Elicitation enhancement of bioactive compound accumulation and antioxidant activity in shoot cultures of Boesenbergia rotunda L.
Keywords:Antioxidant, Elicitation, Fingerroot, Methyl jasmonate, Pinostrobin
Boesenbergia rotunda L. is a tropical plant that yields several medicinal bioactive compounds. Using in vitro cultivation allows the quantity and quality of bioactive products to be controlled, but yields are typically lower than from field-grown plants. Elicitation techniques are used to increase these yields. The main goal of this study was to determine the bioactive compound yields and antioxidant activity from in vitro B. rotunda shoots following treatments with methyl jasmonate (MeJA) or salicylic acid (SA). The levels of pinostrobin, total phenolics and flavonoids, and the antioxidant activity of the in vitro shoots were determined and compared with those of the storage roots, shoot base and mature rhizome of field-grown plants. The in vitro shoots had lower levels of pinostrobin, total phenolics and flavonoids, and lower antioxidant activity than the field-grown extracts. To determine the optimal elicitation regime, the in vitro shoots were elicited for 4 wk using MeJA at 200 μM or 400 μM or with SA at 100 μM or 200 μM. The results were compared with a non-elicited control. The shoots treated with 200 μM MeJA had the highest levels (mean ± SD) of pinostrobin (17.97±0.01 mg/g dry extract), total phenolics (86.01±1.33 mg gallic acid equivalents/g dry extract) and flavonoids (166.60±2.57 mg quercetin equivalents/g dry extract). These were respectively 2.44, 1.81 and 1.25 times greater than those of the control. In addition, the shoots treated with 200 μM MeJA had the strongest antioxidant activity. The study confirmed that application of MeJA to Boesenbergia rotunda shoot cultures enhanced the accumulation of pinostrobin, phenolic compounds and flavonoids, and strengthened the antioxidant activity.