Nishina Atsuyoshi, Ebina Kodai, Ukiya Motohiko, Fukatsu Makoto, Koketsu Mamoru, Ninomiya Masayuki, Sato Daisuke, Kimura Hirokazu
College of Science and Technology, Nihon Univ, Chiyoda-ku, P.O. Box 101-0062, Tokyo, Japan.
Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu Univ, P.O. Box 501-1112, Gifu, Japan.
J Food Sci. 2015 Oct;80(10):H2354-9. doi: 10.1111/1750-3841.13068. Epub 2015 Sep 9.
This study aimed to chemically isolate and explore an antimelanogenesis inducer in extracts of Solanum melongena L. "Usukawamarunasu" eggplant. We successfully identified dioscin ([25R]-Spirost-5-en-3β-yl) 2-O-(6-deoxy-α-L-mannopyranosyl) - 4-O-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranoside] in the plant, and examined the effects of α-melanocyte-stimulating hormone (MSH)-induced melanogenesis in B16 murine melanoma cells by this plant-derived dioscin. Immunoblot analysis suggested that dioscin reduced the expression of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, resulting in inhibition of intracellular production of melanin. In addition, dioscin caused reduction of phosphorylated cAMP-responsive element binding protein 1 transcription factors (CREB), which led to a reduction of microphthalmia-related transcription factor (MITF) in α-MSH-stimulated cells, but did not affect phosphorylation of extracellular signal-regulated kinase. Furthermore, dioscin significantly downregulated the expression of tyrosinase, TRP-1, and TRP-2, which led to the reduction of α-MSH-induced melanogenesis in B16 cells. These results suggest that dioscin may decrease the level of MITF via inhibition of phosphorylation of CREB in α-MSH-induced melanogenesis in B16 cells.
本研究旨在从“Usukawamarunasu”茄子（茄属龙葵）提取物中化学分离并探索一种抗黑色素生成诱导剂。我们成功在该植物中鉴定出薯蓣皂苷元（[25R]-螺旋甾-5-烯-3β-基）2-O-（6-脱氧-α-L-甘露吡喃糖基）-4-O-（6-脱氧-α-L-甘露吡喃糖基）-β-D-吡喃葡萄糖苷]，并通过这种植物来源的薯蓣皂苷元研究了其对α-黑素细胞刺激激素（MSH）诱导的B16小鼠黑色素瘤细胞黑色素生成的影响。免疫印迹分析表明，薯蓣皂苷元降低了酪氨酸酶、酪氨酸酶相关蛋白-1（TRP-1）和TRP-2的表达，从而抑制了细胞内黑色素的产生。此外，薯蓣皂苷元导致磷酸化的cAMP反应元件结合蛋白1转录因子（CREB）减少，这导致α-MSH刺激的细胞中小眼畸形相关转录因子（MITF）减少，但不影响细胞外信号调节激酶的磷酸化。此外，薯蓣皂苷元显著下调酪氨酸酶、TRP-1和TRP-2的表达，从而减少α-MSH诱导的B16细胞黑色素生成。这些结果表明，在α-MSH诱导的B16细胞黑色素生成过程中，薯蓣皂苷元可能通过抑制CREB的磷酸化来降低MITF的水平。
