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Lead (Pb) is a heavy metal, known to induce oxidative stress and produce damage to the antioxidant defence system ultimately leading to cell death. Antioxidants such as epigallocatechin 3-gallate (EGCG), a green tea polyphenol, was shown to play a protective role during Pb-exposure. In this study, human SH-SY5Y neuroblastoma cells were exposed to different concentrations (0.01–10?µM) of Pb for 48?h to determine effects on the viability of cells. It was observed that IC50 was at 5?µM and at this concentration the cells exhibited a significant increase in caspase-3 activity, an indicator of apoptosis at least by 10-fold and the decrease of 59.4% in glutathione (GSH) content. The total cellular prostaglandin-E2 (PGE2) level was found to be elevated at least 10-fold upon Pb exposure. However, the effects of Pb on cells pre-incubated with 50?µM EGCG followed by 5?µM Pb showed 40% inhibition in cell viability, 17.3% decrease in caspase-3 activity, 23% increase in GSH content, and 11.4% fall in PGE2 levels when compared with cells exposed to Pb only. Data suggest that EGCG exerted a significant protection to cell viability in preventing cell death and elevation in levels of GSH in cells exposed to Pb. However, EGCG did not elicit any significant effect on release of PGE2 indicating the nature of EGCG as an effective anti-apoptotic, antioxidant, and anti-inflammatory agent. 相似文献
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Atul C. Sheth David C. Modeste 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1532-1539
Abstract Vehicle gaseous emissions (NO, CO, CO2, and hydrocarbon [HC]) and driver’s particle exposures (particulate matter <1 μm [PM1], <2.5 μm [PM2.5], and<10 μm [PM10]) were measured using a mobile laboratory to follow a wide variety of vehicles during very heavy traffic congestion in Macao, Special Administrative Region, People’s Republic of China, an urban area having one of the highest population densities in the world. The measurements were taken with high time resolution so that fluctuations in the emissions can be seen readily during vehicle acceleration, cruising, deceleration, and idling. The tests were conducted in close proximity to the vehicles, with the inlet of a five-gas analyzer mounted on the front bumper of the mobile laboratory, and the distance between the vehicles was usually within several meters. To measure the driver’s particle exposures, the inlets of the particle analyzers were mounted at the height of the driver’s breathing position in the mobile laboratory, with the driver’s window open. A total of 178 and 113 vehicles were followed individually to determine the gaseous emission factor and the driver’s particle exposures, respectively, for motorcycle, passenger car, taxi, truck, and bus. The gaseous emission factors were used to model the roadside air quality, and good correlations between the modeled and monitored CO, NO2, and nitrogen oxide (NOx) verified the reliability of the experiments. Compared with petrol passenger cars and petrol trucks, diesel taxies and diesel trucks emitted less CO but more NOx. The impact of urban canyons is shown to cause a significant increase in the PM1 peak. The background concentrations contributed a significant amount of the driver’s particle exposures. 相似文献
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Victor Owusu John-Eudes Andivi Bakang Robert Clement Abaidoo Modeste Lawakilea Kinane 《Environment, Development and Sustainability》2012,14(1):135-150
Using household-level survey data, this study investigates farmers’ perceptions on untreated wastewater use for irrigation
of vegetable farms in urban and peri-urban Kumasi of Ghana. Empirical results from an ordered probit model show that there
is some relationship between personal characteristics of farmers such as age, education and gender, and perceptions of farmers
on health-related risks of untreated wastewater use for irrigation. Policy efforts should be geared toward updating the knowledge,
skills and attitudes of producers through frequent training and workshops so that wastewater irrigation farmers in Ghana would
better appreciate health-related risks of waster irrigation and how to adopt risk mitigating strategies. Further research
for a more in-depth analysis on those relationships in the short-term with immediate emphasis on improving adoption of safer
irrigation technologies among wastewater irrigation farmers is recommended. 相似文献
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