Sphingopyxis sp. YF1 and metabolite astaxanthin alleviate MC-LR-induced kidney injury

Microcystin-LR (MC-LR) is a widely distributed cyanotoxin that causes kidney injury. Our previous work identified Sphingopyxis sp. YF1 as a novel bacterial strain capable of efficiently degrading MC-LR, but its protective role and mechanisms against MC-LR-induced kidney injury remain unexplored. In this study, the bioactive metabolite of strain YF1 was identified by mass spectrometry. The beneficial effect of strain YF1 and its bioactive metabolite against MC-LR-induced kidney injury was validated in vivo and in vitro . We found strain YF1 effectively ameliorated MC-LR induced kidney disruption and functional impairment. Mechanistically, strain YF1 significantly improved oxidative stress (SOD, CAT, GSH, and MDA) and inhibited pro-inflammatory factors expression (including IL-6 , IL-18 , IL-1β , and TNF-α ) induced by MC-LR. Notably, strain YF1 not only reduce MC-LR level in mice but also produce a bioactive metabolite astaxanthin. Consistently, both in vivo and in vitro experiments demonstrated that astaxanthin alleviated MC-LR-induced kidney injury by modulating antioxidant pathways and inflammatory cascades. This study suggested that strain YF1 could alleviate MC-LR-induced kidney injury by removing MC-LR and generating astaxanthin that mediated antioxidant and anti-inflammatory effects. These findings highlighted microbial-based antidotes for simultaneously eliminating MC-LR and mitigating its harmful effects.