Cyanidin-3-glucoside, a natural product derived from blackberry, exhibits chemopreventive and chemotherapeutic activity

Epidemiological data suggest that consumption of fruits and vegetables has been associated with a lower incidence of cancer. Cyanidin-3-glucoside (C3G), a compound found in blackberry and other food products, was shown to possess chemopreventive and chemotherapeutic activity in the present study. In cultured JB6 cells, C3G was able to scavenge ultraviolet B-induced *OH and O2-* radicals. In vivo studies indicated that C3G treatment decreased the number of non-malignant and malignant skin tumors per mouse induced by 12-O-tetradecanolyphorbol-13-acetate (TPA) in 7,12-dimethylbenz[a]anthracene-initiated mouse skin. Pretreatment of JB6 cells with C3G inhibited UVB- and TPA-induced transactivation of NF-kappaB and AP-1 and expression of cyclooxygenase-2 and tumor necrosis factor-alpha. These inhibitory effects appear to be mediated through the inhibition of MAPK activity. C3G also blocked TPA-induced neoplastic transformation in JB6 cells. In addition, C3G inhibited proliferation of a human lung carcinoma cell line, A549. Animal studies showed that C3G reduced the size of A549 tumor xenograft growth and significantly inhibited metastasis in nude mice. Mechanistic studies indicated that C3G inhibited migration and invasion of A549 tumor cells. These finding demonstrate for the first time that a purified compound of anthocyanin inhibits tumor promoter-induced carcinogenesis and tumor metastasis in vivo.     

Earthworm effect on root morphology in a split root system

Plants respond to their environment through adaptations such as root proliferation in nutrient-rich patches. Through their burrows and casts production in soil, earthworms create heterogeneity which could lead to local root adaptations or systemic effects. To investigate the effect of earthworms on root system morphology and determine whether earthworm effect is local or systemic, we set up two independent split root experiments with rice or barley, (i) without earthworm (CC), (ii) with earthworms in both compartments (EE), and (iii) with earthworms in one single compartment (CE). Earthworms had an effect on belowground plant biomass. The relative length of thick roots decreased with an increasing abundance of earthworms. Some root diameter classes responded to earthworm number in a linear or curvilinear way, making simple conclusions difficult. We found no difference in root biomass or morphology between the two compartments of the split root system in the CE treatment, but a positive effect of earthworm biomass on root biomass, volume, surface area, and length at the whole plant level. Results supported a systemic effect dependent on earthworm abundance. Modification of nutrient mineralization, soil physical structure, and/or the concentration of signal molecules could all be responsible for this systemic effect.     

<Emphasis Type="Italic">Narcissus tazetta</Emphasis> lectin shows strong inhibitory effects against respiratory syncytial virus,influenza A (H1N1, H3N2, H5N1) and B viruses

A mannose-binding lectin (Narcissus tazetta lectin [NTL]) with potent antiviral activity was isolated and purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis, using ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on mannose-agarose and fast protein liquid chromatography (FPLC)-gel filtration on Superose 12. The purified lectin was shown to have an apparent molecular mass of 26 kDa by gel filtration and 13 kDa by SDS-PAGE, indicating that it is probably a dimer with two identical subunits. The cDNA-derived amino acid sequence of NTL as determined by molecular cloning also reveals that NTL protein contains a mature polypeptide consisting of 105 amino acids and a C-terminal peptide extension. Three-dimensional modelling study demonstrated that the NTL primary polypeptide contains three subdomains, each with a conserved mannose-binding site. It shows a high homology of about 60%–80% similarity with the existing monocot mannose-binding lectins. NTL could significantly inhibit plaque formation by the human respiratory syncytial virus (RSV) with an IC₅₀ of 2.30 μg/ml and exhibit strong antiviral properties against influenza A (H1N1, H3N2, H5N1) and influenza B viruses with IC₅₀ values ranging from 0.20 μg/ml to 1.33 μg/ml in a dose-dependent manner. It is worth noting that the modes of antiviral action of NTL against RSV and influenza A virus are significantly different. NTL is effective in the inhibition of RSV during the whole viral infection cycle, but the antiviral activity of NTL is mainly expressed at the early stage of the viral cycle of influenza A (H1N1) virus. NTL with a high selective index (SI=CC₅₀/IC₅₀≥141) resulting from its potent antiviral activity and low cytotoxicity demonstrates a potential for biotechnological development as an antiviral agent.     

Purification and Functional Reconstitution of the Human CHIP28 Water Channel Expressed inSaccharomyces cerevisiae

The yeastSaccharomyces cerevisiaewas used for heterologous expression of the human CHIP28 water Aquaporin-1 channel (Aquaporin-1). A nine-amino-acid epitope of the influenza hemagglutinin protein (HA epitope), recognized by the monoclonal antibody 12CA5, was chosen to tag CHIP28 at its N-terminus. Epitope-tagged CHIP28 was purified from yeast extracts by immunochromatography on protein A/12CA5-coupled beads, after KI extraction and detergent solubilization, then concentrated by anion exchange chromatography. Purified protein was reconstituted in proteoliposomes and was shown to function as a water channel by stopped-flow spectrophotometry. This study demonstrates that the yeast has the capacity to produce functional aquaporins at levels sufficient for biochemical and biophysical analyses.     

An inside job for siRNAs

Among the three main categories of small silencing RNAs in insects and mammals-siRNAs, miRNAs, and piRNAs-siRNAs were thought to arise primarily from exogenous sources, whereas miRNAs and piRNAs arise from endogenous loci. Recent work in flies and mice reveals several classes of endogenous siRNAs (endo-siRNAs) that contribute to functions previously reserved for miRNAs and piRNAs, including gene regulation and transposon suppression.