Catechin reduces liver inflammation by regulating Kupffer cell activation in rats

The liver is a defense against infections due to its strategic location between the gastrointestinal and systemic circulations. In dogs and cats, infectious hepatitis encompasses a range of contagious diseases affecting the liver either directly or as part of a broader systemic infection, including bacterial, mycobacterial, viral, fungal, protozoal, parasitic, and rickettsial diseases. Catechins possess well-recognized natural antioxidant properties. This study investigated their therapeutic potential for applications in hepatology, evaluating whether catechins reduce hepatic inflammation in rats repeatedly exposed to carbon tetrachloride (CCl₄). Sprague-Dawley rats were given catechin 50 (C50) or 100 (C100) mg/kg body weight orally daily for 3 days. This treatment was given with or without concurrent intraperitoneal injections of CCl₄. Phosphate-buffered saline served as the vehicle control, while silymarin administered at 100 mg/kg was used as the positive control. Gross examination revealed significant enlargement, edema, and darker tissue in CCl₄-induced livers treated with vehicle. Additionally, spotty discoloration was observed on the surface. Kupffer cell activation suppressed the expression of inflammatory mediators, including inducible nitric oxide synthase (iNOS), in groups co-treated with catechin and CCl₄; this effect was reversed when catalase replaced catechin in CCl₄-injured rats. Catechin alleviates hepatic inflammation in rats repeatedly exposed to CCl₄; it also modulates the activation of Kupffer cells and monocytes. These results should lead to new treatments for liver inflammation in veterinary practice.