Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

The biochemistry and medical significance of the flavonoids.

Tetraodon nigroviridis is a freshwater puffer fish with the smallest known vertebrate genome. Here, we report a draft genome sequence with long-range linkage and substantial anchoring to the 21 Tetraodon chromosomes. Genome analysis provides a greatly improved fish gene catalogue, including identifying key genes previously thought to be absent in fish. Comparison with other vertebrates and a urochordate indicates that fish proteins have diverged markedly faster than their mammalian homologues. Comparison with the human genome suggests ∼900 previously unannotated human genes. Analysis of the Tetraodon and human genomes shows that whole-genome duplication occurred in the teleost fish lineage, subsequent to its divergence from mammals. The analysis also makes it possible to infer the basic structure of the ancestral bony vertebrate genome, which was composed of 12 chromosomes, and to reconstruct much of the evolutionary history of ancient and recent chromosome rearrangements leading to the modern human karyotype.

/pdf/genome-duplication-in-the-teleost-fish-tetraodon-qw9iuo5jxx.pdf

Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype

Copper toxicity, oxidative stress, and antioxidant nutrients.

Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we
report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000
protein-coding genes—more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer
than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology
including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism,
and important differences in Ca21 signalling as compared with plants and animals. Neurospora possesses the widest array of
genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced
point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the
creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related
genes.

/pdf/the-genome-sequence-of-the-filamentous-fungus-neurospora-2jw3s2832k.pdf

The genome sequence of the filamentous fungus Neurospora crassa

4 important flavonoid compounds, namely quercetin, kaempferol, neohesperidin dihydrochalcone and rutin, were administered to male mice for the detection of gross chromosomal anomalies by the micronucleus test. The first 3 compounds were positively clastogenic to different extents, whereas the 4th was negative.

Genetic toxicological testing of some plant flavonoids by the micronucleus test

Cytomixis has been observed throughout the year in the pollen mother cells of an apomictic ornamental Ervatamia divaricata (Linn.) Alston (var. single). The frequency of cytomixis was found to be more (8.66-13.95%) during the months of March to June in all the plants. Direct fusion of two pollen mother cells and involvement of a series of PMC's by one or more cytoplasmic connections were also noted.The regular occurrence of this behaviour in all the individuals and in successive years suggests the possibility of genetic control of the process, manifestation being dependent on physiological state of the tissue. Cytomixis, coupled with irregular number and other genetic factors, might have contributed to the failure of sexual reproduction. The absence of seed setting does not indicate any significant role of cytomixis in generating variability in this species.

Cytomixis in Pollen Mother Cells of an Apomictic Ornamental Ervatamia divaricata (Linn.) Alston

Extract of Phyllanthus emblica fruit and ascorbic acid were evaluated separately for protection against clastogenicity induced by lead (Pb) and aluminium (Al) salts on mouse bone marrow chromosomes. Oral administration of Phyllanthus fruit extract (PFE) for 7 days before exposure to both metals by intraperitoneal injection increased the frequency of cell division and reduced the frequency of chromosome breaks significantly. Comparable doses of synthetic ascorbic acid (AA) were less effective and could protect against the effects of Al and only a low dose of Pb (10 mg/kg body weight). AA administered before treatment in mice given higher doses of Pb (40 mg/kg body weight) enhanced the frequency of chromosome breaks, giving a synergistic effect. The higher protection afforded by PFE may be due to the combined action of all ingredients, rather than to AA alone.

Modification of clastogenicity of lead and aluminium in mouse bone marrow cells by dietary ingestion of Phyllanthus emblica fruit extract.

The action of different prefixing agents including water and a dilute CaCl2 solution on plants with high chromosome number showed that all the solutions tried exhibited marked effect on the physical state of the plasma. Also the plasmatic constitution of the pretreated tissue differed from the appearance of one fixed directly in dye-acid mixture for a few seconds without any pre-treatment. For the clarification of the karyotypes, the best results have been obtained with paradichlorobenzene. It was used as a prefixing agent with a short schedule for temporary smears of difficult materials, particularly those with high chromosome number. The method comprised treatment of the root tips in a saturated aqueous solution of the chemical for 3 hours at 12-16°C., followed by 4-5 seconds heating just to boiling in orcein-hydrochloric acid mixture, then smearing in 1% aceto-orcein solution.

Archana Sharma

Papers

Genetic toxicological testing of some plant flavonoids by the micronucleus test

Cytomixis in Pollen Mother Cells of an Apomictic Ornamental Ervatamia divaricata (Linn.) Alston

Modification of clastogenicity of lead and aluminium in mouse bone marrow cells by dietary ingestion of Phyllanthus emblica fruit extract.

Paradichlorobenzene and Other Chemicals in Chromosome Work

Modifying role of Phyllanthus emblica and ascorbic acid against nickel clastogenicity in mice.