Production of adventitious root biomass and bioactive compounds from hypericum perforatum L. Through large scale bioreactor cultures

Abstract

Hypericum perforatum L. (St. John's wort) is a traditional medicinal plant with antidepressive and woundhealing properties. It contains a lot of constituents with documented biological activity including phenolics, a broad range of flavonoids, naphthodianthrones and phloroglucinols. In recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of high value secondary metabolites. The adventitious roots of H. perforatum are regarded as an effective means of biomass production due to their fast growth rates and stable metabolite productivity. To determine optimal culture conditions for the bioreactor culture of H. perforatum adventitious roots, experiments have been conducted on various chemical and physical parameters in flasks and bioreactors. Adoption of elicitation methods have shown enhancement in the accumulation of total phenolics and flavonoids. Based on these results, a large scale bioreactor system at the industrial level (100 and 500 L) was established for the production of biomass and secondary metabolites from the adventitious root cultures. To investigate the usefulness of the adventitious root cultures for the production of secondary metabolites, comparison of ploidy level and the contents of total phenolics and flavonoids in adventitious roots and field-grown plant was conducted. In addition, identification of the major constituents in adventitious roots (hypericin, hyperin, quercetin and chlorogenic acid) were analyzed by Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry (LC-MS/MS). Moreover, 12 isolated phenolic compounds from root cultures were evaluated for anti-inflammatory effects [Nuclear factor kappa B (NF-κB) inhibition and Peroxisome proliferator-activated receptor (PPAR) activation effects] and five xanthones of them were also tested for antioxidant and anticancer activities.