Actinobacteria from Termite Mounds Show Antiviral Activity against Bovine Viral Diarrhea Virus, a Surrogate Model for Hepatitis C Virus.

Extracts from termite-associated bacteria were evaluated for in vitro antiviral activity against bovine viral diarrhea virus (BVDV). Two bacterial strains were identified as active, with percentages of inhibition (IP) equal to 98%. Both strains were subjected to functional analysis via the addition of virus and extract at different time points in cell culture; the results showed that they were effective as posttreatments. Moreover, we performed MTT colorimetric assays to identify the CC50, IC50, and SI values of these strains, and strain CDPA27 was considered the most promising. In parallel, the isolates were identified as Streptomyces through 16S rRNA gene sequencing analysis. Specifically, CDPA27 was identified as S. chartreusis. The CDPA27 extract was fractionated on a C18-E SPE cartridge, and the fractions were reevaluated. A 100% methanol fraction was identified to contain the compound(s) responsible for antiviral activity, which had an SI of 262.41. GC-MS analysis showed that this activity was likely associated with the compound(s) that had a peak retention time of 5 min. Taken together, the results of the present study provide new information for antiviral research using natural sources, demonstrate the antiviral potential of Streptomyces chartreusis compounds isolated from termite mounds against BVDV, and lay the foundation for further studies on the treatment of HCV infection.

Antiviral activity of Bacillus sp. isolated from the marine sponge Petromica citrina against bovine viral diarrhea virus, a surrogate model of the hepatitis C virus.

The Hepatitis C virus causes chronic infections in humans, which can develop to liver cirrhosis and hepatocellular carcinoma. The Bovine viral diarrhea virus is used as a surrogate model for antiviral assays for the HCV. From marine invertebrates and microorganisms isolated from them, extracts were prepared for assessment of their possible antiviral activity. Of the 128 tested, 2 were considered active and 1 was considered promising. The best result was obtained from the extracts produced from the Bacillus sp. isolated from the sponge Petromica citrina. The extracts 555 (500 µg/mL, SI>18) and 584 (150 µg/mL, SI 27) showed a percentage of protection of 98% against BVDV, and the extract 616, 90% of protection. All of them showed activity during the viral adsorption. Thus, various substances are active on these studied organisms and may lead to the development of drugs which ensure an alternative therapy for the treatment of hepatitis C.

Antiproliferative properties of polyketides isolated from Virola sebifera leaves.

An activity-guided fractionation of Virola sebifera Aubl. methylene chloride-soluble fraction provided novel 3,5-dihydro-2-(1'-oxo-3'-hexadecenyl)-2-cyclohexen-1-one (3), two known lignans (1, 2) and dehydro hexadecanoyl resorcinol (4). Isolation and purification were conducted with the application of column chromatography and structures were assigned by spetral analysis (1D and 2D NMR, HREIMS). Compounds 1-4 were evaluated for cytotoxic activities against human tumour cell lines UACC62 (melanoma), MCF-7 (breast), NCI 460 (lung, non-small cells), OVCAR03 (ovarian), PC-03 (prostate), HT-29 (colon), 786-0 (renal) and NCI-ADR (breast expressing phenotype multiple drugs resistance) in vitro. The new polyketide (3) showed selectivity against human OVCAR03 and NCI-ADR cell lines, ranging from 2 to 4 microg/mL.

Antiproliferative activity, isolation and identification of active compound from Gaylussacia brasiliensis

Gaylussacia brasiliensis (Spreng.) Meissn., Ericaceae, is used in folk medicine for treatment of several inflammatory processes and as healing agent. The scope of this work was to evaluate the in vitro antiproliferative activity of crude dichloromethane extract (CHD) and to identify the compound(s) responsible for this activity. CHD was evaluated and showed a concentration dependent inhibition on all cells lines. Therefore CHD was submitted to several classical columns chromatography providing the most active fraction (FC), inhibiting all cells line at 25 µg/mL. FC was further fractionated affording isolated compound 2β, 3β-dihydroxy-urs-12-ene-28-oic acid , identified on basis of 2D-NMR experiments and showed concentration-dependent activity and selectivity for kidney and breast cell lines.

(R)-Goniothalamin: total syntheses and cytotoxic activity against cancer cell lines.

The total syntheses of (R)-goniothalamin (1), a styryl lactone isolated from several Goniothalamus species, via catalytic asymmetric allylation of alpha-benzyloxyacetaldehyde (2), followed by ring-closing metathesis and Wittig olefination and via catalytic asymmetric allylation of trans-cinnamaldehyde (12), followed by ring-closing metathesis are reported. The antiproliferative activities of (R)-1 and its Z-isomer 10 as well as of the synthetic dihydropyranone intermediates 7 and 8 against eight different cancer cell lines are also described.

Cytotoxicity of tamoxifen in normal and tumoral cell lines and its ability to induce cellular transformation in vitro.

Tamoxifen (TAM) is a non-steroidal anti-estrogen used to treat patients with estrogen receptor-positive breast cancer and as a chemopreventive agent against breast cancer in high risk pre- and post-menopausal women. However, recent studies have shown that tamoxifen causes endometrial and hepatic cancer. In this study, we examined the effects of tamoxifen (5, 10, 25 and 50 microM) on the growth and proliferation of nine tumoral cell lines (UACC62, MCF-7, NCI-460, K-562, OVCAR-03, PC-03, HT-29, 786-0, NCI-ADR) and non-tumoral cell lines (3T3, V79, MDCK, VERO). Chinese hamster lung fibroblasts (V79) were the most sensitive lineage to tamoxifen, with 21.6% of the cells showing apoptosis at 50 microM TAM. Microscopic analysis showed that, the cellular transformation caused by TAM in V79 cells was similar to that seen with 7,12-dimethylbenz(a)anthracene, thus indicating the carcinogenicity of TAM.

Enantioselective syntheses of (R)- and (S)-argentilactone and their cytotoxic activities against cancer cell lines.

Concise total syntheses of (R)- and (S)-argentilactone have been developed via enantioselective catalytic allylation (ECA) and ring-closing metathesis pathways (four steps, 39% overall yield and 82-84% ee) from 2-octynal and their in vitro activity against cancer cells is described.