Establishment and elicitation of liquid adventitious root cultures of Inula crithmoides L. for increased caffeoylquinic acids production and hepatoprotective properties

Abstract

This study established a liquid adventitious root culture for Inula crithmoides L. focusing on producing extracts rich in hepatoprotective caffeoylquinic acids through elicitation. Adventitious roots were induced from in vitro-grown plant leaves cultured on MS medium supplemented with 1 mg/L IBA. Growth and secondary metabolites accumulation (phenolics, flavonoids, hydroxycinnamic acids) were monitored weekly to determine the optimal harvesting time. Then, the adventitious roots were elicited for 4 weeks with varying concentrations of yeast extract–YE (50, 100 and 200 mg/L) and extracted with ethanol. The extracts were evaluated for their hepatoprotective effects against ethanol-induced hepatotoxicity and analyzed through high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC–ESI–MS/MS). Roots of greenhouse-cultivated plants were used to compare the results obtained from in vitro -grown adventitious roots. IBA supplementation induced 100% adventitious root formation, with maximum biomass and phenolic accumulation after 4 weeks. Hydroxycinnamic acid levels increased significantly with YE treatment at all the concentrations, particularly in case of chlorogenic acid and di-O-caffeoylquinic acid isomers. The root extracts displayed significant in vitro hepatoprotective effects, particularly at 50 mg/L YE elicitation. Overall, the elicitation of I. crithmoides liquid root cultures with yeast extract offers a promising, efficient, and cost-effective approach for optimizing the production of valuable caffeoylquinic acids having potential pharmaceutical use.