Elicitation of Orthosiphon stamineus cell suspension culture for enhancement of phenolic compounds biosynthesis and antioxidant activity

Our previous studies had showed that there was variation in the total phenolic contents with anti-oxidant activities of the field grown plants of Orthosiphon stamineus Benth (Lamiaceae). This study was hence carried out to evaluate the phenolic compound biosynthesis and the anti-oxidant activities of elicitor treated cells (ec) of O. stamineus compared to the mature plants (mp), in vitro plantlets (tcp) and the non-treated cells (nc). The total phenolic content was determined with Folin-Ciocalteu reagent, while the anti-oxidant activity was evaluated with DPPH and TEAC methods. The anti-oxidant activities of crude extracts decreased in the order of ec > tcp > nc > mp. Among the five tested elicitors, chitosan (150 mg/l) supplemented into the cell proliferation medium, MS + 1.0 mg/l NAA + 1.0 mg/l 2,4-D, enhanced the anti-oxidant activity and increased the total phenolic content of O. stamineus cell cultures. The anti-oxidant activity was correlated positively with the total phenolic content of the chitosan elicited cultured cells. This study indicated that cell suspension cultures of O. stamineus could be used as an alternative system for sustainable and consistent production of biochemical with anti-oxidant activity.