Toxicological evaluation of ginsenoside-rich cell culture biomass of Panax japonicus produced in a large-scale bioreactor system

Abstract

An environmentally friendly, resource-efficient substitute for the production of vegetative biomass and the bioactive components of medicinal plants is provided by novel biotechnology-based suspension cells cultured in bioreactors. Despite the cultured biomass is produced in the controlled conditions, it requires detailed chemical analysis and toxicological evaluation before being approved for human consumption. This study reports the results of biochemical, toxicological, and elemental composition analysis of the suspension cell culture of a medicinal species Panax japonicus (T. Nees) C.A. Mey. cultivated in a large-scale bioreactor system. For the scaling up the process of cultivation, the suspension culture was grown sequentially in a series of laboratory (20-L), pilot (75-L), and industrial (630-L) bioreactors. The biomass productivity of cell culture was comparable or higher than of wild plants or in vitro cultured hairy roots reported in the literature. The resulting cell biomass was analyzed for ginsenoside contents using ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC–ESI–MS). For the elemental composition of cells, inductively coupled argon plasma mass spectrometry (ICP–MS) was used. In addition, the biomass was evaluated for acute toxicity and skin sensibilization effects on in vivo animal models. The analyses confirmed that suspension cells cultured in bioreactors accumulate a broad spectrum of ginsenosides and their malonylated derivatives at a total concentration of 7.54 % (w/w) based on dry weight and contain essential macro- (K, Ca, Mg, Na) and micro- (Zn, Mn, Fe, B, Al, Cu) elements in dietary-safe concentrations. Acute toxicity tests using the administered doses of 2000 and 5000 mg dry biomass per kg animal weight resulted in no changes in animal organ weights and no or minor changes in hematological and biochemical parameters of blood. No skin irritation or sensitizing effects were observed. Therefore, bioreactor cultivation of P. japonicus cell suspension is highly productive and provides a ginsenoside-rich and non-toxic cell biomass which is a potentially valuable component of functional foods, food additives, and natural health products.