Abstract: Objective To investigate the effects of gallotannic acid, the alcohol extract of Galla chinensis, the alcohol extract of Flos carthami and the water extract of Aloe vera on normal human keratinocytes, melanocytes and fibroblasts in vitro, and get a better understanding of the mechanism of action and the possible adverse effects of Galla chinensis in treating keloid. Methods MTT colorimetric assay was used to detect the effects of gallotannin, colchicine and the later two extracts on the growth activity of the different cells. Results ①The inhibitory action of gallotannin to fibroblasts proliferation was similar to that of the alcoholic extract of Galla chinensis, and the inhibitory action of gallotannin at ≥ 20 μg/mL to the proliferation of melanocytes was obvious (the proliferation rate was 73.6%-68% of untreated cells), while gallotannin at ≤ 50 μg/mL slightly enhanced the growth activity of keratinocytes (the proliferation rate was 111%-112% of untreated cells). ②Both the alcoholic extract of Flos carthami and the water extract of Aloe vera enhanced the proliferation of keratinocytes in a dose-dependent mode. The water extract of Aloe vera also enhanced the proliferation of fibroblasts. Conclusions The gallotannin may be the main pharmacologically active component of Galla Chinensis for treating keloid, and its inhibitory activity to human melanocytes may implicate its potential adverse effects on the skin.

Key words: Galla Chinensis, Keratinocytes, Melanocytes, Fibroblasts