Protective role of Picrorhiza kurroa and apocynin against particulate matter from environmental pollutants and tobacco smoke - induced cytotoxicity in yeast model

Respiratory diseases like bronchitis and asthma often originated from prolonged exposure to smoke from tobacco and environmental pollutants. This study investigates the protective effects of Picrorhiza kurroa (PK) and its primary bioactive compound, apocynin (Apo), against oxidative stress (OS) and inflammation caused by various smoke sources. Using yeast cells as a model system, cells were exposed to Tobacco Smoke Extract (TSE; 0.5-5%) and soots from carbon particles, petrol, diesel, candle, and kerosene (0.01-10 μg/ml). To evaluate the protective potential of PK extract (PKE) and Apo, cells were pretreated with PKE (1, 2.5, and 5 μg/ml) and apocynin (0.5 and 1 βg/ml) for 1 h at 37°C before smoke exposure. Pre-treatment significantly prevented the smoke-induced cytotoxicity. In TSE-treated cells, cell viability increased from 14% to 60% (p<0.05) and in carbon particle-treated cells from 12% to 80% (p<0.05), compared to untreated controls. Apocynin also showed positive results on total protein content, enhanced anti-inflammatory and antioxidant responses, as evidenced by elevated superoxide dismutase (SOD) and catalase activities (p<0.05), and reduced levels of nitric oxide synthase, NADPH oxidase, and DNA fragmentation. These findings underscore the potential of P kurroa and apocynin in countering OS and toxicity triggered by environmental pollutants and tobacco smoke exposure. They may serve as promising candidates for therapeutic development against smoke-related respiratory conditions. However, further studies in animal models are required to validate their efficacy and translational potential.