhibited alteration of germinal epithelium, distortion of seminiferous tubules as well as vacuolation of seminiferous tubules. The effects of the extracts on diabetic rats’ testes showed improvements compared to the diabetic control group. It is therefore safe to speculate that the extracts of these plants used especially when combined exert some significant improvement in combating the adverse effects of diabetes on the testes of male rats.