Enhancement of anti-inflammatory and antioxidant metabolites in soybean (Glycine max) calluses subjected to selenium or UV-light stresses

Soybean is an important source of protein and other metabolites with proved biological effects, but its commercial exploitation represents a limitation to obtain high amount of these metabolites. Abiotic stresses such as salinity stress or ultraviolet radiation can induce the accumulation of secondary metabolites in different crops. Selenium incorporation has played an important role in food research due to its function as indirect antioxidant while UV-light had been employed due to its significant effect on production of metabolites in vegetable systems. This study focused on the quantification and bioactivity evaluation of isoflavonoids, valued active metabolites, in soybean calluses submitted to abiotic stresses. Thus, sodium selenite was added to callus growth media culture at 5, 10 or 20 mg L-1 and independently, two different exposure levels of UVC-light were employed (30 or 60 min). Sodium selenite stress induced changes in isoflavonoids content and profile increasing genistein and glycitein approximately 11% and 15%, respectively, compared to the control. UVC-light stress increased genistein-O-glucoside and genistein-O-glucosyl-malonate up to 122% and 196%, respectively. The anti-inflammatory and antioxidant activity of the soybean callus were measured. Concentrations of 5 and 10 mg L-1 of selenium treatments showed higher nitric oxide inhibition (57.8% - 55.2%). Calluses stressed with 10 mg L-1 of sodium selenite induced about 26.9% higher cellular antioxidant activity compared to the control treatment. This research shows that sodium selenite supplementation or exposition to UVC-light induced different phytochemical and bioactivity profiles. in vitro culture of soybean is an efficient strategy to obtain high level of bioactive secondary metabolites.