The fields of dietary modification and chemoprevention show considerable effective approaches against oxidative stress and are the focus of research these days . Various studies have shown that several mutagens and carcinogens cause generation of oxygen-free radicals, which play a major role in the emergence of cancer and other health disturbances [37, 38]. The present study revealed that CCl4-induction in rats remarkably increased the level of ALT, AST, ALP and γ-GT. CCl4 causes acute hepatocyte injuries, altered membrane integrity and as a result enzymes in hepatocytes leak out . However, after treatment with rutin, the pathological increases in ALT, AST, ALP and γ-GT were significantly restored. These results indicate that rutin has the ability to protect against CCl4-induced hepatocyte injury, which is in agreement with a previous study  that reported the protective consequence of polyphenolic compounds against CCl4-induced liver cirrhosis. Importantly, the increased serum concentrations of triglycerides, total cholesterol and LDL, and the decreased level of HDL, were restored to normal values with rutin co-treatment. This may be explained on the basis that rutin has a strong ability to chelate multivalent metal ions, especially zinc, calcium and iron. Indeed, its ability to chelate minerals has been reported to have some protective effects, such as decreasing iron mediated free radical formation and lowering serum cholesterol, triglycerides and lipid peroxides in experimental animals . Similar findings were reported in another study  that investigated the hepatoprotective effects of plant bioactive compounds against CCl4-induced hepatic injury in rats.
ROS formed during the biotransformation process of CCl4 are more reactive and toxic than the parental compound. Biotransformation of CCl4 occurs in the endoplasmic reticulum and the isoenzyme implicated in this process is CYP2E1 [43, 44]. Our results showed that the active free radical/intermediate of CCl4 caused a reduction in CYP2E1, which was markedly restored by rutin treatment. Our results showed conformity with previous investigations, which demonstrated that the polyphenolic natural product is responsible for its protective, effects [45, 46].
Results of the present study revealed that exposure of rats to CCl4 resulted in depletion of antioxidant activities. In consonance with our results, Szymonik-Lesiuk et al. reported that CCl4 intoxication leads to changes in antioxidant enzymes and reactive intermediates involved in the bioactivation of CCl4 that may truss to those enzymes to prevent their inactivation. Furthermore, our results correspond with [11, 12], and are in agreement with an investigation following CCl4 intoxication .
Glutathione provides a first line of defense and scavenges free radical oxygen species (ROS). The decreased concentration of GSH in liver may be due to NADPH reduction or GSH utilization in the exclusion of peroxides . GSH-dependent enzymes offer a second line of protection as they primarily detoxify noxious byproducts generated by ROS and help to avert dissemination of free radicals . GSH-Px detoxifies peroxides by reacting with GSH and converting it into GSSG, which is reduced to GSH by GSR . Our study revealed that CCl4 treatment in rats markedly changed the activity of antioxidant enzymes, which was reverted by the co-administration of rutin. Thiobarbituric acid reactive substances (TBARS), the final metabolites of peroxidized polyunsaturated fatty acids, are considered as a late biomarker of oxidative stress . In our experiments, major decrease in lipid peroxidation and consequent reduction in TBARS were obtained by treatment with rutin. The increment in lipid peroxidation, as assessed by the elevated levels of TBARS following CCl4 administration, has been well documented . Data of the present study indicated that lipid peroxidation induced by oxidative stress caused DNA damage. TBARS react with the DNA strand to form the M1G adduct, the mutagenic pirimedopurinone adduct of deoxyguanosine . Administration of rutin markedly reduced the DNA damage, which is in close agreement with a previous study . This level of DNA damage decreases the expression of p53 and blocks cells in the G phase of the cell cycle, which gives the cells additional time to repair the DNA damage. However, severe DNA damage may elicit apoptosis . The data revealed that CCl4-induction caused marked reduction in p53. This result may be explained on the basis that CCl4 acts as a tumor promoter through increasing the intracellular concentration of ROS necrosis/regeneration and cell proliferation and/or may be due to mutation of p53. Our results regarding p53 are in agreement with previous studies [54, 55].