Fructus Lycii and Salvia miltiorrhiza Bunge extract alleviate retinitis pigmentosa through Nrf2/HO-1 signaling pathway

Abstract

Ethnopharmacological relevanceFructus Lycii and Salvia miltiorrhiza Bunge (FS) are popular Chinese herbs for the treatment of retinitis pigmentosa (RP). Aim of the studyThis study was to evaluate protective effects of FS extract on RP and to explore whether FS extract exerts its protective effects via oxidative stress by regulating Nrf2/HO-1 signaling pathway. Material and methodsFS extract were identified by UPLC chromatographic analysis. Rd10 mice as the model of RP, followed by a 4-week FS extract treatment by intragastric administration. After the animal sacrifice, histopathological examination and Scotopic electroretinography (ERG) analysis were assessed. The oxidative stress markers were determined and the expression levels of Nrf2 and HO-1 mRNA were evaluated by qRT-PCR. The expression and distribution of Nrf2 and HO-1 protein were determined by Western blot and immunohistochemistry. ResultsThe morphological changes of Outer nuclear layer (ONL) thickness and number of the ONL were observed with a significant increased, and the functional changes of a-amplitude and b-wave amplitude were measured with a markedly increased. Treatment with FS extract remarkably increased levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and decreased level of malondialdehyde (MDA). Moreover, FS extract up-regulated mRNA and protein expression of Nrf2 and HO-1. ConclusionsThis study indicated that FS extract can improve retinal morphology and function, which may have occurred through the regulation of the Nrf2/HO-1 pathway to inhibit the oxidative reaction.