Harmine mitigates LPS-induced acute kidney injury through inhibition of the TLR4-NF-κB/NLRP3 inflammasome signalling pathway in mice.

Acute kidney injury is a common clinical condition associated with increased morbidity and mortality. It is essential to find effective drugs with low side effects in the treatment of acute kidney injury. Harmine is one of the major active components of Peganum harmala L. Harmine possesses various pharmacological activities, including anti-inflammatory activity. Nevertheless, the protective effect of harmine in acute kidney injury induced by lipopolysaccharide (LPS) in mice is unknown. Therefore, we investigated the protective effect of harmine in LPS-induced renal inflammation and the involved molecular mechanisms. The results showed that pretreatment with harmine (25 or 50 mg/kg) markedly alleviated kidney injury by reducing the release of kidney biomarkers and inflammatory mediators and the formation of malondialdehyde (MDA) and myeloperoxidase (MPO) while increasing superoxide dismutase (SOD) and glutathione (GSH) activities and improving renal histopathological changes. In addition, immunohistochemistry staining and western blot analysis indicated that harmine treatment suppressed the expression of toll-like receptor 4 (TLR4) and the phosphorylation of nuclear factor-kappa B (NF-κB) p65 and inhibitor of κBα (IκBα) while inhibiting the expression of NLRP3, caspase-1 and interleukin-1β (IL-1β). In brief, harmine protects against acute kidney injury induced by LPS in mice through reducing oxidative stress and inflammation responses. The involved underlying mechanisms of harmine in LPS-induced acute kidney injury might be related to inhibition of the TLR4-NF-κB pathway and NLRP3 inflammasome pathway. Based on the above conclusion, it is possible for harmine to be used to clinically treat acute kidney injury.