IN-VITRO EFFECTS OF A SMOKELESS TOBACCO EXTRACT ON THE PRODUCTION OF REACTIVE OXYGEN SPECIES BY HUMAN ORAL EPIDERMAL-CELLS AND RAT HEPATIC MITOCHONDRIA AND MICROSOMES, AND PERITONEAL-MACROPHAGES

Citation
M. Bagchi et al., IN-VITRO EFFECTS OF A SMOKELESS TOBACCO EXTRACT ON THE PRODUCTION OF REACTIVE OXYGEN SPECIES BY HUMAN ORAL EPIDERMAL-CELLS AND RAT HEPATIC MITOCHONDRIA AND MICROSOMES, AND PERITONEAL-MACROPHAGES, Archives of environmental contamination and toxicology, 30(3), 1996, pp. 418-422
Citations number
26
Categorie Soggetti
Toxicology,"Environmental Sciences
ISSN journal
00904341
Volume
30
Issue
3
Year of publication
1996
Pages
418 - 422
Database
ISI
SICI code
0090-4341(1996)30:3<418:IEOAST>2.0.ZU;2-D
Abstract
The possible role of reaction oxygen species in the toxicity of smokel ess tobacco was explored. In order to determine possible sources of re active oxygen species in response to smokeless tobacco, rat peritoneal macrophages (3 x 10(6)/ml) and hepatic mitochondria and microsomes (1 mg protein/ml) from untreated female Sprague-Dawley rats were incubat ed with an aqueous smokeless tobacco extract (STE) (200 mu g/ml). STE resulted in rapid increases in chemiluminescence with maximum increase s occurring at approximately 6 min for the macrophages and 8 min for m itochondria and microsomes. Maximum increases in chemiluminescence of 1.4-, 3.2-, and 3.1-fold relative to control values occurred for macro phages, mitochondria, and microsomes, respectively. Hepatic mitochondr ia and microsomes (1 mg protein/ml) from female Sprague-Dawley rats we re incubated at 37 degrees C for 60 min in the presence of 0-500 mu g/ ml STE. Potential tissue damage was measured as lipid peroxidation, an d dose-dependent increases of 1.1-2.4-fold occurred in mitochondria an d microsomes. Pre-incubation with various oxygen free radical scavenge rs including superoxide dismutase (SOD) (100 mu g/ml), catalase (100 m u g/ml), SOD + catalase (100 mu g/ml each), mannitol (1.25 mmol/ml), a nd allopurinol (100 mu g/ml) inhibited STE (200 mu g/ml) induced lipid peroxidation by 15% to 70%. Previous studies in our laboratories stro ngly suggest that STE induces the production of oxygen free radicals w hich cause tissue-damaging effects. We therefore examined the cytotoxi city of STE by incubating cultured human oral epidermal carcinoma (KB) cells with STE, and assessing the release of the enzyme lactate dehyd rogenase (LDH) into the media as an indicator of cellular membrane dam age. The amount of LDH released by STE was both concentration- and tim e-dependent. The results demonstrate that oral cells, peritoneal macro phages, and hepatic mitochondria and microsomes produce reactive oxyge n species following in vitro incubation with an aqueous extract of smo keless tobacco. Tissue damage in response to STE may occur as the resu lt of reactive oxygen species production.