D-mannose administration improves autoimmune hepatitis by upregulating regulatory T cells

A recent study revealed that D-mannose suppressed immunopathology in mouse models of autoimmune diabetes and airway inflammation and increased the proportion of regulatory T cells (Tregs) in mice. We investigated the effect of D-mannose on liver injury in murine autoimmune hepatitis (AIH) models induced by concanavalin A (ConA) and α-galactosylceramide (GalCer). Mouse models of AIH were created by intraperitoneal injection of GalCer or intravenous injection of ConA. Drinking water was supplemented with D-mannose and biochemically and pathologically examined over time. The administration of D-mannose to AIH model mice significantly reduced liver injury and reduced inflammatory cytokine expression. In addition, Tregs among splenocytes and intrahepatic lymphocytes were significantly increased by the administration of D-mannose. These results indicate that treatment with D-mannose reduced the inflammatory response in the liver and suppressed liver damage by increasing Tregs.