| Tibial Dyschondroplasia(TD) is an important leg problem in fast growing birds that disturbs the proximal tibial growth plate.TD is characterized by non-vascularized cartilage, a distended growth plate, tibial bone deformation and lameness.1. Hsp90 inhibitor celastrol reinstates growth plate angiogenesis in thiram-induced tibial dyschondroplasia.Celastrol, a medicinal root extract from the plant Tripterygium wilfordii is reported widely as a well-known heat-shock protein 90(Hsp90) inhibitor. In the recent years, Hsp90 inhibition in avascularized and enlarged growth-plate was effective in restoring the morphology of the growth plate and proper chondrocytes differentiation. This study was aimed to investigating Hsp90 inhibition in Tibial dyschondroplasia using Celastrol. The broiler chicks were randomly allocated into three groups; Control; TD induced(40 mg/kg thiram) and Celastrol treatment. Hsp90, VEGF and Flk-1 expressions were evaluated by quantitative real time polymerase chain reaction and the protein levels of Hsp90 were measured by western blot analysis. The expression levels of Hsp90 and VEGF m RNA transcripts were increased while Flk-1 receptor was decreased in TD affected chicks. Celastrol therapy inhibited Hsp90 m RNA and protein levels and up-regulated the expressions of receptor Flk-1 in TD affected tibial growth plates significantly(P<0.05).In conclusion, administering celastrol to dyschondroplastic chicks prevented un-vascularized growth plate, lameness and reinstated growth plate angiogenesis. Celastrol may be efficacious for the treatment of TD through the inhibition of Hsp90 expression in broiler chicken.2. Hsp90 inhibitor Celastrol attenuate liver damage caused by thiram.This study was performed to investigate the beneficial effects of celastrol on the liver. Thiram has reported widely to cause lameness and induce hepatic toxicity in birds. In order to determine hepatic toxicity the changes in serum markers for oxidative stress was evaluated to assess the liver damage caused by thiram. In addition, to explore the beneficial and protective effects of the Celastrol in the treatment of TD affected birds were studied. The broiler chicks were randomly divided into three groups; Control; TD induced(40 mg/kg thiram) and Celastrol treatment group. Results of the experiment indicate that a significant decrease in SOD & GSH-Px antioxidant enzymes and ALP activity along with an increase in ALT, AST and MDA contents in the liver were observed in thiram-fed birds as compared to control. However, the intra peritoneal Celastrol administration caused an increase in SOD & GSH-Px enzymes and ALP activity with a decrease in ALT, AST enzymes and MDA contents significantly. In conclusion, Celastrol alleviated the damaging effects of thiram on the liver and corrected the oxidative imbalance. Celastrol can be used to limiting the liver damage caused by thiram in broiler chickens.3. Gambogic acid inhibits Hsp90 expressions and restored the growth plate width in thiram-induced tibial dyschondroplasia.Gambogic acid(GA) is a brownish to orange resin Chinese herb extracted from the Garcinia hanburyi tree(genus Garcinia, family Guttiferae) has evolved as an antiinflammatory medicine over thousands of years in China. It has also been claimed for clinical trials by acting as a novel hsp-90 inhibitor. This experiment was performed to evaluate the special effects of gambogic acid(GA) on TD affected tibial growth plate width, Hsp-90 expressions and antioxidant capability in thiram-induced TD chicken. A total one hundred and fifty day-old commercial broiler chicks were equally divided into three groups: Control(A), thiram-induced(B) and GA treated(C). Birds were slaughter by cervical dislocation on day 7 and 14, the tibial bone tissue samples were collected from each group to evaluate Hsp-90 expressions, and liver samples were procured at the end of experiment to determine the antioxidant enzymes. Results from the present experiment demonstrate that, As compared to control, enlarged growth plate and significant increased Hsp-90 gene expressions(P<0.05) on day 7 & 14 was observed to contributing the progression of TD while a decrease in antioxidant capacity of liver on day 14 in thiram-induced TD chicks. On administering the GA, the hsp-90 expressions were down-regulated and restored the antioxidant capacity of liver significantly(P<0.05), alongside reduced the growth plate width and eliminated lameness. In conclusion, the GA ameliorated the growth plate vascularization in TD-afflicted chicks, the findings from this research provides a new clinical usage of this promising agent against TD.4. Novobiocin ameliorates tibial dyschondroplasia through inhibition of Hsp90 expressions in avian growth plate.Novobiocin is an antibiotic medicine has been identified as an Hsp90 inhibitor. This experiment was conducted to evaluate ameliorative effect of Novobiocin on the bone deformity, and selective Hsp90 inhibitor on thiram-induced TD in broiler chicken, alongside the protein levels of proteoglycan Aggrecan was examined from TD affected and Novobiocin treated birds. The chicks were divided into three groups; Control; TD induced(50 mg/kg thiram) and Novobiocin(10mg/kg/d) treatment group. After the induction of disease, Hsp90 inhibitor Novobiocin was administered through intraperitoneal route to TD-affected birds until end of the experiment. The expressions and habitation of Hsp90 was evaluated with quantitative real time polymerase chain reaction(q RT-PCR), immunohistochmeistry(IHC). Protein levels of Hsp90 and Aggrecan was analyzed with western blot examination. Morphological and histological examination of the growth plate(GP) was performed to assess specificity of Novobiocin. The results depicted that thiram alter the morphology of growth plate causing enlarged, distended cells, irregular columns of chondrocytes, in addition with reduced protein levels of proteoglycan Aggrecan. The Hsp90 expression was up regulated significantly(P<0.05) in dyschondroplastic birds as compared with control. Novobiocin treatment restored growth plate width, chondrocytes differentiation, sprouting blood vessels and returned Hsp90 expressions to the normal levels, beside the Aggrecan levels was found increased in Novobiocin treated birds, finally abolished lameness in broiler chicken. In conclusion, the accumulation of the cartilage and up-regulated Hsp90 are associated with TD pathogenesis and irregular chondrocytes morphology in TD pathogenesis is linked with reduced Aggrecan levels in the growth plate. These findings suggest the increased Hsp90 and Aggrecan levels contribute the TD pathogenesis and morphology of chondrocytes in avian growth plate respectively. Furthermore, Novobiocin treatment is encouraged here for the controlling of TD and Hsp90 expressions may target to reduce the incidence of Tibial Dyschondroplasia in broiler chicken. |
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