Enrichment of the flavonoid fraction from leaves by a liquid antisolvent precipitation method and evaluation of antioxidant activities and .

leaves originate from the dry leaves of the plant. Flavonoids are the main functional components of leaves. Some flavonoids such as rutin, kaempferol and quercetin are rich in , and they have outstanding antioxidant efficacy.

Platelet-activating factor antagonists decrease follicular dendritic-cell stimulation of human B lymphocytes.

Both B-lymphoblastoid cell lines and tonsillar B lymphocytes express receptors for platelet-activating factor (PAF). In lymph node germinal centres, B lymphocytes interact with follicular dendritic cells (FDCs), which present antigen-containing immune complexes to B lymphocytes. FDCs have phenotypic features that are similar to those of stromal cells and monocytes and may therefore be a source of lipid mediators.

DNA methyltransferase 1 knock down induces gene expression by a mechanism independent of DNA methylation and histone deacetylation.

DNA methyltransferase 1 (DNMT1) catalyzes the post-replication methylation of DNA and is responsible for maintaining the DNA methylation pattern during cell division. A long list of data supports a role for DNMT1 in cellular transformation and inhibitors of DNMT1 were shown to have antitumorigenic effects. It was long believed that DNMT1 promoted tumorigenesis by maintaining the hypermethylated and silenced state of tumor suppressor genes.

Epigenomic stress response. Knockdown of DNA methyltransferase 1 triggers an intra-S-phase arrest of DNA replication and induction of stress response genes.

The DNA methylation pattern is an important component of the epigenome that regulates and maintains gene expression programs. In this paper, we test the hypothesis that vertebrate cells possess mechanisms protecting them from epigenomic stress similar to DNA damage checkpoints. We show that knockdown of DNMT1 (DNA methyltransferase 1) by an antisense oligonucleotide triggers an intra-S-phase arrest of DNA replication that is not observed with control oligonucleotide.

Proliferating cell nuclear antigen associates with histone deacetylase activity, integrating DNA replication and chromatin modification.

Faithful inheritance of the chromatin structure is essential for maintaining the gene expression integrity of a cell. Histone modification by acetylation and deacetylation is a critical control of chromatin structure. In this study, we test the hypothesis that histone deacetylase 1 (HDAC1) is physically associated with a basic component of the DNA replication machinery as a mechanism of coordinating histone deacetylation and DNA synthesis.