Identification and Cytotoxic Evaluation of Pregnane Saponins from the Twigs and Leaves of Dregea volubilis.

Four new polyhydroxy pregnane glycosides, named volubilosides G-K (3, 5-7), along with three known secondary metabolites, dregeoside Da1 (1), dregeoside Ka1 (2), and volubiloside E (4) were isolated from the twigs and leaves of Dregea volubilis (DV). The chemical structures of these compounds (1-7) were elucidated using spectroscopic techniques (1D and 2D NMR and HR-ESI-MS analyses) and compared with those in the published literature. Compounds (1-7) were evaluated for cytotoxicity against eight cancer cell lines (MB49, K562, MKN-7, HT29, A549, MCF-7, MDA-MB-231, and HepG2), revealing varying levels of cytotoxic effects with IC50 values ranging from 4.29 to 21.05 µM. The results indicated that compounds 1-7 may serve as potential lead compounds for the discovery and development of novel anti-cancer drugs.

Cytotoxic Activities and Fingerprint Analysis of Triterpenes by HPTLC Technique for Distinguishing Ganoderma Species from Vietnam and other Asian Countries.

Ganoderma lucidum (Fr.) P. Karst. (Ganodermataceae), commonly called Linhzhi, is traditionally employed in the treatment of human diseases, including hepatitis, liver disorders, hypercholesterolemia, arthritis, bronchitis, and tumorigenic diseases. In this study, the fingerprint profiles of five different strains of G. lucidum originated from Japan, Korea, China, and Vietnam, five samples of G. lucidum growing on Erythrophloeum fordii Oliv. in Vietnam, and five related Linhzhi species (Ganoderma applanatum, Ganoderma australe, Ganoderma clossum, Ganoderma subresinosu, and Ganoderma sp.) were investigated for triterpene derivatives using high-pressure, thin-layer chromatography (HPTLC). The HPTLC fingerprint profiles demonstrated significant differences between G. lucidum and other related Linhzhi species in the presence of triterpene derivatives. Evaluation for the cytotoxicity of these samples against four cancer cell lines, including A549, MCF7, PC3, and HepG2, displayed various levels of cytotoxic effects, with IC50 values of: 15.6-46.3 µg/mL on the A549 cancer cell line, of 18.4-43.6 µg/mL on the MCF7 cancer cell line, of 10.0-32.1 µg/mL on the PC3 cancer cell line, and of 10.6-27.6 µg/mL on the HepG2 cancer cell line. Conclusively, these data contributed to the literature on the cytotoxic activities and fingerprint analysis of triterpenes by the HPTLC technique for distinguishing Ganoderma species from Vietnam and other Asian countries.

Household survey in two provinces in Viet Nam estimates HIV prevalence in an urban and a rural population.

A household-based population study interviewed 2,553 women and 1,984 men aged 15-49 years in urban (Ho Chi Minh City) and rural (Thai Binh) provinces in Viet Nam between July and August 2005. The survey response rate was high--approximately 97% of households and 93% of adults overall, with a >92% acceptance of HIV testing among eligible adults. The unadjusted estimated population HIV prevalence was 0.3% (confidence interval [CI]: 0.1-0.6%) in Thai Binh and 0.7% (CI: 0.3-1.3) in Ho Chi Minh City (HCMC), compared with the national estimates and projections of 0.352% and 1.250%, respectively, for 2005. The ratio of male-to-female prevalence was 10.5:1 in Thai Binh and 1.3:1 in HCMC. A low level of men reported purchasing sex in the last 12 months (2.4%) and there were low self-reports of sexually transmitted infections in all adults (5%). A correct knowledge of HIV/AIDS prevention methods was high in both provinces (83%), although only 24.8% of women knew of the use of antiretroviral therapy to prevent vertical transmission of HIV. The observed population prevalence was consistent with recent projections in Thai Binh, although lower than expected in HCMC, indicating the substantial downward revisions of projected population HIV prevalence may need to be extended. The unequal sex prevalence ratio is consistent with the projected trends of increasing male-to-female sexual transmission in urban areas. The results and experience of this study will inform future population based surveys in Viet Nam and the broader Asian region.

Control of aedes vectors of dengue in three provinces of Vietnam by use of Mesocyclops (Copepoda) and community-based methods validated by entomologic, clinical, and serological surveillance.

We describe remarkable success in controlling dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), in 6 communes with 11,675 households and 49,647 people in the northern provinces of Haiphong, Hung Yen, and Nam Dinh in Vietnam. The communes were selected for high-frequency use of large outdoor concrete tanks and wells. These were found to be the source of 49.6-98.4% of Ae. aegypti larvae, which were amenable to treatment with local Mesocyclops, mainly M. woutersi Van der Velde, M. aspericornis (Daday) and M. thermocyclopoides Harada. Knowledge, attitude, and practice surveys were performed to determine whether the communities viewed dengue and dengue hemorrhagic fever as a serious health threat; to determine their knowledge of the etiology, attitudes, and practices regarding control methods including Mesocyclops; and to determine their receptivity to various information methods. On the basis of the knowledge, attitude, and practice data, the community-based dengue control program comprised a system of local leaders, health volunteer teachers, and schoolchildren, supported by health professionals. Recycling of discards for economic gain was enhanced, where appropriate, and this, plus 37 clean-up campaigns, removed small containers unsuitable for Mesocyclops treatment. A previously successful eradication at Phan Boi village (Hung Yen province) was extended to 7 other villages forming Di Su commune (1,750 households) in the current study. Complete control was also achieved in Nghia Hiep (Hung Yen province) and in Xuan Phong (Nam Dinh province); control efficacy was > or = 99.7% in the other 3 communes (Lac Vien in Haiphong, Nghia Dong, and Xuan Kien in Nam Dinh). Although tanks and wells were the key container types of Ae. aegypti productivity, discarded materials were the source of 51% of the standing crop of Ae. albopictus. Aedes albopictus larvae were eliminated from the 3 Nam Dinh communes, and 86-98% control was achieved in the other 3 communes. Variable dengue attack rates made the clinical and serological comparison of control and untreated communes problematic, but these data indicate that clinical surveillance by itself is inadequate to monitor dengue transmission.