Effects of yeast extract and methyl jasmonate on oleanolic acid biosynthesis and some bioactivities in cell suspension culture of <i>Polyscias fruticosa</i>

This work investigates the effects of two elicitors, yeast extract (YE) and methyl jasmonate (MeJA), on the growth, oleanolic acid (OA) biosynthesis, and biological activities (antioxidant and antibacterial) of <i>Polyscias fruticosa</i> suspension cells. The results showed that while both elicitors inhibited cell growth, with YE having a stronger inhibitory effect, they significantly increased both OA content and the overall biological activity of the cell extracts. The degree of growth inhibition was directly proportional to the elicitor concentration and inversely related to the time of addition. YE proved more effective than MeJA, leading to a higher OA accumulation (78.55 mg/flask) and superior antioxidant activity, as evidenced by a lower IC₅₀ (0.55 mg/mL) and a higher FRAP value (0.46 µmol Fe²⁺/g). Additionally, extracts from YE-treated cells showed stronger antibacterial activity against both Escherichia coli and Staphylococcus aureus compared to the MeJA-treated extracts. The study concludes that there is a tradeoff between cell growth and the biosynthesis of bioactive compounds. Optimizing both the type of elicitor and its application timing is crucial to balance biomass yield with the production of key compounds. YE proved to be a superior elicitor to MeJA in enhancing both OA content and the overall biological activity of the extracts, providing a scientific basis for the future production of highly potent bioactive compounds from <i>P. fruticosa</i> cell cultures.