Biochemical and histological alterations in the liver of albino rats fed a carbohydrate-rich diet under chronic heat and humidity stress

The effects of short-term heat stress on normal-diet rats are well-known, but the impact of long-term heat and humidity on rats fed a carbohydrate-rich diet remains unexplored. The study examined the alterations caused by chronic heat and humidity stress in liver enzymes, blood biochemistry, and histology in rats fed a carbohydrate-rich diet. One hundred and eighty adult rats were divided into routine diet (RD) and carbohydrate-rich diet (CRD) groups, further divided into no stress, heat, and humidity stress conditions. Heat and humidity stress were applied daily for 4 h over 30 days. Blood and liver samples were collected at three decapitation intervals for enzyme (ALT, AST, ALP, GGT) and protein (TP, ALB, TB) analysis, and histological examination. CRD-fed rats exhibited higher ALT, AST, and GGT levels than RD-fed rats, with males showing greater increases, especially under heat stress. ALP levels rose in CRD-fed groups, particularly in females at the 3rd decapitation. TP and ALB levels varied by gender and diet but were not significantly different under stress, while TB showed non-significant results across interactions. Histological analysis indicated normal hepatic structures in controls, whereas CRD-fed rats under heat stress displayed cellular disorganization, inflammatory infiltration, and hepatocyte degeneration. Based on biochemical and histological changes, prolonged heat and humidity stress in CRD-fed rats exacerbates liver damage. The findings emphasize the need for dietary and environmental management strategies to support liver health in stressful conditions.