Kaew Kangsadalampai

Antimutagenicity of some flowers grown in Thailand

The mutagenicity of dichloromethane, methanol and water extracts of Antigonon leptopus Hook. & Arn., Curcuma sessilis Gage, Hibiscus rosa-sinensis Linn., Ixora coccinea Linn., Millingtonia hortensis Linn., Nelumbo nucifera Gaertn., Plumeria obtusa Linn., Punica granatum Linn., Rhinacanthus nasutus ((Linn.) Kurz.) and Syzygium malaccense ((Linn.) Merr.& Perry) before and after nitrite treatment was firstly investigated in the Ames test. Their antimutagenicity against the product of the reaction mixture of 1-aminopyrene nitrite model in the absence of metabolic activation on Salmonella typhimurium TA 98 and TA 100 was evaluated. The results showed that none of the samples was mutagenic. Most nitrite-treated samples but dichloromethane extracts of Hibiscus rosa-sinensis, Plumeria obtusa, Syzygium malaccense, methanol extract of Syzygium malaccense and water extract of Hibiscus rosa-sinensis were mutagenic. The nitrite treated methanol extract of Nelumbo nucifera exhibited the highest mutagenicity on both strains. All dichloromethane extracts of flowers decreased the mutagenicity induced by the product of 1-aminopyrene nitrite model on both tester strains. Methanol extract of Curcuma sessilis and Punica granatum (15 mg/plate) showed the highest antimutagenic activity in TA 98 and TA 100, respectively. The protective effects of these flower extracts might be due to the presence of antimutagenic components that were supposed to be flavonoids.

Direct mutagenicity of the polycylic aromatic hydrocarbon-containing fraction of smoked and charcoal-broiled foods treated with nitrite in acid solution

The polycyclic aromatic hydrocarbons (PAH) containing fractions of smoked and charcoal-broiled foods, namely, Sheat fish (Kytopterus apogon), Mimrow (Crossocheilus reba), Freshwater catfish (Clarias batrachus), chicken wings, rice pork sausage and pork, in addition to naphthalene, acenaphthene, anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, naphthacene, benzo[a]pyrene, benzo[e]pyrene, 9,10-dimethyl-1,2-benzanthracene, dibenz[ah]anthracene, benzo[ghi]perylene and coronene, were evaluated for their mutagenic potential using Salmonella typhimurium strains TA98 and TA100 in the absence of metabolic activation after being treated with nitrite (500 mM) for 4 hr at 37 degrees C and in acid solution pH 3.0-3.5. The presence of N-nitroso compounds was also determined. Results showed that nitrite could convert most samples to direct-acting mutagens towards both strains except for fluoranthene and benzo[ghi]perylene, which exhibit mutagenicity only with TA98. It was demonstrated that treatment of PAHs with nitrite in acid solution produced some non-N-nitroso direct-acting mutagens, suggesting that they might belong to nitro-PAHs. Therefore, the consumption of charcoal-broiled and smoked foods simultaneously with nitrite is not recommended.

Antimutagenicity of Black Glutinous Rice and Hom Nil Rice

Black glutinous rice (Oryza sativa var. glutinosa) and Hom Nil rice (Oryza sativa) are colored rice varieties with antioxidant properties, popular among health conscious consumers. We studied the antimutagenicity of raw, cooked and fermented samples against two direct mutagens - nitrite-treated 1-aminopyrene and nitrite treated chicken essence - in an Ames assay using Salmonella typhi- murium strains TA 98 and TA 100. The extract of each sample with acid alcohol reduced the mutagenicity of both mutagens. In addition, the antimutagenicity of the extracts from the samples made of black glutinous rice was higher than that of the extracts from samples made of Hom Nil rice. The protective effects of these rice varieties might be due to the presence of some phytochemicals, including anthocyanins, which are the main antioxidant. The selected rice va- rieties might be appropriate for p

Induction of Mutation in Drosophila Melanogaster Fed a Hexane Extract of Vegetables Grown in Soil Contaminated with Particulates from Diesel Engine Exhaust

Trans-heterozygous larvae of the improved high-bioactivation cross Drosophila melanogaster (ORR;flr3/TM3, Ser females mated with mwh males) were fed with medium containing hexane extract of the edible portion of five vegetables grown in three different soil treatments for 48 hours. the wing hairs of the surviving flies were analysed for the frequency and size of single and twin spots. It was found that the clone induction frequency of the wing hairs of flies treated with a hexane extract of leaves of sacred basil and green kuang futsoi was not significantly different from that of the controls. Conclusive results were obtained when larvae were raised on the medium containing hexane extracts of lettuce and water spinach grown in contaminated soils. Interestingly, the extracts of multiply onion, grown both in the treated and in the untreated soils, induced mutation in the wing spot test. It was concluded that some plants grown in soil contaminated with diesel exhaust provoked mutagenic responses, whereas some showed negative results.

Antimutagen Formation and Nitrite Scavenging by Unprocessed or Processed Fruit and Vegetable Fibers

Salmonella typhimurium strains TA 98 and TA 100 were used in carrying out the Ames test for the study of antimutagen formation. A variety of fruit and vegetable fibers were tested upon the mutagen-generating reaction between aminopyrene and sodium nitrite in a gastric simulation. The nitrite-scavenging capability (NSC) of such fibers was also determined. Thai style cooking or the maturity of fruits and vegetables (raw and ripe) had no significant effect on the formation of antimutagen, detected with aminopyrene plus nitrite, or on the NSC. The scavenging activity of fibers was found to range from 0.1 to 0.25 fig nitrite per mg fiber. The incorporation of selected fibers into western-style baked products, and deep-fat frying of starchy foods, resulted in a reduction of the NSC.