From extraction to formulation: evaluating the polyol-assisted microwave extraction of phenolic compounds from...

Tiliacora triandra is a medicinal plant with promising cosmetic applications owing to its rich phytochemical composition. This study aims to investigate the microwave-assisted extraction (MAE) of phenolic compounds from T. triandra leaves using conventional and polyol-based green solvents, evaluate the bioactivity of the selected extracts, characterize their phytochemical profiles, and assess their potential for cosmetic formulations.

Seven solvents, including water, ethanol, and five polyols, were evaluated. Extraction conditions were investigated based on the total phenolic content (TPC), and the best-performing conditions within the investigated range were selected. The selected extracts were further assessed for antioxidant activity, mushroom tyrosinase inhibition, metabolite profiling by LC-QTOF-MS/MS, cellular anti-melanogenic and anti-tyrosinase activities, and formulation stability.

Among the tested solvents, 1,2-hexanediol (HDO) achieved the highest extraction efficiency. The best-performing conditions within the investigated range were 60% solvent concentration, a 1:30 g/mL solid-to-liquid ratio, 90 °C, and 10 min extraction time. MAE with HDO produced higher TPC, antioxidant activity, and tyrosinase inhibition than ethanol and conventional extraction. LC-QTOF-MS/MS identified 12 metabolites, including phenolic acids, flavonoids, alkaloids, terpenes, and ubiquinones. The extracts exhibited concentration-dependent anti-melanogenic and anti-tyrosinase activities in B16F10 cells. Gel-based serum formulations containing 1% and 3% extract showed acceptable physicochemical stability during storage.

MAE using HDO is an efficient, eco-friendly strategy for producing bioactive-rich T. triandra extracts with promising antioxidant and skin-lightening properties for cosmetic applications.