Application of a combined sulphorhodamine B and melanin assay to the evaluation of Chinese medicines and their constituent compounds for hyperpigmentation treatment

Aim of the studyTo investigate the efficacy of traditional Chinese medicine (TCM) in the treatment of hyperpigmentation problems, extracts of herbs selected based on traditional Chinese medical literature were screened.Materials and methodsForty extracts were extracted from 10 selected herbs using hexane, dichloromethane, methanol and water. They were then screened using melan-a cells, an immortalized non-tumorigenic mouse melanocyte cell line. Sulphorhodamine B (SRB) assay and measurement of melanin production were performed to examine the effects of the extracts as well as some natural compounds from these herbs on melanogenesis in the melan-a cells.ResultsThe hexane and dichloromethane extracts of Angelica sinensis exhibited strong hypopigmentary effects.ConclusionsNatural compounds occurring in this herb were also investigated. Among them 4-ethylresorcinol, 4-ethylphenol and 1-tetradecanol demonstrated positive effects in attenuating melanin synthesis in the cultured cells.