Shuhei Yamada1, Nobuhiro Zaima1, Yukihiro Yoshimura2, Shiori Inaba1, Takamichi Fujimori1, Tetsuya Sogon3, Tatsuya Moriyama1. 1. Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, Nara, 631-8505, Japan. 2. Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama, 719-1197, Japan. 3. WAKASA SEIKATSU, Sanko Bldg. 22, Naginataboko-cho, Shijo-Karasuma Shimogyo-ku, Kyoto, 600-8008, Japan.
Abstract
RATIONALE: Anthocyanins, which belong to a class of molecules called flavonoids, are known to have beneficial effects for both humans and animals. Many physiological functions have been attributed to anthocyanins since ancient times. The most important function is the relief of eyestrain, but the biodistribution of anthocyanins remains unknown. In this study, we analyzed the kinetics of anthocyanin species in mice eyeballs and surrounding tissues. METHODS: We used mice that were administered bilberry extract solution intraperitoneally. After harvesting eyeballs, cross-sections were prepared using a cryostat and analyzed using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). RESULTS: Various ions of anthocyanin species, m/z 419, 449, 463, 465, 479, and 493, were observed in MALDI-MSI spectra. Most of these peaks corresponded to places considered to be extraocular muscles with the outer layer of the retina. CONCLUSIONS: Through MALDI-MSI and MALDI-MS/MS analyses, we demonstrated that anthocyanin species are distributed at muscle tissues with the outer layer of the retina. It is speculated that anthocyanin species directly improve eyestrain at the extraocular muscles.
RATIONALE: Anthocyanins, which belong to a class of molecules called flavonoids, are known to have beneficial effects for both humans and animals. Many physiological functions have been attributed to anthocyanins since ancient times. The most important function is the relief of eyestrain, but the biodistribution of anthocyanins remains unknown. In this study, we analyzed the kinetics of anthocyanin species in mice eyeballs and surrounding tissues. METHODS: We used mice that were administered bilberry extract solution intraperitoneally. After harvesting eyeballs, cross-sections were prepared using a cryostat and analyzed using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). RESULTS: Various ions of anthocyanin species, m/z 419, 449, 463, 465, 479, and 493, were observed in MALDI-MSI spectra. Most of these peaks corresponded to places considered to be extraocular muscles with the outer layer of the retina. CONCLUSIONS: Through MALDI-MSI and MALDI-MS/MS analyses, we demonstrated that anthocyanin species are distributed at muscle tissues with the outer layer of the retina. It is speculated that anthocyanin species directly improve eyestrain at the extraocular muscles.