Secondhand Smoke and Socio-Demographic Associated Factors: Results From the Vietnam Population-Based Provincial Global Adult Tobacco Survey in 2022.

Background: Secondhand smoke (SHS) has detrimental effects on community health, including coronary heart diseases, stroke, lung cancer etc. This manuscript exploited data from the Vietnam Population-based Provincial Global Adult Tobacco Survey (PGATS) in 2022 to update the prevalence of adult exposure to SHS and associated socio-demographic factors. Methods: With the sample size of 71,981 adults aged 15+ throughout 30 provinces and cities in Vietnam, data was collected using the Global Adult Tobacco Survey (GATS) questionnaire. Bivariate analysis and multivariate logistic regression modelling were performed. Results: In the past 30 days, 44.4% (95% CI: 44.0%-44.9%) adults aged 15+ exposed to SHS at home while 23.1% (95% CI: 22.6%-23.6%) exposed to SHS at work. Female exposure to SHS in the past 30 days was higher at homes but lower at indoor workplaces. Participants aged 15-24 were likely to have higher odds of SHS exposure in the past 30 days to other age groups. Those living in the urban areas had 1.15 times higher odds (95% CI: 1.08-1.22) of exposure to SHS than those in the rural areas. Current smokers tended to have 2.2 times higher odds of exposure to SHS at the indoor workplaces compared to non-smokers (95% CI: 2.05-2.37). Conclusions: The prevalence of exposure to SHS at home was still relatively high amongst the adult population. While there was a significant reduction of SHS exposure at indoor workplaces, there was a higher prevalence of women being exposed to SHS at home. The Government of Vietnam should continue to strictly implement the smoke-free environment resolution at indoor workplaces and appropriate communication campaigns to protect people, especially women from SHS exposure at homes.

Glycoside constituents from Cayratia geniculata.

Using various chromatographic separations, six glycoside derivatives (1-6), including one new ent-labdane glucoside named cayratioside (1), were isolated from the methanol extract of Cayratia geniculata stems and leaves. Their structures were elucidated by detailed analysis of the 1D, 2D NMR, and HRESIQTOF mass spectra. The inhibitory effect of 1-6 on LPS-induced NO production in RAW264.7 cells was also evaluated. Among isolated compounds, 1 exhibited moderate activity with an IC50 value of 59.65 ± 1.85 µM.

Caffeoylquinic acid esters, lignans and flavones from Yua thomsonii with cytotoxic and nitric oxide inhibitory activities.

Phytochemical study on the aerial parts of Yua thomsonii resulted in the isolation of 11 secondary metabolites, including a new caffeoyl quinic acid derivative, 3-O-trans-caffeoyl-4-O-acetylquinic acid methyl ester (1), a new dihydrobenzofuran neolignan, 3,5-dimethoxy-4-(1″,3″-dihydroxy-2″-propyloxyl)-4',7-epoxy-8,5'-neolignan-4,9,9'-triol (3) and nine known compounds, methyl 4-O-coumaroylquinate (2), (7S*,8S*)-3-methoxy-3',7-epoxy-8,4'-oxyneolignan-4,9,9'-triol (4), kompasinol A (5), lyoniresinol (6), schizandriside (7), (-)-isolariciresinol 3a-O-ß-D-xylopyranoside (8), lyoniside (9), vitexin (10) and luteolin 4'-O-ß-glucopyranoside (11). Their structures were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR and HRESI mass spectra. The absolute configurations of 1 and 3 were deduced by electronic circular dichroism spectroscopy. Compounds 1, 3, 5 and 6 exhibited nitric oxide (NO) inhibitory effects, with IC50 values ranging from 12.18 to 29.45 µM. However, compounds 1, 3, 6 and 8 were non-cytotoxic towards HepG2 and MCF-7 carcinoma cells.

A study implementing real-time PCR to identify Strongyloides species of third-stage larvae in human stool samples from Southern Vietnam.

