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.

The Application of Sample Pooling for Mass Screening of SARS-CoV-2 in an Outbreak of COVID-19 in Vietnam.

We sampled nasal-pharyngeal throat swabs from 96,123 asymptomatic individuals at risk of SARS-CoV-2 infection, and generated 22,290 pools at collection, each containing samples from two to seven individuals. We detected SARS-CoV-2 in 24 pools, and confirmed the infection in 32 individuals after resampling and testing of 104 samples from positive pools. We completed the testing within 14 days. We would have required 64 days to complete the screening for the same number of individuals if we had based our testing strategy on individual testing. There was no difference in cycle threshold (Ct) values of pooled and individual samples. Thus, compared with individual sample testing, our approach did not compromise PCR sensitivity, but saved 77% of the resources. The present strategy might be applicable in settings, where there are shortages of reagents and the disease prevalence is low, but the demand for testing is high.

Traphanoside GO1, a new triterpenoid saponin from the aerial parts of Glinus oppositifolius with the inhibitory effect on PGE2 production in LPS-induced HepG2 cells.

A new saponin, 3-O-[α-ʟ-rhamnosyl-(1→3)-ß-D-glucopyranosyl]-28-O-ß-D-glucopyranosyl serjanic acid (Traphanoside GO1, 11) along with eleven compounds (1-10 and 12) were isolated from the aerial parts of Glinus oppositifolius. The structures of all isolates were elucidated by analyzing extensive 1 D- and 2 D-NMR and HR-ESI-MS, comparing with reported literature data. Compounds 7-8, 10-11, and 90% ethanol extract (GOE90) were evaluated for the inhibitory effect on PGE2 production from activated HepG2 cells. Among these, new compound 11 showed the most potent inhibitory activity by suppressing LPS-induced PGE2 production on the HepG2 cells.

Cytotoxic sesquiterpene glucosides from Fissistigma pallens.

Six undescribed sesquiterpene glucosides, fissispallins A-F, and one known sesquiterpene glucoside, fissispallin, were discovered in the leaves of Fissistigma pallens (Finet & Gagnep.) Merr. The structures were determined using spectroscopic methods, including 1D, 2D NMR, and MS. All compounds were evaluated for cytotoxic activity against three human cancer cell lines, HT-29, A-2058, and A-549. Fissispallin A showed potent activity with the IC50 values less than 1.5 µM against all tested human cancer cell lines. Fissispallin also showed potent activity with IC50 value of 0.4 ± 0.3 on the A-2058 cancer cell lines. Fissispallins B-D showed significant cytotoxic activity against all the tested cancer cell lines with IC50 values ranging from 3.8 to 7.2 µM.

Three new flavonol glycosides from Fissistigma pallens.

Three new flavonol glycosides, fissflavosides A-C (1-3), together with six known flavonol glycosides, kaempferol 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-galactopyranoside (4), kaempferol 3-O-α-L-rhamnopyranosyl-(1→6)-ß-D-galactopyranoside (5), kaempferol 3-O-α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranoside (6), rhamnetin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside (7), rutin (8), and isorhamnetin 3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-galactopyranoside (9) were isolated from the methanol extract of the Fissistigma pallens leaves. Their chemical structures were determined by 1D-, 2D-NMR, and MS data as well as in comparison with reported data in the literature. Compounds 1-9 showed weak cytotoxic activity on three human cancer cell lines, HT-29, A-2058, A-549 with IC50 ranging from 134.6 to 162.6 µM. In addition, the antioxidant capacities of compounds were also tested by ORAC assay. All compounds showed significant antioxidant with trolox equivalents ranging from 4.4 to 8.6 µM at the concentration of 1.0 µM. The results indicated 7 and 8 having meaningful reducing capacity of copper (I) ions of 2.7 to 6.9 µM at the concentrations of 1 and 2 µM.

An Update on Anti-CD137 Antibodies in Immunotherapies for Cancer.

