Effects of MeJA and SA on Total Phenolic Content, Antioxidant and Tyrosinase Inhibitory Activities of in vitro Hedychium coronarium Shoots

Abstract

Increased secondary metabolite contents of medicinal plants under aseptic culture using the elicitation method could be useful for pharmaceutical and cosmetic industries. The objective of this experiment was to investigate the effect of methyl jasmonate (MeJA) and salicylic acid (SA) at different concentrations on total phenolic content, antioxidant, and tyrosinase inhibitory activities in shoot cultures of Hedychium coronarium. The in vitro shoots were cultured for four weeks on Murashige and Skoog (MS) medium supplemented with 8.87 µM 6-benzyladenine (BA), 2.69 µM 1-naphthaleneacetic acid (NAA), and 200 – 400 µM MeJA or 100 – 200 µM SA. The results revealed that SA was more effective than MeJA for enhancing total phenolic content, antioxidant, and tyrosinase inhibitory activities. The highest total phenolic content of 57.67±1.80 mg GAE/g dry extract was obtained from 100 µM SA treated shoots or 1.24 times higher than that of the control (46.49±4.60 mg GAE/g dry extract). The greatest DPPH and ABTS•+antioxidant (EC₅₀ of 71.53±2.71 and 326.22±18.91 µg/mL), and tyrosinase inhibitory activities (28.09±0.94%) were also recorded from this treatment. Therefore, 100 µM SA was effective for enhancing antioxidant contents and tyrosinase inhibitory activity of in vitro H. coronarium shoots.