Mitigation of cadmium-induced lung injury by Nigella sativa oil

Induction of oxidative stress and inflammation are considered the primary mechanism of cadmium (Cd) toxicity. Nigella sativa (NS) seeds and their oil (NSO) have been reported to possess antioxidant and anti-inflammatory potential. This study was conducted to assess the protective effect of NSO on Cd-induced lung damage in rat. Forty adult male Wistar rats were divided equally into 4 groups. Animals in groups I, II, and III received 1 ml of isotonic saline intraperitoneally (IP), 2 mg/kg of cadmium chloride (CdCl₂) dissolved in isotonic saline IP, and 1 ml/kg of NSO by gastric gavage, respectively. Group IV rats received NSO an hour prior to CdCl₂ administration via the same routes and doses as previously described. All animals were treated for 28 days. At the end of the study, animals were sacrificed; lungs were harvested for histopathological studies using light and electron microscopy. Saline-treated and NSO-treated rats showed normal lung parenchyma. However, CdCl₂-treated rats showed massive degenerative changes in alveolar epithelial lining, disrupted interalveolar septa, and hemolytic debris in alveoli. Rats treated with both NSO and CdCl₂ (group IV) showed amelioration of most Cd-induced lung damage with minimal histopathological changes in lung architecture. This study elucidates the protective effects of NSO on Cd-induced lung injury in rats and highlights the possibility of using NSO as a protective agent in individuals at high risk of Cd-induced lung toxicity.