Enhancing bioactive compounds in hairy roots culture of precious medicinal plant Eurycoma longifolia Jack. through LED elicitation

Eurycoma longifolia Jack. is a commercially valuable medicinal plant with clinically proven anti-cancer and aphrodisiac properties. To ensure the sustainability of the production of E. longifolia products on a commercial scale, hairy roots (HR) were engineered. In this study, we used light-emitting diodes (LEDs) as elicitation agents to enhance the synthesis of three (3) anticancer compounds (eurycomanone, 9-hydroxycanthin-6-one and 9-methoxycanthin-6-one). HR cultures were cultured for 12 weeks under four different LED treatments, including blue light (100%), red light (100%) and a combination of blue and red light (60%: 40%). In addition, a white LED was used as a control. The effects of the treatments on growth, synthesis and anti-cancer properties were determined. The results show a significant difference (p < 0.05) between the treatments. The combination of blue and red LED produced the highest dried biomass of 0.316, 0.391 and 0.459 g/50mL at weeks 6, 8 and 10, respectively, which is 2.2, 1.7 and 1.5 times that of the white LED. In addition, the red LED produced the highest level of eurycomanone at the 8th and 12th week of culture, the combination of blue and red LED produced the highest level of 9-hydroxycanthin-6-one at the 8th and 12th week of culture, and 9-methoxycanthin-6-one at the 4th and 8th week of culture. The MTT assay showed significant activity of the crude extracts from all treatments against MCF-7 cancer cells. These results indicate that LED excitation is a promising technique for the production of anticancer agents from HR cultures of E. longifolia.