Salivary biomarkers for chewing betel (areca) nut

Abstract

ObjectiveBetel nut (Areca catechu L.) chewing is carcinogenic to humans and strongly associated with oral cancer, especially in Guam. We identified chemicals specific for the 3 most commonly consumed betel nut preparations in Guam [mature nut (BN), mature nut+ betel leaf (BL), and betel quid (BQ) consisting of the young nut+betel leaf, lime and tobacco]; and identified salivary compounds extracted from betel chewers chewing these preparations to establish a salivary profile specific for BN, BL and BQ chewers.Methods15 betel chewers in Guam were randomized evenly to BN, BL or BQ. Betel material was extracted with PBS buffer. Saliva was precipitated with acetonitrile, diluted with formic acid and analyzed by LCMS. Saliva levels before and after chewing were compared by t‐tests; ANOVA compared differences between groups. p<0.05 indicated significance.ResultsLevels of arecoline and guvacine were highest in the young and mature BNs, respectively; chavibetol was found only in leaf extracts. Significant increases from before vs. after saliva levels were observed for guvacine (BN, BQ), arecoline (BN, BL, BQ), guvacoline (BN), arecaidine (BN, BL, BQ), nicotine (BQ), and chavibetol (BL, BQ). Pharmacokinetic parameters were also determined.ConclusionOur results suggest the presence of 1) areca alkaloids (arecoline, guvacine, and arecaidine), chavibetol, and tobacco‐specific alkaloids (nicotine, cotinine, hydroxycotinine, NNK, NNN and NAT) can identify BQ chewers; 2) areca alkaloids and chavibetol can identify BL chewers and 3) salivary areca alkaloids can identify BN chewers.This research was supported by the NCI awards U54CA143727 and U54 CA143728