Meta-topolin-mediated regeneration and accumulation of phenolic acids in the critically endangered medicinal plant Crinum malabaricum (Amaryllidaceae): A potent source of galanthamine

Crinum malabaricum (Family: Amaryllidaceae) is a critically endangered aquatic medicinal plant endemic to India. This species is a promising natural source of bioactive compounds including galanthamine (GAL), an anti-Alzheimer drug. In vitro regeneration in the Amaryllidaceae is often challenging. This study assessed the use of meta -Topolin ( m T) on in vitro regeneration of C. malabaricum . Shoot explants were cultured on Murashige and Skoog (MS) medium supplemented with 0.5, 2.5, 5.0, 7.5 and 10.0 µM m T for six weeks, whereby 7.5 µM m T resulted in the maximum multiplication of adventitious shoots, much higher than the control. The biochemical accumulation of eleven different phenolic acids was quantified by UHPLC-MS/MS analysis, and it appeared that m T-treated cultures exhibited the highest concentration of phenolic acids. In particular, increased concentrations of gallic acid, protocatechuic acid, syringic acid, p -hydroxybenzoic acid, salicylic acid and vanillic acid were detected compared to the control. m T (2.5 and 5.0 µM) produced the maximum amount of chlorogenic acid, ferulic acid, p-coumaric acid and sinapic acid. However, an increased content of caffeic acid was produced on PGR-free medium. These findings highlight the beneficial effect and validate the rising importance of m T for in vitro regeneration studies. This study will serve as a potential protocol to conserve and restore the medically important C. malabaricum .