英国研究人员最近发现了一些强有力的证据表明:吸食大麻会提高人体患癌症的风险,破坏人体DNA,改变DNA结构。
据报道,使用新开发的高度敏感的液体色谱法中的串联质谱法,英国莱斯特大学的科学家们发现,在实验室条件下,吸食大麻会损害DNA 。此项研究结果发表在最新一期的《毒理学化学研究》杂志上。
这项研究的参写者包括拉吉德·辛格(Rajinder Singh), 贾亭德帕·桑德(Jatinderpal Sandhu), 包文德·考尔 (Balvinder Kaur),蒂娜·仁(Tina Juren),威廉·彼·斯特瓦德(William P. Steward),丹·斯格巴克(DanSegerback)和彼得波·法莫(Peter B. Farmer),他们分别来自瑞典癌症生物标记和预防组、癌症研究和分子医学部门和卡罗林斯卡研究所。
研究专家拉吉德·辛格说: “部分植物大麻,也被称为大麻或印度大麻,通常作为消遣性毒品吸食,但它们在许多国家吸食大麻是违法的 。” 目前为止,有许多有关烟草烟雾毒性的研究。据悉,烟草烟雾含有4000种化学物质,其中60种被列为致癌物质。相比之下,有关大麻的研究不是很多。因为大麻的可燃性没有烟草强,它们往往被掺杂在烟草里一起使用。研究结果表明,大麻烟雾中包含400种化合物 ,然而,由于其较低的可燃性,它比烟草烟雾含有多50 %以上的致癌多环芳烃,包括萘,苯并蒽和苯并芘。
有关这项研究的报告中提到,随着光谱测定法的改进,越来越多的实验结果表明:吸食大麻会损害DNA。其中一位专家表示:“众所周知,烟草烟雾中的有毒物质会损害DNA和增加患肺癌和其他癌症的风险。科学家们以前不确定是否大麻烟雾也具有同样的效果。我们目前主要集中于研究乙醛的毒性,因为烟草和大麻中都含有乙醛。”
研究人员还补充说:“大麻烟破坏DNA的能力更强,对人类健康的影响更大,特别是当吸食者吸大麻烟时比吸烟草烟更深入地吸入肺部,从而增加了呼吸的负担。一天吸食3到4根大麻烟对支气管黏液膜的损害程度相当于一天吸20根或更多烟草香烟的程度。”
研究人员研究后得出的结论,为大麻损害人体DNA提供了充足的证 据,这也意味着吸食大麻烟危害人体健康,诱发癌症。(生物谷Bioon.com)
生物谷推荐原始出处:
Chem. Res. Toxicol., 2009, 22 (6), pp 1181–1188 DOI: 10.1021/tx900106y
Evaluation of the DNA Damaging Potential of Cannabis Cigarette Smoke by the Determination of Acetaldehyde Derived N2-Ethyl-2′-deoxyguanosine Adducts
Rajinder Singh*, Jatinderpal Sandhu?, Balvinder Kaur?, Tina Juren?, William P. Steward§, Dan Segerbck? and Peter B. Farmer?
Cancer Biomarkers and Prevention Group, Biocentre, Department of Cancer Studies and Molecular Medicine, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom, Department of Biosciences and Nutrition, Unit of Molecular Epidemiology, Karolinska Institute, S-141 57 Huddinge, Sweden, and Cancer Biomarkers and Prevention Group, Department of Cancer Studies and Molecular Medicine, University of Leicester, Fifth Floor RKCSB, Leicester Royal Infirmary, Leicester, LE2 7LX United Kingdom
Acetaldehyde is an ubiquitous genotoxic compound that has been classified as a possible carcinogen to humans. It can react with DNA to form primarily a Schiff base N2-ethylidene-2′-deoxyguanosine (N2-ethylidene-dG) adduct. An online column-switching valve liquid chromatography tandem mass spectrometry (LC-MS/MS) selected reaction monitoring (SRM) method was developed for the determination of N2-ethylidene-dG adducts in DNA following reduction with sodium cyanoborohydride (NaBH3CN) to the chemically stable N2-ethyl-2′-deoxyguanosine (N2-ethyl-dG) adduct. Accurate quantitation of the adduct was obtained by the addition of the [15N5]N2-ethyl-dG stable isotope-labeled internal standard prior to enzymatic hydrolysis of the DNA samples to 2′-deoxynucleosides with the incorporation of NaBH3CN in the DNA hydrolysis buffer. The method required 50 μg of hydrolyzed DNA on column for the analysis, and the limit of detection for N2-ethyl-dG was 2.0 fmol. The analysis of calf thymus DNA treated in vitro with acetaldehyde (ranging from 0.5 to 100 mM) or with the smoke generated from 1, 5, and 10 cannabis cigarettes showed linear dose-dependent increases in the level of N2-ethyl-dG adducts (r = 0.954 and r = 0.999, respectively). Similar levels (332.8 ± 21.9 vs 348.4 ± 19.1 adducts per 108 2′-deoxynucleosides) of N2-ethyl-dG adducts were detected following the exposure of calf thymus DNA to 10 tobacco or 10 cannabis cigarettes. No significant difference was found in the levels of N2-ethyl-dG adducts in human lung DNA obtained from nonsmokers (n = 4) and smokers (n = 4) with the average level observed as 13.3 ± 0.7 adducts per 108 2′-deoxynucleosides. No N2-ethyl-dG adducts were detected in any of the DNA samples following analysis with the omission of NaBH3CN from the DNA hydrolysis buffer. In conclusion, these results provide evidence for the DNA damaging potential of cannabis smoke, implying that the consumption of cannabis cigarettes may be detrimental to human health with the possibility to initiate cancer development.