Pharmacological Evaluation of Glutamine Against Isoniazid Induced Hepatotoxicity in Laboratory Rat

The liver plays an important role in maintaining vital functions in our body including maintenance and regulation of homeostasis. It is involved with almost all the biochemical pathways to growth, fight against disease, nutrient supply, energy provision and reproduction (Sharma et al., 1991). Metabolism of carbohydrate, protein, fat, detoxification, secretion of bile and storage of vitamins are the major functions of hepatocytes. Maintenance of healthy liver is a crucial factor for overall health and wellbeing (Subramaniam & Pushpangadan, 1999). Hepatotoxicity refers to liver injury or dysfunction that is associated with an overload of drugs or xenobiotics (Navarro & Senior, 2006). Since 1998, many researchers clearly identified drug-induced hepatotoxicity as an endemic problem (Njoku, 2014). During this time, Schiodt (1999), Temple & Himmel (2002), Ostapowicz (2002) and Lee & Senior (2005) identified specific drugs and outcomes directly associated with drug-induced hepatotoxicity. As expected, these landmark discoveries in the population statistics of drug-induced hepatotoxicity as well as key discoveries in the area of pathogenesis of drug-induced toxicity produced even more questions about its metabolic, genetic and immunologic basis (Njoku, 2014; Tujios & Fontana, 2011; Garcia-Cortes et al., 2011). Certain medicinal agents when taken in overdoses and sometimes even when taken within therapeutic range may cause the damage of liver. Some chemicals used in laboratories and industries, herbal remedies and natural chemicals (such as microcystins) may also induce hepatotoxicity. There are more than 900 drugs involved in liver injury and it is the most common reason for withdrawal of the drug from the market (Pandit et al., 2012). Hepatotoxins often cause subclinical injury to liver which manifests only as abnormal liver enzyme tests.