Combination of green tea catechins, polysaccharides, and flavonols against urban fine dust particle-induced bronchial damage mediated by modulation of inflammation factors and airway cilia

Background Many studies have reported that environmental pollution has become a serious public health issue. Airborne fine dust particles (FDPs) have been identified as major toxins in air pollution that threaten human respiratory health. Developing strategies for defense against FDPs is one of the primary goals of air pollution research. Results While searching for an anti-FDP reagent, we found that green tea extract (GTE) and green tea fractions rich in flavonol glycosides (FLGs) and crude green tea polysaccharides (CTPs) had protective effects against FDP-stimulated cellular damage in the BEAS-2B airway epithelial cell line. The results demonstrated that GTE, FLGs, and CTPs significantly increased viability and lowered oxidative stress levels in FDP-treated cells. Major catechin and flavonol compounds increased cell survival, and (-)-epigallocatechin gallate (EGCG) and myricetin exerted synergistic effects on cell survival under FDP stimulation. Combined treatment with GTE, FLGs, and CTPs also exerted synergistic protective effects on cells, and the green tea components attenuated FDP-induced elevations in inflammatory gene expression. Moreover, the green tea components increased the proportion of ciliated cells and upregulated ciliogenesis in the airway in FDP-stimulated BEAS-2B cells. Conclusions Our findings provide insights into how natural phytochemicals protect the airway and suggest that green tea could be used to reduce FDP-induced airway damage as an individual therapeutic agent or as an ingredient in pharmaceutical and cosmeceutical products.