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Viola dalatensis, belonging to the Violaceae family, is an endemic species to Vietnam. The present study aimed to determine phenolic compounds in extracts from aerial parts of the plant species using high performance liquid chromatography with diode-array detection (HPLC-DAD). In addition, free radical scavenging and bovine albumin denaturation inhibition assays were performed to evaluate the antioxidant and in vitro anti-inflammatory activities of the extracts. Most of the phenolic compounds in the methanolic extract were detected at the greatest concentrations compared to the other extracts, which was also supported by the highest total phenolic content (26.70 ± 0.1059 mg GAE/g). In general, the antioxidant activities of the methanolic and ethanolic extracts were found to be stronger than those of the other extracts. The aqueous extract exhibited the most potent inhibitory effect on albumin denaturation (IC50 = 90.39 ± 8.415 µg/mL), comparable with that of diclofenac. Through principal component analysis, 88.60% of the total variance in the phenolic dataset was explained. The correlation analysis showed that chlorogenic acid, ferulic acid, epigallocatechin gallate, rutin, and kaempferol may play important roles in antioxidant activity while gallic acid could contribute to in vitro anti-inflammatory activity of the extracts. The findings of this study provide the first evidence of the bioactive compounds present in V. dalatensis and shed light on the potential health-promoting properties linked to its aerial parts. [ABSTRACT FROM AUTHOR]

Symplocos cochinchinensis (Lour.) Moore ssp. laurina (Retz) Noot. has been commonly used in traditional medicine to treat different ailments in many Asian countries. This study aimed to compare phenolics, antioxidant activity, and inhibitory effects on α-amylase, α-glucosidase, and albumin denaturation of S. cochinchinensis leaf extracts obtained by different extraction methods. 9 phenolics in the extracts were quantified and the results showed the 50% methanol extract contained the greatest sum of phenolics (193.72 mg/g) compared to the others. The 50% acetone extract exhibited the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (IC50= 183.88 μg/mL) while the 50% ethanol extract showed the most potent activity predicted by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) assay (IC50= 365.05 αg/mL). In general, all the S. cochinchinensis leaf extracts had comparatively low inhibitory effects on α-amylase and α-glucosidase compared to acarbose used as a reference standard. The ethanol extract presented the lowest IC50 values (184.49 μg/mL), indicating the strongest protection of albumin from denaturation. The results also the applications of enzyme and ultrasound to extraction of S. cochinchinensis leaves proved effective in extracting phenolics. The findings of the study provide a better understanding of phytochemicals and potential health benefits of S. cochinchinensis leaves, which is useful for development of new naturally occurring agents for disease prevention and treatment. [ABSTRACT FROM AUTHOR]

The ginger family (Zingiberaceae) is one of the most diverse and abundant families in the plant kingdom in terms of number of species. In terms of chemistry, this is a family of plants containing much essential oil with mainly monoterpene and sesquiterpene derivatives, which has been widely used in medicine, food, and flavor industries. In our series of studies on ginger family plants, the two new species including Wurfbainia schmidtii (K. Schum.) Škorničk. & A.D. Poulsen and Zingiber atroporphyreus Škorničk. & Q.B. Nguyen has been investigated for the first time. This study aimed to identify the chemical compositions of essential oils extracted from the rhizomes and leaves of these two species using gas chromatography-mass spectrometry (GC/MS) analysis and evaluate their hypoglycemic effects through the α-glucosidase and α-amylase inhibitory assays. In terms of chemical composition, in general, the main compounds appearing in the essential oils of both leaves and rhizomes of each species are similar but they are differences in the percentage of the main components, for example, 1,8-cineole is a main component in leaves whereas fenchyl acetate is the main one in rhizomes of W. schmidtii. Several distinctive compounds, in comparison with other members in the genus Zingiber, namely β-pinene, α-pinene, β-elemene, and sabinene, were found in the essential oil of Z. atroporphyreus. Regarding hypoglycemic effects, the essential oils from the two species tested possessed weak α-glucosidase and α-amylase inhibitory effects. For the first time, this study was designed to investigate the chemical composition as well as the hypoglycemic effect of essential oils distilled from the rhizomes and leaves of two species W. schmidtii and Z. atroporphyreus have been reported, serving as a premise for further systematic research on their phytochemistry and pharmacological effects being conducted. [ABSTRACT FROM AUTHOR]

