Hypoglycemic Potentials and Toxicity studies of Garcinia kola Seed Tincture in Alloxan-Induced Diabetic Rats

Aim: The aim of this study was to evaluate the hypoglycemic potentials and toxicity studies of Garcinia kola seed tincture in Alloxan-induced Diabetic Rats.

Study Design: This study is an interventional study.

Place and Duration of Study: A total of fifty one (51) adult wister rats weighing 180 – 200g were used. The rats weighed and grouped into 6 groups of 6 rats each. Group 1 (negative control) were placed on normal diet, while groups 2 to 6 were administered with 150mg/kg alloxan(Sigma-Aldrich) to achieve the animal model of Type 2 diabetes mellitus. Glibenclamide was used for this study. Treatments were given according to the groupings by means of oral gavage for a period of 21 days. At the end of the treatments, the rats were anaesthetized and blood samples collected for biochemical analysis. The heart, liver and kidneys were also harvested for histological analysis. Fasting plasma glucose (FPG) was estimated using the glucose oxidase method. Enzymatic method was used for the determination of total cholesterol (TC), triglyceride (TG), and high density lipoprotein cholesterol (HDL-C), whereas low density lipoprotein cholesterol (LDL-C) was calculated from the friedewald equation. Reitman-Frankel method was used for the determination of liver transaminases, while phenolophthalein method was used for the determination of alkaline phosphatase. The heart, liver and kidney sections were stained with the standard haemotoxylin and eosin staining technique.

Results: The results showed significantly higher mean FPG levels (p<0.05) in all groups that received alloxan, as compared to the negative control. Extract of Garcinia kola combined with glibenclamide produced significant blood glucose-lowering effects in diabetic rats (p<0.05) when compared to the positive control group, revealing a potentiating drug interaction between the extract and glibenclamide. Troponin showed no significant difference (p>0.05) in all groups when compared to the positive control. There was a significant elevation (p<0.05) of total cholesterol, triglyceride and LDL-C in all groups induced with diabetes when compared to the negative control. HDL-C however, was lowered significantly (p>0.05) in all groups when compared to the negative control. Liver enzyme levels were significantly higher in diabetic control compared to negative control, except in groups 4 (glibenclamide), and 6 (alcohol). Histological analysis of the heart showed normal branching muscle fibres and peripherally placed nuclei in all groups. Liver sections showed normal histoarchitecture in the negative control compared to the diabetic control which had sinusoids filled with inflammatory cells. The treatment groups showed nearly normal liver architecture with hepatic artery and portal vein.

Conclusion: In conclusion, the combined treatment with the tincture and glibenclamide showed hepatoprotective potentials in addition to its hypoglycaemic effects.