Ameliorative Effect of Plectranthus amboinicus Ethanolic Extract and Its Chitosan Nanoformulation Against Lambda-Cyhalothrin-Induced Toxicity in Male Mice.

Plectranthus amboinicus leaves are rich in bioactive phytochemicals with documented antioxidant and anti-inflammatory activities. The present study was conducted to discuss the protective potentials of free ethanolic extracts of P. amboinicus leaves (PAEE) and its chitosan (CS)-based nanoformulation against lambda-cyhalothrin (LCT)-induced oxidative stress, inflammation, and DNA damage in male mice. Animals were equally distributed into five experimental groups as follows: control, LCT-treated (1 mg/kg b.wt), PAEE (200 mg/kg b.wt) + LCT, CS-loaded PAEE nanoformulation (200 mg/kg body weight) + LCT, and CS nanoparticle control. All treatments were administered orally for 28 days. At the end of the experiment, blood samples were collected and serum samples were analyzed for oxidative stress markers (SOD, CAT, GPx), pro-inflammatory cytokines (TNF-α, IL-6, IL-33, IL-17), the autoimmune antinuclear antibody marker (ANA) and hematological parameters. Moreover, DNA damage was assessed by comet assay. Spleen tissues were harvested for histopathological examination. Results of the present study revealed that LCT exposure resulted in significant oxidative stress, evidenced by reduced antioxidant enzyme activities (SOD, CAT, GPx), elevated pro-inflammatory cytokines (TNF-α, IL-6, IL-33, IL-17) and ANA, altered hematological parameters, increased DNA damage, and histopathological alterations in spleen tissue. Pretreatment with PAEE significantly attenuated these effects, while the nanoformulation demonstrated superior protective efficacy compared to the free extract. The enhanced efficacy of CS/PAEE may be attributed to improved stability, bioavailability, and sustained release of PAEE bioactive compounds resulting in prolonged antioxidant and anti-inflammatory effects. These findings demonstrate that P. amboinicus-based nanoformulations may represent a promising, eco-friendly approach for mitigating pesticide-induced toxicological effects associated with environmental exposure.