Terminalia bellirica (Gaertn.) Roxb. extracts reshape the perifollicular microenvironment and regulate the MAPK pathway for androgenetic alopecia treatment

Terminalia bellirica (Gaertn.) Roxb. (TBR), a popular herbal remedy in India and Southeast Asia, has been demonstrated to possess multiple pharmacological activities. However, systematic studies on the medicinal effects and mechanism of TBR for the androgenetic alopecia (AGA) treatment are deficient. Human Umbilical Vein Endothelial Cells (HUVECs) and testosterone-induced AGA mice were used to evaluate the hair regrowth activity of TBR extracts. Chemical constituents and potential active components of TBR extracts were analyed by UPLC-Q-TOF-MS in vitro/vivo. The hair regrowth mechanisms of TBR were elucidated through network pharmacology and experimental validation. Totally 28 chemical constituents in TBR were identified, of which 15 were predicted as potential active components for AGA therapy. TBR could significantly scavenge ROS, promote VEGF level/cell migration of HUVECs, and inhibiting type II 5α-reductase activity (the inhibit rate: 82.35 ± 1.02 %). Pharmacodynamic evaluation suggested that TBR effectively led to hair regrowth in C57BL6 mice compared to minoxidil. TBR promoted the hair follicle (HF) transition from the telogen phase to anagen phase by decreasing MDA levels, increasing VEFG expression and up-regulating phosphorylated P38/ERK protein levels in the MAPK signaling pathway. TBR reversed AGA via inhibiting SRD5A2 activity and stimulating the MAPK pathway. Meantime, TBR could remodel the follicle microenvironment by reducing oxidative stress and increasing angiogenesis.