Green Remedies: Pharmacological potential of phytonutrients for combatting air pollution-related respiratory diseases

Millions of people die from air pollution each year, posing a worldwide threat to health. Hazardous gases such as nitrogen dioxide (NO2) and particulate matter (PM) with aerodynamic dimensions of 10 µm (PM10), 2.5 µm (PM2.5) and 0.1 µm (PM0.1) are examples of air pollutants which can travel deep into the airways and alveolar regions of the lungs. Inhalation of PM and other gaseous pollutants induces oxidative stress and damage in the airway epithelium, resulting in activation of pro-inflammatory responses and attraction of immune cells. This review discusses the prevalence and consequences of air pollutants on respiratory illnesses, emphasizing the necessity for effective treatments. It also spotlights promising natural products and their derived compounds, which have demonstrated favourable pharmacological properties in managing oxidative stress and inflammation, crucial contributors to respiratory diseases, based on a thorough analysis of existing literature. Among these, marine algae have emerged as a particularly rich source of bioactive compounds including sulfated polysaccharides, phlorotannins, carotenoids, and sterols that exhibit potent antioxidant, anti-inflammatory, and immunomodulatory effects. These algae-derived phytonutrients interact with key molecular targets and signalling pathways involved in airway inflammation, oxidative stress, immune responses, and airway remodelling.Understanding the mechanism of PM induced lung pathology provides insights into the potential efficacy of natural products, especially marine algae, in managing respiratory conditions. The review also addresses challenges and limitations associated with the use of phytochemical compounds derived from natural products, including standardization, safety, and clinical translation. Through a deep understanding of their phytochemical makeup and underlying mechanisms, researchers and healthcare practitioners can investigate innovative therapeutic approaches and develop targeted interventions to improve respiratory health.