Enhancement of the Enzymatic and Non-Enzymatic Antioxidant Activities of Cultured Sauropus androgynus L. Merr. Shoots Treated with UV-C Irradiation

The stimulation of enzymatic and non-enzymatic antioxidant activities of Sauropus androgynus L. Merr. shoot cultures treated with UV-C irradiation was investigated. The shoots were first cultured on Murashige and Skoog (MS) medium containing 1 mg/L 6-benzyladenine (BA) for 6 weeks. Multiple shoot formations were then treated with UV-C irradiation for 0 min (control group), 5, 10 min (experimental groups), and cultivated field. After 3 weeks of culture the shoots were extracted with methanol and analyzed for enzymatic antioxidant activities (with superoxide dismutase; SOD and glutathione peroxidase; GPX) and non-enzymatic antioxidant activities (with DPPH, ABTS and FRP assays) and total phenolic and flavonoid compound contents. The result indicate that the shoot treated with UV-C irradiation for 5 min exhibited the highest enzymatic antioxidant activities (SOD and GPX values of 2.26, 2.37 unit/mg soluble proteins, respectively). Non-enzymatic antioxidant activities determined by using DPPH, ABTS and FRP assays were found to be IC50 values of 10.13 mg/mL, 166.48 mg TEAC/100 g fresh weight (FW), and 22.72 mM FeSO4 /100 g FW, respectively. Total phenolic and flavonoid compound contents had values at 15.54 mg GAE/100 g FW and 63.64 mg QE/100 g FW, respectively. Antioxidant activities revealed a positive moderate high correlation (r2 = 0.729 - 0.980).