IN-VITRO EFFECT OF VEGETABLE AND FRUIT JUICES ON THE MUTAGENICITY OF 2-AMINO-3-METHYLIMIDAZO[4,5-F]QUINOLINE, 2-AMINO-3,4-DIMETHYLIMIDAZO[4,5-F]QUINOLINE AND 2-AMINO-3,8-DIMETHYLIMIDAZO[4,5-F]QUINOXALINE

The antimutagenic potencies of the juices of 28 fruits and 34 vegetabl es commonly consumed in Germany were investigated with respect to the mutagenic activities induced by 2-amino-3-methyl[4,5-f]quinoline (IQ), and in part by 2-amino-3,4-dimethylimidazo[4,5-f]quinol (MeIQ) or 2-a mino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in Salmonella typhi murium TA98 and TA100. With IQ, weak to strong antimutagenic activitie s were found in 68% of the fruits and 73% of the vegetables that were tested. In fruits, strong antimutagenic activities were detected in ba nanas, blackberries, blueberries, sweet and sour cherries, blackcurran ts and redcurrants, pineapple and watermelon. Moderate antimutagenic a ctivities were detected in greengage, kiwi, mangos, honeydew melons an d plums. Weak antimutagenic activities were detected in apple, apricot , mirabelle, pears, peaches and strawberries, whereas white and red gr apes and raspberries were inactive, and gooseberries and citrus fruits in general possessed marginal or no antimutagenic activities. In vege tables, strong to moderate antimutagenic activities were found for all cruciferous vegetables, except Chinese cabbage, which had only weak a ntimutagenic activity. Other vegetables with strong antimutagenic acti vities were beets, chives, horseradish, onions, rhubarb and spinach. M oderate antimutagenic activities were found with green beans and tomat oes, weak activities in eggplant, garden cress, many lettuces, leeks, mangold, cucumber, pumpkin, radish and summer squash. Asparagus, carro ts, fennel leaves, parsley, green peppers and radishes were inactive. When fruit and vegetable juices were heated, a considerable reduction of antimutagenic potencies was seen with apple, apricot, kiwi, pineapp le, beets, cabbage (Chinese, Savoy, red and white), cauliflower, leafy lettuce, cucumber, onions, radish and rhubarb. Antimutagenic factors in blackberries, blueberries, sweet and sour cherries, honeydew melons , mirabelle, plums, strawberries, Brussels sprouts, chicory greens, eg gplant, garden cress, mangold, pumpkin, lamb's lettuce and spinach wer e, however, remarkably heat stable. Antimutagenic potencies in bananas , blackcurrants and redcurrants, greengages, gooseberries, mangos, wat ermelon, green beans, kohlrabi, horseradish, tomatoes and chives were partially reduced. Antimutagenic activities in the juices of eight app le cultivars were moderate in two, weak in four, and marginal or absen t in two. No major differences, however, were detected in five batches of oranges and three batches each of grapefruits, asparagus, green be ans, broccoli, cauliflower, spinach and tomatoes. No (or only minor) d ifferences were seen between IQ, MeIQ and MeIQx and tester strains TA9 8 and TA100. Pineapple and celeriac juices inhibited the enzymatic sys tem responsible for the activation of IQ, but had no desmutagenic acti vity. Peroxidase activity found to be present in broccoli, cauliflower , green beans and tomatoes may contribute to antimutagenic activities in these vegetables.