Effect and mechanism of citral against methicillin-resistant Staphylococcus aureus in vivo

BACKGROUNDCitral is an active component of many plant extracts, and it is a safe additive used in food and cosmetics. A previous study showed that citral has a good antibacterial effect against methicillin-resistant Staphylococcus aureus (MRSA) in vitro, but its in vivo anti-infective activity has not been studied. Anti-MRSA activity and the preliminary mechanism of citral against MRSA were investigated in MRSA-infected KM mice. The ED50 was calculated using Karber's method. Groups were selected for inflammatory and oxidative stress level tests, and lung and liver tissues were counterstained with HE for detection of pathological changes. Cytokines and oxidative factors were evaluated using the ELISA method (one-way ANOVA computed using SPSS 19.0.). RESULTSWith the increase in the concentration of citral, the survival rate of MRSA-infected mice increased accordingly. The ED50 values of citral for intramuscular injection and intragastric administration were 0.09 and 0.26gkg(-1) respectively. Citral significantly reduced cytokines (IL-1 beta, IL-6, TNF-alpha) and oxidative factors (malondialdehyde and hydroxyl radicals) of MRSA-infected mice, whereas it increased gluthtione and superoxide dismutase levels. Citral can reduce the lung inflammatory infiltrates infected by MRSA. CONCLUSIONSCitral exerted a dose-dependent anti-MRSA effect and ameliorated MRSA-induced abnormal changes in inflammation and oxidative stress. This indicates that citral has the potential for development as a new anti-MRSA drug. (c) 2019 Society of Chemical Industry