Background: Strongyloidiasis, a neglected disease caused by intestinal nematodes of the genus, is endemic to tropical and subtropical areas such as Vietnam. Morphological methods only identify the genus, while DNA-molecular techniques are susceptible in Strongyloides spp. detection. The study aims to determine the prevalence of dominant Strongyloides species among the population in Duc Hoa district, Long An, Vietnam. Methods: A cross-sectional study used 1190 stool specimens collected from July 2017 to November 2018. All samples were transported within 2 h, stored at 2-8°C, and processed within 48 h for microscopy smear and culture at the Laboratory of Medical Parasitology, Pham Ngoc Thach University of Medicine (PNT). Then all positive samples with the above 2 methods were verified by real-time PCR technique. Real-time PCR amplification was conducted at the Laboratory of Molecular Biology, PNT. Results: Direct microscopy and modified Harada-Mori culture detected Strongyloides spp. larvae in 79/1190 samples (6.6%). About 94.2% of the DNA samples were Strongyloides stercoralis, 2.9% were co-infections with Strongyloides ratti and S. stercoralis, and 2.9% were patients with S. ratti. The identity of 12/14 sequences was confirmed as S. stercoralis with a high level of similarity (91.3%-100%) and over 98% for S. ratti. Conclusion: DNA-molecular techniques and sequence analysis are highly suitable for identifying Strongyloides species isolated from stool samples. It is remarkable evidence of the presence of zoonosis S. ratti disease in human, not just the known S. stercoralis. It is likely to result in a certain proportion of people being infected by this animal-borne infectious pathogen.

Acylated flavonoid glycosides from Barringtonia pendula and their inhibition on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells.

Six new acylated flavonoid glycosides namely barringosides J - O (1-6) along with tephrokaempferoside and barringoside D were isolated from the branches and leaves of Barringtonia pendula. The structural elucidation was confirmed by extensive analysis of their spectroscopic data including HRQTOFMS, 1D and 2D NMR experiments. Moderate inhibitory effects on LPS-induced NO production in RAW264.7 cells were observed for barringosides M (4) and N (5) with IC50 values of 48.40 ± 3.01 and 56.61 ± 3.87 µM, whereas weak inhibition was found for compounds 1-3, 6, and 7 with IC50 values ranging from 64.91 ± 3.68 to 79.80 ± 3.90 µM.

Diterpenoid and phenolic constituents from corn silk (Zea mays) with PTP1B inhibitory activity.

Chemical investigation of corn silk resulted in the isolation of nine secondary metabolites, including a new ent-kaurane diterpenoid, zeamaysditerpene A (1) and eight known compounds, stigmaydene A (2), stigmaydene J (3), stigmaydene L (4), stigmane D (5), demethyltorosaflavone D (6), chrysoeriol 6-C-ß-boivinopyranosyl-7-O-ß-D-glucopyranoside (7), deoxypodophyllotoxin (8), and α-peltatin glucoside (9). Their structures were elucidated using a combination of spectroscopic methods, including 1D and 2D NMR and HRESIQTOF mass spectra. The absolute configuration of 1 was deduced by applying electronic circular dichroism (ECD) calculation method. Among the isolates, only 6 displayed significant inhibition against PTP1B activity in a dose-dependent manner, with an IC50 value of 10.7 ± 0.1 µM. Furthermore, molecular docking simulation was carried out to explore the action perspective of 6 inside the enzyme PTP1B. This finding suggests that 6 might be a potential lead for the development of a new anti-diabetic agent.

Asterosaponins from the starfish Protoreaster nodosus.

Five asterosaponins (1-5), including one new compound named protonodososide (1), were isolated from the methanol extract of the starfish Protoreaster nodosus, after subjecting to various chromatographic separations. The structural elucidation was confirmed by careful analysis of the 1D, 2D NMR, and HR ESI QTOF mass spectra. The cytotoxicity of isolated compounds was evaluated on five human cancer cell lines including HepG2, KB, MCF7, LNCaP, and SK-Mel2.

Isoryanodane diterpene derivatives from Barringtonia macrocarpa.

From the MeOH residue of Barringtonia macrocarpa branches and leaves, one new isoryanodane diterpene, barringisol (1), and two new isoryanodane diterpene glucosides, barringisosides A and B (2 and 3), were obtained using various chromatographic isolations. The structural characterization was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-QTOF-MS. This is the first isolation of isoryanodane diterpene derivatives from Barringtonia species. Moreover, the in vitro cytotoxicity of 1-3 on three human cancer cell lines (HepG2, LNCaP and MCF7) was also accessed using SRB assays.

Effects of Heatwaves on Hospital Admissions for Cardiovascular and Respiratory Diseases, in Southern Vietnam, 2010-2018: Time Series Analysis.

