TOXICOLOGICAL EVALUATION OF ACETYLENE AND LIQUEFIED PETROLEUM GAS ON CARDIAC AND HEPATIC FUNCTION: AMELIORATIVE EFFECTS OF POLYPHENOLS

Abstract

The demand pattern of industrial gases is rapidly changing with increasing industrialization. Data on toxicity of these industrial gases and studies to identify potential therapy for their toxicity are lacking. In this study, the toxicological effects of two industrial gases (acetylene and liquefied petroleum gas) and the ameliorative roles of polyphenols were investigated. Adult male Wistar rats were subjected to inhalation of liquefied petroleum gas (LPG) at 1000 ppm and crude acetylene (ACT) at 58,000 ppm for 10 min at 12 h interval for 30 days in a 36 L glass inhalation chamber. Animals were divided into control group, gas - exposed group and group treated with 50 mg/kg b.w of rutin, quecetin, gallic acid and tannic acid apiece. After 30 days of exposure and treatment, animals were sacrificed, liver and heart excised and blood collected and processed for biochemical estimations. Assays for oxidative stress markers (activity of superoxide dismutase, reduced gluthatione level, lipid peroxidation level and ferric reducing antioxidant power), marker of inflammation (nitric oxide level), hepatic function biomarkers (activities of aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, bilirubin level, plasma albumin level), cardiac function biomarkers (creatine kinase-MB activity, atherogenic index, coronary risk index, lactate dehydrogenase activity) and lipid profile analysis were carried out. Histopathological assessment of the liver and heart was also performed. Results showed a significant (p<0.0001) decrease in superoxide dismutase activity, reduced gluthatione level, ferric reducing antioxidant power and increase in lipid peroxidation level in rats exposed to gases when compared to the control group. A significant (p<0.0001) increase was observed in nitric oxide level, liver function biomarkers (aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, bilirubin level) and decrease in plasma albumin level of rat exposed to gas when compared to the control group. Also, significant (p<0.0001) increase was observed in cardiac function biomarkers (creatine kinase-MB, atherogenic index, coronary risk index, lactate dehydrogenase) and imbalance in lipid profile of rat exposed to gas when compared to the control group. Altered histoarchitecture was observed in the liver and heart of rats exposed to gases compared to control. Administration of 50 mg/kg rutin, quecetin, gallic acid and tannic acid significantly reduced oxidative stress (p<0.0001), nitric oxide level (p<0.0001), hepatic function markers (p<0.0001) and cardiac function markers (p<0.0001); ameliorated the imbalance in lipid profiles (p<0.0001) and reversed the histopathological alterations in liver and heart. Analysis of the result showed that tannic acid exhibited better activity than gallic acid in ameliorating the effect of the gases which may be due to presence of one or more galloyl residue in tannic acid while quercetin showed superior activity to rutin, which 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 heart and liver related diseases and rutin, quecetin, gallic acid and tannic acid exhibit both hepatoprotective and cardioprotective effects and could show potential therapy in managing health related symptoms and clinical abnormalities that arise from the continuous exposure to acetylene and liquefied petroleum gas.