Beyond traditional cosmetics: exploring endophytic fungal-derived tyrosinase inhibitors

Tyrosinase is a copper-containing monooxygenase that catalyzes the O-hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine and subsequently to dopaquinone. The enzyme is essential for the formation of melanin in eukaryotes, and its over-activation is linked to hyperpigmentation, which is metabolically associated with severe clinical conditions. The most efficient way to regulate the overproduction of melanin and its harmful effects is to suppress tyrosinase. Endophytic fungi are of immense importance in producing the pharmacologically active and structurally diverse range of secondary metabolites with the host plant and even as sole producers. These fungi have been widely reported to produce a myriad of potent tyrosinase inhibitors, which can pave the path for discovering new treatment approaches, especially for melanin-induced hyperpigmentation. To utilize tyrosinase inhibitors as active pharmaceutical or cosmeceutical ingredients, however, extensive studies are required to evaluate them under <i>in vivo</i> conditions, and there is also a need to explore novel fungal endophytes from diverse sources.