Review of natural products with hepatoprotective effects

The liver is one of the most important organs in the body,performing a fundamental role in the regulationof diverse processes,among which the metabolism,secretion,storage,and detoxification of endogenous and exogenous substances are prominent.Due to these functions,hepatic diseases continue to be among the main threats to public health,and they remain problems throughout the world.Despite enormous advances in modern medicine,there are no completely effective drugs that stimulate hepatic function,that offer complete protection of the organ,or that help to regenerate hepatic cells.Thus,it is necessary to identify pharmaceutical alternatives for the treatment of liver diseases,with the aim of these alternatives being more effective and less toxic.The use of some plants and the consumption of different fruits have played basic roles in human health care,and diverse scientific investigations have indicated that,in those plants and fruits so identified,their beneficial effects can be attributed to the presence of chemical compounds that are called phytochemicals.The present review had as its objective the collecting of data based on research conducted into some fruits(grapefruit,cranberries,and grapes)and plants[cactus pear(nopal)and cactus pear fruit,chamomile,silymarin,and spirulina],which are consumed frequently by humans and which have demonstrated hepatoprotective capacity,as well as an analysis of a resin(propolis)and some phytochemicals extracted from fruits,plants,yeasts,and algae,which have been evaluated in different models of hepatotoxicity.

Protective effect of some vitamins against the toxic action of ethanol on liver regeneration induced by partial hepatectomy in rats

AIM: To investigate the effects of vitamins (A, C and E) on liver injury induced by ethanol administration during liver regeneration in rats. METHODS: Male Wistar rats subjected to 70% partial hepatectomy were divided into five groups (groups 1-5). During the experiment, animals of Group 1 drank only water. The other four groups (2-5) drank 30 mL of ethanol/L of water. Group 3 additionally received vitamin A, those of group 4 vitamin C and those of group 5 received vitamin E. Subsequently serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin and bilirubin were measured colorimetrically. Lipid peroxidation (thiobarbituric-acid reactive substances, TBARS) both in plasma and liver was measured, as well as liver mass gain assessment and total DNA. RESULTS: Compared with sham group, serum AST and ALT increased significantly under ethanol treatment (43% and 93%, respectively, with P < 0.05). Vitamin C and vitamin E treatment attenuated the ethanol-induced increases in ALT and AST activity. Ethanol treatment also decreased serum albumin concentration compared to sham group (3.1 ± 0.4 g/dL vs 4.5 ± 0.2 g/dL; P < 0.05). During liver regeneration vitamins C and E significantly ameliorated liver injury for ethanol administration in hepatic lipid peroxidation (4.92 nmol/mg and 4.25 nmol/mg vs 14.78 nmol/mg, respectively, with P < 0.05). In association with hepatic injury, ethanol administration caused a significant increase in both hepatic and plasma lipid peroxidation. Vitamins (C and E) treatment attenuated hepatic and plasma lipid peroxidation. CONCLUSION: Vitamins C and E protect against liver injury and dysfunction, attenuate lipid peroxidation, and thus appear to be significantly more effective than vitamin A against ethanol-mediated toxic effects during liver regeneration.

Hepatoprotective effect of silymarin

The use of medicinal plants in treating illnesses has been reported since ancestral times.In the case of hepatic diseases,several species such as Silybum marianum,Phyllanthus niruri,and Panus giganteus(Berk.)have been shown to ameliorate hepatic lesions.Silymarin is a natural compound derived from the species Silybum marianum,which is commonly known as Milk thistle.This plant contains at least seven flavoligands and the flavonoid taxifolin.The hepatoprotective and antioxidant activity of silymarin is caused by its ability to inhibit the free radicals that are produced from the metabolism of toxic substances such as ethanol,acetaminophen,and carbon tetrachloride.The generation of free radicals is known to damage cellular membranes and cause lipoperoxidation.Silymarin enhances hepatic glutathione and may contribute to the antioxidant defense of the liver.It has also been shown that silymarin increases protein synthesis in hepatocytes by stimulating RNA polymerase I activity.A previous study on humans reported that silymarin treatment caused a slight increase in the survival of patients with cirrhotic alcoholism compared with untreated controls.

Hepatoprotective effect of Geranium schiedeanum against ethanol toxicity during liver regeneration

AIM: To evaluate the effect of an extract of Geranium schiedeanum(Gs) as a hepatoprotective agent against ethanol(Et OH)-induced toxicity in rats. METHODS: Male Wistar rats weighing 200-230 g were subjected to a 70% partial hepatectomy(PH); they were then divided into three groups(groups 1-3). During the experiment, animals in group 1 drank only water. The other two groups(2-3) drank an aqueous solution of Et OH(40%, v/v). Additionally, rats in group 3 received a Gs extract daily at a dose of 300 mg/kg body weight intragastically. Subsequently, to identify markers of liver damage in serum, alanine aminotransferase, aspartate aminotransferase, albumin and bilirubin were measured by colorimetric methods. Glucose, triglyceride and cholesterol concentrations were also determined. In addition, oxidative damage was estimated by measuring lipid peroxidation [using thiobarbituric-acid reactive substances(TBARS)] in both plasma and the liver and by measuring the total concentration of antioxidants in serum and the total antioxidant capacity in the liver. In addition, a liver mass gain assessment, total DNA analysis and a morpho-histological analysis of the liver from animals in all three groups were performed and compared. Finally, the number of deaths observed in the three groups was analyzed.RESULTS: Administration of the Geranium shiedeanum extract significantly reduced the unfavorable effect of ethanol on liver regeneration(restitution liver mass: PHEt OH group 60.68% vs PH-Gs-Et OH group 69.22%). This finding was congruent with the reduced levels of hepatic enzymes and the sustained or increased levels of albumin and decreased bilirubin in serum. The extract also modified the metabolic processes that regulate glucose and lipid levels, as observed from the serum measurements. Lower antioxidant levels and the liver damage induced by Et OH administration appeared to be mitigated by the extract, as observed from the TBARs(PH-Et OH group 200.14 mmol/mg vs PH-Gs-Et OH group 54.20 mmol/mg; P < 0.05), total status of antioxidants(PH-Et OH group 1.43 mmol/L vs PH-Gs-Et OH group 1.99 mmol/L; P < 0.05), total antioxidant capacity values, liver mass gain and total DNA determination(PH-Et OH group 4.80 mg/g vs PH-Gs-Et OH 9.10 mg/g; P < 0.05). Overall, these processes could be related to decreased mortality in these treated animals.CONCLUSION: The administered extract showed a hepatoprotective effect, limiting the Et OH-induced hepatotoxic effects. This effect can be related tomodulating oxido-reduction processes.