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Zhao Z, Li H, Wei Y, Fang G, Jiang Q, Pang Y, Huang W, Tang M, Jing Y, Feng X, Luo XS, Berkemeier T. Airborne environmentally persistent free radicals (EPFRs) in PM 2.5 from combustion sources: Abundance, cytotoxicity and potential exposure risks. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172202. [PMID: 38599399 DOI: 10.1016/j.scitotenv.2024.172202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/12/2024]
Abstract
As an emerging atmospheric pollutant, airborne environmentally persistent free radicals (EPFRs) are formed during many combustion processes and pose various adverse health effects. In health-oriented air pollution control, it is vital to evaluate the health effects of atmospheric fine particulate matter (PM2.5) from different emission sources. In this study, various types of combustion-derived PM2.5 were collected on filters in a partial-flow dilution tunnel sampling system from three typical emission sources: coal combustion, biomass burning, and automobile exhaust. Substantial concentrations of EPFRs were determined in PM2.5 samples and associated with significant potential exposure risks. Results from in vitro cytotoxicity and oxidative potential assays suggest that EPFRs may cause substantial generation of reactive oxygen species (ROS) upon inhalation exposure to PM2.5 from anthropogenic combustion sources, especially from automobile exhaust. This study provides important evidence for the source- and concentration-dependent health effects of EPFRs in PM2.5 and motivates further assessments to advance public health-oriented PM2.5 emission control.
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Affiliation(s)
- Zhen Zhao
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China; Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Hanhan Li
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Yaqian Wei
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Guodong Fang
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Qian Jiang
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yuting Pang
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China; Zhejiang Institute of Meteorological Sciences, Hangzhou 310008, China
| | - Weijie Huang
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China; Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Mingwei Tang
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Yuanshu Jing
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xinyuan Feng
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xiao-San Luo
- International Center for Ecology, Meteorology, and Environment, School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
| | - Thomas Berkemeier
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
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Yi JF, Lin ZZ, Li X, Zhou YQ, Guo Y. A short review on environmental distribution and toxicity of the environmentally persistent free radicals. CHEMOSPHERE 2023; 340:139922. [PMID: 37611755 DOI: 10.1016/j.chemosphere.2023.139922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/09/2023] [Accepted: 08/21/2023] [Indexed: 08/25/2023]
Abstract
Environmentally Persistent Free Radicals (EPFRs) are usually generated by the electron transfer of a certain radical precursor on the surface of a carrier. They are characterized with high activity, wide migration range, and relatively long half-life period. In this review, we summarized the literature on EPFRs published since 2010, including their environmental occurrence and potential cytotoxicity and biotoxicity. The EPFRs in the atmosphere are the most abundant in the environment, mainly generated from the combustion of raw materials or biochar, and the C-center types (quinones, semiquinones radicals, etc.) may exist for a relatively long time. These EPFRs can transform into other substances (such as reactive oxygen species, ROS) under the influence of environmental factors, and partly enter soil and water by wet and dry deposition of particulate matter, which may promote the generation of EPFRs in those media. The wide distribution of EPFRs in the environment may lead to their exposure to biota including humans, resulting in cytotoxicity and biotoxicity. The EPFRs can influence the normal redox process of the biota, and generate a large number of free radicals like ROS. Exposure to EPFRs may change the expression of gene and activity of metabolic enzymes, and damage the cells, as well as some organs such as the lung, trachea, and heart. However, due to the difficulty in sample extraction, identification, and quantification of the specific EPFR individuals, the toxicity and exposure evaluation of biota are still limited which merits study in the future.
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Affiliation(s)
- Jing-Feng Yi
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China
| | - Ze-Zhao Lin
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China
| | - Xing Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China
| | - Yue-Qiao Zhou
- Department of Department of Medical Oncology, Qionghai People's Hospital, Qionghai, 571499, China.
| | - Ying Guo
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
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Wang Y, Huang J, Li S, Xu W, Wang H, Xu W, Li X. A mechanistic and kinetic investigation on the oxidative thermal decomposition of decabromodiphenyl ether. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:121991. [PMID: 37328125 DOI: 10.1016/j.envpol.2023.121991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/30/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
The thermal processes of materials containing decabromodiphenyl ether (BDE-209) normally result in the exposure of BDE-209 to high-temperature environments, generating a series of hazardous compounds. However, the evolution mechanisms of BDE-209 during oxidative thermal processes remain unclear. Thus, this paper presents a detailed investigation on the oxidative thermal decomposition mechanism of BDE-209 by utilizing density functional theory methods at the M06/cc-pVDZ theoretical level. The results show that the barrierless fission of the ether linkage dominates the initial degradation of BDE-209 at all temperatures, with branching ratio over 80%. The decomposition of BDE-209 in oxidative thermal processes is mainly along BDE-209 → pentabromophenyl and pentabromophenoxy radicals → pentabromocyclopentadienyl radicals → brominated aliphatic products. Additionally, the study results on the formation mechanisms of several hazardous pollutants indicate that the ortho-phenyl-type radicals created by ortho-C-Br bond fission (branching ratio reached 15.1% at 1600 K) can easily be converted into octabrominated dibenzo-p-dioxin and furan, which require overcoming the energy barriers of 99.0 and 48.2 kJ/mol, respectively. The O/ortho-C coupling of two pentabromophenoxy radicals also acts as a non-negligible pathway for the formation of octabrominated dibenzo-p-dioxin. The synthesis of octabromonaphthalene involves the self-condensation of pentabromocyclopentadienyl radicals, followed by an intricately intramolecular evolution. Results presented in this study can enhance our understanding of the transformation mechanism of BDE-209 in thermal processes, and offer an insight into controlling the emissions of hazardous pollutants.
