Evaluation of the Antioxidant, Antidiabetic and Hypolipidemic Potential of Garcinia kola Seed Tincture in Streptozotocin-Induced Diabetic Albino Wistar Rats

Aim: The aim of this study was to evaluate the antioxidant, antidiabetic and hypolipidemic potential of Garcinia kola seed tincture in streptozotocin-induced diabetic albino Wistar rats. 
Study Design:  This study is a non-randomized experimental study. 
Place and Duration of Study: This study was conducted at the Animal House of the Department of Applied and Environmental Biology, Rivers State University, Port Harcourt, Nigeria, between August and December, 2019. 
Methodology: A total of 46 male Albino rats were used. Garcinia kola seed was bought and 10g of the seed was macerated with 50 mL of 43% alcoholic Gordon and stored at 4°C. Six rats were used for the pilot study to determine the concentration of streptozotocin that could induce diabetes, the remaining 40 rats were divided into 8 groups of 5 rats each, with different experimental treatments. “Streptozotocin diabetes” was achieved by intraperitoneally injecting the rats with 45 mg/kg streptozotocin, glibenclamide and metformin doses were extrapolated from human doses and rats treated with Garcinia kola seed tincture were separately given low (1 ml/kg), high (3 ml/kg) of the tincture or in combination with the either glibenclamide or metformin once per day for 30 days. Rat ELISA kits were used to determine the levels of total antioxidant capacity (TAC), total oxidant status (TOS) and malondaldehyde (MDA). An autoanalyzer was used to assay for fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), HDL-cholesterol, while oxidative stress indices (OSI) and LDL-cholesterol were calculated. SPSS version 22.0 for Windows was used for statistical analysis and P<.05 was considered statistically significant. 
Results: The results showed that there were significantly higher (P<.001) MDA, TOS, OSI and FBG levels after streptozotocin induction. On treatment with G. kola seed tincture, values were observed to have significantly reduced. Only TG level was significantly higher after induction and a significant lower TG level was also observed only in the group of rats treated with the higher dose of the tincture. Liver enzyme activities did not show any significantly higher values after induction, but values were significantly raised after treatment with tincture and alcohol separately. 
Conclusion: From the results, we conclude that Garcinia kola seeds tincture has both hypoglycemic and antioxidant attenuating effects in “streptozotocin diabetes” albino wistar rats.