Antioxidant and antimutagenic activity of extracts from pericarp and seed of zanthoxylum limonella alston

Abstract

This study was conducted to investigate the antioxidant and antimutagenic activity of Zanthoxylum limonella seed extract and that of Z. limonella pericarp extract. The total phenolic contents and antioxidant activity assay including DPPH assay and FRAP assay were performed. The results showed that the antioxidant activity of pericarp extract was higher than that of the seed extract. The direct mutagenicity assay was determined, with and without nitrite treatment using the Ames test towards Salmonella typhimurium strains TA98 and TA100. The mutagenic modification assay was performed by measuring the interfering effect of the pericarp extract and the seed extract on the formation of standard mutagens during the reaction between 1-aminopyrene and sodium nitrite (antiformation) and on the standard mutagen produced from the same reaction (antimutagen). For the seed extract, there was not direct mutagenic either with or without nitrite treatment on both tester strains, and it could interfere the formation of mutagen by decreasing the mutagenic activity. On the other hand, it was found that the seed extract slightly enhance the mutagenic activity of the standard mutagen. In addition, pericarp extract exhibited direct mutagenic activity after being treated with nitrite and increased the mutagenic activity on the formation of standard mutagen. However, the antimutagenic activity of the pericarp extract on the standard mutagen obtained from 1-aminopyrene reacted with sodium nitrite on S. typhimurium strains TA98 and TA100 was observed. The present study revealed the different inhibitory mechanisms of Z. limonella seed extract and that of Z. limonella pericarp extract on mutagenic activity of standard mutagen. However, the consumption of fruits from Z. limonella with nitrite or nitrite containing food products should be avoided to prevent the formation of mutagen.