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Affiliation(s)
- Yao Wang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Jinbao Huang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China.
| | - Sijia Li
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Weifeng Xu
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Hong Wang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Weiwei Xu
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Xinsheng Li
- School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China
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Xu Y, Lu X, Su G, Chen X, Meng J, Li Q, Wang C, Shi B. Scientific and regulatory challenges of environmentally persistent free radicals: From formation theory to risk prevention strategies. JOURNAL OF HAZARDOUS MATERIALS 2023; 456:131674. [PMID: 37236112 DOI: 10.1016/j.jhazmat.2023.131674] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 05/28/2023]
Abstract
EPFRs (Environmentally Persistent Free Radicals) are a class of pollutants that have been identified as potential environmental contaminants due to their persistence and ability to generate reactive oxygen species (ROS) that can cause oxidative stress in living organisms. However, no study has comprehensively summarized the production conditions, influencing factors and toxic mechanisms of EPFRs, impeding exposure toxicity assessments and risk prevention strategies. To bridge the gap between theoretical research and practical application, a thorough literature review to summarize the formation, environmental effects, and biotoxicity of EPFRs are conducted. A total of 470 relevant papers were screened in Web of Science Core collection databases. The transfer of electrons between interfaces and the cleavage of covalent bonds of persistent organic pollutants is crucial to the generation of EPFRs, which is induced by external sources of energy, including thermal energy, light energy, transition metal ions, and others. In the thermal system, the stable covalent bond of organic matter can be destroyed by heat energy at low temperature to form EPFRs, while the formed EPFRs can be destroyed at high temperature. Light can also accelerate the production of free radicals and promote the degradation of organic matter. The persistence and stability of EPFRs are synergistically influenced by individual environmental factors such as environmental humidity, oxygen content, organic matter content, and environmental pH. Studying the formation mechanism of EPFRs and their biotoxicity is essential for fully understanding the hazards posed by these emerging environmental contaminants.
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Affiliation(s)
- Yulin Xu
- School of Municipal and Environmental Engineering, Shenyang Jianzhu University, Shenyang 110168, China; Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaofei Lu
- School of Municipal and Environmental Engineering, Shenyang Jianzhu University, Shenyang 110168, China
| | - Guijin Su
- Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing Chen
- School of Municipal and Environmental Engineering, Shenyang Jianzhu University, Shenyang 110168, China; Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jing Meng
- Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qianqian Li
- Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenxi Wang
- School of Municipal and Environmental Engineering, Shenyang Jianzhu University, Shenyang 110168, China; Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Bin Shi
- Key Laboratory of Environmental Nanotechnology and Health Effects Research, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Ahmad M, Chen J, Yu Q, Tariq Khan M, Weqas Ali S, Nawab A, Phairuang W, Panyametheekul S. Characteristics and Risk Assessment of Environmentally Persistent Free Radicals (EPFRs) of PM 2.5 in Lahore, Pakistan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2384. [PMID: 36767750 PMCID: PMC9915328 DOI: 10.3390/ijerph20032384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Environmentally persistent free radicals (EPFRs) are an emerging pollutant and source of oxidative stress. Samples of PM2.5 were collected at the urban sites of Lahore in both winter and summertime of 2019. The chemical composition of PM2.5, EPRF concentration, OH radical generation, and risk assessment of EPFRs in PM2.5 were evaluated. The average concentration of PM2.5 in wintertime and summertime in Lahore is 15 and 4.6 times higher than the national environmental quality standards (NEQS) of Pakistan and WHO. The dominant components of PM2.5 are carbonaceous species. The concentration of EPFRs and reactive oxygen species (ROS), such as OH radicals, is higher in the winter than in the summertime. The secondary inorganic ions do not contribute to the generation of OH radicals, although the contribution of SO42+, NO3-, and NH4+ to the mass concentration of PM2.5 is greater in summertime. The atmospheric EPFRs are used to evaluate the exposure risk. The EPFRs in PM2.5 and cigarette smoke have shown similar toxicity to humans. In winter and summer, the residents of Lahore inhaled the amount of EPFRs equivalent to 4.0 and 0.6 cigarettes per person per day, respectively. Compared to Joaquin County, USA, the residents of Lahore are 1.8 to 14.5 times more exposed to EPFRs in summer and wintertime. The correlation analysis of atmospheric EPFRs (spin/m3) and carbonaceous species of PM2.5 indicates that coal combustion, biomass burning, and vehicle emissions are the possible sources of EPFRs in the winter and summertime. In both winter and summertime, metallic and carbonaceous species correlated well with OH radical generation, suggesting that vehicular emissions, coal combustion, and industrial emissions contributed to the OH radical generation. The study's findings provide valuable information and data for evaluating the potential health effects of EPFRs in South Asia and implementing effective air pollution control strategies.
