TOXICOLOGICAL EVALUATION OF LIQUEFIED PETROLEUM GAS AND IN-SITUACETYLENE ON PULMONARY AND CEREBRAL HEALTH: MODULATORY ROLE OF POLYPHENOLS

Abstract

Increasing use and exposure to industrial gases have been implicated in adverse health effects and toxicity. There are little or no identified therapies for toxicity associated with exposure to industrial gases. Hence, this study evaluated the effects of exposure to liquefied petroleum gas (LPG) and crude acetylene (ACT) on pulmonary and cerebral parameters and also assesses the modulatory role of selected polyphenols in male Wistar rats. Animals were exposed to 1000 ppm and 58000 ppm of LPG and ACT respectively, for 10 min at 12 h intervals for 30 days. Some animals exposed to the industrial gases also received orally administered 50 mg/kg polyphenols (quercetin, rutin, gallic acid or tannic acid). Animals were divided into normal control group, LPG and ACT exposed groups and groups exposed to the industrial gases as well as treated with the polyphenols. Exposure to each gas led to cerebral and pulmonary oxidative stress (significant (p<0.0001) decrease in catalase and superoxide dismutase activities, as well as significant decrease in reduced glutathione level and increased lipid peroxidation compared to the control animals), proinflammatory events in brain and lungs (increased activity of myeloperoxidase and levels of nitrite and Nf-kβ), stress hormone (increased level of corticosterone and decreased level of adrenocorticotropic hormone), neurochemical imbalance (significant (p<0.0001) increase monoamine oxidase activity and decreased activities of acetylcholinesterase, tyrosine hydroxylase glutamate dehydrogenase, Na+ K+ ATPase, and glutamine synthetase and dopamine level) and altered cerebral and pulmonary histoarchitecture in rats. All the polyphenols (quercetin, rutin, gallic acid or tannic acid) remarkably ameliorated all the biochemical and histopathological consequences of exposure to the gases. Analysis of the result showed that the activity of tannic acid was clearly superior to that of gallic acid which may be due to the viii presence of more than one galloyl residue in tannic acid while quercetin exhibited better activity compared to rutin, this may be due to the absence of hydroxyl group on rutin which has been substituted with glycoside. Conclusively, exposure to LPG and ACT can l Increasing use and exposure to industrial gases have been implicated in adverse health effects and toxicity. There are little or no identified therapies for toxicity associated with exposure to industrial gases. Hence, this study evaluated the effects of exposure to liquefied petroleum gas (LPG) and crude acetylene (ACT) on pulmonary and cerebral parameters and also assesses the modulatory role of selected polyphenols in male Wistar rats. Animals were exposed to 1000 ppm and 58000 ppm of LPG and ACT respectively, for 10 min at 12 h intervals for 30 days. Some animals exposed to the industrial gases also received orally administered 50 mg/kg polyphenols (quercetin, rutin, gallic acid or tannic acid). Animals were divided into normal control group, LPG and ACT exposed groups and groups exposed to the industrial gases as well as treated with the polyphenols. Exposure to each gas led to cerebral and pulmonary oxidative stress (significant (p<0.0001) decrease in catalase and superoxide dismutase activities, as well as significant decrease in reduced glutathione level and increased lipid peroxidation compared to the control animals), proinflammatory events in brain and lungs (increased activity of myeloperoxidase and levels of nitrite and Nf-kβ), stress hormone (increased level of corticosterone and decreased level of adrenocorticotropic hormone), neurochemical imbalance (significant (p<0.0001) increase monoamine oxidase activity and decreased activities of acetylcholinesterase, tyrosine hydroxylase glutamate dehydrogenase, Na+ K+ ATPase, and glutamine synthetase and dopamine level) and altered cerebral and pulmonary histoarchitecture in rats. All the polyphenols (quercetin, rutin, gallic acid or tannic acid) remarkably ameliorated all the biochemical and histopathological consequences of exposure to the gases. Analysis of the result showed that the activity of tannic acid was clearly superior to that of gallic acid which may be due to the viii presence of more than one galloyl residue in tannic acid while quercetin exhibited better activity compared to rutin, this may be due to the absence of hydroxyl group on rutin which has been substituted with glycoside. Conclusively, exposure to LPG and ACT can lIncreasing use and exposure to industrial gases have been implicated in adverse health effects and toxicity. There are little or no identified therapies for toxicity associated with exposure to industrial gases. Hence, this study evaluated the effects of exposure to liquefied petroleum gas (LPG) and crude acetylene (ACT) on pulmonary and cerebral parameters and also assesses the modulatory role of selected polyphenols in male Wistar rats. Animals were exposed to 1000 ppm and 58000 ppm of LPG and ACT respectively, for 10 min at 12 h intervals for 30 days. Some animals exposed to the industrial gases also received orally administered 50 mg/kg polyphenols (quercetin, rutin, gallic acid or tannic acid). Animals were divided into normal control group, LPG and ACT exposed groups and groups exposed to the industrial gases as well as treated with the polyphenols. Exposure to each gas led to cerebral and pulmonary oxidative stress (significant (p<0.0001) decrease in catalase and superoxide dismutase activities, as well as significant decrease in reduced glutathione level and increased lipid peroxidation compared to the control animals), proinflammatory events in brain and lungs (increased activity of myeloperoxidase and levels of nitrite and Nf-kβ), stress hormone (increased level of corticosterone and decreased level of adrenocorticotropic hormone), neurochemical imbalance (significant (p<0.0001) increase monoamine oxidase activity and decreased activities of acetylcholinesterase, tyrosine hydroxylase glutamate dehydrogenase, Na+ K+ ATPase, and glutamine synthetase and dopamine level) and altered cerebral and pulmonary histoarchitecture in rats. All the polyphenols (quercetin, rutin, gallic acid or tannic acid) remarkably ameliorated all the biochemical and histopathological consequences of exposure to the gases. Analysis of the result showed that the activity of tannic acid was clearly superior to that of gallic acid which may be due to the viii presence of more than one galloyl residue in tannic acid while quercetin exhibited better activity compared to rutin, this may be due to the absence of hydroxyl group on rutin which has been substituted with glycoside. Conclusively, exposure to LPG and ACT can lead to brain and lung related diseases while quercetin, rutin, gallic acid and tannic acid exhibit both neuroprotective and pulmonoprotective effects in exposed rats. Treatment with polyphenols may attenuate clinical abnormalities that arise from the exposure to liquefied petroleum gas and acetylene.