目的 研究不同质量分数高良姜素对人黑色素瘤A375细胞黑素合成及酪氨酸酶基因（TYR）、酪氨酸酶相关蛋白-1（TRP-1）、酪氨酸酶相关蛋白-2（TRP-2）mRNA和蛋白表达的影响。方法 采用MTT法测定细胞增殖，左旋多巴氧化法测定酪氨酸酶活性，NaOH裂解法测定黑素合成，采用RT-PCR法、Western-blotting法检测A375细胞中TYR、TRP-1、TRP-2 mRNA和蛋白表达。结果 90%高良姜素浓度为1.0～10.0 μmol/L对A375细胞具有显著的促增殖作用（P＜0.01），而在浓度为20.0 μmol/L时，无促A375细胞增殖作用（P＞0.05），浓度为0.5～20.0 μmol/L均能促进酪氨酸酶活性的升高（P＜0.05、0.01），浓度为1.0～20 μmol/L具有显著促进黑素升高的作用（P＜0.05、0.01），且随着浓度的增加呈增强趋势；99%高良姜素浓度在0.5～20.0 μmol/L具有显著促进A375细胞增殖和酪氨酸酶活性升高作用（P＜0.01），而对黑素合成无促进作用（P＞0.05）。90%高良姜素对TYR、TRP-1 mRNA表达基本无影响，1.0 μmol/L时上调TRP-2 mRNA表达（P＜0.05）；99%高良姜素能上调TYR、TRP-1及TRP-2 mRNA表达；二者均促进TYR蛋白表达，但对TRP-1及TRP-2蛋白表达基本无影响。结论 99%高良姜素能够促进A375细胞增殖及酪氨酸酶活性升高，可能是通过上调TYR、TRP-1、TRP-2的mRNA表达和TYR蛋白表达实现的；而90%高良姜素能够显著促进细胞增殖、酪氨酸酶活性升高及黑素增加，表明90%高良姜素能够促进黑素的合成，但不是通过调节TYR、TRP-1、TRP-2的mRNA表达，可能是通过促进TYR蛋白表达实现的。

Objective To study the effects of galangin with different purity on the synthesis of melanin and the expression of mRNA and protein of tyrosine (TYR), TRP-1, and TRP-2 in hunman melanoma A375 cells. Methods The cell proliferation, tyrosinase activity, and melanin synthesis were measured by MTT assay, L-dopa oxidation method, and NaOH asssay, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) and Western-blotting were used to analyze the mRNA and protein expression of TYR, TRP-1, and TRP-2 in A375 cells. Results The cell proliferation was promoted by 90% galangin (0.5—10.0 μmol/L, P < 0.01) but was not changed by galangin (20 μmol/L, P > 0.05); The tyrosinase activity was promoted by galangin (0.5—20.0 μmol/L, P < 0.05, 0.01), and the synthesis of melanin was significantly promoted by galangin (1.0—20 μmol/L, P < 0.05, 0.01), with concentration increasing an increasing tendency was shown. The cell proliferation and tyrosinase activity in A375 cells were significantly promoted after the treatment with 99% galangin (0.5—20 μmol/L, P < 0.01), but no influence was observed on the synthesis of melanin (P > 0.05). Galangin (90%) had no influence on the mRNA expression of TYR and TRP-1, but the mRNA expression of TRP-2 was upregulated by 90% galangin (1.0 μmol/L, P < 0.05). The mRNA expression of TYR, TRP-1, and TRP-2 was significantly upregulated after the treatment with 99% galangin; They (90% and 99% galangin) all promoted the expression of protein for TYR, but no influence for TRP-1 and TRP-2. Conclusion The 99% galangin could promote the cell proliferation and tyrosinase activity in A375 cells, maybe related with the upregulation of mRNA expression of TYR, TRP-1, and TRP-2 and downregulation of TYR protein expression; The 90% galangin could promote the cell proliferation, tyrosinase activity, and melanin synthesis, maybe related with promoting the protein expression of TYR, but without regulation of the mRNA expression of TYR,TRP-1 and TRP-2.