The selective expression of CD137 on cells of the immune system (e.g., T and DC cells) and oncogenic cells in several types of cancer leads this molecule to be an attractive target to discover cancer immunotherapy. Therefore, specific antibodies against CD137 are being studied and developed aiming to activate and enhance anti-cancer immune responses as well as suppress oncogenic cells. Accumulating evidence suggests that anti-CD137 antibodies can be used separately to prevent tumor in some cases, while in other cases, these antibodies need to be co-administered with other antibodies or drugs/vaccines/regents for a better performance. Thus, in this work, we aim to update and discuss current knowledge about anti-cancer effects of anti-CD137 antibodies as mono- and combined-immunotherapies.

CDKN2A-rs10811661 polymorphism, waist-hip ratio, systolic blood pressure, and dyslipidemia are the independent risk factors for prediabetes in a Vietnamese population.

BACKGROUND: People with prediabetes are at greater risk for heart attack, stroke, kidney disease, vision problems, nerve damage and high blood pressure, compared to those without the disease. Prediabetes is a complex disorder involving both genetic and environmental factors in its pathogenesis. This cross-sectional study aimed to investigate the independent risk factors for prediabetes, considering the contribution of genetic factors (TCF7L2-rs7903146, IRS1-rs1801278, INSR-rs3745551, CDKN2A-rs10811661, and FTO-rs9939609), socio-economic status, and lifestyle factors. RESULTS: Among the candidate genes studied, the CDKN2A-rs10811661 polymorphism was found to be the most significant factor associated with prediabetes in the model unadjusted and adjusted for age, sex, obesity-related traits, systolic blood pressure, dyslipidemia, socio-economic status, and lifestyle factors. In the final model, the CDKN2A-rs10811661 polymorphism (OR per T allele = 1.22, 95 % CI = 1.04-1.44, P = 0.017), systolic blood pressure (OR per 10 mmHg = 1.14, 95 % CI = 1.08-1.20, P < 0.0001), waist-hip ratio (OR = 1.25, 95 % CI = 1.10-1.42, P < 0.0001), dyslipidemia (OR = 1.57, 95 % CI = 1.15-2.14, P = 0.004), and residence (OR = 1.93, 95 % CI = 2.82-4.14, P < 0.0001) were the most significant independent predictors of prediabetes, in which the power of the adjusted prediction model was 0.646. CONCLUSIONS: The study suggested that the CDKN2A-rs10811661 polymorphism, waist-hip ratio, systolic blood pressure, and dyslipidemia were significantly associated with the increased risk of prediabetes in a Vietnamese population. The studied genetic variant had a small effect on prediabetes.

HIV service delivery models towards 'Zero AIDS-related Deaths': a collaborative case study of 6 Asia and Pacific countries.

BACKGROUND: In the Asia-Pacific region, limited systematic assessment has been conducted on HIV service delivery models. Applying an analytical framework of the continuum of prevention and care, this study aimed to assess HIV service deliveries in six Asia and Pacific countries from the perspective of service availability, linking approaches and performance monitoring for maximizing HIV case detection and retention. METHODS: Each country formed a review team that provided published and unpublished information from the national HIV program. Four types of continuum were examined: (i) service linkages between key population outreach and HIV diagnosis (vertical-community continuum); (ii) chronic care provision across HIV diagnosis and treatment (chronological continuum); (iii) linkages between HIV and other health services (horizontal continuum); and (iv) comprehensive care sites coordinating care provision (hub and heart of continuum). RESULTS: Regarding the vertical-community continuum, all districts had voluntary counselling and testing (VCT) in all countries except for Myanmar and Vietnam. In these two countries, limited VCT availability was a constraint for referring key populations reached. All countries monitored HIV testing coverage among key populations. Concerning the chronological continuum, the proportion of districts/townships having antiretroviral treatment (ART) was less than 70% except in Thailand, posing a barrier for accessing pre-ART/ART care. Mechanisms for providing chronic care and monitoring retention were less developed for VCT/pre-ART process compared to ART process in all countries. On the horizontal continuum, the availability of HIV testing for tuberculosis patients and pregnant women was limited and there were sub-optimal linkages between tuberculosis, antenatal care and HIV services except for Cambodia and Thailand. These two countries indicated higher HIV testing coverage than other countries. Regarding hub and heart of continuum, all countries had comprehensive care sites with different degrees of community involvement. CONCLUSIONS: The analytical framework was useful to identify similarities and considerable variations in service availability and linking approaches across the countries. The study findings would help each country critically adapt and adopt global recommendations on HIV service decentralization, linkages and integration. Especially, the findings would inform cross-fertilization among the countries and national HIV program reviews to determine county-specific measures for maximizing HIV case detection and retention.

