Nasra Naeim Ayuob , Ahlam Abdulaziz Al-Ahmadi, Soad Shaker Ali , Ali Ahmed Al-Robai , Nabil Abdulaziz Abo-Khatwa , Effect of (+)-Usnic Acid as a Fat Burner on the Rat Hepatocyte; Correlated Histological and Biochemical in vivo Study, Journal of Animal and Veterinary Advances, Volume 11,Issue 9, 2012, Pages 1368-1377, ISSN 1680-5593, javaa.2012.1368.1377, (https://makhillpublications.co/view-article.php?doi=javaa.2012.1368.1377) Abstract: Liver injury from dietary supplement mimicking other liver diseases is increasingly recognized. Usnic acid has been marketed as weight-loss aid many years ago in spite its chronic or subchronic effects on animal were not studied. To assess the effect of Usnic acid on the structure of the hepatocytes of male rats and correlate this effect to those changes detected if any in the biochemical study. Forty adult male rats were divided into four groups ten animals each (n = 10); control received standard diet, G1 received 1% carboxymethyl cellulose water solution, G2 received 100 mg usnic acid kg-1 and G3 received 300 mg usnic acid/ kg, 5 days for 7 weeks using gastric gavages. Serum glucose, liver functions, lipid profile, lipase, leptin and Insulin were estimated. Liver was processed for electron microscope studies and results were analyzed using SPSS. The liver index was increased significantly in high-dose Usnic acid compared to the control. Hepatocytes showed an increase in lipid droplets, swollen mitochondria, fragmented rough endoplasmic reticulum cisterns, abundant smooth endoplasmic reticulum and focal damage of hepatocyte membranes near bile canaliculi, all these changes were dose dependent. There was significant increase in total protein, albumin and total bilirubin in group received low-dose of Usnic acid. Glucose, magnesium, total protein, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and total bilirubin were significantly increased in group received Usnic acid at high-dose. Serum cholesterol and high density lipoprotein were significantly increased in all treated groups while triglycerides were slightly increased. Keywords: Biochemical;hepatocytes;histological;in vitro;rat;usnic acid