Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show
tyrosinase inhibitory activity and
melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of
tyrosinase and reduction of
melanin pigments. Al and Gg extracted by maceration in 70% and 95%
ethanol were analyzed for
oxyresveratrol and
glabridin using Ultra High Performance Liquid Chromatography. Extracts of Al and Gg singly and combinations of Al95 and Gg95 were tested for cytotoxicity,
tyrosinase inhibitory activity, and reduction of
melanin pigments in
melanoma B16 cells. Al95 had higher
antioxidant,
tyrosinase inhibitory activity and reduced more
melanin pigments in B16 cells compared to Al70, and exhibited higher levels of
oxyresveratrol. Gg95 inhibited oxidative stress and mushroom
tyrosinase better than Gg70, and exhibited higher levels of
glabridin. Combinations of Al95 and Gg95 at various ratios (concentration of 0.1 mg/mL) were not cytotoxic to B16 cells. Interestingly, Al95 and Gg95 combined at a ratio 9:1 reduced
melanin pigment up to 53% in B16 cells. This combination of Al95 and Gg95 extracts exhibited the additive effect of reducing
melanin pigments by suppressing the expression of
microphthalmia-associated transcription factor (MITF),
tyrosinase (TYR) and
tyrosinase-related protein-2 (TRP-2) in B16 cells. The combination of Al and Gg extracts could be developed as
skin care products for
hyperpigmentation treatment.