Studies on the Effect of Polyphenol of Cocoa (Theobroma cacao L.) Seeds on Specific Carbohydrate-Degrading Enzymes in Streptozotocin-Induced Diabetic Rats

Abstract

This study focused on the investigation of the anti-hyperglycaemic potentials of polyphenols extracted from fermented and unfermented Theobroma cacao seeds in Wistar rats with a view to investigating the use of cocoa tea in the management of hyperglycaemic conditions. Fresh seeds of cocoa were collected, divided into two groups, a group was sun dried immediately for 7 days and used as unfermented seeds. The other group was fermented traditionally for 5 days; sun dried for 7 days and used as fermented seeds. The seeds (fermented and unfermented) were then ground to powder. The aqueous extracts of the seeds (fermented and fermented) were prepared, phytochemically screened; polyphenols were extracted with 80% (v/v) acetone from both extracts and assayed for α-amylase and α-glucosidase activities. The polyphenols were termed fermented (FP) and unfermented (UP) respectively. Preliminary assays showed that the polyphenol of the fermented T. cacao seeds exhibited a higher α-amylase inhibitory potential of 99.25 ± 2.24 % at 400 µg/ ml (IC50 142.62 ± 6.03 µg/ ml) compared to the unfermented polyphenol 83.30 ± 6.25 % at 400 µg/ ml (IC50188.56 ± 15.32 µg/ ml), as such FP was used for further studies. The effects of the fermented polyphenols (150 mg/kg bwt and 300 mg//kg bwt) on total cholesterol, triacylglycerols, and α-amylase and α-glucosidase activities were examined in diabetic and non-diabetic rats. The results of the findings revealed that 150 mg/kg bwt fermented polyphenol proved to be more potent and efficient in reducing the activities of the carbohydrate-degrading enzymes, thus more anti-hyperglycaemic.