Herbal medicine for melanin regulation: biological synthesis, effective formulas/compounds, and biopharmaceutical methods.

Melanin is omnipresent across diverse taxa in the biosphere, spanning microorganisms to multicellular eukaryotes. This pervasive distribution reflects its multifaceted roles, encompassing pigmentation, radical quenching, photoprotective barriers and immunomodulatory activity. The process of melanin biosynthesis can be simply defined as the conversion of tyrosine into melanin through a complex series of steps in melanosomes within melanocytes. Skin pigmentation results from melanin production by melanocytes in the epidermis. With the development of society, people are becoming increasingly concerned about their skin appearance, particularly issues related to pigmentation and skin radiance. Elevated melanin levels may lead to skin disorders associated with excessive pigmentation, including age spots, freckles and even melanoma, which cause distress and lower the life quality. In recent years, the high demand for skin whitening and brightening has promoted the exploration of whitening active ingredients and melanin biosynthesis mechanisms. In this paper, the biosynthetic signaling pathways, generating factors, active natural compounds and advanced delivery system related to the deposition of melanin were systematically reviewed. Moreover, we were the first to introduce Chinese herbal formulas, TCM therapeutic techniques, and several advanced delivery systems designed to enhance the transdermal absorption of traditional Chinese medicines. The ideology, technologies and herbal drugs originated from Chinese medicine are expected to be an important development field for skin whitening and pigmentation prevention.