Meistera, belongs to the Zingiberaceae family, is a genus of medicinal plants that contain a rich resource of essential oils (EOs) as well as have many valuable bioactivities. The aim of the present study was to investigate the EOs of Meistera vespertilio, which has not been reported before. The EOs were distilled by hydrodistillation method from M. vespertilio rhizomes collected in two different regions (Phu Tho and Nghe An Provinces) of Vietnam. The compositional analysis of two EO samples was carried out using Gas Chromatography-Mass Spectroscopy (GC-MS). GC-MS analysis showed that the two samples had a different number of chemical components. The Phu Tho EO sample consisted of more components (51 compounds) compared to the Nghe An EO sample (41 compounds). However, the two EOs were identified with some similar components including α-pinene, camphene, β-pinene, and limonene. Furthermore, both EO samples possessed good inhibitory effects on α-amylase, with average IC50 values ranging from 0.61 to 0.91 (mg/mL). Especially, the EO of M. vespertilio rhizomes from Nghe An Province showed intense α-amylase inhibitory activity (IC50 value of 0.61 ± 0.00 mg/mL) which was stronger than acarbose, an antidiabetic drug (IC50 value of 0.92 ± 0.01 mg/mL), while the figure for Phu Tho EO showed approximately equivalent activity. The results obtained in the present study showed the potential of M. vespertilio EOs as a valuable source of chemical compounds for the food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Hedychium yunnanense Gagnep., belonging to the Zingiberaceae family, has aroused much interest due to its non-volatile chemical constituents. Nevertheless, no data about essential oils (EOs) of this species is available. In this study, the chemical composition and antimicrobial activity of EOs from leaves and rhizomes of H. yunnanense collected in Vietnam were analyzed. The EOs of the rhizomes and leaves were obtained as yellow oils with extraction yields of 0.21 and 0.09%, respectively. Fifty-seven chemical components, accounting for 94.35-98.92%, were identified in the two EOs. The rhizomes EO mainly contains β-pinene (21.07%), 1,8-cineole (20.63%), α-pinene (8.80%) and camphene (6.35%), while the leaves EO was rich in β-pinene (45.92%), α-pinene (19.48%), and β-caryophyllene (18.26%). Both EOs exhibited more potent antimicrobial activities than the standard drug, streptomycin, as they demonstrated significantly lower minimum inhibitory concentrations against the tested bacteria and fungus. Additionally, the leaves EO may possess stronger antimicrobial activities than the rhizomes EO. The findings of the study will provide a better understanding of the chemical composition and bioactivities of H. yunnanense. [ABSTRACT FROM AUTHOR]

Vietnam, a Southeast Asian country, has documented 1,515 polymerase chain reaction-positive confirmed coronavirus disease 2019 (COVID-19) cases with 35 deaths a year after the first infection recorded in Ha Noi on January 23, 2020. Half of the infected patients are at the age of 21 to 40 y. While numbers of infections in many countries in the region continue to surge, Vietnam is seeing decreases in the number of daily new cases. As a result of COVID-19 trajectory different from the other countries, as of April 23, 2020, Vietnam is no longer under lockdown and is slowly restarting its socioeconomic activities. This report aims to provide a summary of the COVID-19 situation and response to the pandemic in Vietnam.

While many nations are struggling to slow the transmission rate of the coronavirus disease 2019 (COVID-19), Vietnam has seen no new locally acquired cases since April 16. After implementing 22 d of nationwide social distancing, on April 23, the government of Vietnam announced the easing of social distancing measures. This allows the country to restart its socio-economic activities in a gradual, prudent manner. Domestic tourism and exports of agricultural and anti-COVID-19 medical products take priority over the other sectors in this postpandemic economic recovery. Importantly, the country needs to stay vigilant on the fight against the disease to prevent a possibility of another outbreak.

