Kassie F, Darroudi F, Kundi M, Schulte-Hermann R, Knasmüller S
Institute of Cancer Research, Vienna, Austria.
Int J Cancer. 2001 May 1;92(3):329-32. doi: 10.1002/ijc.1195.
We used the micronucleus (MN) test to determine the genetic damage caused by khat, a widely consumed psychostimulant plant, in exfoliated cells of volunteers who chewed the drug on a regular basis. In the first study in which we compared the frequency of MN in buccal and bladder mucosa cells in 20 khat consumers (10-160 g/day) and 10 controls, a pronounced (8-fold) increase in micronucleated buccal mucosa cells was seen among khat consumers; khat consumption did not lead to a detectable elevation of micronucleated bladder mucosa cells. Among heavy khat chewers, 81% of the MN had a centromere signal indicating that khat is aneuploidogenic. To investigate the effect of simultaneous consumption of tobacco and alcoholic beverages, we compared the MN frequency in buccal cells of 25 khat consumers (20-85 g/day) who smoked cigarettes (15-60/day) and drank alcoholic beverages (15-80 g of pure ethanol/day) with a control group (control group I) of 25 individuals matched for age, body weight, tobacco and alcohol consumption and with another control group of 25 individuals (control group II) not consuming any of the drugs. The frequency of buccal mucosa cells with MN was higher in control group I than in group II and the effect of khat, tobacco and alcohol was found to be additive. A time-kinetics study on khat-induced MN showed that the highest frequency of MN was observed during the fourth week after consumption. In light of the large body of evidence on the close association between genetic damage and cancer, these results suggest that khat consumption, especially when accompanied by alcohol and tobacco consumption, might be a potential cause of oral malignancy.
我们使用微核（MN）试验来确定巧茶（一种广泛食用的精神刺激植物）对定期咀嚼该药物的志愿者脱落细胞造成的遗传损伤。在第一项研究中，我们比较了20名巧茶消费者（每天10 - 160克）和10名对照者颊黏膜和膀胱黏膜细胞中的微核频率，发现巧茶消费者的微核化颊黏膜细胞显著增加（8倍）；食用巧茶并未导致微核化膀胱黏膜细胞有可检测到的升高。在重度巧茶咀嚼者中，81%的微核有着丝粒信号，表明巧茶具有非整倍体诱导作用。为了研究同时食用烟草和酒精饮料的影响，我们将25名每天吸食香烟（15 - 60支/天）和饮用酒精饮料（每天15 - 80克纯乙醇）的巧茶消费者（每天20 - 85克）的颊细胞微核频率与年龄、体重、烟草和酒精消费相匹配的25名个体组成的对照组（对照组I）以及另外25名不食用任何这些药物的个体组成的对照组（对照组II）进行了比较。对照组I中带有微核的颊黏膜细胞频率高于对照组II，并且发现巧茶、烟草和酒精的影响是相加的。一项关于巧茶诱导微核的时间动力学研究表明，在食用后的第四周观察到微核频率最高。鉴于大量证据表明遗传损伤与癌症之间密切相关，这些结果表明食用巧茶，尤其是在伴有酒精和烟草消费时，可能是口腔恶性肿瘤的一个潜在原因。
