Physcion, a novel inhibitor of 5α-reductase that promotes hair growth in vitro and in vivo.

Androgenic alopecia (AGA) has a high incidence. Excess dihydrotestosterone in blood capillaries, which is converted from testosterone by 5α-reductase, is an AGA causative factor. We identified the inhibitory activity of four Polygonum multiflorum compounds against 5α-reductase via high-performance liquid chromatography, and the results showed that Physcion was a potent 5α-reductase inhibitor. Additionally, we found that through inhibiting 5α-reductase expression, Physcion could shorten the time of dorsal skin darkening and hair growth, improve hair follicle morphology, and significantly increase hair follicle count. Eventually, through molecular docking study, we found the binding energy and molecular interactions between Physcion and 5α-reductase type II. These results suggested that Physcion is a potent 5α-reductase inhibitor, as well as a new natural medicine for treating AGA.

Anxiolytic and neuroprotective effects of the Traditional Chinese Medicinal formulation Dan-zhi-xiao-yao-san in a rat model of chronic stress.

Dan-zhi-xiao-yao-san is a Traditional Chinese Medicinal formulation widely used for the treatment of neuropsychological disorders. The present study examined the anxiolytic and neuroprotective effects of Dan-zhi-xiao-yao-san in a rat model of chronic stress. The results of an elevated plus maze test showed that Dan­zhi­xiao­yao­san significantly attenuated the levels of anxiety-induced stress as evidenced by increases in the time spent in the open arm region, as well as the percentage of entries into this area. In addition, Dan-zhi-xiao-yao-san alleviated stress­induced neuronal death, as indicated by histological examination. Furthermore, mechanistic studies suggested that the anxiolytic and neuroprotective effects of Dan-zhi-xiao-yao-san may be mediated via attenuation of chronic stress­induced upregulation of α­synuclein and corticosterone, and downregulation of protein phosphatase 2A (PP2A) in the hippocampal region of the brain at the mRNA and protein level. In addition, Dan­zhi­xiao­yao­san decreased the serum levels of stress­induced corticosterone in the model animals. In conclusion, the present study demonstrated that Dan­zhi­xiao­yao­san exerted anxiolytic and neuroprotective effects in a rat model of chronic stress via attenuation of stress­induced upregulation of α­synuclein and corticosterone, and downregulation of PP2A in the hippocampus.

White pepper and piperine have different effects on pharmacokinetics of puerarin in rats.

This study attempted to explore the effects of white pepper and its major component piperine on puerarin administered to rats. Pharmacokinetic parameters of puerarin in rats were determined by oral administration (400 mg/kg) or intravenous injection (40 mg/kg) of puerarin, pretreated with or without white pepper and piperine given orally. Compared to the control group given oral puerarin only, the combined use of piperine (10 or 20 mg/kg) increased the C max of puerarin by 1.30-fold or 1.64-fold and the AUC0-∞ by 133% or 157%, respectively. In contrast, coadministration of white pepper (125 or 250 mg/kg) decreased oral absorption of puerarin to 83% or 74%, respectively. On the other hand, pretreatment with piperine orally did not alter the intravenous pharmacokinetics of puerarin, while the AUC of puerarin after intravenous administration was increased by pretreatment with white pepper. The results indicate that pretreatment with piperine or pepper exerts different effects on pharmacokinetics of puerarin administrated via intragastric and intravenous routes. Therefore, it is suggested that the combined application of piperine or white pepper with puerarin should be carefully monitored for potential diet-drug interactions.