The protective effect of rosemary, sage, green-coffee, and oregano extract on mitigating the respiratory distress in wistar albino rats exposed to corn oil fumes inhalation

Corn oil fumes (COF) are significant indoor air pollutants linked to respiratory dysfunction. This study evaluates COF-induced toxicity in bronchial epithelial cells and explores mechanisms to restore pulmonary health using rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), green coffee (Coffea arabica), and oregano (Origanum vulgare) extracts. Doses were selected based on pretrial on antioxidant activity and supported with previous studies, where between the studied concentrations, rosemary and sage extract (300 mg/kg), green coffee (200 mg/kg), and oregano (20 mg/kg) scavenged 91 %, 88 %, 90, and 92 % of DPPH radicals, respectively. Thirty Wistar rats were divided into six groups: untreated control (G1), COF-exposed (G2), and COF-exposed groups treated with rosemary (G3: 300 mg/kg), sage (G4: 300 mg/kg), oregano (G5: 20 mg/kg), or green coffee (G6: 200 mg/kg) for 30 days. Assessments included lung ultrastructure (TEM), apoptosis markers (caspase-3, Bax via flow cytometry), histopathology, and hepatic/kidney enzyme analysis. COF exposure significantly elevated reactive oxygen species (ROS) biomarkers, including MDA, serum hydrogen peroxide (H2O2) and thiobarbituric acid-reactive substances (TBARS), compared to the control group (G1). All extracts reduced H2O2 levels, with green coffee (G6) showing the most pronounced decrease (42 % vs. G2). TBARS levels normalized to control values in rosemary- (G3), sage- (G4), and green coffee-treated (G6) groups, indicating mitigation of lipid peroxidation. COF-induced suppression of hepatic antioxidant enzymes (SOD, CAT, GPx) was reversed by all extracts. Rosemary (G3) and sage (G4) at 300 mg/kg restored SOD activity to 98 % and 94 % of control levels, respectively, while oregano (G5) at 20 mg/kg elevated GPx by 87 %1. Green coffee (G6) uniquely enhanced total antioxidant capacity (TAC) to 112 % of control levels. Flow cytometry revealed COF-induced apoptosis (increased caspase-3 and Bax) in lung and liver tissues. All extracts reduced caspase-3 activity, with oregano (G5) showing the strongest inhibition (63 % vs. G2). Rosemary (G3) and sage (G4) preferentially suppressed Bax expression, aligning with their structural repair efficacy 1. Transmission electron microscopic (TEM) images of the lung tissue's ultra-structure showed a positive effect of the rosemary, sage, green-Coffee, and oregano extracts administration; where alveoli, alveolar sacs, and bronchioles were less inflammation and restored tissue integrity with rosemary, sage, green coffee, and oregano treatments, in an attempt to adapt the situation and return the lung to normal, with a normalization of apoptosis markers in the flow-cytometry assay for caspase-3, and Bax protein. All extracts counteracted COF-induced oxidative stress, with dose-dependent efficacy linked to their bioactive profiles beside improving lung ultrastructure, apoptosis markers, and flow cytometry. This supports using plant extracts as natural adjuvants against indoor air pollution toxicity.