Figure 4.

This scheme indicates the probable mechanisms of hepatoprotective activity of palm kernel cake extract. The heat stress triggers the TNF-like release in chicken hepatocyte which then activates the proinflammatory cytokines (IL-1β and INF-γ). As a result, NF-κB is activated and it is followed by increase in the expression of COX-2 and iNOS production. The consequence is the inflammation and hepatocyte malfunction. The palm kernel cake exerts the hepatoprotective activity through inhibition of ROS and NO• radicals and inhibiting inflammatory pathways downstream of cytokine release (NF-κB, iNOS and COX-2) and also by decreasing proinflammatory factors TNF-like, IL1-β and INF-γ. The heat stress increases the Hsp70 expression. This over expression alleviates the deleterious effects of heat stress through inhibition of ROS and regulation of TNF-like, NF-κB, iNOS and COX-2 expression.