Suspension Cell Culture of Polyscias fruticosa (L.) Harms in Bubble-Type Bioreactors-Growth Characteristics, Triterpene Glycosides Accumulation and Biological Activity.

Polyscias fruticosa (L.) Harms, or Ming aralia, is a medicinal plant of the Araliaceae family, which is highly valued for its antitoxic, anti-inflammatory, analgesic, antibacterial, anti-asthmatic, adaptogenic, and other properties. The plant can be potentially used to treat diabetes and its complications, ischemic brain damage, and Parkinson's disease. Triterpene glycosides of the oleanane type, such as 3- O -[β- D -glucopyranosyl-(1→4)-β- D -glucuronopyranosyl] oleanolic acid 28- O -β- D -glucopyranosyl ester (PFS), ladyginoside A, and polysciosides A-H, are mainly responsible for biological activities of this species. In this study, cultivation of the cell suspension of P. fruticosa in 20 L bubble-type bioreactors was attempted as a sustainable method for cell biomass production of this valuable species and an alternative to overexploitation of wild plant resources. Cell suspension cultivated in bioreactors under a semi-continuous regime demonstrated satisfactory growth with a specific growth rate of 0.11 day -1 , productivity of 0.32 g (L · day) -1, and an economic coefficient of 0.16 but slightly lower maximum biomass accumulation (~6.8 g L -1 ) compared to flask culture (~8.2 g L -1 ). Triterpene glycosides PFS (0.91 mg gDW -1 ) and ladyginoside A (0.77 mg gDW -1 ) were detected in bioreactor-produced cell biomass in higher concentrations compared to cells grown in flasks (0.50 and 0.22 mg gDW -1 , respectively). In antibacterial tests, the minimum inhibitory concentrations (MICs) of cell biomass extracts against the most common pathogens Staphylococcus aureus , methicillin-resistant strain MRSA, Pseudomonas aeruginosa , and Escherichia coli varied within 250-2000 µg mL -1 which was higher compared to extracts of greenhouse plant leaves (MIC = 4000 µg mL -1 ). Cell biomass extracts also exhibited antioxidant activity, as confirmed by DPPH and TEAC assays. Our results suggest that bioreactor cultivation of P. fruticosa suspension cell culture may be a perspective method for the sustainable biomass production of this species.