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Affiliation(s)
- Mushtaq Ahmad
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
- Department of Environmental Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jing Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Qing Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Muhammad Tariq Khan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
- Department of Science and Environmental Studies, The Education University of Hong Kong, Taipo, New Territories, Hong Kong, China
| | - Syed Weqas Ali
- Department of Environmental Sciences, Abdul Wali Khan University, Mardan 23200, Pakistan
| | - Asim Nawab
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Worradorn Phairuang
- Faculty of Geosciences and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Ishikawa, Japan
| | - Sirima Panyametheekul
- Department of Environmental Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
- Thailand Network Centre on Air Quality Management: TAQM, Chulalongkorn University, Bangkok 10330, Thailand
- Research Unit: HAUS IAQ, Chulalongkorn University, Bangkok 10330, Thailand
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Li H, Li H, Zuo N, Liu Y, Lang D, Steinberg C, Pan B, Xing B. Direct toxicity of environmentally persistent free radicals to nematode Caenorhabditis elegans after excluding the concomitant chemicals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156226. [PMID: 35643143 DOI: 10.1016/j.scitotenv.2022.156226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/18/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
Environmentally persistent free radicals (EPFRs) have attracted extensive attention due to their potential toxicity. However, EPFRs-containing particles always coexist with their parent organic contaminants and intermediate degradation products (IM), which may have hindered the toxicity assessment of EPFRs. In this study, the toxicity of EFFRs was specifically verified after comparing the systems without EPFRs, such as the immediate mixture of catechol (CT) and particles, solutions of CT only, IM extracted from the particles, as well as particles after EPFRs quenching. Caenorhabditis elegans (C. elegans) were used as model organisms. Our results showed that EPFRs-containing particles (Si-Al-CT) exhibited significant toxicity to C. elegans, but not for the parent chemical CT and IM on the particles. Higher levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the Si-Al-CT system were attributed to the mediated generation of ·O2- and ·OH via EPFRs. EPFRs could increase gene expressions related not only to oxidative stress and biotransformation in C. elegans, but also to indications of disturbances in energy homeostasis, survival, proliferation, cell and embryonic development. Overall, these results confirmed the direct toxicity of EPFRs and highlighted the key role of EPFRs which may be neglected in assessing the environmental risks of organic contaminants.
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Affiliation(s)
- Huijie Li
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China
| | - Hao Li
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China.
| | - Ning Zuo
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China
| | - Yi Liu
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China
| | - Di Lang
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China
| | - Christian Steinberg
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China; Faculty of Life Sciences, Laboratory of Freshwater & Stress Ecology, Humboldt-Universität zu Berlin, Arboretum, Späthstr. 80/81, 12437 Berlin, Germany
| | - Bo Pan
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States
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Characteristics of Environmentally Persistent Free Radicals in PM2.5 and the Influence of Air Pollutants in Shihezi, Northwestern China. TOXICS 2022; 10:toxics10070341. [PMID: 35878247 PMCID: PMC9321939 DOI: 10.3390/toxics10070341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/15/2022] [Accepted: 06/18/2022] [Indexed: 11/17/2022]
Abstract
Environmentally persistent free radicals (EPFRs) are a kind of hazardous substance that exist stably in the atmosphere for a long time. EPFRs combined with fine particulate matter (PM2.5) can enter the human respiratory tract through respiration, causing oxidative stress and DNA damage, and they are also closely related to lung cancer. In this study, the inhalation risk for EPFRs in PM2.5 and factors influencing this risk were assessed using the equivalent number of cigarette tar EPFRs. The daily inhalation exposure for EPFRs in PM2.5 was estimated to be equivalent to 0.66–8.40 cigarette tar EPFRs per day. The concentration level and species characteristics were investigated using electron paramagnetic resonance spectroscopy. The concentration of EPFRs in the study ranged from 1.353–4.653 × 1013 spins/g, and the types of EPFRs were mainly oxygen- or carbon-centered semiquinone-type radicals. Our study showed that there is a strong correlation between the concentrations of EPFRs and conventional pollutants, except for sulfur dioxide. The major factors influencing EPFR concentration in the atmosphere were temperature and wind speed; the higher the temperature and wind speed, the lower the concentration of EPFRs. The findings of this study provide an important basis for further research on the formation mechanism and health effects of EPFRs.
