*Communication* **Monocaprin Enhances Bioavailability of Fucoxanthin in Diabetic/Obese KK-***Ay* **Mice**

**Kodai Nagata 1, Naoki Takatani 1, Fumiaki Beppu 1, Aya Abe 2, Etsuko Tominaga 2, Tomohisa Fukuhara 2, Makoto Ozeki 2 and Masashi Hosokawa 1,\***


**Abstract:** Fucoxanthin is a marine carotenoid found in brown seaweeds and several microalgae. It has been reported that fucoxanthin has health benefits such as anti-obesity and anti-diabetic effects. To facilitate fucoxanthin applications in the food industry, it is important to improve its low bioavailability. We attempted the combined feeding of fucoxanthin-containing seaweed oil (SO) and monocaprin in a powder diet and analyzed the fucoxanthin metabolite contents in the liver, small intestine and serum of diabetic/obese KK-*Ay* mice. After 4 weeks of feeding with the experimental diets, the serum fucoxanthinol concentrations of the mice fed 0.2% SO and 0.5% monocaprin were higher than those of the 0.2% SO-fed mice. Furthermore, fucoxanthinol accumulation in the liver and small intestine tended to increase in a combination diet of 0.2% SO and 0.125–0.5% monocaprin compared with a diet of 0.2% SO alone, although amarouciaxanthin A accumulation was not different among the 0.2% SO-fed groups. These results sugges<sup>t</sup> that a combination of monocaprin with fucoxanthin-containing SO is an effective treatment for improving the bioavailability of fucoxanthin.

**Keywords:** fucoxanthin; monocaprin; bioavailability; fucoxanthinol
