Tibial Dyschondroplasia (TD) is an important leg problem in fast growing birds that disturbs the proximal tibial growth plate. A study was conducted to evaluate the effects of gambogic acid (GA) on hsp-90 expressions and antioxidant capability in thiram-induced TD chicken. One hundred and fifty day-old commercial broiler chicks were distributed into three groups: Control (A), thiram-induced (B) and GA treated (C). Tibial bone samples were collected at day 7 & 14 to evaluate hsp-90 expressions and liver samples were procured at the end of experiment to determine the antioxidant enzymes. As compared to control, the results demonstrated that significant increased hsp-90 gene expressions (P<0.05) in thiram-induced TD chicks on day 7 & 14 contributing to the progression of TD while a decrease in antioxidant capacity of liver on day 14. On administering the GA, the hsp-90 expressions were down-regulated and restored the antioxidant capacity of liver significantly (P<0.05). In conclusion, the GA ameliorated the growth plate vascularization in TD-afflicted chicks which provides a new clinical usage of this promising agent against TD.

Key words: Gambogic Acid, Hsp-90, Liver, Tibial Dyschondroplasia