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Zhao J, Shi L, Duan W, Li H, Yi P, Tao W, Shen G, Tao S, Pan B, Xing B. Emission factors of environmentally persistent free radicals in PM 2.5 from rural residential solid fuels combusted in a traditional stove. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145151. [PMID: 33940719 DOI: 10.1016/j.scitotenv.2021.145151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Emission factors (EFs) are crucial for establishing emission inventory and subsequent health risk assessment of pollutants. However, the EFs of environmentally persistent free radicals (EPFRs) in PM2.5 have not been well investigated. We measured EPFRs in PM2.5 from burning of different solid fuels in a traditional stove widely used in rural China and calculated the EFs of EPFRs (EFEPFRs). The characteristics of EPFRs varied greatly with PM2.5 depending on the feedstock, and the EFEPFRs of crop residue, firewood and bitumite was 2.13 ± 1.04, 1.40 ± 0.76 and 1.08 ± 0.39 (1020 spins·kg-1), respectively. The estimated results of EPFRs emission associated with PM2.5 showed that the crop residue was the main contributor to the top four provinces with high EPFRs emissions in China in 2010. A wide range (0.03-4.89 cig·person-1·day-1) of equivalent cigarette number converted by inhaling EPFRs in PM2.5 was observed. Provinces with higher equivalent cigarette number were mainly agricultural provinces, because the rural residents tend to use readily available fuels. Additionally, EPFRs in collected PM2.5 during 2 - month photoaging were more stable in particles with higher organic carbon contents. Our findings provided a new insight into the risk assessment of PM2.5 from different sources by taking EPFRs into consideration.
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Affiliation(s)
- Jinfeng Zhao
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Lin Shi
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Wenyan Duan
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Hao Li
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Peng Yi
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Wenmei Tao
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China
| | - Guofeng Shen
- College of Urban and Environmental Sciences, Peking University, 100871 Beijing, China
| | - Shu Tao
- College of Urban and Environmental Sciences, Peking University, 100871 Beijing, China
| | - Bo Pan
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China.
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States
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Liu X, Yang L, Liu G, Zheng M. Formation of Environmentally Persistent Free Radicals during Thermochemical Processes and their Correlations with Unintentional Persistent Organic Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6529-6541. [PMID: 33956443 DOI: 10.1021/acs.est.0c08762] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Attention is increasingly being paid to environmentally persistent free radicals (EPFRs), which are organic pollutants with the activities of free radicals and stabilities of organic pollutants. EPFRs readily form during thermal processes through the decomposition of organic precursors such as phenols, halogenated phenols, and quinone-type molecules, which are also important precursors of toxic unintentionally produced persistent organic pollutants (UPOPs). We have found that EPFRs are important intermediates for UPOP formation during thermal-related processes. However, interest in EPFRs is currently mostly focused on the toxicities and formation mechanisms of EPFRs themselves. Little information is available on the important roles EPFRs play in toxic UPOP formation during thermal processes. Here, we review the mechanisms involved in EPFR formation and transformation into UPOPs during thermal processes. The review is focused on typical EPFRs, including cyclopentadiene, phenoxy, and semiquinone radicals. The reaction temperature, metal species present, and oxygen concentration strongly affect EPFR and UPOP formation during thermal-related processes. Gaps in current knowledge and future directions for research into EPFR and UPOP formation, transformation, and control are presented. Understanding the relationships between EPFRs and UPOPs will allow synergistic control strategies to be developed for thermal-related industrial sources of EPFRs and UPOPs.
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Affiliation(s)
- Xiaoyun Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
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Zhao Z, Chen Q, Li H, Lang D, Wu M, Zhou D, Pan B, Xing B. The exposed hematite surface and the generation of environmentally persistent free radicals during catechol degradation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:109-116. [PMID: 33300898 DOI: 10.1039/d0em00416b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Environmentally persistent free radicals (EPFRs) have drawn increasing attention. It is reported that EPFR formation is dependent on the presence of transition metals; however the size of the metal particles is ignored. In this study, we hypothesized that transition metals in smaller particle sizes could more efficiently promote the generation of EPFRs and thus have higher risks. Nanosized hematite (nanoHMT) and microsized hematite (microHMT) were studied and compared. We monitored the degradation of catechol and the generation of EPFRs under both dark and ultraviolet light conditions. Catechol degradation was inhibited in the presence of hematite in the dark, with more significant inhibition by nanoHMT. However, under ultraviolet light, catechol degradation was promoted by hematite, with more significant promotion by nanoHMT. The yield of free radicals in the nanoHMT system was always higher than that in the microHMT system. More dimers were detected in the nanoHMT system, which may have played an important role in stabilizing free radicals. More trivalent Fe was converted to divalent Fe in the nanoHMT system than in the microHMT system. The relatively more active sites for the catechol interaction promoted EPFR generation. These results highlighted that size-dependent reactions should be well considered when predicting the environmental behavior and risks of organic contaminants.
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Affiliation(s)
- Ziyu Zhao
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Quan Chen
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Hao Li
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Di Lang
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Meixuan Wu
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Dandan Zhou
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Bo Pan
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan 650500, China.
