MiR-182-5p/TLR4/NF-κB axis contributes to the protective effect of caffeic acid phenethyl ester against cadmium-induced spleen toxicity and associated damage in mice.

Cadmium (Cd) is a toxic heavy metal pollutant that can be accumulated in organs including the spleen, thereby threatening human health. In this study, the effect of caffeic acid phenethyl ester (CAPE, a bioactive component of honeybee propolis) on CdCl-induced spleen toxicity and underlying mechanisms were examined in mice. Histological examinations revealed that CAPE (10 μmol/kg/day b.w.) could mitigate spleen damage induced by CdCl (1.5 mg/kg/day b.w.) in mice. Compared to the mice treated only by CdCl, CAPE administration increased the body weight while decreasing the spleen weight, spleen Cd content and spleen to body ratio of the CdCl-treated mice. Western blot and ELISA tests revealed that CAPE suppressed CdCl-induced inflammation (indicated by the decreases in the levels of inflammatory indictors). TUNEL and Western blot results showed that CAPE suppressed CdCl-induced apoptosis through reducing the percentage of TUNEL-positive cells and regulating apoptosis factors. The antagonistic effect of CAPE against CdCl-induced spleen toxicity was realized by increasing miR-182-5p expression to regulate the TLR4/NF-κB pathway. Therefore, CAPE could be a food-derived spleen protector to counteract Cd-induced spleen toxicity through alleviating apoptosis and inflammation via the miR-182-5p/TLR4/NF-κB axis.