Effect of khat, its constituents and restraint stress on free radical metabolism of rats
Effect of khat, its constituents and restraint stress on free radical metabolism of rats
复制标题
DOI：
10.1016/s0378-8741(02)00251-9
复制
发表时间：
2002-12-01
影响因子：
5.4
通讯作者：
Banu, N
中科院分区：
文献类型：
--
作者：
Al-Qirim, TM;Shahwan, M;Banu, N
阿拉伯茶（Catha edulis）的叶子被发现具有刺激和愉悦的效果，东非和阿拉伯半岛的人们习惯咀嚼。由于阿拉伯茶具有多种毒性和精神刺激作用，本研究评估了单独灌胃阿拉伯茶或其主要成分黄酮/生物碱以及固定应激前后4小时对大鼠自由基清除/代谢酶、尿酸和葡萄糖的影响。与对照大鼠相比，口服哈茶、生物碱或4 h抑制应激导致循环中超氧化物歧化酶、过氧化氢酶、谷胱甘肽- s -转移酶和葡萄糖水平降低，尿酸浓度升高。口服阿拉伯茶黄酮类成分可提高GST和过氧化氢酶的活性，但对SOD无影响，同时降低葡萄糖水平，升高尿酸水平。与应激前相比，应激后阿拉伯茶/生物碱处理大鼠的这些生化参数水平发生了更多的变化。除了葡萄糖水平进一步降低外，应激阿拉伯茶处理大鼠的SOD、GST、过氧化氢酶和尿酸水平的变化与单独使用阿拉伯茶的大鼠相当。在上述生化指标方面，阿拉伯茶黄酮组分降低了应激诱导的氧化应激。本研究表明，单独使用阿拉伯茶或在应激前食用阿拉伯茶/生物碱可显著降低自由基代谢/清除酶和葡萄糖的水平，从而导致自由基浓度和毒性增加，这可能是由于其生物碱部分被发现具有抗氧化作用，因为黄酮类化合物对应激过程中产生的氧化应激具有抗氧化作用。(C) 2002爱思唯尔科学爱尔兰有限公司版权所有。
The leaves of khat (Catha edulis) are found to have stimulating and pleasurable effect and are chewed habitually by people of East Africa and Arabian Peninsula. Due to various toxic and psychostimulative effect of khat the present study was undertaken to evaluate the effect of intragastric khat alone or its major constituents flavonoids/alkaloids administration and before and after 4 h of immobilization stress in terms of alteration of free radical scavenging/metabolizing enzymes, uric acid and glucose in rats. Oral khat, alkaloid administration or 4 h restraint stress resulted in the decrease of the circulating levels of superoxide dismutase, catalase, glutathione-S-transferase and glucose with enhanced uric acid concentrations as compared with control rats. Oral treatment with flavonoid fraction of khat was found to enhance the activities of GST and catalase but showed no effect on SOD while the level of glucose was decreased and uric acid increased. The levels of these biochemical parameters were more altered in post stress khat/alkaloid treated rats than pre stress khat/alkaloid treated rats. The alteration in the levels of SOD, GST, catalase and uric acid in the pre stress khat treated rats were comparable with that of khat alone, except the level of glucose which was further decreased in pre stress khat treated rats. The flavonoid fraction of khat reduced the stress induced oxidative stress in terms of above mentioned biochemical parameters. The present study suggests that khat alone or khat/alkaloid consumption preceding stress may significantly decrease the levels of free radical metabolizing/scavenging enzymes and glucose leading to enhanced free radical concentration and toxicity of khat, which could be due to its alkaloid fraction as flavonoids were found to show antioxidant properties for oxidative stress generated during restraint stress. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.