Preventive effect of lemon seed flavonoids on carbon tetrachloride-induced liver injury in mice

The aim of this study was to determine the preventive effect of lemon seed flavonoids (LSF) on carbon tetrachloride-induced liver injury in mice. Liver injury was induced by injection with 2 mL kg^-1 of carbon tetrachloride after administration of LSF by gavage. Liver index, serological parameters, and expression intensities of related mRNA and protein in the liver tissue were observed. The results indicated that LSF reduced liver weight and liver index, downregulated serum levels of AST, ALT, ALP, TG, TC, BUN, NO, and MDA, and upregulated levels of ALB, SOD, CAT, and GSH-Px in the mice with liver injury. It also downregulated serum cytokines, such as IL-6, IL-12, TNF-α, and IFN-γ in these mice. qPCR and western blot confirmed that LSF upregulated mRNA and protein expression of Mn-SOD, Cu/Zn-SOD, CAT, GSH-Px, and IκB-α, and downregulated expression of NF-κB-p65, iNOS, COX-2, TNF-α, IL-1β, and IL-6 in the liver tissue of mice with liver injury. The preventive effect on carbon tetrachloride-induced liver injury was attributed to (-)-epigallocatechin, caffeic acid, (-)-epicatechin, vitexin, quercetin, and hesperidin, which were active substances that were detected in LSF by HPLC. Moreover, the effect of LSF is similar to that of silymarin, but the synergistic effect of the five active substances working in concert acted to produce a more robust liver-protecting effect.