Physiological changes due to hepatotoxicity and the protective role of some medicinal plants

AbstractThe liver is the largest, important organ and the site for essential biochemical reactions in the human body. It has the function to detoxify toxic substances and synthesize useful biomolecules. Therefore, damage to the liver leads to grave consequences. This damage resulted from chronic alcoholic abuse, viral hepatitis or inherited metabolic disease. Liver damage is associated with cellular necrosis, fibrosis, and increase in tissue lipid peroxidation and depletion in tissue glutathione level. Most of the hepatotoxic chemicals damage liver cells mainly by inducing lipid peroxidation and other oxidative damages in the liver. Natural antioxidants are found in many compounds classified as secondary plant metabolites, e.g. polyphenols (phenolic acids and flavonoids) and terpenoids (carotenoids), and the consumption of foods that contain these compounds in large quantities seems to play an important role in prophylaxis against many diseases. Herbal medicines derived from plant extracts are being increasingly utilized to treat a wide variety of clinical disease. More attention has been paid to the protective effects of natural antioxidants against drug induced toxicities especially whenever free radical generation is involved. Popularity of herbal remedies is increasing and at least one quarter of patients with liver disease use botanicals. The World Health Organization (WHO) estimates that 80 percent of the population of some Asian and African countries presently use herbal medicine for some aspect of primary health care. Some medicinal herbs have proven hepatoprotective potential. Silybum marianum (milk thistle) has been used to treat liver diseases since the 16th century. Its major constituents are the flavonoids silibinin, silydianin, silychristin, and isosilibinin, of which silibinin is the biologically most active compound and used for standardization of pharmaceutical products