The Efficacy of Acetium Lozenges in Intervention for Smoking Cessation: A Double-blind, Placebo-controlled Trial

Background: Smoking dependence has been traditionally ascribed to nicotine, the major psychoactive component of tobacco (nicotine addiction). Dependence on smoking, however, is a much more complex issue than just nicotine addiction, and during the past several decades, a wide variety of approaches have been used in intervention for smoking cessation, with variable success.

Tobacco smoke contains several classes of carcinogens, including acetaldehyde in high concentrations. Acetaldehyde from the tobacco smoke is easily dissolved into the saliva during smoking, and thus, toxic aldehydes could mediate the carcinogenic effect of tobacco smoke through the saliva. In 2009, IARC proclaimed acetaldehyde as Group I carcinogen, equivalent to asbestos, formaldehyde and others.

Based on observations that in rodents, acetaldehyde induces reinforcing effects acting in concert with nicotine, Talhout et al (2007) hypothesized that harmans (condensation products of acetaldehyde and biogenic amines) may be responsible for these nicotine-reinforcing effects of acetaldehyde. Harmans are formed in cigarette smoke, and blood harman levels among smokers appear to be 2-10 times higher than in non-smokers. Harmans inhibit monoamine oxidase (MAO), and like other MAO-inhibitors, these might help maintaining the behavioral sensitization to nicotine. This led these authors to speculate that acetaldehyde may increase the addictive potential of tobacco products via formation of harmans in cigarette smoke.

It has been known for several decades that L-cysteine (a nonessential amino acid) is able to eliminate the toxicity of acetaldehyde by reacting covalently with acetaldehyde to form a stable 2-methylthiazolidine-4-carboxylic acid (MTCA). This simple principle was used in the recent innovation of Biohit HealthCare's Acetium™ capsule containing 100mg L-cysteine. Oral administration of Acetium was confirmed to effectively bind acetaldehyde originated from ethanol metabolism in the stomach, raising the idea that L-cysteine could also be used to eliminate acetaldehyde dissolved into the saliva during smoking. Indeed, Salaspuro et al. (2006) confirmed that orally administered L-cysteine (5mg)-containing sucking tablet (lozenge) totally inactivated acetaldehyde in the saliva during smoking.

Given the above, it is tempting to speculate that elimination of acetaldehyde in the saliva during cigarette smoking by L-cysteine sucking tablets, might effectively block (or reduce) the formation of harmans, reduce their high blood levels, and thus alleviate the acetaldehyde-enhanced nicotine addiction (by reducing MAO-inhibition) among smokers. The present study is designed to validate the novel hypothesis that regular use of Acetium lozenges in context with smoking is an effective intervention for cessation of cigarette smoking.