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
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Odinga ES, Waigi MG, Gudda FO, Wang J, Yang B, Hu X, Li S, Gao Y. Occurrence, formation, environmental fate and risks of environmentally persistent free radicals in biochars. ENVIRONMENT INTERNATIONAL 2020; 134:105172. [PMID: 31739134 DOI: 10.1016/j.envint.2019.105172] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/04/2019] [Accepted: 09/08/2019] [Indexed: 05/22/2023]
Abstract
Biochars are used globally in agricultural crop production and environmental remediation. However, environmentally persistent free radicals (EPFRs), which are stable emerging pollutants, are generated as a characteristic feature during biomass pyrolysis. EPFRs can induce the formation of reactive oxygen species, which poses huge agro-environmental and human health risks. Their half-lives and persistence in both biochar residues and in the atmosphere may lead to potentially adverse risks in the environment. This review highlights the comprehensive research into these bioreactive radicals, as well as the bottlenecks of biochar production leading up to the formation and persistence of EPFRs. Additionally, a way forward has been proposed, based on two main recommendations. A global joint initiative to create an all-encompassing regulations policy document that will improve both the technological and the quality control aspects of biochars to reduce EPFR generation at the production level. Furthermore, environmental impact and risk assessment studies should be conducted in the extensive applications of biochars in order to protect the environmental and human health. The highlighted key research directions proposed herein will shape the production, research, and adoption aspects of biochars, which will mitigate the considerable concerns raised on EPFRs.
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Affiliation(s)
- Emmanuel Stephen Odinga
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Michael Gatheru Waigi
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Fredrick Owino Gudda
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jian Wang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Bing Yang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojie Hu
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Shunyao Li
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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Atkins HM, Bharadwaj MS, O’Brien Cox A, Furdui CM, Appt SE, Caudell DL. Endometrium and endometriosis tissue mitochondrial energy metabolism in a nonhuman primate model. Reprod Biol Endocrinol 2019; 17:70. [PMID: 31445519 PMCID: PMC6708555 DOI: 10.1186/s12958-019-0513-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/16/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Endometriosis is the growth of uterine lining (endometrium) outside of the uterus. In other chronic inflammatory diseases, mitochondrial dysfunction is suspected of playing a role in disease pathogenesis. However, little is known about endometriosis mitochondrial function or its effects on tissue metabolism. The objectives of this study were to analyze mitochondrial function in nonhuman primate (NHP) endometrium and endometriosis tissue and to identify the metabolic features of these tissues that may contribute to disease. METHODS Mitochondrial function in endometriosis tissue and endometrium was measured using mitochondrial respirometry analysis to determine if changes in oxidative phosphorylation exist in endometrium and endometriosis tissue compared to control endometrium from clinically healthy NHPs. Targeted metabolomics and multidimensional statistical analysis were applied to quantify key metabolites in energy and amino acid biosynthesis pathways. RESULTS Mitochondrial respirometry assays showed endometrium from NHPs with endometriosis had reduced complex II-mediated oxygen consumption rates (OCR) across all energy states (basal, p = 0.01; state 3, p = 0.02; state 3u, p = 0.04; state 4o, p = 0.008) and endometriosis tissue had reduced state 3, complex I-mediated OCR (p = 0.02) and respiratory control rates (p = 0.01) compared to normal endometrium. Targeted metabolomics performed on tissue revealed carnitine (p = 0.001), creatine phosphate (p = 0.01), NADH (p = 0.0001), FAD (p = 0.001), tryptophan (p = 0.0009), and malic acid (p = 0.005) were decreased in endometriosis tissue compared to normal endometrium samples. FAD (p = 0.004), tryptophan (p = 0.0004) and malic acid (p = 0.03) were significantly decreased in endometrium from NHPs with endometriosis compared to normal endometrium. Significant metabolites identified in endometriosis and endometrium samples from animals with endometriosis were part of amino acid biosynthesis or energy metabolism pathways. CONCLUSIONS Here, endometrial mitochondrial energy production and metabolism were decreased in endometrium and endometriosis tissue. Decreased mitochondrial energy production may be due to oxidative stress-induced damage to mitochondrial DNA or membranes, a shift in cell metabolism, or decreased energy substrate; however, the exact cause remains unknown. Additional research is needed to determine the implications of reduced mitochondrial energy production and metabolism on endometriosis and endometrium.
