Abstract

Nicotine is the main psychoactive component of tobacco and is considered to be the main substance responsible for the development of tobacco addiction. The main enzyme responsible for nicotine metabolism, CYP2A6, catalyzes the conversion of nicotine to cotinine and the subsequent metabolism of cotinine to trans-3′-hydroxycotinine. CYP2A6 activity is known to be modulated by various compounds, such as quercetin. This repeated-measures study examined the effects of short-term quercetin supplementation on urinary nicotine metabolism biomarkers in adult users of conventional and alternative nicotine products. Seventy-two participants completed a two-week study protocol involving first-morning urine collection at four time points: baseline, immediately after three days of quercetin supplementation (500 mg/day), seven days after supplementation, and ten days after supplementation. Urinary nicotine, cotinine, and trans-3′-hydroxycotinine concentrations were measured, and the nicotine metabolite ratio was calculated as trans-3′-hydroxycotinine/cotinine. Repeated-measures analysis of variance was used to evaluate biomarker changes over time according to sex, nicotine product type, and self-reported nicotine consumption intensity. Quercetin supplementation did not consistently alter nicotine metabolism biomarkers, while a descriptive increase in median urinary nicotine concentration after supplementation was observed in participants reporting lower daily nicotine consumption compared with other groups. These findings suggest that further studies are warranted to better clarify the effects of quercetin on nicotine metabolism across different levels of nicotine exposure.

IPC Classification

Keywords