Enhancing Secondary Metabolite Production in <i>Pelargonium graveolens</i> Hort. Cell Cultures: Eliciting Effects of Chitosan and Jasmonic Acid on Bioactive Compound Production

This study explores the effects of chitosan (CHT) and jasmonic acid (JA) elicitors on rose-scented geranium (<i>Pelargonium graveolens</i> Hort.) cell suspension cultures, aiming to enhance the production of phenolics and flavonoids and antioxidant properties. Elicitation with CHT and JA resulted in varied biomass yields and callus characteristics, with higher concentrations generally leading to increased phenolic accumulation. Optimal biomass was achieved with CHT4 (75 mg/mL) and JA3 (50 µM) treatments. HPLC-DAD analysis revealed changes in phenolic compound composition and quantities, with specific compounds induced by either CHT₄ or JA₃. For instance, gallic acid content increased significantly in CHT₄-treated cells, while catechin content increased notably in both CHT₄ and JA₃ treatments. Antioxidant enzyme activities like superoxide dismutase and peroxidase increased with elicitor concentration, particularly in CHT₄ and JA₃ treatments. Both treatments exhibited potent antioxidant activity, with JA₃ exhibiting the lowest IC₅₀ value in the DPPH assay and highest total antioxidant capacity (TAC) values. Surprisingly, both CHT₄ and JA₃ extracts effectively inhibited tyrosinase activity. These findings underscore the efficacy of CHT and JA elicitors in enhancing phenolic and flavonoid production, boosting antioxidant capacity, and inhibiting tyrosinase activity in <i>P. graveolens</i> cultures, offering promising implications for further research and industrial applications in pharmaceutical and cosmetic sectors.