CHEMOPREVENTIVE EFFECT OF HASKAP BERRY POLYPHENOLS AGAINST TOBACCO SPECIFIC NITROSAMINE-INDUCED DNA DAMAGE IN NORMAL LUNG EPITHELIAL CELLS IN VITRO

Abstract

The protective effect of polyphenol-rich haskap berry extracts against tobacco-specific nitrosamine ketone (NNK)-induced DNA damage was studied in vitro. Normal lung epithelial BEAS-2B cells were exposed to NNK, and to its precursor, 4-[(acetoxymethyl) nitrosamino]-1-(3-pyridyl)-1-butanone (NNKOAc), to induce DNA damage. Polyphenols present in haskap berries were extracted using ethanol and water, separately. Quercetin-3-O-glucoside (Q3G) and cyanidin-3-O-glucoside (C3G) were used as the reference compounds. BEAS-2B cells were pre-incubated with non-cytotoxic concentrations of haskap extracts, Q3G, and C3G separately, and investigated for their protective effects against NNK- and NNKOAc-induced DNA damage. Pre-incubation of BEAS-2B cells with haskap extracts, Q3G, and C3G, significantly suppressed the NNK- and NNKOAc-induced DNA strand breaks, and intracellular reactive oxygen species generation. The protective effect of haskap extracts could be related to their polyphenol content and high antioxidant capacity. An experimental animal model is proposed to further investigate the chemopreventive potential of haskap polyphenols against NNK-induced lung tumorigenesis.