Prevention of ambient particulate matte rpm induced toxicity by reverting mirna expression

Abstract

Anthropogenic interventions pollute the ambient air extensively with countless pollutants of distinct sources including Particulate Matter (PM). Among the PM, fine PM also known as PM2.5 with particle size less than 2.5 microns are observed to be more toxic since they can infiltrate and perpetuate the respiratory organs. Chronic PM2.5 exposure causes oxidative stress and leads to many diseases in human like respiratory and cardiovascular disorders, lung cancer etc. The physicochemical characteristics like size, source and composition including presence of metals, PAHs are decisive for the toxic responses elicited by PM2.5 inside human body. The PM2.5 observed to cause toxicity through excessive ROS production and creation of oxidative stress environment in the cells that lead to many detrimental responses. In this study PM2.5were collected from rural, urban, industrial and traffic regions in and around Coimbatore City, Tamilnadu, India. In the physical and chemical characteristic analysis, all the PM2.5 particles were in the sub micron range; Industrial and traffic PM2.5 comparably contained more metals and PAHs. The PM2.5 samples also showed higher levels of oxidative potential, induced more intracellular Reactive Oxygen Species (ROS) and caused more levels of cell death and DNA damage in human respiratory cells. Among the four PM2.5 samples, traffic PM2.5 was more toxic to the cells. PM2.5 exposure modulated the expression of the 11 miRNAs (miR146a, miR21, miR222, miR24, miR421, miR210, miR101, miR34a, miR93, miR28 and miR200a) and 8 genes (Nrf2, NFand#954;B, MycN, CDKN1A, CDKN1B, Rad52C, BIM and BAG1) that are related to oxidative stress, DNA damage and inflammation. Many dietary polyphenolic compounds hold strong antioxidant and free radical scavenging activity and this potential could be exploited to mitigate the PM2.5 induced oxidative stress thereby reducing the related adverse effects. An efficient phytochemical was selected for the study by comparing the potentialof 7 phytochemicals (Curcumin, Morin, Quercetin,