Scientists have discovered active ingredients in a herb used in traditional Chinese medicine for skin whitening.
The ingredients are poised for clinical trials as a safer, more effective alternative to skin whitening creams and lotions that millions of women and some men use in Asia and elsewhere, they said.
The finding, which caps an intense search for these natural skin lightening substances, could be a boon to women in Asian countries, said study leader Hui-Min Wang.
“Toxic skin whitening creams are a growing threat to women’s health, especially in Asia. We hope that our product will improve lives and provide a safer, more natural way to lighten skin. A cream based on these herbal ingredients could be available on store shelves in as little as a year,” Wang said.
Wang and colleagues say that they have found a promising alternative in the form of an herbal “cure-all” used in traditional Chinese medicine in the form of soup or tea.
The evergreen bush, Cinnamomum subavenium, is a close relative of the trees whose inner bark is the source of cinnamon. The scientists isolated two chemicals from the plant that have the ability to block tyrosinase, an enzyme that controls the synthesis of melanin, a dark pigment responsible for colouring skin, hair, and eyes.
Inhibiting tyrosinase is one of the major strategies for skin-whitening, Wang said.
They tested these so-called “melanogenesis inhibitors” on the embryos of zebrafish, which are widely used as stand-ins for people and other animals in biomedical research.
The embryos contain a highly visible band of black pigment. Exposure to low levels of the two chemicals reduced melanin production in the fish embryos by almost 50 percent within just four days, turning the embryos snowy white, the scientists said.
“When we saw the results, we were amazed. My first thought was, well, ‘If these herbal whiteners can transform zebrafish embryos from black to white, maybe they can also lighten women’s skin,’” said Wang, who is with Kaohsiung Medical University in Taiwan.
He estimated that the chemicals are 100 times more effective in reducing melanin pigmentation than the common skin whitening agents kojic acid and arbutin, which have been used in cosmetics for more than 30 years.
The substances did not appear to be toxic when tested in low doses on both cultured human skin cells and zebrafish embryos, Wang noted.
The finding was presented at the 241st National Meeting and Exposition of the American Chemical Society