Mutagenicity and antimutagenicity of water extracts from gac fruit (Momordica cochinchinensis Spreng)
Keywords:
Momordica cochinchinensis Spreng, Gac fruit, Mutagenicity, Antimutagenicity, Ames testAbstract
Background: Gac fruit (Momordica cochinchinensis Spreng) was used as food, colourant and medicine for a period of time. Moreover, several in vitro and in vivo studies showed that gac fruit contained many phytochemicals and exerted bioactive effects, including pro-vitamin A, antioxidant and antitumor activity. This study aimed to investigate the mutagenicity and the antimutagenicity against a standard mutagen; nitrite treated 1-aminopyrene (1-AP) of gac fruit.
Method: The water extracts from unripe pulp, half-ripe pulp, fully ripe pulp and aril of gac fruit were treated with and without nitrite and investigated for their mutagenicity using Ames test with modified pre-incubation method on Salmonella typhimurium strain TA98 and TA100 without enzymatic activation. The antimutagenicity against nitrite treated 1-AP of these fruit extracts was also evaluated.
Results: The results showed that none of them showed mutagenicity on both strains of S. typhimurium either with or without nitrite treatment. For the antimutagenicity, the extracts from various parts of gac fruit, especially the extracts from unripe pulp inhibited the mutagenicity of nitrite treated 1-AP with dose response manner on S. typhimurium strain TA98. According to the results from S. typhimurium strain TA100, the two higher amounts of the extracts from unripe pulp and half-ripe pulp showed weak to moderate degree of inhibition while the extracts from fully ripe pulp showed negligible effect. The extracts from aril also showed negligible effect at the study concentrations, although they tended to enhance the mutagenicity of nitrite treated 1-AP. Overall, the mutagenicity of nitrite treated 1-AP can be inhibited by the addition of the water extracts from gac fruit.
Conclusion: This study indicated that the water extracts from gac fruit showed no mutagenic activity and exhibited antimutagenic activity against nitrite treated 1-AP, especially from unripe pulp.