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Affiliation(s)
- Hannah M. Atkins
- 0000 0001 2185 3318grid.241167.7Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, One Medical Center Blvd, Winston-Salem, NC 27157 USA
| | - Manish S. Bharadwaj
- 0000 0001 2107 5309grid.422638.9Agilent Technologies, Cell Analysis Division, Lexington, MA USA
| | - Anderson O’Brien Cox
- 0000 0001 2185 3318grid.241167.7Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Cristina M. Furdui
- 0000 0001 2185 3318grid.241167.7Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Susan E. Appt
- 0000 0001 2185 3318grid.241167.7Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, One Medical Center Blvd, Winston-Salem, NC 27157 USA
| | - David L. Caudell
- 0000 0001 2185 3318grid.241167.7Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, One Medical Center Blvd, Winston-Salem, NC 27157 USA
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Cong Y, Chi Q, Teng X, Li S. The Protection of Selenium Against Cadmium-Induced Mitochondrial Damage via the Cytochrome P450 in the Livers of Chicken. Biol Trace Elem Res 2019; 190:484-492. [PMID: 30392018 DOI: 10.1007/s12011-018-1557-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/23/2018] [Indexed: 12/14/2022]
Abstract
Cadmium (Cd) is a heavy metal in natural environment and has extreme toxicity. Selenium (Se) has protective effect against heavy metal-induced injury or oxidative stress. Cytochrome P450 (CYP450) enzymes are a family of hemoproteins primarily responsible for detoxification functions. In order to investigate whether CYP450 is related to the damage of livers caused by Cd exposure, we chose forty-eight 28-day-old healthy Hailan cocks for four groups: control group, Se group, Cd group, and Se + Cd group. After 90-day treatment, euthanized for experiment. Based on an established subchronic Cd poisoning model in chicken, this experiment was designed to detect mitochondrial structure, malondialdehyde (MDA), glutathione (GSH), DNA and protein crosslink (DPC) and protein carbonyl (PCO) content, the CYP450 and b5 contents, the aminopyrine-N-demethylase (AND), erythromycin N-demethylase (ERND), aniline 4-hydroxylase (AH) and NADPH-cytochrome C reducatase (CR) activities, and mRNA expression level in the livers. The present results indicated that the MDA content, PCO content, and DPC index in Cd group were higher than those observed in other three groups. Most of the mitochondrial structure is incomplete in Cd group. The contents of CYP450 and b5 were decreased in Cd group. The activities of AND, ERND, AH, and CR got reduced after Cd exposure, as observed in CYP450 gene expression. Our results showed that CYP450 system was involved in the entire process of injury and protection. This research provides a comprehensive evaluation of the oxidative stress effects of Cd related to CYP450 in chicken.
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Affiliation(s)
- Yimei Cong
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Qianru Chi
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xiaohua Teng
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
| | - Shu Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
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Pan B, Li H, Lang D, Xing B. Environmentally persistent free radicals: Occurrence, formation mechanisms and implications. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:320-331. [PMID: 30802746 DOI: 10.1016/j.envpol.2019.02.032] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 05/23/2023]
Abstract
Environmentally persistent free radicals (EPFRs) are defined as organic free radicals stabilized on or inside particles. They are persistent because of the protection by the particles and show significant toxicity to organisms. Increasing research interests have been attracted to study the potential environmental implications of EPFRs. Because of their different physical forms from conventional contaminants, it is not applicable to use the commonly used technique and strategy to predict and assess the behavior and risks of EPFRs. Current studies on EPFRs are scattered and not systematic enough to draw clear conclusions. Therefore, this review is organized to critically discuss the current research progress on EPFRs, highlighting their occurrence and transport, generation mechanisms, as well as their environmental implications (including both toxicity and reactivity). EPFR formation and stabilization as affected by the precursors and environmental factors are useful breakthrough to understand their formation mechanisms. To better understand the major differences between EPFRs and common contaminants, we identified the unique processes and/or mechanisms related to EPFRs. The knowledge gaps will be also addressed to highlight the future research while summarizing the research progress. Quantitative analysis of the interactions between organic contaminants and EPFRs will greatly improve the predictive accuracy of the multimedia environmental fate models. In addition, the health risks will be better evaluated when considering the toxicity contributed by EFPRs.
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Affiliation(s)
- Bo Pan
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, Yunnan, China; Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, Yunnan, China
| | - Hao Li
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, Yunnan, China; Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, Yunnan, China; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, United States
| | - Di Lang
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, Yunnan, China; Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, Yunnan, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, United States.
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Elucidation of pharmacokinetics of novel DNA ligase I inhibitor, S012-1332 in rats: Integration of in vitro and in vivo findings. J Pharm Biomed Anal 2019; 162:205-214. [DOI: 10.1016/j.jpba.2018.09.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 09/10/2018] [Accepted: 09/15/2018] [Indexed: 11/21/2022]
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Reed JR, Backes WL. The functional effects of physical interactions involving cytochromes P450: putative mechanisms of action and the extent of these effects in biological membranes. Drug Metab Rev 2017; 48:453-69. [PMID: 27500687 DOI: 10.1080/03602532.2016.1221961] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cytochromes P450 represent a family of enzymes, which are responsible for the oxidative metabolism of a wide variety of xenobiotics. Although the mammalian P450s require interactions with their redox partners in order to function, more recently, P450 system proteins have been shown to exist as multi-protein complexes that include the formation of P450•P450 complexes. Evidence has shown that the metabolism of some substrates by a given P450 can be influenced by the specific interaction of the enzyme with other forms of P450. Detailed kinetic analysis of these reactions in vitro has shown that the P450-P450 interactions can alter metabolism by changing the ability of a P450 to bind to its cognate redox partner, NADPH-cytochrome P450 reductase; by altering substrate binding to the affected P450; and/or by changing the rate of a catalytic step of the reaction cycle. This review summarizes the known examples of P450-P450 interactions that have been shown in vitro to influence metabolism and categorizes them according to the mechanism(s) causing the effects. P450-P450 interactions have the potential to cause major changes in the metabolism and elimination of drugs in vivo. This review summarizes the evidence that the P450-P450 interactions influence metabolism in biological membranes and discusses the studies, which will provide further insight into the extent of these effects in the future.
