# Introduction he liver is an organ of paramount importance not only for its metabolism of various xenobiotics and environmental pollutants [1] but for its unique and considerable regenerative capacity, even a moderate cell injury is not reflected by measurable change in its metabolic functions. However, some of its functions are so sensitive that abnormalities start appearing depending upon the nature and degree of its initial damage [2] . Reactive Oxygen Species (such as H 2 O 2 , O 2 2-, and OH -, collectively known as ROS) play important physiological functions and can also cause extensive cellular damage. Cells are provided with efficient molecular strategies to control strictly the intra cellular ROS level and to maintain the balance between oxidant and antioxidant molecules. Oxidative stress, resulting from an imbalance between the generation of ROS and the antioxidant defense capacity of the cell [3] , effects major cellular components including lipids, proteins and DNA. This phenomenon is closely associated with a number of human disorders such as many degenerative diseases including cardiovascular disease, diabetes, cancer, neurodegenerative disorders [4,5] and with almost all liver pathologies [6][7][8] . All these conditions appear mostly related to chronic oxidative stress. However, the acute exposure to high levels of ROS seems to be responsible for the development of different damages such as during ischemis/reperfusion is acute hepatotoxic agent, which induces peroxidative degeneration of membrane lipids causing hypo perfusion of the membrane. Cytosolic enzyme like SGPT, SGOT and ALP. A number of medicinal plants are used in traditional system of medicinal for the management of liver disorders. Nature has given us a large number of medicinal plants, some of which are yet to be explored and validated for their medicinal value. The 21 st century has seen a paradigm shift toward therapeutic evaluation of herbal products in liver diseases, carefully synergizing the strengths of traditional medicine with the modern concept of evidence based medical evaluation, standardization and randomized placebo controlled clinical trials to support clinical efficacy. Several herbs are known to possess antioxidant properties and may be useful as liver protective agents [10] . The herbs containing antioxidant principles are reported to be highly effective in preventing or curing the liver toxicities due to above mentioned challenges. In the present study, the herb Phyllanthus amarus containing polyphenolic compounds is selected to assess hepatoprotective activity [11] . # II. # Materials and Methods # a) Plant Material The seeds of Phyllanthus amarus were collected from local gardens of Tirupathi. The plant was b) Preparation of Extracts The crushed and dried seeds of Phyllanthus amarus were divided into two parts; one part was extracted successively with petroleum ether, benzene, chloroform and finally with methanol by soxhlet extraction and concentrated by rotary vacuum [12] . The other part is extracted by cold maceration process for aqueous extraction [13] . The obtained extracts were dried by evaporation. The yield 30% w/w and 15.6% w/w were stored in refrigerator and weighed quantities were suspended in tween 80 and 2% tragacanth solution respectively for the experiment. The extracts were used for In-vitro and In-vivo studies to analyze the reparative activity of liver injury due to CCl 4 treated rats. # c) Experimental Animals Male albino rats weighing 130-160g were obtained from the animal house of Nizam Institute of Pharmacy, Hyderabad and housed in Polycarbonate cages. The rats had free access to standard pellet chow and water ad libitum throughout the experiment with the exception of some experiments (see below) in which the animals were deprived of food, but not water, for 18-24 hr. before the experiments were performed. After procurement, all the animals were divided into different groups and were left for one week for acclimatization to experimentation room and were maintained on standard conditions (23 o c, 60%-70% relatively humidity and 12 hr. photo period). There were five animals in each group for observational screening. All experimental protocols described below were approved by the ethical board. # d) Acute Oral Toxicity Studies The acute oral toxicity study is determined according to the guidelines of Organization for Economic Co-operation & Development (OECD) following the up & down method (OECD guideline No. 423). Based on the method, a limit test was performed to categorize the toxicity class of the compound and then main test was performed on three female rats to estimate the exact LD50. The animals were fasted overnight with free access to water, weighed and a single dose of the test substance was administered. Animals were observed individually during first 30 min, periodically during 48 h with special attention given during first 4 h (short-term toxicity) and daily, thereafter for total of 14 days (short-term toxicity). LD50 was found to be greater than 2500 mg/kg, in limit test. The test substance could be classified in the hazard classification as Class 5 -2000 mg/kg