Patra Manomita, Halder Ajanta, Bhowmik Niladri, De Madhusnata
Department of Biochemistry, University of Calcutta, Kolkata, India.
J Environ Pathol Toxicol Oncol. 2005;24(3):201-10. doi: 10.1615/jenvpathtoxoncol.v24.i3.60.
The concentration of arsenic in drinking water has far exceeded the permissible limit of 0.001 mg/L and has reached epidemic proportions, with a maximum of 3.7 mg/L in several districts of West Bengal and in the adjoining Bangladesh. Because inorganic arsenic is a documented human carcinogen, arsenic in drinking water may cause 200,000-270,000 deaths per year from cancer in India alone. Tea has a protective effect against the clastogenicity of arsenic. We investigated whether tea extracts could protect against the damage caused by arsenic in vivo. Our experiments were carried out with black tea in mice with the end points of incidence of chromosomal aberrations and damaged cells. Analysis of variance of chromosomal aberrations showed a significant difference in the toxic effects of arsenic, which were reduced by tea infusion. The frequency of chromosomal aberrations was close to the corresponding effects of tea alone. Continued dietary administration of black tea infusion protects against the chromosome-damaging effects of sodium arsenite at a statistically significant level. The degree of protection increases with duration of tea consumption, which may be attributed to the antioxidant and scavenging properties of tea infusion.
饮用水中的砷浓度已远远超过0.001毫克/升的允许限度，且已达到流行程度，在西孟加拉邦的几个地区以及毗邻的孟加拉国，砷浓度最高达3.7毫克/升。由于无机砷是已被记录在案的人类致癌物，仅在印度，饮用水中的砷每年可能导致20万至27万人死于癌症。茶对砷的致断裂性具有保护作用。我们研究了茶提取物在体内是否能预防砷造成的损害。我们用红茶对小鼠进行了实验，以染色体畸变和细胞损伤的发生率为终点指标。染色体畸变的方差分析表明，砷的毒性作用存在显著差异，而茶浸液可降低这种毒性。染色体畸变的频率接近单独饮茶的相应效果。持续给予茶浸液饮食在统计学显著水平上可预防亚砷酸钠对染色体的损伤作用。保护程度随饮茶时间的延长而增加，这可能归因于茶浸液的抗氧化和清除特性。
