2020 年 11 巻 1 号 p. 21-29
It is known that human placenta extract (HPE), which contains numerous bioactive substances, can improve symptoms of hair loss. However, the mechanisms underlying this effect are unclear. It is reported that androgenetic alopecia (AGA) is induced and/or suppressed by arachidonic acid metabolites that affect hair follicle component cells. We investigated the effect of HPE on arachidonic acid metabolism using cultured hair follicle-derived keratinocytes. PG-E2, PG-F2a, PG-I2 (6keto-PG-F1a), PG-D2 and TX-A2 (TX-B2) were measured in medium cultured with HPE. The cultured cells were used for the expression analysis of these five prostanoid synthase genes. The cultured keratinocytes produced all five types of prostanoids. However, the synthase genes of PG-D2 and PG-I2, i.e., PTGDS and PTGIS, did not express in cultured keratinocytes. In contrast, PG-E2 and PG-F2a synthase genes, i.e., PTGES and AKR1C3, could be detected. HPE enhanced the production of PG-E2 and PG-F2a, whereas that of PG-D2 was decreased. Minoxidil had no effect on arachidonic acid metabolism. HPE significantly increased the PG-E2/PG-D2 and PG-F2a/PGD2 ratios, whereas minoxidil showed no significant effect. HPE enhanced the production of PG-E2 and PG-F2a and suppressed that of PG-D2. The effects of HPE on hair growth could be mediated by its effects on arachidonic acid metabolism.
