Abstract

Tyrosinase is a key enzyme in melanin biosynthesis, catalyzing reactions that produce melanin in melanocytes and contributing to pigmentation in mammals and plants. This enzyme overactivity is a major contributing factor in hyperpigmentation disorders including as melasma, lentigo, and freckles. Current study has focused on combining active substances under the formulation D-Qonamide™: Dong Quai (Angelica sinensis) extract, grape (Vitis vinifera) skin extract (resveratrol), astragalus (Astragalus membranaceus) extract, and nicotinamide, to efficiently inhibit this enzyme, resulting in potential treatments for controlling various skin problems. The objective of this study is to evaluate the efficacy of these ingredients in addressing anti-tyrosinase activity. D-Qonamide™ were evaluated for their in vitro tyrosinase inhibitory effect. The enzymatic assay of D-Qonamide™ showed concentration-dependent tyrosinase inhibition, with activity reduced by 35.240±1.092% to 70.989±0.790% at concentrations of 2.00–10.00 mg/mL. Its IC50 was 4.948±0.126 mg/mL, indicating moderate inhibitory potency. In contrast, Kojic acid had a much lower IC50 of 0.674±0.002 mg/mL, making it approximately seven times more effective than D-Qonamide™. Together, these findings suggest that these ingredients, either individually or in combination, offer substantial potential for applications in nutraceuticals, cosmeceuticals, and functional health products targeting pigmentation and skin health.