Improving antioxidant and anti-hyperglycemic potential of germinating fenugreek seeds through natural phenolic elicitors

Abstract

The present study investigated the use of natural elicitors (vitamin C, folic acid, and lactoferrin) to stimulate the phenylpropanoid pathway in germinating fenugreek sprouts, with the aim of increasing their total phenolic phytochemical compounds responsible for imparting antioxidant and anti-hyperglycemic properties. Observations revealed that germinating fenugreek sprouts of the IM3 genotype, pre-treated with 500 µM vitamin C (T1) on the 4th day, exhibited maximal elicitation of total phenolic content (3680 mg/100 g DW) and antioxidant activity (2607.5 µM/100 g DW) compared to other genotypes. Moreover, T1-treated IM3 fenugreek sprouts demonstrated the highest anti-hyperglycemic activity by inhibiting α-amylase (48.96%), α-glucosidase (92.60%), and invertase (45.65%) enzyme activities under in vitro conditions. Interestingly, the selected treatments did not affect the diosgenin and trigonelline content of germinating sprouts, which decreased in a time-dependent manner during germination. However, the quercetin content (0.01365%) of T1-treated germinating sprouts continued to increase appreciably, even after the 4th day of germination. A direct positive correlation was established between the increase in total phenols, especially quercetin, and the antioxidant potential as well as the anti-hyperglycemic activity in germinated fenugreek sprouts on the 4th day. Thus, T1-treated sprouts hold promise for managing diabetes-related hyperglycemia and oxidative stress, emphasizing the efficacy of vitamin C in enhancing their bioactive properties. This research pioneers the use of natural elicitors to enhance the health benefits of fenugreek sprouts, notably by identifying an optimal treatment and elucidating quercetin dynamics during germination. Such findings are pivotal for advancing our understanding of sprouting processes and provide valuable insights into the development of therapeutic functional foods. However, further research is necessary to validate their efficacy before considering them as futuristic functional foods.