Monosodium glutamate aggravates lipopolysaccharide-induced liver injury via inflammation and oxidative stress in rats

Purpose Available epidemiological reports have indicated an increase in the incidence of liver damage globally. Monosodium glutamate (MSG) is a widely used food additive in many processed foods which has been associated with tissue injury. However, there is a paucity of information on its effect on hepatic injury. Therefore, the present study examined the possible influence of high intake of MSG on lipopolysaccharide (LPS)-induced liver injury. Methods Twenty-eight healthy male Wistar rats were used for the study. MSG (1500 mg/kg) was administered orally for 14 days while LPS (0.25 mg/kg) was administered intraperitoneally for 7 days. Results Administration of MSG to rats with hepatocyte injury intensified liver damage with a marked increase in the activities of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Moreover, MSG aggravated (P < 0.05) LPS-mediated hepatic oxidative stress as evidenced by a marked decrease in enzymatic and non-enzymatic antioxidants with a concomitant increase in lipid peroxidation. The increase in inflammatory biomarkers, in addition to histological damage in the liver, was aggravated following the administration of MSG to rats with liver injury. Conclusion Taken together, MSG exacerbated liver injury via mechanisms relating to increased oxidative stress and inflammation.