Protective Effects of Nelumbo nucifera Extracts on Lung Exposed to Polystyrene Nanoplastics; Histological and Phytochemical Analysis

Polystyrene nanoplastics (Ps-NPs) are emerging environmental contaminants known to cause significant respiratory damage due to oxidative stress and inflammation. This study aimed to evaluate the protective effects of Nelumbo nucifera extracts derived from leaves (T1), flowers (T2), and rhizomes (T3) on lung histology in rats exposed to 2 µL/kg body weight of Ps-NP administered orally. The study involved 25 rats divided into five groups: negative control, positive control, T1, T2, and T3, with treatment groups receiving 200 mg/kg body weight of the respective extracts. Histological parameters analyzed included inflammatory cell count, alveolar wall thickness, and alveolar lumen dilation score. The results showed significant differences among groups (p<0,05), with T3 (rhizome extract) demonstrating the most effective histological recovery. The phytochemical screening revealed that N. nucifera leaves, flowers, and rhizomes contain flavonoid, phenol, steroid, tannin, terpenenoid, and saponin (exception in rhizome), and the amount of flavonoid levels is 20.04 ± 0.03 mg QE/g (leaves), 14.46 ± 0.08 mg QE/g (flowers), and 9.23 ± 0.04 mf QE/g (rhizomes). These findings indicate that extracts of N. nucifera exert significant protective effects against Ps-NP induced pulmonary damage. This suggests their potential as natural therapeutic agents for mitigating lung injury caused by environmental nanoplastic exposure.