The Antioxidant Activity of Tobacco Smoke

Abstract

Cigarette smoke has been shown to contain free radicals in both the vapour and particulate phases. The present investigation was undertaken to find out whether these radicals could initiate or promote the formation of radical peroxides which might in turn lead to lipid peroxidation. To investigate this, a system involving the coupled oxidation of b-carotene and linoleic acid was utilized. In this coupled reaction, b-carotene is destroyed through oxidation by free peroxy radicals. The system can therefore be used as a convenient detector of auto-oxidative mechanisms in which peroxide radicals participate, as well as provide an assay for antioxidants, since in their presence oxidative destruction of b-carotene is blocked. Our results show that smoke did not contribute to the oxidative destruction of b-carotene but rather behaved as an antioxidant. Both smoke vapour and particulate matter were found to be highly antioxidant. A number of pure vapour phase components were tested and the bulk of antioxidant activity was found to be due to HCN. Smoke condensates from different tobacco types were compared and differentiated according to their relative efficiencies of antioxidant activities. For comparison, units of antioxidant activity were expressed as rate of change of optical density with time. The highest antioxidant activities were obtained with air-, flue-cured (cut) and perique tobaccos. Pipe tobacco had the least activity while cigar and flue-cured (granulated), stem and sheet tobaccos had intermediate values. Tests done on smoke fractions derived from the fractionation of total condensate revealed that antioxidant activity resided largely in the neutral and water-insoluble acid fractions with virtually no activity in the basic fractions. The mode of antioxidant action of tobacco smoke is discussed in terms of free-radical mechanisms.

Assessment of Nicotine Degradation in Cigarette Smoke under Different Storage Conditions (Light and Duration)

“…The duration required for cigarette smoke generation and collection typically ranges from 10 min to 1 h, depending on the type of cigarette, and is based on 30 cigarettes. The desiccation process for the moisture-laden Cambridge filter postcollection spans approximately 6-24 h [26,27]. Furthermore, preliminary treatment of the nicotine sample (i.e., solvent extraction, solvent removal, concentration, etc.)…”

The Reducing Property of Tobacco Smoke: 1. Modified FIue-Cured Tobacco and Other Smoking Products

“…On account of our interest in the chemical reactivity of tobacco smoke as an indicator of its biological activity, we have examined [I] the redox property of smoke (1, 2. ), [II] photosensitized oxidation of aqueous extracts of smoke (3), [Ill] inhibition by smoke of radicalinitiated polymerisation of vinyl acetate (4,5), [IV] inhibition by smoke of the terminal respiratory enzyme, cytochrome oxidase {6)~ and [V] the antioxidant activity of smoke utilising the coupled oxidation of ~-carotene and linoleic aCid (7). The redox property of tobacco smoke has been the subject •of researdt in several laboratories (8, g, :to, :r.:t), and our interest in this property stemmed from an observation made during enzyme inhibition studies in which it was found that cigarette smoke itself could bring about reduction of cytochrome c (:r.).…”

The Reducing Property of Tobacco Smoke: 2. The Influence of Smoking Vehicle, with Particular Reference to the Pipe

“…To monitor these changes we have developed relatively simple chemical and biochemical tests which are indicators of the chemical reactivity of tobacco smoke (1)(2)(3)(4)(5). Thus, we have found that monitoring the dichlorophenolindophenol +-reducing property of tobacco smoke is useful in studying such modifications of chemical composition of smoke and have used this property extensively (6}. As part of these studies, we have already shown that air-cured tobaccos, such as those used in the manufacture of cigars and pipe tobaccos, when smoked in the form of cigars or in stainless steel pipes, gave condensates that were much lower in DCIP-reducing activity than condensates obtained by smoking Canadian fluecured cigarettes (1).…”