There is important evidence of the hepatoprotective effects of milk thistle in animals against various toxins and hepatotoxic drugs. In a study of the hepatoprotective effects of milk thistle extract in rat, it was demonstrated that this extract can effectively prevent dysfunction and hepatic fibrosis caused by methotrexate.(1) Non-alcoholic Fatty Liver Disease (NAFLD) is one of the most common chronic liver conditions in the west. Patients suffering NAFLD concurrently suffer other significant conditions such as diabetes, hypothyroidism, and metabolic syndrome. Due to the epidemics of obesity and type II diabetes, the prevalence of fatty liver is fast on the rise both in adults and in children. Obesity, insulin resistance, oxidative stress, cytokines and adipokines are among the factors effective in the pathogenesis of NAFLD. The common therapeutic approach in this condition is lifestyle intervention; however, there is no consensus regarding the ideal drug regimen. Drugs used in the treatment of NAFLD should reduce weight, improve the resistance to insulin and other metabolic changes, act as an anti-inflammatory and immunomodulator agent and reduce the relation between the fat tissue and liver function and -through halting oxidative stress- balance the progress of hepatic steatosis towards inflammation and fibrosis. Pharmacologic studies have shown that the active ingredients in milk thistle (silymarin and silybin) have hepatoprotective, antioxidant, anti-inflammatory and anti-fibrotic properties; furthermore, they stimulate protein biosynthesis and hepatic cell regeneration and are immunomodulators. Several studies have shown that the active ingredient in milk thistle called silymarin has major hepatoprotective properties; in recent years, several pre-clinical and clinical reports have introduced silymarin as the treatment for NAFLD.
In a double-blind, placebo-controlled clinical trial carried out on 57 patients suffering acute, viral hepatitis, the group receiving milk thistle showed considerable improvement. Also, in a double-blind, placebo-controlled clinical trial on 106 Finnish soldiers with alcoholic hepatotoxicity, in the group treated with milk thistle, considerable reduction in hepatic enzymes and histological improvement was observed within 4 weeks by carrying out biopsy on 29 patients. In another double-blind, placebo-controlled clinical trial on 170 patients with alcoholic or non-alcoholic hepatic cirrhosis, the 4-year survival rate was 58% in the milk thistle group and 38% in the placebo group and the difference was statistically significant. Furthermore, in an analysis of 19 randomized trials, the researchers concluded that milk thistle was considerably more effective in reducing deaths due to hepatic cirrhosis compared to placebo.(3)
Based on a study carried out on rat, treatment with artichoke extract protects the liver against hepatic damage due to CCI4 and might be valuable in treatment of chronic liver conditions in human. In this study, there was no preference in favor of a combination of artichoke and silymarin, silymarin alone or artichoke extract alone.(4) Furthermore, another study showed that prescribing 900 mg per kg of body weight per day artichoke leaves and 450 mg per kg of body weight per day chicory root removes the change in hepatic enzymes and histopathological damages due to CCI4.(5) Turmeric has hepatoprotective properties resembling that of silymarin. Animal studies have shown the hepatoprotective effects of turmeric against hepatotoxicity due to CCI4, galactosamine, acetaminophen and Aspergillus aflatoxin. The hepatoprotective effects of turmeric are mainly due to its anti-oxidant properties and its ability in reducing proinflammatory cytokines. Turmeric and curcumin cause reversal of hyperplasia of bile ducts, lipid change and necrosis due to aflatoxin. Sodium curcuminate shows its chlorotic effects by increasing secretion of choleric salts, cholesterol and bilirubin and increasing bile solubility; therefore, it could play a role in prevention and treatment of gallbladder stone.(6) In one study, the hepatoprotective effects of ethanolic extract of turmeric rhizome was studied in a hepatic cirrhosis model caused by thioacetamide in rat. The researchers concluded that the antioxidant and anti-inflammatory effects of turmeric rhizome can limit the progress of hepatic cirrhosis and so the normal condition of liver is sustained.(7) Also, in a study on the aqueous extract of turmeric rhizome in swiss albino mice with CCI4 poisoning, it was demonstrated that this extract has immunotherapeutic effects and can eradicate hepatotoxicity. In this study, turmeric rhizome extract reduced levels of SGOT (AST) and SGPT (ALT).(8) In a study of the hydro-alcoholic extract of dandelion root on mice liver fibrosis due to CCI4, it was demonstrated that the therapeutic effect of this extract is due to the inactivation of stellate liver cells and an increase in the regeneration capacity of the liver. This study is a scientific evidence for the traditional use of dandelion root in hepatic disorders.(7) Furthermore, in a study carried out on mice, it was demonstrated that the hepatoprotective effects of dandelion leaf extract against acetaminophen hepatotoxicity is due to the anti-oxidant properties of this extract. The plausible mechanism is the scavenging of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species, which is related to the phenolic compounds in the extract.(10) Also, in another study, it was demonstrated that the extract of dandelion root has protective properties against alcohol-related hepatotoxicity, as it increases the anti-oxidative potential and reduces fat peroxidation.(11)