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Affiliation(s)
- James R Reed
- a Department of Pharmacology and Experimental Therapeutics, and The Stanley S. Scott Cancer Center , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - Wayne L Backes
- a Department of Pharmacology and Experimental Therapeutics, and The Stanley S. Scott Cancer Center , Louisiana State University Health Sciences Center , New Orleans , LA , USA
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Feinberg T, Alkoby-Meshulam L, Herbig J, Cancilla JC, Torrecilla JS, Gai Mor N, Bar J, Ilouze M, Haick H, Peled N. Cancerous glucose metabolism in lung cancer-evidence from exhaled breath analysis. J Breath Res 2016; 10:026012. [PMID: 27272440 DOI: 10.1088/1752-7155/10/2/026012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cancer cells prefer hyperglycolysis versus oxidative phosphorylation, even in the presence of oxygen. This phenomenon is used through the FDG-PET scans, and may affect the exhaled volatile signature. This study investigates the volatile signature in lung cancer (LC) before and after an oral glucose tolerance test (OGTT) to determine if tumor cells' hyperglycolysis would affect the volatile signature. Blood glucose levels and exhaled breath samples were analyzed before the OGTT, and 90 min after, in both LC patients and controls. The volatile signature was measured by proton transfer reaction mass spectrometry (PTR-MS). Twenty-two LC patients (age 66.6 ± 12.7) with adenocarcinoma (n = 14), squamous (n = 6), small cell carcinoma (n = 2), and twenty-one controls (age 54.4 ± 13.7; 10 non-smokers and 11 smokers) were included. All LC patients showed a hyperglycolytic state in their FDG-PET scans. Both baseline and post OGTT volatile signatures discriminate between the groups. The OGTT has a minimal effect in LC (a decrease in m/z 54 by 39%, p v = 0.0499); whereas in the control group, five masses (m/z 64, 87,88, 142 and 161) changed by -13%, -49%, -40% and -29% and 46% respectively. To conclude, OGTT has a minimal effect on the VOC signature in LC patients, where a hyperglycolytic state already exists. In contrast, in the control group the OGTT has a profound effect in which induced hyperglycolysis significantly changed the VOC pattern. We hypothesized that a ceiling effect in cancerous patients is responsible for this discrepancy.
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Affiliation(s)
- Tali Feinberg
- Thoracic Cancer Research and Detection Center, Sheba Medical Center, Tel-Aviv University, Ramat-Gan, Israel. These authors made an equal contribution to this work
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Goswami SK, Gangadarappa SK, Vishwanath M, Razdan R, Jamwal R, Bhadri N, Inamdar MN. Antioxidant Potential and Ability of Phloroglucinol to Decrease Formation of Advanced Glycation End Products Increase Efficacy of Sildenafil in Diabetes-Induced Sexual Dysfunction of Rats. Sex Med 2016; 4:e104-12. [PMID: 26831914 PMCID: PMC5005294 DOI: 10.1016/j.esxm.2015.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/15/2015] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Diabetes-induced sexual dysfunction is associated with an increase in oxidative stress. Scavengers of reactive oxygen species (ROS) have been shown to reduce oxidative stress and aid in the management of sexual dysfunction in diabetes. AIM The aim of the study was to test the hypothesis that antioxidant, which scavenge ROS and reduce formation of advanced glycation end products (AGEs), can potentiate efficacy of phosphodiesterase type 5 inhibitors in diabetes-induced sexual dysfunction that is associated with oxidative stress. MATERIALS AND METHODS Effect of phloroglucinol and sildenafil on serum glucose level, sexual function, penile smooth muscle : collagen ratio, and phenylephrine precontracted corpus cavernosum smooth muscle (CCSM) was studied. The ability of phloroglucinol to reduce the formation of AGEs and its ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) was also evaluated. MAIN OUTCOME MEASURES Antioxidant potential of phloroglucinol was studied in addition to its effect on diabetes-induced sexual dysfunction in presence and absence of sildenafil. RESULTS Phloroglucinol (50 mg/kg, p.o.) significantly decreased serum glucose level and increased sexual function in streptozotocin-induced diabetic rats when compared with diabetic control rats. Sildenafil (5 mg/kg, p.o.) had no effect on glycemia but significantly increased sexual function of diabetic rats. Coadministration of phloroglucinol increased the efficacy of sildenafil by improving sexual function. Treatment of diabetic rats with phloroglucinol + sildenafil maintained smooth muscle : collagen levels similar to that of normal rat penile tissue. Phloroglucinol decreased formation of AGEs and significantly scavenged DPPH radical activity in vitro. Sildenafil relaxed isolated CCSM of normal rat and diabetic rat significantly, but phloroglucinol did not show any significant effect. Phloroglucinol also inhibited human CYP3A4 enzyme activity in vitro. CONCLUSION Phloroglucinol coadministration increases efficacy of sildenafil in diabetes-induced sexual dysfunction. However, further studies are required to ascertain the benefits of phloroglucinol owing to its undesirable CYP3A4 inhibition activity.
