Protective effect of Carica papaya ethanolic leaf extract against lead-induced toxicity in Wistar rats

Lead poisoning remains a significant public health issue globally, with varied negative health outcomes, particularly in developing countries. Lead is a pervasive environmental pollutant that induces systemic toxicity, largely through oxidative stress resulting from its tissue bioaccumulation and disruption of normal physiological processes in a biological system. Plant-derived chelators and antioxidants may provide low-cost strategies to mitigate Pb-induced damage in both humans and animals. This study was aimed at evaluating the protective effect of Carica papaya leaf ethanolic extract against lead-induced toxicity in Wistar rats.

The protective effect of Carica papaya leaf ethanolic extract was evaluated in Wistar rats exposed to Pb - acetate, 50 mg/kg body weight. Thirty animals were assigned to six groups (n = 5) and treated for 30 days with vehicle - double distilled water, Pb - acetate alone, or Pb - acetate in combination with Carica papaya leaf ethanolic extract (50, 100, 200 and 400 mg/kg body weight). Weekly changes in body weight were monitored across all exposure groups. Lead concentrations were then quantified in blood, liver, kidney, and bone tissues. Additionally, oxidative stress and lipid peroxidation were evaluated by measuring malondialdehyde levels in liver homogenates for all treatment groups.

Pb - acetate exposure led to significant Pb accumulation in blood, liver, kidney, and bone, as well as increased hepatic malondialdehyde levels (p<0.05). Co-administration of the extract particularly at doses ≥100 mg/kg BW, showed significant corresponding reduction of Pb accumulation in blood, liver, and kidney, and liver malondialdehyde levels. This study provides preliminary indications that Carica papaya leaf ethanolic extract may provide protection against Pb-induced toxicity, likely through its flavonoid and phenolic chelation and antioxidant activities, coupled with Pb tissue deposition mitigation. These findings suggest Carica papaya leaf ethanolic extract could have potential, to be a low-cost phytotherapeutic candidate for managing Pb poisoning.