A high production of flavonoids and anthraquinones via adventitious root culture of Oplopanax elatus and evaluating antioxidant activity

Abstract

Adventitious root (AR) culturing is an effective approach for obtaining bioactive compounds from the endangered plant species of Oplopanax elatus Nakai. In the present study, flavonoids and anthraquinones, both important bioactive compounds were identified via HPLC-ESI–MS/MS, and flavonoid monomers of quercetin and kaempferide and anthraquinone monomers of aloe-emodin, rhein, and emodin were detected in O. elatus AR cultures. To enhance synthesis of both compounds, methyl jasmonate (MeJA) was used as the elicitor to treat ARs. At 200 µM, MeJA significantly increased the contents of quercetin, aloe-emodin, rhein, and emodin, whereas 225 µM was the optimal concentration for kaempferide accumulation. The antioxidant property in ARs was evaluated by determining activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and alkyl radical scavenging using the an electron spin resonance spectrometer. The IC50 of DPPH (6.2 µg/mL) and alkyl (20.2 µg/mL) radical scavenging activities with MeJA treatment were lower than that of the control, thereby indicating that ARs treated with MeJA possess stronger antioxidant activity. Hence, AR cultures can be deployed as raw materials or additives in the production of antioxidant-related O. elatus products using the MeJA as elicitor.