EVALUATION OF ANTIOXIDANT AND IN VITRO ANTIDIABETIC POTENTIAL OF TAGETES PATULA L. FLOWER EXTRACTS

Abstract

Tagetes patula L. (French marigold) is an ornamental plant rich in bioactive phytochemicals yet remains insufficiently studied for its therapeutic potential. This research investigates its antioxidant and in vitro antidiabetic activities using aqueous flower extract. Antioxidant capacity was evaluated through DPPH, FRAP, TPC, and TFC assays. The extract showed dose-dependent DPPH radical scavenging activity ranging from 33.09% to 57.24%, while FRAP values increased from 28.87 to 57.48 µg/mL across 50–250 µg/mL concentrations. Phenolic and flavonoid contents also rose progressively, with TPC increasing from 41.40 to 67.90 µg GAE/mL, and TFC from 20.66 to 55.33 µg QE/mL, confirming strong antioxidant potential. Antidiabetic activity was assessed through starch hydrolysis and α-amylase inhibition. In starch hydrolysis, T. patula produced 45.00% inhibition at 20 µg/mL and 52.2% at 30 µg/mL, compared to acarbose showing 62.5% and 67.5%, respectively. α-Amylase inhibition increased from 41.39% to 64.94% (10–30 µg/mL), demonstrating effective enzyme suppression though slightly lower than acarbose (57.61–75.92%). These findings confirm that T. patula possesses meaningful antioxidant and moderate antidiabetic properties, supporting its traditional applications. Further phytochemical investigation is recommended to identify the key bioactive constituents.