Activated charcoal filter effectively reduces p-benzosemiquinone from the mainstream cigarette smoke and prevents emphysema

Abstract

In this paper, we have made a comparative evaluation of the cytotoxicity and pathophysiological effects of mainstream smoke from cellulose acetate (CA)-filtered cigarettes with that of charcoal-filtered cigarettes developed in our laboratory. Previously, we had demonstrated that the mainstream smoke from an Indian CA-filtered commercial cigarette contains p-benzosemiquinone (p-BSQ), a major, highly toxic, long-lived water-soluble radical. Here, we have examined 16 brands of different CA-filtered cigarettes including Kentucky research cigarettes, and observed that mainstream smoke from all the cigarettes contains substantial amounts of p-BSQ (100-200 μg/cigarette). We also show that when the CA filter is replaced by a charcoal filter, the amount of p-BSQ in the mainstream smoke is reduced by 73-80%, which is accompanied by a reduction of carbonyl formation in bovine serum albumin to the extent of 70- 90%. The charcoal filter also prevented cytotoxicity in A549 cells as evidenced by MTT assay, apoptosis as evidenced by FACS analysis, TUNEL assay, overexpression of Bax, activation of p53 and caspase 3, as well as emphysematous lung damage in a guinea pig model as seen by histology and morphometric analysis. The results indicate that the charcoal filter developed in our laboratory may protect smokers from cigarette smoke-induced cytotoxity, protein modification, apoptosis and emphysema.

Glutathione peroxidase inhibitory assay for electrophilic pollutants in diesel exhaust and tobacco smoke

“…Specifically, the arylating p -benzoquinone (BQ) is known for its strong electrophilic character and rapid Michaels adduct formation with cellular nucleophiles [44]. BQ is a major oxidative product of aromatic hydrocarbons from air pollution and also found in the tar-phase from CS extracts [45,46]. Figure 4 shows the direct inhibition of GPx-1 activity by two a,β -unsaturated carbonyls and BQ in the low millimolar range confirming the feasibility of the 96-well plate assay system to screen for the inhibitory capacity of electrophilic air pollutant components on antioxidant GPx-1 enzyme activities.…”

NAD(P)H: Quinone Oxidoreductase 1 Deficiency Conjoint with Marginal Vitamin C Deficiency Causes Cigarette Smoke Induced Myelodysplastic Syndromes

“…CS contains substantial amount of p-BSQ, [15], [17] a major long-lived radical. We had shown before that p-BSQ is oxidized to p-BQ by transition metal containing proteins [14].…”

“…CS does not contain p-BQ. p-BQ is produced from p-BSQ, which is present in CS in substantial amounts depending on the brand of the cigarette (100–200 µg/cigarette) [14], [15], [17]. p-BSQ is converted to p-BQ by disproportionation: 2p-BQ→p-BQ+Hydroquinone [16] as well as oxidation by transition metal (M) containing proteins: p-BSQ+M ox −Protein→p-BQ+M red −Protein [14].…”

“…Apoptosis was measured by using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL) [14] as well as by flow cytometry analysis (FACS) using Annexin V-propidium iodide (PI), as described previously [17].…”

“…p-BQ is not present in CS, but it is apparently produced in vivo from p-benzosemiquinone (p-BSQ) of CS [13]–[15] by disproportionation [16] and oxidation by transition metal containing proteins [14]. p-BSQ is present in substantial amounts (100–200 µg/cigarette) in smoke from all commercial cigarettes examined as well as Kentucky research cigarettes [14], [17]. p-BQ is detoxified and thereby inactivated by NAD(P)H: quinone oxidoreductase 1 (NQO1), an enzyme ubiquitously present in all tissues, including the bone marrow [6], [18]–[20].…”