Histological and antioxidant evaluation of an aqueous extract of hibiscus on the heart of cadmium-induced Wistar rats

This study investigated the protective effects of Hibiscus sabdariffa aqueous extract against cadmium-induced cardiotoxicity in Wistar rats. Twenty-four rats (150–200 g) were divided into four groups (n = 6): Group A (control), Group B (cadmium only), Group C (cadmium + hibiscus), and Group D (hibiscus only). Groups B and C received 14 mg/kg of cadmium via intraperitoneal injection, while Groups A and D were not injected with cadmium. After 72 hours, Groups C and D were administered 100 mg/kg of hibiscus extract orally for four weeks, while Groups A and B received saline as a control. Group B exhibited a significant reduction in body and relative heart weights (p < 0.05) compared to the control group, while Group C mitigated these effects, showing no significant difference (p > 0.05). Histological analysis revealed disrupted cardiomyocytes in Group B, whereas Groups A, C, and D maintained a normal cardiac structure. Periodic acid-Schiff (PAS) staining displayed abnormal reactivity in cadmium-exposed rats, while the hibiscus-treated groups exhibited normal PAS patterns. Additionally, depletion of reduced glutathione (GSH) and superoxide dismutase (SOD) was observed in the cadmium-only group, whereas the cadmium + hibiscus group showed levels comparable to the control group. In conclusion, the extract of Hibiscus sabdariffa attenuated cadmium-induced cardiotoxicity, preserving heart weight, structure, and biochemical integrity. These findings suggest its potential as a protective agent against heavy metal toxicity.