The effects of galangin on a mouse model of vitiligo induced by hydroquinone.

Galangin, the main active component of Alpinia officinarum Hance, was tested in a mouse model of vitiligo induced in C57BL/6 mice by the topical application of 2mL of 2.5% hydroquinone daily to shaved areas (2x2cm) of dorsal skin for 60days. Thirty days after the final application of hydroquinone, galangin (0.425, and 4.25mg/kg) was administered orally for 30days. The hair colour darkened when it grew back after treatment, and histological analysis showed that the number of melanin-containing hair follicles had increased after treatment with all doses of galangin groups and 8-methoxypsoralen (8-MOP, the positive control) compared with the untreated vitiligo group (p<0.05). The number of skin basal layer melanocytes and melanin-containing epidermal cells had also increased significantly with the application of 4.25mg/kg of galangin. The concentration of tyrosinase (TYR) in serum was found to have increased, whereas the content of malondialdehyde and the activity of cholinesterase had decreased after treatment with all doses of galangin and 8-MOP, compared with control (p<0.05). The expression of TYR protein in treated areas of skin also increased with the application of 4.25mg/kg galangin and 8-MOP. In conclusion, the results showed that galangin was able to improve vitiligo induced by hydroquinone in mice, with the activity related to concentrations of TYR, expression of TYR protein, activity of malondialdehyde and content of cholinesterase. Galangin may therefore be a potential candidate for the treatment of vitiligo, subject to further investigation. Copyright (c) 2014 John Wiley & Sons, Ltd.