Tomatoes in Diet Protect Mice from Skin Cancer

By LabMedica International staff writers
Posted on 31 Jul 2017

Image: Lycopene, the antioxidant red pigment that colors tomatoes (Photo courtesy of Wikimedia Commons).

Cancer researchers working with a mouse model showed that a diet supplemented with tomatoes could protect against skin cancer.

Based on previous studies that had found that prolonged tomato consumption could mitigate ultraviolet (UV) light induced sunburn via unknown mechanisms, investigators at Ohio State University (Columbus, USA) hypothesized that tomato consumption would protect against skin cancer.

To test this theory, the investigators fed diets supplemented with 10% tangerine or red tomato powder to a population of SKH-1 hairless and immunocompetent mice for 35 weeks. From weeks 11 to 20, the mice were exposed to UV light, three times per week, and tumors were tracked weekly. Control mice were fed the same diets but not exposed to UV light.

Results published in the July 11, 2017, online edition of the journal Scientific Reports revealed that significantly fewer tumors developed in male mice consuming red tomato diets or pooled tomato diets compared to controls. Carotenoid levels in plasma and skin were quantitated, with total lycopene higher in skin of tangerine fed animals despite a lower dose. Lycopene, the primary carotenoid in tomatoes, has been shown to be the most effective antioxidant of these pigments.

Metabolomic analyses elucidated compounds derived from tomato glycoalkaloids (including tomatidine and hydroxylated-tomatidine) as significantly different metabolites in skin after tomato supplementation.

Results showing that there were no significant differences in tumor number for female mice in the study confirmed previous findings that male mice developed tumors earlier after UV exposure and that their tumors are more numerous, larger, and more aggressive.

"This study showed us that we do need to consider sex when exploring different preventive strategies," said senior author Dr. Tatiana Oberyszyn, professor of pathology at Ohio State University. "What works in men may not always work equally well in women and vice versa."

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Ohio State University