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Affiliation(s)
- Sumanta Kumar Goswami
- Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore, India; Currently pursuing postdoctoral training at University of California, Davis, CA, USA.
| | | | | | - Rema Razdan
- Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore, India
| | - Rohitash Jamwal
- College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Naini Bhadri
- Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore, India
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Reed JR, dela Cruz ALN, Lomnicki SM, Backes WL. Environmentally persistent free radical-containing particulate matter competitively inhibits metabolism by cytochrome P450 1A2. Toxicol Appl Pharmacol 2015; 289:223-30. [PMID: 26423927 DOI: 10.1016/j.taap.2015.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 09/24/2015] [Accepted: 09/25/2015] [Indexed: 01/17/2023]
Abstract
Combustion processes generate different types of particulate matter (PM) that can have deleterious effects on the pulmonary and cardiovascular systems. Environmentally persistent free radicals (EPFRs) represent a type of particulate matter that is generated after combustion of environmental wastes in the presence of redox-active metals and aromatic hydrocarbons. Cytochromes P450 (P450/CYP) are membrane-bound enzymes that are essential for the phase I metabolism of most lipophilic xenobiotics. The EPFR formed by chemisorption of 2-monochlorophenol to silica containing 5% copper oxide (MCP230) has been shown to generally inhibit the activities of different forms of P450s without affecting those of cytochrome P450 reductase and heme oxygenase-1. The mechanism of inhibition of rat liver microsomal CYP2D2 and purified rabbit CYP2B4 by MCP230 has been shown previously to be noncompetitive with respect to substrate. In this study, MCP230 was shown to competitively inhibit metabolism of 7-benzyl-4-trifluoromethylcoumarin and 7-ethoxyresorufin by the purified, reconstituted rabbit CYP1A2. MCP230 is at least 5- and 50-fold more potent as an inhibitor of CYP1A2 than silica containing 5% copper oxide and silica, respectively. Thus, even though PM generally inhibit multiple forms of P450, PM interacts differently with the forms of P450 resulting in different mechanisms of inhibition. P450s function as oligomeric complexes within the membrane. We also determined the mechanism by which PM inhibited metabolism by the mixed CYP1A2-CYP2B4 complex and found that the mechanism was purely competitive suggesting that the CYP2B4 is dramatically inhibited when bound to CYP1A2.
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Affiliation(s)
- James R Reed
- Department of Pharmacology and Experimental Therapeutics and The Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, 533 Bolivar St., New Orleans, LA 70112, USA.
| | - Albert Leo N dela Cruz
- The Department of Environmental Sciences and LSU Superfund Research Center, Louisiana State University A&M College, Baton Rouge, LA 70803, USA.
| | - Slawo M Lomnicki
- The Department of Environmental Sciences and LSU Superfund Research Center, Louisiana State University A&M College, Baton Rouge, LA 70803, USA.
| | - Wayne L Backes
- Department of Pharmacology and Experimental Therapeutics and The Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, 533 Bolivar St., New Orleans, LA 70112, USA.
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Inhibition of cytochrome P450 2B4 by environmentally persistent free radical-containing particulate matter. Biochem Pharmacol 2015; 95:126-32. [PMID: 25817938 DOI: 10.1016/j.bcp.2015.03.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/17/2015] [Indexed: 01/18/2023]
Abstract
Combustion processes generate particulate matter (PM) that can affect human health. The presence of redox-active metals and aromatic hydrocarbons in the post-combustion regions results in the formation of air-stable, environmentally persistent free radicals (EPFRs) on entrained particles. Exposure to EPFRs has been shown to negatively influence pulmonary and cardiovascular functions. Cytochromes P450 (P450/CYP) are endoplasmic reticulum resident proteins that are responsible for the metabolism of foreign compounds. Previously, it was shown that model EPFRs, generated by exposure of silica containing 5% copper oxide (CuO-Si) to either dicholorobenzene (DCB230) or 2-monochlorophenol (MCP230) at ≥ 230 °C, inhibited six forms of P450 in rat liver microsomes (Toxicol. Appl. Pharmacol. (2014) 277:200-209). In this study, the inhibition of P450 by MCP230 was examined in more detail by measuring its effect on the rate of metabolism of 7-ethoxy-4-trifluoromethylcoumarin (7EFC) and 7-benzyloxyresorufin (7BRF) by the purified, reconstituted CYP2B4 system. MCP230 inhibited the CYP2B4-mediated metabolism of 7EFC at least 10-fold more potently than non-EPFR controls (CuO-Si, silica, and silica generated from heating silica and MCP at 50 °C, so that EPFRs were not formed (MCP50)). The inhibition by EPFRs was specific for the P450 and did not affect the ability of the redox partner, P450 reductase (CPR) from reducing cytochrome c. All of the PM inhibited CYP2B4-mediated metabolism noncompetitively with respect to substrate. When CYP2B4-mediated metabolism of 7EFC was measured as a function of the CPR concentration, the mechanism of inhibition was competitive. EPFRs likely inhibit CYP2B4-mediated substrate metabolism by physically disrupting the CPR·P450 complex.
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