Genetic analysis of ORF5 porcine reproductive and respiratory syndrome virus isolated in Vietnam.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important swine pathogens because it is highly infectious and causes economic losses due to decreased pig productivity. In this study, the 603 bp complete major envelope protein encoding gene (ORF5) of 32 field PRRSV isolates from Vietnam collected during 2008-2012 were sequenced and analyzed. Multiple nucleotide (nt) and deduced amino acid (aa) alignments of ORF5 were performed on the 32 isolates: the representative strains (European and North American genotypes), Chinese strains available in GenBank and vaccine strains licensed for use in Vietnam. The results showed 94.8-100.0% nt identity and 94.0-100% aa similarity among the 32 isolates. These isolates shared similarities with the prototype of the North American PRRSV strain (VR-2332; nt 87.8-89.3%, aa 87.5-90.0%), and Lelystat virus, the prototype of the European PRRSV strain (LV; nt 61.1-61.9%, aa 55.1-57.0%). There was greater similarity with QN07 (nt 96.5-98.5%, aa 96.0-99.0%) from the 2007 PRRS outbreak in QuangNam Province, CH-1a (nt 93.2-95.1%, 91.5-93.5%) isolated in China in 1995 and JXA1 (nt 96.5-98.6%, aa 95.0-98.0%), the highly pathogenic strain from China isolated in 2006. The Vietnamese isolates were more similar to JXA1-R (nt 96.5-98.6%, aa 95.0-98.0%), the strain used in Chinese vaccines, than to Ingelvac MLV/BSL-PS (nt 87.2-89.0%, aa 86.0-89.0%). Phylogenetic analysis showed that the 32 isolates were of the North American genotype and classified into sub-lineage 8.7. This sub-lineage contains highly pathogenic Chinese PRRSV strains. This study documents genetic variation in circulating PRRSV strains and could assist more effective use of PRRS vaccines in Vietnam.

Cooking temperature, heat-generated carcinogens, and the risk of stomach and colorectal cancers.

BACKGROUND: Food change due to cooking temperature and unrecognized heat-formed chemical carcinogens may impact on the risk of stomach and colo-rectal cancers. To test this hypothesis a case-control study was performed. METHODS: A total of 670 cases of stomach and colo-rectal cancers matched with 672 hospital controls for sex and -/+5 years age admitted to three hospitals in Hanoi city in the North Viet Nam from October 2006 to September 2007 were the subjects. Five levels of food change due to cooking temperature were based on food color; white, pale yellow, yellow, dark yellow, and burnt. We asked study subjects to themselves report which of these five colors was their preferable intake before the onset of disease. The present study included; fried fishes-meats-eggs-potato-tofu; grilled foods; roasted foods; sugar, bread, heated wheat, and biscuits. These were cooked at temperatures as high as from 165 to 240 degrees C, based on the literature. Adjusted estimation of odds ratio was conducted controlling for possible confounding factors using STATA 8.0. RESULTS: A high intake of roasted meats, bread and biscuit significantly increased the risk of cancer as much as OR= 1.63, 95%CI= 1.04-2.54; OR= 1.40, 95%CI= 1.03-1.90; OR= 1.60, 95%CI= 1.03-2.46 with probabilities for trend = 0.029, 0.035, and 0.037, respectively. For exposure among controls: 529 (79%) were not exposed at all to roasted meats; 449 (67%) were not exposed at all to bread; and 494 (74%) were not exposed at all to biscuit. CONCLUSIONS: Observation of food change due to cooking temperature based on color is practically feasible for detecting associations with risk of developing cancer.

