Apigenin alleviates DFZ-induced cardiac, renal, and intestinal injury in carp by modulating oxidative stress and inflammatory responses.

The triazole fungicide difenoconazole (DFZ) is widely used in agriculture and frequently detected in aquatic environments, posing potential risks to non-target organisms despite its regulatory classification as low toxicity. This study investigated the protective effects of apigenin (API), a natural flavonoid, against DFZ-induced multi-organ toxicity in carp (Cyprinus carpio). Fish were exposed to DFZ (0.3906 mg/kg body weight) alone or in combination with dietary API (50 mg/kg feed) for 30 days. Chronic DFZ exposure induced severe histopathological lesions in the heart, kidney, and intestine, increased serum cardiac injury markers (CK and CK-MB), disrupted redox homeostasis-evidenced by elevated ROS and MDA and reduced CAT, GSH, and T-AOC-and upregulated pro-inflammatory cytokine mRNA (tnf-α, il-1β, il-6, inos). At the protein/transcriptional level, DFZ increased iNOS while decreasing Nrf2/HO-1, and suppressed antioxidant genes (cat, sod, gpx). Apigenin supplementation significantly attenuated tissue damage, restored antioxidant capacity, suppressed inflammatory responses while promoting il-10, normalized iNOS and Nrf2/HO-1, up-regulated cat/sod/gpx, and alleviated DFZ-induced impairment of growth performance. These results demonstrate that apigenin alleviates DFZ-induced cardiorenal and intestinal injury by modulating oxidative stress and inflammation. Our findings highlight the potential of apigenin as a dietary protective agent against environmental fungicide toxicity in aquatic species.