• Environmental Analysis Health and Toxicology
• /
• 제29권
• /
• pp.9.1-9.3
• /
• 2014

Diesel exhaust particles (DEP) contain elemental carbon, organic compounds including Polyaromatic hydrocarbons (PAHs), metals, and other trace compounds. Diesel exhaust is complex mixture of thousands of chemicals. Over forty air contaminants are recognized as toxicants, such as carcinogens. Most diesel exhaust particles have aerodynamic diameters falling within a range of 0.1 to $0.25{\mu}m$. DEP was classified as a definite human carcinogen (group 1) by the International Agency for Research on Cancer at 2012 based on recently sufficient epidemiological evidence for lung cancer. Significant decreases in DEP and other diesel exhaust constituents will not be evident immediately, and outworn diesel car having longer mileage still threatens health of people in spite of recent remarkable development in diesel engine technology. Policy change in South Korea, such as introduction of diesel taxi, may raise health risk of air pollution in metropolitan area with these limitations of diesel engine. To protect people against DEP in South Korea, progressive strategies are needed, including disallowance of diesel taxi, more strict regulation of diesel engine emission, obligatory diesel particulate filter attachment in outworn diesel car, and close monitoring about health effects of DEP.

• Environmental Analysis Health and Toxicology
• /
• 제19권1호
• /
• pp.59-64
• /
• 2004

Metallothionein gene expression of diesel exhaust particles (DEP) was investigated in human lung epithelial cell line. DEP was collected from diesel motor bus and soluble fraction in water was obtained. Cells, grown to near confluence, were exposed to 5-50 ppm DEP for 6 hours. Regarding the metallothionein gene expressions, MT-1 and MT-2 were induced in the DEP-treated cell by using RT-PCR and real-time PCR. However, MT-3 which is known to be brain specific, and another isoform MT-4 were not expressed in cadmium-treated groups as well as control group. Heavy metal of DEP was also analyzed and Zn was found as the major component of heavy metals in DEP used in this study.

• Asian Journal of Atmospheric Environment
• /
• 제1권1호
• /
• pp.28-35
• /
• 2007

Accumulated epidemiological and animal studies have suggested that prolonged exposure to ambient particulate matter (PM) is associated with an increased risk of cardiovascular disease and pulmonary dysfunction. While diesel exhaust particles (DEP) contain large variety of compounds, polycyclic aromatic hydrocarbons (PAHs) are a dominant component contaminated in DEP. This article reviews effects of two PAH quinones, 9,10-phenanthraquinone (9,10-PQ) and l,2-naphthoquinone (l,2-NQ), on vascular and respiratory systems.

• Environmental Analysis Health and Toxicology
• /
• 제19권1호
• /
• pp.109-117
• /
• 2004

The purpose of the present study was to examine the effect of diesel exhaust particles on human aortic vascular smooth muscle cells (VSMCs). DNA synthesis, cell viability and morphology of VSMCs after treatment of diesel exhaust particles (DEP) and fine particulate matter (PM$_{2.5}$) were assayed. PM$_{2.5}$ inhibited the DNA synthesis of VSMCs in a concentration -dependent manner, whereat DEP did not affect VSMCs up to 50$\mu\textrm{g}$/mL. These results were confirmed by morphological examination of VSMCs. PM$_{2.5}$ showed a dose-dependent cytotoxicity of VSMCs by MTT assay. Fraction 4 (organic acids) and fraction 8 (moderately polar compounds) showed the most potent inhibition of DNA synthesis of VSMCs, and fraction 7 (slightly polar compounds), fraction 9 (higher polar compounds), and fraction 6 (aromatic compounds) were next order. These results were confirmed by morphological examination of VSMCs. These results suggest that PM$_{2.5}$ inhibits the DNA synthesis of VSMCs through the cytotoxicity.oxicity.

