Total Peperomia pellucida Extract-Mediated Reversal of Renal Structural Damage Following Cessation of Cigarette Smoke Exposure in Wistar Rats

Cigarette smoking is a recognized risk factor for chronic kidney disease, and experimental data suggest that renal damage may persist even after smoking cessation. Peperomia pellucida, a traditional medicinal plant, has documented antioxidant and anti-inflammatory activities and is used empirically for kidney disorders, but its role in reversing smoke-related renal injury is unclear. This study aimed to evaluate whether total P. pellucida extract can reverse established renal structural damage following cessation of cigarette smoke exposure in a Wistar rat model. Eighteen healthy male Wistar rats (8–12 weeks, 180–220 g) were randomly assigned to control (CON), cigarette smoke–exposed (CSE), and cigarette smoke–exposed plus P. pellucida (CSE+PP400) groups (n=6 each). CSE and CSE+PP400 animals were exposed to cigarette smoke in a whole-body chamber (two cigarettes/rat/day, 4 h/day, 7 days/week) for 4 weeks. Smoke exposure was then discontinued for 4 weeks. During this post-cessation period, CSE+PP400 rats received total P. pellucida extract 400 mg/kg/day orally; CON and CSE received vehicle only. At study end, kidneys were processed for hematoxylin–eosin staining and scored using the EGTI (Endothelial, Glomerular, Tubular, Interstitial) system by two blinded pathologists. Data were analyzed using two-way ANOVA. CSE rats showed marked renal injury, with significantly higher EGTI scores in all compartments versus CON. Post-cessation P. pellucida treatment significantly reduced endothelial, glomerular, tubular, and interstitial scores compared with untreated CSE rats, although values remained above control levels. No treatment-related mortality was observed. In conclusion, total P. pellucida extract administered after smoking cessation partially reverses cigarette smoke–induced renal structural damage in Wistar rats, supporting its potential as an adjunctive nephroprotective option in cigarette smoke-related kidney injury.