title: Siphonaxanthin, a green algal carotenoid, as a novel functional compound.
abstract: Siphonaxanthin is a specific keto-carotenoid in green algae whose bio-functional properties are yet to be identified. This review focuses on siphonaxanthin as a bioactive compound and outlines the evidence associated with functionality. Siphonaxanthin has been reported to potently inhibit the viability of human leukemia HL-60 cells via induction of apoptosis. In comparison with fucoxanthin, siphonaxanthin markedly reduced cell viability as early as 6 h after treatment. The cellular uptake of siphonaxanthin was 2-fold higher than fucoxanthin. It has been proposed that siphonaxanthin possesses significant anti-angiogenic activity in studies using human umbilical vein endothelial cells and rat aortic ring. The results of these studies suggested that the anti-angiogenic effect of siphonaxanthin is due to the down-regulation of signal transduction by fibroblast growth factor receptor-1 in vascular endothelial cells. Siphonaxanthin also exhibited inhibitory effects on antigen-induced degranulation of mast cells. These findings open up new avenues for future research on siphonaxanthin as a bioactive compound, and additional investigation, especially in vivo studies, are required to validate these findings. In addition, further studies are needed to determine its bioavailability and metabolic fate.
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. sugawara@kais.kyoto-u.ac.jp.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Sugawara
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. ganesan381980@yahoo.com.
authors.forename: Ponesakki
authors.initials: P
authors.lastname: Ganesan
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. lizhuosi@kais.kyoto-u.ac.jp.
authors.forename: Zhuosi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. yuukim@kais.kyoto-u.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Manabe
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. hiratan@kais.kyoto-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirata
mesh_terms: D020533:Angiogenesis Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D000460:Chlorophyta / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects; D006801:Humans; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D024341:Xanthophylls / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D020533:Angiogenesis Inhibitors; D024341:Xanthophylls; C025164:fucoxanthin; C003314:siphonaxanthin