<i>Mangifera Indica</i> leaf extracts promote hair growth via activation of Wnt signaling pathway in human dermal papilla cells

The crosstalk between androgens and Wnt signaling pathways is critical in the hair growth cycle. Therefore, natural products that target these two pathways for the inhibition of hair loss are sought after. In this study, we investigated the effect of water extracts of <i>Mangifera indica</i> leaves (WEML) on hair growth. WEML treatment significantly reduced the expression levels of both dickkopf-1 (<i>DKK1</i>) and type 2 5α-reductase (SRD5A2) involved in Wnt signal suppression activity and dihydrotestosterone (DHT) synthesis, respectively, in human follicle dermal papilla cells (HFDP). In addition, WEML treatment effectively upregulated Wnt target genes and downregulated <i>DKK</i>1 expression that was increased by DHT treatment. Degranulation analysis in rat basophilic leukemia mast cell line (RBL-2H3) using β-hexosaminidase release assay confirmed that WEML did not exhibit allergenic activity. Furthermore, hair growth was significantly enhanced in <i>in vivo</i> mice model treated with WEML. These results suggest that <i>M. indica</i> leave extract contains bioactive materials that can be used to treat hair loss.雄激素（androgens）与Wnt信号通路（Wnt signaling pathways）之间的串扰，是毛发生长周期中的关键调控环节。因此，能够靶向这两条通路以实现脱发抑制的天然产物，备受学界关注。本研究针对芒果叶水提取物（WEML）对毛发生长的作用展开了系统探究。在人毛囊真皮乳头细胞（HFDP）中，WEML处理可显著下调两类靶标的表达水平：其一为参与Wnt信号抑制活性的DKK1蛋白（dickkopf-1），其二为参与二氢睾酮（DHT）合成的2型5α-还原酶（SRD5A2）。此外，WEML处理可有效上调Wnt靶基因的表达，并逆转DHT诱导上调的DKK1表达水平。采用β-己糖胺酶释放实验对大鼠嗜碱性粒细胞白血病肥大细胞系（RBL-2H3）开展脱颗粒分析后证实，WEML未表现出致敏活性。进一步体内实验显示，经WEML处理的小鼠模型中，毛发生长得到显著促进。上述结果表明，芒果叶提取物中含有可用于脱发治疗的生物活性成分。