Pollen induced stress in human lung carcinoma A549 cells

Abstract

The pollen grains are important aeroallergens causing allergic disorders like rhinitis and asthma. Chronic asthma often leads to carcinogenesis in lungs. The various mediators of inflammation like reactive oxygen and nitrogen species (ROS/RNS), cytokines and chemokines form a link between oxidative stress, inflammation and cancer. This study involves induction of oxidative stress by pollen extracts derived from two varieties of prickly poppy in small lung carcinoma A549 cells. To rule out the pathway responsible for pro-inflammatory and oxidative stress enhancer we used the inhibitors of the classical ROS sources such as NADPH oxidase, Xanthine oxidase, mitochondria and general ROS scavenger (NAC). In addition, we also used NF-kB blocking peptide to see whether blocking NF-kB pathway can attenuate the pollen induced stress. It was observed that there was no significant difference in inflammation and/or oxidative stress in the purified pollen antigen versus the crude pollen extract. Lipid peroxidation was significantly increased in pollen extract treated cells whereas no change in MPO activity was observed. The NF-kB levels were significantly reduced in pollen extract treated cells whereas the levels were normalised when treated with NOX inhibitor (DPI) and mitochondria uncoupler (FCCP) suggesting the role of mitochondrial and phagocytic ROS in activating NF-kB. This study signifies the role of pollen as aero-allergens which are very common in Malwa region of Punjab as a key player in enhancing the allergy related complications and chronic lung diseases.