Environmental and Molecular Mutagenesis 30:346–353 (1997) Antimutagenic Activity of Natural Xanthophylls Against Aflatoxin B 1 in Salmonella typhimurium Elvira Gonza ´lez de Mejı B a, Minerva Ramos-Go ´mez, and Guadalupe Loarca-Pin ˜a* Research and Graduate Studies in Food Science, School of Chemistry, Universidad Auto ´ noma de Quere ´ taro, Quere ´ taro, Qro., Me ´ xico Carotenoids (carotenes and xanthophylls) are ex- AFB 1 mutagenicity than pure lutein. The percent- cellent antioxidants with antimutagenic and anticar- ages of inhibition on AFB 1 mutagenicity were 37, cinogenic properties. They occur naturally in some 66, and 76% for lutein, oleoresin, and xanthophyll foods such as carrots, red tomatoes, butter, cheese, plus at the dose of 2 mg/plate, respectively. Lutein paprika, palm oil, corn kernels, Marigold petals, had a modest effect on the DNA-repair system of annatto, and red salmon. In the present study, we YG1024. In spectrophotometric studies, a new ab- used the Salmonella plate incorporation test to ex- sorption peak was detected at 378 nm when lutein amine the effect of xanthophylls extracted from and AFB 1 were incubated together, and lutein re- Aztec Marigold (Tagetes erecta) on the AFB 1 muta- acted with AFB 1 metabolites. The results suggest that genicity, using tester strain YG1024. The effect of the inhibitory mechanism of lutein against AFB 1 mu- lutein on the DNA-repair system in YG1024 was tagenicity is most probably the result of a combina- investigated by a pre-incubation test. In a dose-re- tion of the following events: formation of a complex sponse curve of AFB 1 , the mutagenic potency was between lutein and AFB 1 , direct interaction be- 1,031 revertants/nmol. The dose of 0.5 mg AFB 1 / tween lutein and AFB 1 metabolites, and finally that plate was chosen for the antimutagenicity studies. the lutein may also affect the metabolic activation Pure lutein and xanthophylls from Aztec Marigold of AFB 1 by S9 and the expression of AFB 1 -modified flower (oleoresin and xanthophyll plus) inhibited the Salmonella DNA. Environ. Mol. Mutagen. mutagenicity of AFB 1 in a dose-dependent manner. 30:346–353, 1997  1997 Wiley-Liss, Inc. The pigments were more efficient at inhibiting the Key words: xanthophylls; lutein; aflatoxin B 1 ; mutagenicity; Salmonella typhimurium INTRODUCTION Salmonella typhimurium strains TA98 and TA100 [Wong and Hsieh, 1976; Jorgensen et al., 1987; Larson and Tjalve, 1993]. However, AFB 1 requires metabolic activa- Aztec Marigold (Tagetes erecta) is widely grown in tion by specific microsomal and nuclear cytochrome P- Mexico and in the United States. It is commercially culti- 450 associate enzymes to produce the highly reactive vated and harvested, and the flowers are dried to obtain AFB 1 -8,9-epoxide, the ultimate carcinogenic compound color extracts which are used as poultry feed supplements [Mehta et al., 1993]. The AFB 1 -8,9-epoxide readily binds for direct coloring of shanks, broiler skin, and yolks. Mar- to nucleophilic centers in many cellular macromolecules igold flowers are rich in lutein, which occurs acylated such as proteins and N-7 guanine of DNA [Groopman et with fatty acids [Philip and Berry, 1975; Gregory et al., al., 1992]. 1986]. Carotenoids are present in a wide variety of food In the present study, we examined the effect of carot- and feeds such as yellow and green vegetables, tomatoes, enoids extracted from Aztec Marigold flower, on the apricots, oranges, peppers, egg yolk, chicken, butter, AFB 1 mutagenicity, using the plate-incorporation test. shrimp, lobsters, trout, and yellow corn [Tee, 1992]. Ca- The possible mechanism of lutein on AFB 1 mutagenicity rotenoids have excellent antioxidant properties; a or b- was also investigated. carotene, xanthophylls (mainly lutein and its isomers), and retinoids have been reported to inhibit some types of cancers [Mathews-Roth, 1982; Moon et al., 1983; Knekt, 1994; Krinsky, 1994]. *Correspondence to: Dr. Ma. Guadalupe Flavia Loarca-Pin ˜a, De- Aflatoxin B 1 (AFB 1 ) is a potent mutagenic and carcino- partamento de Investigacio ´n y Posgrado en Alimentos, Facultad de genic mycotoxin produced by A. flavus and A. parasiticus. Quı B mica, Universidad Auto ´noma de Quere ´taro, Centro Universitario, Cerro de las Campanas S/N, Quere ´taro, Qro., 76010, Mexico; E-mail: It is frequently found in foodstuffs such as corn, peanuts, loarca@sunserver.uaq.mx. and cotton seeds [Hsieh, 1986, 1989; Carrillo et al., 1990; Liu and Massey, 1992]. AFB 1 is highly mutagenic to Received 23 December 1996; revised and accepted 27 April 1997.  1997 Wiley-Liss, Inc. EM-525 / 8I20$$0525 09-29-97 12:28:28 wlema W Liss: EM