Comparison of antioxidant activity of insulin, Ocimum gratissimum L., and Vernonia amygdalina L. in type 1 diabetic rat model

OBJECTIVE： Diabetes mellitus （DM） is known to be associated with increase of oxidative stress products. The direction of effect of any treatment on these products could therefore be a reliable measure of its efficacy on DM. So the aim of this study was to investigate the activity of insulin, Ocimum gratissimum L. （OG） and Vernonia amygdafina L. （VA） on oxidative stress products.METHODS： Thirty-six female Wistar rats weighing 150-200 g were randomly divided into six groups of six rats each. Thirty rats were induced for type 1 DM （DM1） with a single intraperitoneal administration of 65 mg/ kg body weight of streptozotocin. Group 1 was normal control and was administered distilled water while Group 2 served as DM1 control group; Groups 3, 4, 5 and 6 were diabetic rats treated with 208 mg/kg OG （DM1 ＋ OG）, 52 mg/kg VA （DM1 ＋ VA）, 208 mg/kg OG ＋ 52 mg/kg VA （DMI＋OG ＋VA） and 0.16 IU insulin （DM1 ＋ insulin） respectively. Determination of methemoglobin and sulfhemoglobin was achieved by the absorption spectrum principle. Red blood cell （RBC） catalase was assayed by continuous spectrophotometric method.RESULTS： The RBC catalase concentration was significantly decreased in the DM1 and DMI＋VA groups when compared with the normal control. DM1 ＋ OG significantly increased RBC-catalase when compared to DMI. The methemoglobin concentration was significantly reduced in the DM1, DM1 ＋ VA, DM1 ＋ OG ＋ VA and DM1 ＋ insulin groups when compared to the normal control group. The sulfhemoglobin concentration was significantly increased in the diabetic control and the diabetic treated groups when compared to the normal control. DM1 ＋ OG reduced the sulfhemoglobin concentration when compared to DM1. The blood glucose concentration of all the diabetic groups was significantly raised compared to normal control. OG, VA and insulin significantly reduced the blood glucose concentration with the efficacy of OG and VA higher than insulin.CONCLUSION： Adverse alteration of oxidative indices were observed in type 1 DM model. Treatment with OG and insulin showed potent antioxidant activity, while the hypoglycemic efficacy of OG and VA were higher than insulin.

Hypoglycemic efficacy of Ocimum gratissimum and Vernonia amygdalina compared with insulin and glibenclamide in type Ⅰ and type Ⅱ diabetic rat models

Objective: To compare the efficacy of Ocimum gratissimum (O. gratissimum) and Vernonia amygdalina (V. amygdalina) with those of insulin and glibenclamide.Methods: Type Ⅰ and Ⅱ diabetes mellitus (DM) were induced by a single intraperitoneal injection of 65 mg/kg of streptozotocin and intraperitoneal administration of nicotinamide (100 mg/kg) along with streptozotocin, respectively. The state of diabetes was confirmed weekly by testing blood glucose level using a glucometer.Results: The weekly blood glucose levels were higher in type I DM than in type Ⅱ DM. Type Ⅰ DM plus O. gratissimum showed a weekly progressive significant reduction in blood glucose compared to type Ⅰ DM control. Type Ⅰ DM control showed a duration dependent significant higher blood glucose concentration compared to normal control. Type I DM plus V. amygdalina also showed a time dependent significant lower glucose level compared to normal control and type Ⅰ DM control. Combination treatment of type Ⅰ DM (O. gratissimum plus V. amygdalina) showed a significantly elevated glucose concentration compared to normal control which was similar to type I DM control. Insulin treatment in type I DM showed a weekly progressive significant reduction of glucose concentration compared to normal control and type I DM control. Type Ⅱ DM control showed a fairly constant blood glucose concentration throughout the duration of treatment that was significantly higher than that of the normal control. Type Ⅱ DM plus O. gratissimum showed a fairly steady significant reduction of glucose concentration compared to type Ⅱ DM control and normal control. Type Ⅱ DM plus V. amygdalina also showed a fairly constant significant reduction of glucose concentration compared to type Ⅱ DM control and normal control. Type II DM (O. gratissimum plus V. amygdalina) showed a slightly progressive significant reduction of glucose concentration compared to normal control and type Ⅱ DM control. Type Ⅱ DM with glibenclamide showed almost steady significant reduction in glucose concentration compared to normal control and type Ⅱ DM control. Conclusions: From the result, it is evident that O. gratissimum and V. amygdalina administration produces more potent hypoglycemic activity than insulin and glibenclamide in type I and Ⅱ DM models, respectively.