Inhibitory Activities of Puerariae Flos Against Testosterone 5α-Reductase and Its Hair Growth Promotion Activities

The study from 2011 examined the effects of Puerariae Flos extract (PF-ext) on hair growth and its potential as a treatment for androgenic alopecia. PF-ext was found to inhibit testosterone 5α-reductase by 60.2% at a concentration of 500 µg/ml, which is more potent than the extract from Puerariae Radix. In vivo tests on male C57BL/6NCrSlc strain mice showed that PF-ext promoted hair growth and exhibited anti-androgenic activity. Two saponins, soyasaponin I and kaikasaponin III, were identified as active components responsible for the inhibitory activity. Additionally, topical application of PF-ext at 2 mg/mouse/day encouraged hair growth in C3H/He mice. These findings suggest that Puerariae Flos could be an effective treatment for hair loss related to androgenic alopecia. The number of mice used in the study was not specified, although one group mentioned included 10 mice. The research was part of the "Antiaging Center Project" funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology from 2008 to 2012.