This study investigated the associations between heatwaves and daily hospital admissions for cardiovascular and respiratory diseases in two provinces in Viet Nam known to be vulnerable to droughts during 2010-2018. This study applied a time series analysis with data extracted from the electronic database of provincial hospitals and meteorological stations from the corresponding province. To eliminate over-dispersion, this time series analysis used Quasi-Poisson regression. The models were controlled for the day of the week, holiday, time trend, and relative humidity. Heatwaves were defined as the maximum temperature exceeding P90th over the period from 2010 to 2018 during at least three consecutive days. Data from 31,191 hospital admissions for respiratory diseases and 29,056 hospitalizations for cardiovascular diseases were investigated in the two provinces. Associations between hospital admissions for respiratory diseases and heatwaves in Ninh Thuan were observed at lag 2, with excess risk (ER = 8.31%, 95% confidence interval: 0.64-16.55%). However, heatwaves were negatively associated with cardiovascular diseases in Ca Mau, which was determined amongst the elderly (age above 60), ER = -7.28%, 95%CI: -13.97--0.08%. Heatwaves can be a risk factor for hospital admission due to respiratory diseases in Vietnam. Further studies need to be conducted to assert the link between heat waves and cardiovascular diseases.

Two new eudesmane sesquiterpene glucosides from the aerial parts of Artemisia vulgaris.

Using combined chromatographic methods, two new sesquiterpene glucosides, vulgarosides A (1) and B (2), and two known analogs ainsliaside E (3) and pumilaside A (4) were isolated from the aerial parts of Artemisia vulgaris. Their chemical structures were established by spectroscopic methods, including one and two-dimensional nuclear magnetic resonance (1 D and 2 D-NMR) spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). In addition, their cytotoxicity on five human cancer cell lines, including KB (epidermoid carcinoma), HepG2 (hepatocarcinoma), MCF7 (breast carcinoma), SK-Mel-2 (melanoma), and LNCaP (prostate cancer) was also evaluated by the SRB assay. However, none of the tested eudesmane sesquiterpene glycosides showed significant cytotoxicity (IC50>100 µM).

Secondary metabolites from the fruit peels of Durio zibethinus L. and their cytotoxic activity.

Three new glucosides, ziberthinosides A-C (1-3), and six known compounds, cleomiscosins A-D (4-7), sporogen AO-2 (8) and sapinofuranone A (9), were isolated from a methanol extract of Durio zibethinus fruit peels. Their chemical structures were elucidated by analyses of their 1 D/2D NMR and HR-ESI-MS data as well as by comparison with the literature values. The absolute configuration of sporogen AO-2 (8) was confirmed by ECD calculation. Of the isolates, compounds 8 and 9 were cytotoxic toward all MCF7, HepG2 and SK-LU-1 cell lines, with IC50 values ranging from 10.7 to 34.9 µM. Our results contribute to better understanding of the chemical constituents of the high valued durian fruit and their pharmacological effect, such as cytotoxicity.

Tobacco and electronic cigarette smoking among in-school adolescents in Vietnam between 2013 and 2019: prevalence and associated factors.

BACKGROUND: Smoking among adolescents in schools is a major global public health concern. There is limited evidence regarding prevalence and associated factors in Vietnam. OBJECTIVE: To compare the prevalence of smoking and associated factors among in-school adolescents aged 13-17 years in Vietnam between 2013 and 2019. METHODS: Data were collected from two rounds of the national representative Vietnam Global School-based Student Health Survey (GSHS) conducted in 2013 (n = 3,331) and 2019 (n = 7,690). Logistic regression was used to identify the factors associated with tobacco and electronic cigarette smoking among in-school adolescents. RESULTS: There was a significant reduction in the prevalence of current smoking (water pipes and cigarettes) from 5.4% (95% CI: 4.0-7.2) in 2013 to 2.8% (95% CI: 2.2-3.6) in 2019. In 2019, 2.6% of the in-school adolescents reported having used electronic cigarette products 30 days prior to the survey. Factors associated with a significantly higher likelihood of current smoking status included gender, loneliness, suicidal ideation, sexual activity, truancy, and alcohol consumption. Similar patterns were observed for e-cigarettes. CONCLUSION: Smoking among in-school adolescents in Vietnam decreased between 2013 and 2019. Follow-up studies are needed to further investigate causal factors so that future policies and communication programmes can be more effectively targeted to reduce smoking in adolescents.

Deep learning models for forecasting dengue fever based on climate data in Vietnam.

