Effect of extracts from green vegetables on modification of mutagenicity of nitrite-treated aminopyrene and nitrite-treated chicken extract using ames test

Abstract

The extracts from leaves of raw and blanched vegetables, namely Cha-Plu (Piper sarmentosum Roxb.), Yor (Morinda citrifolia L.), Pak-Waan-Bann (Sauropus androgynus Merr.), and Pak-Khom (Amaranthus lividus Linn.) did not have mutagenicity when they were tested by using Salmonella typhimurium strain TA98 and TA100 of the Ames test. However, they were mutagenic after reacted with nitrite in an acidic condition (pH3-3.5) without activating system on both strains. The standard mutagen models were 1-aminopyrene treated with nitrite and chicken extract treated with nitrite. The results revealed that the extracts from raw and blanched vegetables could reduce the direct-acting mutagenicity of compounds that occurred in the two models on both tester strains. The antimutagenicity of each extract added to the first model was strong (>60% inhibition) while it was moderate to weak in the second model, except the extract from raw Pak-Khom showed no active on both strains in second model. The results showed that the potency of antimutagenicity was not dose-dependent. Antimutagenicity of compounds in vegetable extracts might counteract the direct-acting mutagenicity of nitrite treated 1-aminopyrene and nitrite treated chicken extract. The results indicated that antimutagenic effect of extracts from blanched vegetables was not reduced compared with raw vegetables. It was concluded that heat processing had not an effect on antimutagenic activity of each vegetable. This experiment suggested that consumption of nitrite-containing foods with these vegetables (raw and blanched) should prevent the mutagenicity of direct mutagen occurring in gastric like condition.