Similar to other nations in the world, Vietnam has swiftly implemented measures to contain the spread of COVID-19, and these have been transforming many aspects of society. The country is showing resilience to fear, stress, and anxiety related to the COVID-19 pandemic. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

With growing consumption of aquaculture products, there is increasing demand on rapid and sensitive techniques that can detect prohibited substances in the seafood products. This study aimed to develop a novel surface-enhanced Raman spectroscopy (SERS) method coupled with simplified extraction protocol and novel gold nanorod (AuNR) substrates to detect banned aquaculture substances (malachite green [MG] and crystal violet [CV]) and their mixture (1:1) in aqueous solution and fish samples. Multivariate statistical tools such as principal component analysis (PCA) and partial least squares regression (PLSR) were used in data analysis. PCA results demonstrate that SERS can distinguish MG, CV and their mixture (1:1) in aqueous solution and in fish samples. The detection limit of SERS coupled with standing AuNR substrates is 1 ppb for both MG and CV in fish samples. A good linear relationship between the actual concentration and predicted concentration of analytes based on PLSR models with R 2 values from 0.87 to 0.99 were obtained, indicating satisfactory quantification results of this method. These results demonstrate that the SERS method coupled with AuNR substrates can be used for rapid and accurate detection of MG and CV in fish samples., (© 2017 Institute of Food Technologists®.)

Engineered nanoparticles (ENPs), such as metallic or metallic oxide nanoparticles (NPs), have gained much attention in recent years. Increasing use of ENPs in various areas may lead to the release of ENPs into the environment and cause the contamination of agricultural and food products by ENPs. In this study, we selected two important ENPs (zinc oxide [ZnO] and silver [Ag] NPs) as potential food contaminants and investigated their toxicity via an in vitro model using Caco-2 cells. The physical properties of ENPs and their effects on Caco-2 cells were characterized by electron microscopy and energy dispersive X-ray spectroscopic (EDS) techniques. Results demonstrate that a significant inhibition of cell viability was observed after a 24-h of exposure of Caco-2 cells to 3-, 6-, and 12-mM ZnO NPs or 0.5-, 1.5-, and 3-mM Ag NPs. The noticeable changes of cells include the alteration in cell shape, abnormal nuclear structure, membrane blebbing, and cytoplasmic deterioration. The toxicity of ZnO NPs, but not that of Ag NPs after exposure to simulated gastric fluid, significantly decreased. Scanning transmission electron microscopy shows that ZnO and Ag NPs penetrated the membrane of Caco-2 cells. EDS results also confirm the presence of NPs in the cytoplasm of the cells. This study demonstrates that ZnO and Ag NPs have cytotoxic effects and can inhibit the growth of Caco-2 cells., (© 2016 Institute of Food Technologists®)

In recent years, novel nanomaterials have received much attention due to their great potential for applications in agriculture, food safety, and food packaging. Among them, graphene and graphene oxide (GO) are emerging as promising nanomaterials that may have a profound impact on food packaging. However, there are some concerns from consumers and the scientific community about the potential toxicity and biocompatibility of nanomaterials. In this study, we investigated the antibacterial properties of GO against human intestinal bacteria. The cytotoxicity of GO was also studied in vitro using the Caco-2 cell line derived from a colon carcinoma. Electron microscopy was used to investigate the morphology of GO and the interaction between GO flakes and Caco-2 cells. GO at different concentrations (10 to 500 μg/ml) exhibited no toxicity against the selected bacteria and a mild cytotoxic action on Caco-2 cells after 24 h of exposure. The results show that weak adsorption of medium nutrients may contribute to GO's low toxicity. This study suggests that GO is biocompatible and has a potential to be used in agriculture and food science, indicating that more studies are needed to exploit its potential applications.