• Journal of Korean Society for Atmospheric Environment
• /
• 제18권E2호
• /
• pp.121-128
• /
• 2002

This study was carried out to investigate if nitric oxide synthase (NOS) inhibitors modulate airway inflammation induced by diesel exhaust particles (DEP). N$\^$G/-nitro-L-arginine methyl ester (L-NAME), a potent constitutive NOS (cNOS) inhibitor, and aminoguanidine (AG), a selective inducible NOS (iNOS) inhibitor, were administered to mice in their drinking water for 7 weeks. Airway inflammation was elicited by the repeated intratracheal administration of DEP. The results showed that macrophages, inflammatory eosinophils and neutrophils in bronchoalveolar lavage (BAL) fluids by intratracheal DEP instillation were significantly suppressed in the mice treated with two NOS inhibitors toghther with DEP. The suppression of these cells was more effective in AG treated groups than in L -NAME treated groups. NOS inhibitor treatment also reduced interleukin -5 (IL-5 in the BAL fluids and lung homogenates. Additionally, it was found that eosinophil peroxidase (EPO) activity in the BAL fluids was also decreased by NOS inhibitor treatment. These results suggest that nitric oxide (NO) is produced in airway inflammation by repeated DEP instillation, and that iNOS inhibition as well as cNOS inhibition can play a modulating role in this airway inflammation by DEP.

• 한국약용작물학회지
• /
• 제17권2호
• /
• pp.90-96
• /
• 2009

The objective of this study was to investigate the effect of crude ginseng total saponins (CGS) against airway inflammation (AI) and airway hyperresponsiveness (AH) induced by diesel exhaust particles (DEP) in mice. AI and AH were induced by the intratracheal instillation with 0.1 $mg/m{\ell}$ of DEP suspension once a week for 10 weeks combined with ovalbumin (OVA) sensitization. Mice were also treated orally with 75 $mg/m{\ell}$ of CGS, 5 days a week for 10 weeks. Oral CGS treatment decreased in the level of serum immunoglobulin (IgE) and histamine increased by DEP and OVA, and declined respiratory resistance. It also dropped an enhanced infiltration of eosinophils in the bronchoalveolar lavage fluid (BALF) of mice, and an increased T helper type 2 cell derived cytokine levels such as of interleukin (IL)-4, IL-13 and IL-5 in the BALF. However, it did not influence T helper type 1 cytokine such as interferon-gamma in the BALF. These results indicate that CGS may alleviate allergen-related AI and AH in mice and may play an important role in the modulation of asthmatic inflammation.

• Environmental Analysis Health and Toxicology
• /
• 제21권2호
• /
• pp.127-138
• /
• 2006

In urban areas, diesel exhaust particles (DEP) are probably a major component of particulate matters, especially in Korea where drive many diesel vehicles. The aim of this study was to investigate genotoxic effects of DEP using single ceil gel electrophoresis. In order to evaluate the mechanisms of DEP genotoxicity, the rat microsome mediated and DNA repair enzyme treated comet assays together with conventional comet assay were performed. Total diesel particles (DEPT) was collected without site fractionation from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEPT revealed DNA damage itself in NIH/3T3 cells. The level of DNA breaks plus oxidative DNA lesions and microsome mediated DNA damage was assessed by modified single cell gel eletrophoresis. DEPT was able to induce oxidative DNA damage as well as microsome mediated DNA damage. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor. reduced DNA damage in the presence of S-9 mixture. $DEP_T$ is the sources of oxidative stress, but antioxidants can significantly reduce oxidative DNA dmage. And $DEP_T$ may contain indirect mutagens which can be inhibited by CYP1A1 inhibitors. The ethanol extracts of the mixed vegetables (BV) or the mixed fruits (BF) were evaluated for their in vitro antigenotoxic effects. BV and BF showed potent Inhibitory effects against DEPT induced DNA damage with oxidative DNA lesions and in the prescence of S-9 mixture. These results indicate that BV and BF could prevent cellular DNA damage by inhibiting oxidative stress and suppressing cytochrome P4501A1 in cell culture.

