Antimutagenic activity of phenolic compounds, oligosaccharides and quinolizidinic alkaloids from Lupinus campestris seeds

Abstract

There are some foods that contain mutagenic or carcinogenic agents, some of which occur naturally and others that may be formed during preparation or cooking. Several foods such as legumes, also contain natural antimutagens and/or anticarcinogens. Lupine is one such legume that contains high amounts of protein (40%) and oils (14%). About 90 species of lupine have been reported throughout Mexico. However, the use of this crop as a source of food has been limited by the presence of antinutritional agents such as phenolic compounds (PC), carbohydrates (CH) and quinolizidinic alkaloids (Qas). It has also been suggested that consuming these compounds can affect human health and may even reduce the risk of disease. The objective of this work was to determine the effect of PC, CH and Qas, isolated and quantified from Lupinus campestris on the mutagenicity of 1-nitropyrene (1-NP) as a model mutagen and we used the Salmonella typhimurium tester strain YG1024 by the Kado microsuspension method. The results indicate that L. campestris seeds have 11 mg (+)catechin equivalent g⁻¹ seed coat; 120.3 mg g⁻¹ seeds and 2.13 mg g⁻¹ seeds of PC, CH and Qas, respectively. 1-NP mutagenicity was inhibited by 86% for PC, 76% for CH and 75% for Qas at concentrations of 200, 512 and 13.6 μg/tube, respectively.

Keywords:

• phenolic compounds
• quinolizidinic alkaloids
• carbohydrates
• 1-nitropyrene
• antimutagenicity
• mutagenicity
• microsuspension assay

Acknowledgements

The authors thank the Instituto Politécnico Nacional (IPN) and Consejo Nacional de Ciencia y Tecnología (CONACyT) through 33995 Project for financial support. Cristian Jiménez Martinez acknowledges a study grant from CONACyT. The authors thank Paul Kuzmicky, the University of California at Davis, for comments on the manuscript.

Notes

¹ Concentration is expressed as mg g⁻¹ seed (dry weight). Results are the average of three independent experiments ± SD. Quantification of carbohydrates from L. campestris was done according to Muzquiz et al. (1992).

¹ Concentration is expressed as mg g⁻¹ seed (dry weight). Results are the average of three independent experiments ± SD. Quantification of quinolizidinic alkaloids was done according to Muzquiz et al. (1994); as described in the Material and methods.

¹ Concentration of PC expressed as μg equivalent (+) catechin/tube.

² 1-NP-nitropirene (400 ng/tube). Results are the average of two independent experiments. Triplicates were tested per dose per experiment. Spontaneous mutation rate was 64 ± 3 revertants/plate. Different letters mean a statistical significant difference (Dunnett α = 0.05).

¹ Concentration of CH expressed as µg/tube.

² 1-NP-nitropirene (400 ng/tube). Results are the average of two independent experiments. Triplicates were tested per dose per experiment. Spontaneous mutation rate was 4  ± 2.5 revertants/plate. Different letters mean a statistical significant difference (Dunnett α = 0.05).

¹ Concentration of QA expressed as µg/tube.

²1-NP-nitropirene (400 ng/tube). Results are the average of two independent experiments. Triplicates were tested per dose per experiment. Spontaneous mutation rate was 38  ± 2 revertants/plate. Different letters mean a statistical significant difference (Dunnett α = 0.05).