The nephroprotective effects and mechanisms of rehmapicrogenin include ROS inhibition via an oestrogen-like pathway both in vivo and in vitro.

BACKGROUND

The root of Rehmannia glutinosa (R. glutinosa) is commonly used in various traditional Chinese herbal formulae to ameliorate nephropathy; however, little is known about its active component(s) and mechanisms.

AIM

In the present study, we examined the protective effect and potential mechanism of rehmapicrogenin, a monomeric compound extracted from R. glutinosa, against Adriamycin (ADR)-induced nephropathy (AN) in vivo and in vitro.

METHODS

In this study, an ADR-induced kidney injury model was employed to investigate the nephroprotective effects of rehmapicrogenin in mice. In vivo, ELISA kits, flow cytometry, haematoxylin-eosin staining, immunofluorescence techniques, and western blotting were used to evaluate the effect of rehmapicrogenin on kidney injury in mice. In vitro, the effects of rehmapicrogenin on NRK-52E cellular damage induced by ADR were determined using the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The mechanism was investigated using ELISA kits, flow cytometry and In-Cell Western™ blotting.

RESULTS

In vivo, rehmapicrogenin treatment significantly attenuated the pathological changes in the kidney induced by ADR; rescued weight, serum creatinine (Scr), blood urea nitrogen (BUN) and urine albumin (U-ALB) levels; reduced reactive oxygen species (ROS) accumulation; and decreased oxidative stress, the apoptosis rate, and cell survival in ADR-treated mice. Importantly, both in vivo and in vitro experimental results demonstrated that rehmapicrogenin regulates the Nrf2/ARE signalling pathway, the most important pathway for oxidative stress. Rehmapicrogenin attenuated ADR-induced kidney damage by reducing oxidative stress through the oestrogen receptor pathway. Moreover, after treatment with ICI 182780 (the oestrogen receptor-nonspecific antagonist Faslodex), the improvement induced by rehmapicrogenin was significantly reversed.

CONCLUSIONS

In conclusion, rehmapicrogenin attenuates kidney damage by reducing inflammatory factor release through the oestrogen signalling pathway.