Abstract: Objective To study the effects on berberine hydrochloride on the mitochondria membrane potential and free intracellular calcium of HaCaT cells, and elucidate the mechanism of action of berberine on keratinocytes. Methods Rhodamine-123 fluorescence (very sensitive to mitochondria membrane potential) and Fluo-3/AM fluorescence (suitabe to detect free intracellular calcium in single HaCaT cell) were measured by laser scanning confocal technique. Results Fluo-3/AM fluorescence intensity of HaCaT cells was persistently increased after treating with berberine at concentrations of 5×10^-5M, 2.5×10^-5M and 1.25×10^-5M, and significant differences were observed as compared with the PBS control. The intensity of rhodamine-123 fluorescence in HaCaT cells was decreased immediately when exposed to berberine, with significant difference from that of the PBS control. Conclusions It is suggested that berberine could increase free intracellular calcium and decrease mitochondria membrane potential of HaCaT cells, induce overload of intracellular calcium, influence energy metabolism, and then inhibit the proliferation of keratinocytes.

Key words: Berberine, Cells, cultured, Cations, divalent, Mitochondria, Membrane potentials