Development of a semi-quantitative food frequency questionnaire for dietary studies--focus on vitamin C intake.

The present work aimed to provide a basis for examination of intake of selected food items determined with a semi-quantitative food frequency questionnaire (SQFFQ) and planned-food selection (PFS). From February to July of 2003, ninety one cancer patients and 90 matched (same sex and age within 5 years) non-cancer patients were directly interviewed by trained interviewers using the designed questionnaire at the inpatient-department of Viet Duc hospital, Ha Noi City, Viet Nam. Study subjects consumed more SQFFQ-food items than PFS-food items, so that the latter method might not accurately reflect dietary habits regarding estimation of nutrient intake, especially vitamins. Because these are beneficial factors acting against cancer development at many sites, the absence of food items selected by SQFFQ may result in a poor database regarding possible confounding factors. For futher clarification we then focused on vitamin C contributions of Vietnamese food and analyzed data of the National Nutritional Household Survey in 2000: 7,686 households throughout the country (vitamin C intake status) and 158 households with 741 persons of the population of Hanoi city (individual food items contributing to vitamin C). Direct interview using a validated questionnaire with an album of current Vietnamese food items-recipes and weighing checks was conducted to obtain information regarding all types of food intake over the last 24-hours. Contribution analysis using the Nutritive Composition Table of Vietnamese Foods, revision 2000, and stepwise regression analysis was applied. Average intake adjusted by ages of vitamin C per person per day was estimated. In total, the study subjects were found to currently consume 184 food items. Average intake of vitamin C was 72.5 mg per person per day at the national level: 57.9% from leafy vegetables, 33.4% from fresh fruits, and 6.4% from non-leafy vegetables. For vitamin C contribution, the highest 25 food items contributed to a cumulative 95.3% of vitamin C intake with a cumulative R2=0.99.

Gastric and colo-rectal cancer mortality in Viet Nam in the years 2005-2006.

BACKGROUND: The International Collaborative Epidemiological Study of Host and Environmental Factors for Stomach and Colorectal Cancers in Southeast Asian Countries (SEACs) has been conducted in Viet Nam from 2003 to 2008 on a case-control basis. For further effective primary prevention, we examined gastric and colorectal cancer mortality nationwide in eight regions of Viet Nam in 2005-06. METHODS: Both demographic data and lists of all deaths in 2005-06 were obtained from all 10,769 commune health stations in Viet Nam. Five indicators included name, age, sex, date of death and cause of death was collected for each case. We selected only communes having the list of deaths with clear cause for each case and crude mortality rate for all causes from 300-600/100,000 as published by the Ministry of Health for a reasonable accuracy and completeness. Obtained data for all causes, all cancers, stomach and colorectal cancer deaths as well as demographic information were processed using Excel software and exported to STATA 8.0 for estimation of world age-standardized cancer mortality rates per 100,000. RESULTS: Data were available for 1,246 gastric cases, (819 male and 427 female) with age-standardized mortality rates from 12.7 to 31.3 per 100,000 in males and from 5.9 to 10.3 per 100,000 in females in the 8 regions of the country. For colorectal cancers, 542 cases (268 male and 274 female) gave mortality rates from 4.0 to 11.3 per 100,000 in males and from 3.0 to 7.8 per 100,000 in females. DISCUSSION: Stomach cancer mortality in males in the region of North East in the North Viet Nam (2005-06) was higher than that in Japan (2002) (31.3 versus 28.7 per 100,000) while colorectal cancer in Viet Nam was lower. While prevalence of Helicobacter pyloris infection in Viet Nam was from 70-75% in both males and females, the stomach cancer rate in males was significantly higher than in females, 31.3 versus 6.8 per 100,000, suggesting an influence of other environmental risk factors. Whether protective factors are operating against colorectal cancer in Viet Nam now needs to be explored.