Parquetina nigrescens leaf extract mitigates aflatoxin B1-induced stress, immune and growth disruptions in broilers.

Aflatoxin B1 (AFB1) contamination in poultry feed impairs immunity, induces oxidative stress, and reduces growth and carcass quality. This study assessed the protective role of Parquetina nigrescens leaf extract (PNLE) against AFB1-induced immuno-inflammatory, oxidative, and metabolic disturbances in broiler chickens. Two hundred day-old Cobb 500 broiler chicks were assigned to four groups: NOC (control), AFCP0 (AFB1 only, 0.5 mg/kg feed), AFCP1 (AFB1 + 1 g PNLE/L water), and AFCP2 (AFB1 + 2 g PNLE/L). AFB1 exposure (AFCP0) significantly reduced relative growth rate (RGR), dressing percentage, and catalase activity, while increasing liver and spleen weights, lipid/protein peroxidation, and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Immunoglobulins (IgG, IgM, IgA), triiodothyronine (T3), and leptin levels were suppressed, with elevations in Hsp70 and adiponectin. PNLE, particularly at 2 g/L, significantly improved antioxidant status, immune response, inflammatory balance, and performance metrics. Correlation analysis revealed strong positive associations between RGR and IgM (r = +0.84) and IgA (r = +0.65), and negative correlations with IL-1β (r = -0.72) and IL-6 (r = -0.61). Dressing percentage correlated positively with IgG, IgM, IgA, and IFN-γ, but negatively with TNF-α, IL-6, and IL-1β (p < 0.01). These findings underscore the relevance of immune competence and inflammation control in broiler productivity. In conclusion, PNLE mitigates AFB1-induced toxicity and supports health and performance. A supplementation level of 2 g/L in drinking water is recommended as a practical strategy to reduce aflatoxicosis risk in poultry production.