BACKGROUND: Dengue fever (DF) represents a significant health burden in Vietnam, which is forecast to worsen under climate change. The development of an early-warning system for DF has been selected as a prioritised health adaptation measure to climate change in Vietnam. OBJECTIVE: This study aimed to develop an accurate DF prediction model in Vietnam using a wide range of meteorological factors as inputs to inform public health responses for outbreak prevention in the context of future climate change. METHODS: Convolutional neural network (CNN), Transformer, long short-term memory (LSTM), and attention-enhanced LSTM (LSTM-ATT) models were compared with traditional machine learning models on weather-based DF forecasting. Models were developed using lagged DF incidence and meteorological variables (measures of temperature, humidity, rainfall, evaporation, and sunshine hours) as inputs for 20 provinces throughout Vietnam. Data from 1997-2013 were used to train models, which were then evaluated using data from 2014-2016 by Root Mean Square Error (RMSE) and Mean Absolute Error (MAE). RESULTS AND DISCUSSION: LSTM-ATT displayed the highest performance, scoring average places of 1.60 for RMSE-based ranking and 1.95 for MAE-based ranking. Notably, it was able to forecast DF incidence better than LSTM in 13 or 14 out of 20 provinces for MAE or RMSE, respectively. Moreover, LSTM-ATT was able to accurately predict DF incidence and outbreak months up to 3 months ahead, though performance dropped slightly compared to short-term forecasts. To the best of our knowledge, this is the first time deep learning methods have been employed for the prediction of both long- and short-term DF incidence and outbreaks in Vietnam using unique, rich meteorological features. CONCLUSION: This study demonstrates the usefulness of deep learning models for meteorological factor-based DF forecasting. LSTM-ATT should be further explored for mitigation strategies against DF and other climate-sensitive diseases in the coming years.

Perceptions and Use of Electronic Cigarettes Among Young Adults in Vietnam 2020.

Electronic cigarette use among adolescents has increased in the past decade. Little is known about the perception and use of e-cigarettes in Vietnam, especially among young people. This study examines the perceptions and use of electronic cigarettes among young adults in Vietnam. The study uses data from a survey of adult tobacco consumption among adults at the provincial level in 2020, which was funded and managed by the Vietnam Tobacco Control Fund-Ministry of Health. Data were collected from 34 provinces and cities throughout Vietnam and managed using REDCap software. The survey engaged 80,166 participants, of which 9478 were young adults aged 15-24 were selected and reported in this paper. The results show that, at the time of the survey, 2.4% of young Vietnamese adults were smoking e-cigarettes. Many survey participants cited more than one reason for smoking e-cigarettes. These reasons included preferring the taste of e-cigarettes (64.0%), disliking the odour of other cigarettes (46.2%), following the example of family members (44.9%), and believing e-cigarettes threatened fewer health risks (39.1%). Almost half of the e-cigarette users wanted to quit (48%). E-cigarette use was associated with males living in urban areas who are aware of the Law on Prevention and Control of Tobacco Harms. The findings of this study provide evidential data that support public health policies aimed at reducing and ceasing e-cigarette use among young people.

Sulfated Naphthopyrones and Anthraquinones from the Vietnamese Crinoid Comanthus delicata.

Three new sulfated naphthopyrone derivatives namely delicapyrons F-H (1-3) and two new sulfated anthraquinone derivatives namely delicaquinons A (4) and B (5), together with 6-methoxycomaparvin-5-methylether-8-O-sodium sulfate (6), 6-methoxycomaparvin-8-O-sodium sulfate (7), comaparvin-8-O-sodium sulfate (8), and 3-propyl-1,6,8-trihydroxy-9,10-anthraquinone-6-O-sodium sulfate (9) were isolated from the Vietnamese crinoid Comanthus delicata. Their chemical structures were elucidated by extensive analysis of the one dimensional (1D) and 2D-NMR, high resolution electrospray ionization quadrupole time-of-flight (HR-ESI-QTOF) mass spectra as well as calculation of optical rotation. In addition, significant cytotoxicity was observed for 6 against LNCaP (prostate cancer) cell line with IC50 value of 20.29 ± 2.43 µM, whereas moderate or weak cytotoxic effects were observed for 1-3 and 5-8 on SK-Mel-2 (melanoma) cell line and 7 and 8 against LNCaP cell line, with IC50 values ranging from 49.96 ± 1.74 to 76.92 ± 5.85 µM.

Cytotoxic and nitric oxide inhibitory activities of triterpenoids from Lycopodium clavatum L.

Using combined chromatographic separation techniques, three new triterpenoids named lycomclavatols A-C (1-3), a new natural product, methyl lycernuate-A (4), as well as seven known compounds (5-11), were isolated from the methanol extract of the whole plants of Lycopodium clavatum. Their chemical structures were established based on 1 D/2D NMR and HR-ESI-MS spectroscopic analyses. Among the isolates, compound 1 exhibited inhibitory activity on NO production in LPS-stimulated BV2 cells (IC50 = 36.0 µM). In addition, 1 was cytotoxic against both HepG2 and A549 cancer cell lines, with IC50 values of 40.7 and 87.0 µM, respectively. Compounds 10 and 11 showed cytotoxicity on only HepG2 and A549 cells, with IC50 values of 91.2 and 57.6 µM, respectively. Our results contribute to understanding more the secondary metabolites produced by L. clavatum and provide a scientific rationale for further investigations of anti-inflammatory and anticancer effects for this valuable medicinal plant.

