Gingko biloba extract EGB761 alleviates heat-stress damage in chicken heart tissue by stimulating Hsp70 expression in vivo in vascular endothelial cells.

1. This study aimed to investigate the protective effects of Gingko biloba extract EGB761 on heat-stressed chicken heart in vivo and its underlying relevance to Hsp70.2. A total of 50 one-day-old female chicks were randomly divided into five groups: control (Con), heat-stress (HS), 0.1% EGB761 plus heat-stress (0.1%EGB+HS), 0.3%EGB761 plus heat-stress (0.3%EGB+HS) and 0.6%EGB761 plus heat-stress (0.6%EGB+HS) groups. After administration of EGB761 for 45 days, the chickens in each group were exposed to a single heat-stress event at 38 ± 1°C for 3 h.3. EGB761 attenuated the abnormal symptoms and pathological scores of myocardium of heat-stressed chickens. Despite a reduction in the transcription and translation of the Hsp70 gene in heat-stressed myocardium, EGB761 induced the expression of Hsp70 in endothelial cells of the microarteries and venules into the blood, and reduced heat-stress damage in vascular endothelial cells.4. Supplementation with EGB761 before heat-stress exposure protected chicken myocardium from damage by increasing serum Hsp70 protein from myocardial cells and cardiac microvascular endothelial cells and protected the microvascular system from adverse injury.