Earlier studies have reported that tamarind seed, which is an underused part of the tamarind fruit tree, may be able to help treat diabetes. The seed has rich nutrient content, but its consumption is limited due to its hard structure and the presence of anti-nutrients. To get over this constraint, the seed is usually pre-treated to minimize anti-nutrients and improve palatability. This study was carried out to determine the effect of fermentation on the ameliorative properties of tamarind seeds in sucrose-induced diabetic-like biochemical alterations in Drosophila melanogaster. Flies were divided into six (6) groups of 40 flies each; group I (control) was fed a basal diet, group II was fed 30% sucrose only, and groups III–VI were fed 30% sucrose each and treated with varying concentrations of the sample (raw and fermented) for 14 days. The survival rate and behavioral studies were assessed after treatment. Furthermore, the homogenates were assayed for inhibitory activities of carbohydrate metabolizing enzymes (α-amylase and α-glucosidase). Total thiol content and antioxidant enzyme activities like catalase, superoxide dismutase, and glutathione-S-transferase were also carried out. The results showed a reduction in survival rate and locomotor performance in the flies fed with high-sucrose diet (HSD). Elevated levels of α-amylase, α-glucosidase, ROS, and significantly reduced antioxidant enzyme activities were also observed in flies fed with HSD. These alterations were ameliorated in flies treated with dietary inclusions of both raw and fermented seeds; while no significant difference was observed between the ameliorative effects of raw and fermented samples against elevated α-amylase and α-glucosidase activities. However, fermented samples exhibited significantly higher antioxidant properties. Conclusively, this study revealed that the antidiabetic properties of tamarind seeds were conserved by fermentation with improved antioxidant properties in the Drosophila model of diabetes-like biochemical alteratios.

Practical applications

The fermentation processing method is one of the earliest in food processing and preservation. This approach has a variety of consequences for the bioactive elements in functional foods, hence, it is important to consider. Tamarind seeds have been reported in several studies for their anti-hyperglycemic properties, but with a dearth of information on how different processing methods could affect this therapeutic effect. Therefore, this study was carried out to determine the effect of fermentation, a food processing, and preservation method, on some behavioral and biochemical indices in the Drosophila model of diabetes-like biochemical alterations.