Chemical constituents from the branches and leaves of Alchornea annamica.

Phytochemical investigation of the branches and leaves of Alchornea annamica led to isolation of ten secondary metabolites, including two new megastigmane glucosides alnamicosides A (1) and B (2). The structure elucidation was confirmed by 1 D and 2 D NMR, ECD as well as HR-QTOF-MS experiments. The megastigmane derivatives 1 - 3 exhibited inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC50 values of 78.72 ± 1.90, 77.40 ± 9.40 and 82.16 ± 4.56 µM, respectively. This is the first report on chemical constituents and biological activity of the plant A. annamica.

Polyhydroxylated steroid derivatives from the starfish Pentaceraster regulus.

A new polyhydroxysteroid glycoside, regulusoside D (1), and a new polyhydroxylated steroid, (24S)-cholestane-3ß,5,6ß,8,15α,24-hexol (2), together with seven known compounds were purified from the starfish Pentaceraster regulus collected near Con Co Islands, Vietnam. The structure elucidation was confirmed by extensive analysis of their NMR and HR-QTOF mass experiments. Among isolated compounds, regulusoside D (1), (24S)-cholestane-3ß,5,6ß,8,15α,24-hexol (2), granulatoside A (4), 5α-cholestane-3ß,6ß,7α,15α,16ß,26-hexol (6), 5α-cholestane-3ß,6ß,7α,8ß,15α,16ß,26-heptol (7) and 5α-cholestane-3ß,6α,8,15α,16ß,26-hexol (8) exhibited strong inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC50 values of 9.13 ± 1.17, 9.19 ± 0.77, 8.63 ± 3.31, 12.61 ± 0.51, 14.83 ± 3.02 and 10.98 ± 1.22 µM, respectively.

Secondary metabolites from a peanut-associated fungus Aspergillus niger IMBC-NMTP01 with cytotoxic, anti-inflammatory, and antimicrobial activities.

Chemical investigation of a peanut-associated fungal strain Aspergillus niger IMBC-NMTP01 resulted in isolation and identification of 14 secondary metabolites, including two new, epi-aspergillusol (1) and aspernigin (3), and 12 known compounds: pyrophen (2), 2-(hydroxyimino)-3-(4-hydroxyphenyl)propanoic acid (4), aspergillusol A (5), rubrofusarin B (6), nigerasperone A (7), fonsecin (8), TMC-256C1 (9), pyranonigrin A (10), orlandin (11), nigerasperone C (12), asperpyrone A (13), and 5-(hydroxymethyl)-2-furancarboxylic acid (14). Compounds 9, 12-14 showed cytotoxicity toward all six human cancer cell lines, including HepG2, KB, HL-60, MCF-7, SK-Mel2, and LNCaP, with IC50 values ranging from 8.4 to 84.5 µM, compounds 3-5 were cytotoxic against five cancer cell lines except HepG2, whereas 1 exhibited cytotoxicity toward HepG2, KB, and MCF-7 cells. All of the compounds, except 2 and 13, inhibited NO overproduction in LPS-induced RAW264.7 cells. In addition, all of the compounds displayed antimicrobial effects against Enterococcus faecalis, whereas 13 compounds, except 10, significantly inhibited the growth of the yeast Candida albicans.

Polyacetylene and phenolic constituents from the roots of Codonopsis javanica.

Chemical investigation of the roots of Codonopsis javanica resulted in isolation of 12 compounds, including one new polyacetylene, codojavanyol (1), one new phenolic glycoside, codobenzyloside (7), and 10 known compounds, (2E,8E)-9-(tetrahydro-2H-pyran-2-yl)nona-2,8-diene-4,6-diyl-1-ol (2), lobetyol (3), lobetyolin (4), lobetyolinin (5), cordifolioidyne B (6), benzyl-α-L-arabinopyranosyl (1-6)-ß-D-glucopyranoside (8), (Z)-8-ß-D-glucopyranosyloxycinnamic acid (9), syringin (10), syringaresinol (11), and tryptophan (12). Their structures were elucidated by 1 D and 2 D NMR and MS spectroscopic analyses in comparison with the data reported in the literature. The stereochemistry of the C-2' position of 1 was identified based on time-dependent density functional theory (TDDFT) electronic circular dichroism (ECD) calculation. Among the isolates, compounds 3-5 were shown to have weak cytotoxicity toward three human carcinoma cell lines, including lung (A549), liver (HepG2), and breast (MCF7), with the induction of 41.4 to 55.6% cell death at the concentration of 100 µM.