Stich H F, Dunn B P
Int J Cancer. 1986 Nov 15;38(5):713-7. doi: 10.1002/ijc.2910380515.
The usefulness of an in vitro test system to predict the inhibitory effect of beta-carotene on the genotoxic activity of carcinogens/mutagens was explored. To facilitate the comparison of data obtained from cultured cells (CHO) and from exfoliated human cells, endpoints were used which can be quantitated in both cell systems: the frequency of micronuclei for estimating the effect of genotoxic agents, and cellular levels of beta-carotene as a protective agent. In CHO cells, beta-carotene inhibited the clastogenic and micronucleus-forming effect of methyl methanesulfonate (MMS) and 4-nitroquinoline-1-oxide (4NQO), but had no protective action against gallic acid, tannic acid, and aqueous extract of areca nut or H2O2. The extent of inhibition depended on the ratio of beta-carotene to MMS. Doses of beta-carotene which exerted a protective effect in vitro ranged from approximately 2 to 5 ng per 10(6) CHO cells. Comparable levels of beta-carotene were previously found to reduce the frequency of micronucleated exfoliated cells from the buccal mucosa of tobacco and areca-nut chewers (Stich et al., 1984b).
探讨了一种体外测试系统预测β-胡萝卜素对致癌物/诱变剂遗传毒性活性抑制作用的有效性。为便于比较从培养细胞（CHO）和人脱落细胞获得的数据，采用了在两种细胞系统中均可定量的终点指标：用于评估遗传毒性剂作用的微核频率，以及作为保护剂的β-胡萝卜素细胞水平。在CHO细胞中，β-胡萝卜素抑制了甲基磺酸甲酯（MMS）和4-硝基喹啉-1-氧化物（4NQO）的致断裂和形成微核的作用，但对没食子酸、单宁酸、槟榔水提取物或过氧化氢没有保护作用。抑制程度取决于β-胡萝卜素与MMS的比例。在体外发挥保护作用的β-胡萝卜素剂量范围为每10⁶个CHO细胞约2至5纳克。先前发现，相当水平的β-胡萝卜素可降低烟草和槟榔咀嚼者颊黏膜微核化脱落细胞的频率（Stich等人，1984b）。
