BackgroundHigh dietary intake of vegetable products is beneficial against obesity and its related diseases such as dyslipidemia, nonalcoholic fatty liver disease, and cancer. We previously developed a diet-induced obesity model of zebrafish (DIO-zebrafish) that develops visceral adiposity, dyslipidemia, and liver steatosis. Zebrafish is a polyphagous animal; thus we hypothesized that DIO-zebrafish could be used for transcriptome analysis of anti-obesity effects of vegetables.ResultsEach vegetable exhibited different effects against obesity. We focused on "Campari" tomato, which suppressed increase of body weight, plasma TG, and lipid droplets in livers of DIO-zebrafish. Campari tomato decreased srebf1 mRNA by increase of foxo1 gene expression, which may depend on high contents of β-carotene in this strain.ConclusionsCampari tomato ameliorates diet-induced obesity, especially dyslipidemia and liver steatosis via downregulation of gene expression related to lipogenesis. DIO-zebrafish can discriminate the anti-obesity effects of different strains of vegetables, and will become a powerful tool to assess outcomes and find novel mechanisms of anti-obesity effects of natural products.

The genus Tuber is an ectomycorrhizal ascomycetous taxon that belongs to the Pezizales. All members of this genus form symbiotic associations with forest tree species in families such as Fagaceae and Pinaceae and produce hypogeous fruiting bodies that are known as truffles (Hall, Brown, & Zambonelli, 2007). Some species of truffles are sought after as gourmet foods (e.g., the black truffle T. melanosporum Vittad. and the white truffle T. magnatum Pico), and the discovery of new taxa is expected to contribute to our understanding of fungal diversity and may provide new food resources.In our previous phylogenetic study of Japanese Tuber specimens, we found that the genus contains 20 phylotypes, two of which form a novel lineage: the Japonicum clade (Kinoshita, Sasaki, & Nara, 2011). The clade is composed of two Japanese species,