ANTIHYPERGLYCEMIC AND ANTI-OXIDANT POTENTIAL OF ETHANOL EXTRACT OF VITEX THYRSIFLORA LEAVES ON DIABETIC RATS

Theodora Kopa Kowa; Nyemb Nyunaï; Thierry Gilbert Nkoulou Tabi; Armelle Deutou Tchamgoue

doi:10.22270/ujpr.v3i3.161

Theodora Kopa Kowa Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies (IMPM), P. O. Box 13033 Yaoundé, Cameroon
Nyemb Nyunaï Medical Research Centre, Institute of Medical Research and Medicinal Plant Studies (IMPM), P. O. Box 13033 Yaoundé, Cameroon
Thierry Gilbert Nkoulou Tabi Department of Animal Biology and Physiology, University of Yaoundé I, P. O. Box 812 Yaoundé, Cameroon
Armelle Deutou Tchamgoue Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies (IMPM), P. O. Box 13033 Yaoundé, Cameroon.

10.22270/ujpr.v3i3.161

Keywords:

antihyperglycemic, antioxidant, diabetic rats, Vitex thyrsiflora

Abstract

Objective: Vitex thyrsiflora Baker (Verbenaceae) is a glabrous under shrub that is widely distributed in Cameroon. Diabetes is characterized by chronic hyperglycemia, a source of increased oxidative stress and tissue oxidative damage. The objective of current study was to estimate the antihyperglycemic and anti-oxidant potential of ethanol extract of Vitex thyrsiflora leaves on diabetic rats

Methods: The antihyperglycemic effect of an ethanol extract of Vitex thyrsiflora leaves was investigated in normal male rats and streptozotocin induced diabetic male rats and its antioxidant potential was evaluated. After preparation of the extract, it was subjected to a phytochemistry screening, and tested on male rats made hyperglycemic in the Oral Glucose Tolerance Test (OGTT) and in streptozotocin diabetic rats. Glibenclamide (10 mg/Kg) was served as a positive control in both experiments. The evaluation of the antioxidant potential was done through the determination of the total polyphenols and total flavonoid contents, and by using the ferric reducing antioxidant power assay and the free radical scavenging activity on DPPH method.

Results: The results show that the extract contains alkaloids, flavonoids, steroids, saponins and phenolic compounds. The test on hyperglycemic rats in OGTT showed that, the extract was effective (at a dose of 200 mg/Kg) to significantly decreased glucose-induced hyperglycemia (**p ˂ 0.01). The extract was ineffective on streptozotocin induced diabetic rats. The study of the antioxidant potential showed that, polyphenols and flavonoids increase with the concentration of the extracts. IC₅₀ value was found to be 65.97, based on the log (inhibitor) vs. normalized response-Variable slope.

Conclusion: FRAP appears to be significantly highly correlated with total polyphenols content and total flavonoids content. This shows that the ethanol extract of V. thyrsiflora leaves could be served to prevent acute hyperglycema, but not a chronic hyperglycemic state.