1.Low oxygen tension and relative defined culture medium with 3, 4-dihydroxyflavone are beneficial for yak-bovine interspecies somatic cell nuclear transfer embryo.
Xiong X1, Li J, Wang L, Zhong J, Zi X, Wang Y. Reprod Domest Anim. 2014 Feb;49(1):126-33. doi: 10.1111/rda.12240. Epub 2013 Sep 17.
With an aim to improve the efficiency of yak-bovine interspecies somatic cell nuclear transfer (iSCNT), this study investigated the effect of different culture systems on the development, quality and gene expression profile of yak-bovine iSCNT embryo. Reconstructed embryos were cultured in modified synthetic oviductal fluid (mSOF) or relative defined culture medium (RDCM) with 5% or 20% oxygen tension. Relative mRNA abundance of Oct-4, IFNT, IGF-2, Bax, GPX-1, SOD-1, CAT and GSS was analysed in blastocysts with qRT-PCR. The blastocyst formation rate in RDCM under 5% oxygen tension was significantly higher than that under 20% oxygen tension (P < 0.05). The total cell number of blastocyst derived from RDCM with 20% oxygen tension was lower than that of other groups, whereas the group of RDCM with 5% oxygen tension showed a beneficial effect on apoptosis index and tolerance to cryopreservation (P < 0.05). However, under the same oxygen tension, the mRNA abundance of IFNT of RDCM groups was higher than that of the mSOF groups.
2.3,3',4',5,5'-Pentahydroxyflavone is a potent inhibitor of amyloid β fibril formation.
Ushikubo H1, Watanabe S, Tanimoto Y, Abe K, Hiza A, Ogawa T, Asakawa T, Kan T, Akaishi T. Neurosci Lett. 2012 Mar 28;513(1):51-6. doi: 10.1016/j.neulet.2012.02.006. Epub 2012 Feb 11.
The natural flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) is neurotrophic and prevents fibril formation of amyloid β protein (Aβ). It is a promising lead compound for the development of therapeutic drugs for Alzheimer's disease. To find even more effective drugs based on the structure of fisetin, we synthesized a series of fisetin analogues lacking the 7-hydroxyl group and compared their effects on Aβ fibril formation determined by the thioflavin T fluorescence assay. 3,3',4'-Trihydroxyflavone and 3',4'-dihydroxyflavone inhibited Aβ fibril formation more potently than fisetin or 3',4',7-trihydroxyflavone, suggesting that the 7-hydroxy group is not necessary for anti-amyloidogenic activity. 3,3',4',5'-Tetrahydroxyflavone and 3',4',5'-trihydroxyflavone inhibited Aβ fibril formation far more potently than 3,3',4'-trihydroxyflavone and 3',4'-dihydroxyflavone, suggesting that 3',4',5'-trihydroxyl group of the B ring is crucial for the anti-amyloidogenic activity of flavonoids.