4种植物药单体或提取物对中波紫外线诱导黑素细胞生物学活性的影响

目的 研究和比较川芎嗪（tetramethylpyrazine，TMP）、表没食子儿茶素没食子酸酯（epigallocatechingallate，EGCG）、银杏叶提取物和人参皂苷Rg1对不同剂量中波紫外线（ultraviolet B，UVB）诱导的原代人黑素细胞生物学活性的影响。方法 分离培养原代人黑素细胞，分别以30，90 mJ·cm^-2的UVB照射细胞，然后用不同浓度的各植物药单体或提取物（TMP 100，300，600 μg·mL^-1；EGCG 10，20，40 μg·mL^-1；银杏叶提取物40，80，160 μg·mL^-1；人参皂苷Rg1 50，100，200 μmol·L^-1）孵育至72 h，MTT法测定细胞增殖情况；多巴氧化法测定酪氨酸酶活性；NaOH裂解法测定黑素含量。结果 30 mJ·cm^-2 UVB能诱导黑素细胞增殖，加强酪氨酸酶活性，促进黑素生成，TMP、EGCG、银杏叶提取物能不同程度地抑制该效应，以EGCG最为显著；90 mJ·cm^-2 UVB对黑素细胞产生明显的细胞毒作用，细胞增殖下降，黑素合成减少，TMP、EGCG、银杏叶提取物和人参皂苷Rg1则均能减轻该效应，以TMP最为显著。结论 TMP、EGCG、银杏叶提取物不但能抑制低剂量UVB诱导的黑素细胞增殖和黑素合成，还能减轻高剂量UVB对黑素细胞的细胞毒作用，对黑素细胞起一定的光保护作用。

Effect of Four Plant Drug Monomers or Extracts on Ultraviolet B-induced Biological Behavior of Melanocytes

OBJECTIVE To investigate and compare the effect of tetramethylpyrazine(TMP), epigallocatechingallate (EGCG), extracts of gingko and ginsenoside Rg1 on different dosages of ultraviolet B(UVB)-induced biological behavior of primary human melanocytes. METHODS Primary melanocytes were separated and developed, cells were irradiated with different dosages of UVB(30, 90 mJ·cm^-2 respectively), and then incubated with different concentrations of four plant drug monomers or extracts(TMP 100, 300, 600 μg·mL^-1; EGCG 10, 20, 40 μg·mL^-1; extracts of gingko 40, 80, 160 μg·mL^-1; ginsenoside Rg1 50, 100, 200 μmol·L^-1) for 72 h. Cell proliferation was determined by MTT assay, tyrosinase activity was determined by DOPA oxidization reaction assay and melanin synthesis was determined by NaOH assay. RESULTS The 30 mJ·cm^-2 UVB promoted the proliferation of melanocytes, tyrosinase activities and melanin synthesis, while TMP, EGCG and extracts of gingko inhibited these effects in various degree, and the effect of EGCG was the most obvious; 90 mJ·cm^-2 UVB showed toxicity to melanocytes, as the cell proliferation, melanin synthesis, were all declined, and TMP, EGCG, extracts of gingko and ginsenoside Rg1 especially TMP could retrieve this effect distinctly. CONCLUSION TMP, EGCG and extracts of gingko can not only inhibit the proliferation of melanocytes and melanin synthesis induced by low-dosage of UVB irradiation, but also retrieve the toxic effect of melanocytes induced by high-dosage UVB irradiation and have a certain photoprotective effect on melanocytes.