Macleaya cordata extract alleviated oxidative stress and altered innate immune response in mice challenged with enterotoxigenic Escherichia coli.

This study examines the effects of dietary Macleaya cordata extract (MCE) on bacterial burden and resistance to enterotoxigenic Escherichia coli (ETEC) in ICR mice. ICR mice were randomly distributed into one of the following groups: (i) basal diet; (ii) basal diet with 200 mg kg^-1 MCE; (iii) basal diet challenged with ETEC; and (iv) basal diet with 200 mg kg^-1 MCE and challenged with ETEC. Following a 7-day period of pre-treatment, CTRL-ETEC and MCE-ETEC mice were subjected to oral infection using 5×10⁸E. coli SEC 470. The results showed dietary 200 mg kg^-1 MCE markedly reduced intestinal ETEC burden (P < 0.05) and the disease-associated mortality was significantly alleviated in the MCE treated group (P < 0.05). In addition, dietary MCE markedly alleviated ETEC-induced oxidative stress, evidenced by the lowered methane dicarboxylic aldehyde (MDA) abundance and enhanced activities of catalase and glutathione peroxidase (P < 0.05). Furthermore, MCE mice exhibited higher immune activity, which might have further mediated ETEC infection. These results indicate MCE plays a preventative role with respect to ETEC infection. Future research should aim to develop MCE as a therapeutic approach to the promotion of intestinal health and a safeguard against ETEC infection.