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

• The present study focuses on the use of natural substances like vitamin C , folic acid , and lactoferrin to stimulate the phenylpropanoid pathway in germinating fenugreek sprouts. • Among the different genotypes studied, germinated fenugreek sprouts of the IM6 genotype pre-treated with 500 µM vitamin C (T1) demonstrated the highest increase in total phenolic content and antioxidant activity on the 4th day of germination. • The T1-treated IM3 fenugreek sprouts also exhibited the most significant anti-hyperglycemic activity. They were able to inhibit the activities of key enzymes involved in carbohydrate digestion, including α-amylase, α-glucosidase, and invertase under in vitro conditions. • The treatments did not significantly affect the levels of diosgenin and trigonelline in germinating sprouts. These compounds are known for their health benefits and remained relatively stable during germination. • Notably, the quercetin content in T1-treated germinating sprouts continued to increase, even beyond the fourth day of germination. Quercetin is a type of flavonoid with antioxidant properties. • The study established a positive correlation between the increase in total phenol content, especially quercetin , and the antioxidant potential as well as anti-diabetic activity observed in the 4th day germinated sprouts. • These findings suggest that using T1-treated fenugreek sprouts may be a promising dietary approach for managing diabetes-related hyperglycemia and oxidative stress . 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.