Functional components in Portulaca oleracea explored to scavenge nitrite and block nitrosamines in tobacco using affinity ultrafiltration with Nitrate Reductase

Tobacco-Specific Nitrosamines (TSNAs) are a class of common carcinogens that are widely present in cigarette products and smoke, which seriously affect the health of smokers and vastly restrict the safety of tobacco products. In our present research, the effects of Portulaca oleracea on nitrite scavenging and nitrosamine formation were evaluated through in vitro and tobacco field experiments. Further, four compounds Ferulic Acid O-Glucoside, Ellagic Acid, 13:4 + 4O Fatty Acyl Hexoside, and Feruloylmalic Acid were tentatively screened as potential Nitrate Reductase (NR) ligands by affinity ultrafiltration HPLC-MS. Molecular docking was then carried out to further verify the inhibitory activities of these potential ligands and elucidate their interaction mechanisms with NR. The results showed that P. oleracea exhibited substantial abilities in scavenging nitrite and blocking the formation of nitrosamines, which was mainly attributed to its abundant reductive components, especially its phenolics. In conclusion, the current study provided new insight into new strategies to reduce tobacco toxicity based on natural extracts, which is of great value to the tobacco industry.