• 생명과학회지
• /
• 제16권2호
• /
• pp.192-198
• /
• 2006

본 연구에서는 DEP의 노출이 새로운 호흡기계 질환 유발의 가능성과 호흡기계의 염증성인자로 잘 알려진 lipopolysaccharide (LPS)의 역할에 어떠한 영향을 미치는 지를 확인하고자 폐에서 염증성 반응 시 생성이 증가하는 것으로 알려진 Nitric Oxide (NO)의 형성과 NO의 생성에 관련된 효소인 inducible nitric oxide synthase (iNOS) 및 NO에 의하여 형성되는 것으로 알려진 nitrotyrosilated-protein을 폐포 대식세포를 통해 분석하였다. 폐포대식세포에 DEP를 농도 별로 단독 처리하였을 때와 동일한 농도에서 배양시간을 달리하였을 때는 NO가 생성되지 않았으나 DEP와 함께 LPS를 처리하였을 때는 LPS를 단독으로 처리했을 때보다. 유의성이 있게 증가함을 확인할 수 있었다. 또한 NO의 생성에 관련된 효소인 iNOS 및 NO에 의하여 형성되는 것으로 알려진 nitrotyrosilated-protein 발현의 정도를 면역화학염색과 Western analysis로 확인할 수 있었다. DEP는 폐포대식세포에서 직접적으로 NO생성에 영향을 미치지 않았으며, NO를 생성하는 iNOS나 nitrotyrosilated-protein의 발현에도 영향을 주지 않았으나 세균성 염증인자의 한 종류인 LPS가 NO를 형성하는 데에는 통계학적인 상승효과가 있었다. 결론적으로 본 연구에서는 염증성질환의 환자에서 DEP의 흡입은 간접적으로 NO를 형성하는데 영향을 미쳐 질환을 악화시킬 것으로 판단한다.

• Toxicological Research
• /
• 제22권1호
• /
• pp.9-13
• /
• 2006

Diesel exhausted particles (DEP), a kind of fine particles with aerodynamic diameters less than $2.5{\mu}m$ (PM2.5), is of great concern to human health because they remain in atmosphere for long periods, invade an indoor air environment, and can be breathed most deeply into lung and reached the alveoli because of their small size ($0.1{\sim}0.4\;{\mu}m$ in diameter). Epidemiological and experimental studies suggested that DEP may play an active role in the increased respiratory mortality and morbidity. In addition to their physical characteristics, the chemical components including polyaromatic hydrocarbon (PAH) are regarded as a carcinogen causing pulmonary tumors. PLD plays an important role in cell proliferation with various physiological phenomena and affects other enzymes by activating signal transduction pathway. We investigated the cytotoxic mechanism of DEP on RAW 264.7 cells focusing on the role in activation of PLD. Our results suggested DEP induced PLD activity through a specific signaling pathway involving phospholipase $A_2$, PLC, PKC and $Ca^{2+}$ mobilization.

• 한국약용작물학회지
• /
• 제20권2호
• /
• pp.129-135
• /
• 2012

The feature of asthma are airway inflammation (AI), reversible airway obstruction, and an increased sensitivity to bronchoconstricting agents, elevated airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. This study was performed to investigate if oral administration of $Scutellaria$ $baicalensis$ Georgi water extracts (SBG) have the antiasthmatic potential for the treatment of asthma. Asthmatic HI and AHR were induced by systemic sensitization to ovalbumin (OVA) with intratracheal instillation with 0.1 mg/mL of diesel exhaust particles (DEP) suspension once a week for 10 weeks in BALB/c mice. SBG was orally administered with the concentraion of 200 mg/kg 5 days a week for 10 weeks. Long-term SBG treatment suppressed the eosinophil infiltration into airways from blood, the asthmatic AI and AHR by attenuating the production of cytokine IL-4, IL-5 and IL-13, histamine and OVA-specific IgE. Our data suggest that SBG has inhibitory effects on AI and AHR in a mouse model of asthma, may act as a potential Th2 cytokine antagonist, and may have a therapeutic effect on allergic asthma.