Exploring the Phytochemical Diversity and Antioxidant Potential of the Vietnamese Smilax glabra Roxb: Insights from UPLC-QTOF-MS/MS and Zebrafish Model Studies.

Research on natural products is growing due to their potential health benefits and medicinal properties. Despite regional variations in phytochemical composition and bioactivity, Smilax glabra Roxb (SGB) has attracted the interest of researchers. Scientists are particularly interested in the Vietnamese SGB variant, which is influenced by biological and environmental factors. Despite geographical differences in phytochemical makeup and bioactivities, SGB remains a fascinating subject in traditional herbal medicine. Using ultra-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), the phytochemicals in Vietnamese SGB extracts were investigated. This study revealed a wide range of phytochemical compounds, including flavonoids, terpenoids, glycosides, alkaloids, organic acids, phenolics, and steroids. Furthermore, utilizing zebrafish as a model organism, we discovered that these extracts have the surprising ability to greatly improve the survival rate of zebrafish larvae exposed to oxidative stress caused by arsenite (NaAsO2) and hydrogen peroxide (H2O2). Notably, our discoveries suggest the occurrence of new antioxidative pathways in addition to the kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, expanding the understanding of the antioxidant properties and potential therapeutic uses of these plants. To summarize, our research findings shed light on the phytochemical composition of Vietnamese SGB, revealing its potential as a natural antioxidant and encouraging further exploration of its underlying mechanisms for future innovative antioxidant therapies.

Assessment and source quantification of heavy metal(loid)s in surface water using multivariate analyses from the Saigon River, Vietnam.

The metal concentration in surface water of a river could be affected by season, position, and oceanic process such as tide. The current study aimed to (1) examine the heavy metal(loid) concentration in surface water from the Saigon River as affected by the combination of season, tide, and position and (2) apportion and quantify pollution sources. Ninety-six surface water samples were collected from 13 sites on the River in four campaigns (rainy season + ebb tide, rainy season + flood tide, dry season + ebb tide, and dry season + flood tide). Eight heavy metal(loid)s (Al, B, Bi, Fe, Mn, Pb, Sr, and Zn) were measured and subjected to multivariate analyses. Three-way ANOVA showed that in the rainy season, the total concentration of the metal(loid)s (TCM) in two tides was not clearly different from each other while in the dry season the TCM was significantly higher during the ebb tide than during the flood tide. Principal component analysis/factor analysis and Pearson correlation matrix showed that the TCM could be derived from three main sources, grouped into anthropogenic activities such as industrial, agricultural, and domestic wastes from inside Ho Chi Minh city, and natural origins from lowland area and acid sulfate soil. Three pollution sources explained 70% and 68% of the total variance of TCM in the rainy and dry seasons, respectively. In brief, the metal(loid) concentration was significantly affected by the season and tide and the pollution sources could be derived from inside Ho Chi Minh City and from lowland areas beyond the river estuary.

Seasonal, spatial variation, and pollution sources of heavy metals in the sediment of the Saigon River, Vietnam.

The current study was conducted to (1) examine seasonal and spatial distribution of heavy metals and metalloid in sediment from the Saigon River and (2) apportion and quantify their pollution sources. Ninety-six sediment samples were taken in the rainy and dry season on 13 sampling sites, distributed over the lower reaches of the River, to analyze for exchangeable concentration of 11 heavy metals and metalloid (Al, B, Cd, Co, Fe, In, Mn, Ni, Pb, Sr, and Zn), pH, EC, organic carbon content, and particle-size distribution. Generally, the concentration of 11 elements was ranked in the order Mn > Al > Fe > Zn > Sr > In > B > Ni > Co > Pb > Cd. Hierarchical cluster analysis grouped 13 sampling sites into two parts based on the similar concentration of the 11 elements. Three-way analysis of variance showed that the total exchangeable concentration of 11 elements was significantly higher in the rainy season than in the dry season and in the upper part than in the lower part of the river. Principal component analysis/factor analysis and correlation analysis revealed that three pollution sources (PS) may contribute to enriching the 11 examined elements in the sediment. These sources included (PS1) from catchment through water erosion over natural areas, explaining 83%, (PS2) mixed sources from catchment through water erosion over agricultural fields and inside Ho Chi Minh City, accounting for 6%, and (PS3) mixed sources from lowland areas, explaining 7.8% of the total variance of the elements. In brief, the sediment concentration of 11 metals and metalloid varied with season and space and three major pollution sources from river catchment, inside Ho Chi Minh City, and lowland contributively enriched the elements in the sediment of the River.

Seasonal, Spatial Variation, and Potential Sources of Organochlorine Pesticides in Water and Sediment in the Lower Reaches of the Dong Nai River System in Vietnam.

The goals of the current study were (1) to examine seasonal and spatial variation of selected OCPs concentrations and (2) to identify potential sources of the pollutants in the lower reaches of the Dong Nai River system. Forty-eight water and sediment samples were taken from 12 stations in the dry and rainy seasons to determine the concentrations of dichlorodiphenyltrichloroethane and its metabolites (total DDTs), hexachlorocyclohexane isomers (total HCHs), heptachlor, aldrin, dieldrin, and endrin. The concentrations of total DDTs (0.30), total HCHs (0.29), Aldrin (0.068), heptachlor (0.04, µg L-1) in water, and total DDTs (8.04), total HCHs (4.51), and Aldrin (1.52, µg kg-1) in sediment were significantly higher in the rainy season than in the dry season (0.14, 0.12, 0.008, 0.009 in water and 3.49, 2.29, and 0.4 in sediment, respectively). Cluster analysis grouped 12 sampling stations into 2 groups, of which group 1 (3 stations) had higher concentrations of total DDTs, total HCHs, Aldrin, heptachlor, and dieldrin in both water and sediment than in group 2. Compositional analysis of total DDTs revealed that DDT residue could be decomposed significantly for the past years and that anaerobic decomposition could be predominant. Principal component analysis/factor analysis (PCA/FA) indicated that the potential sources of OCPs in the study stations could come from residential and agricultural areas located in the upper catchment or areas surrounding the studied stations. In short, OCPs concentration in the studies area could depend on seasonal, spatial variation, and transport of OCPs from upper parts or surrounding areas.

The interactive effect of the season and estuary position on the concentration of persistent organic pollutants in water and sediment from the Cua Dai estuary in Vietnam.

The current study was conducted in the Cua Dai estuary, Vietnam, (1) to assess the status of persistent organic pollutants (POPs) and (2) to examine the interactive effect of season and estuary position on the concentration of the pollutants in surface water and sediment. Fifty-two water and sediment samples were taken in the dry and rainy seasons from inner- and outer-estuary positions to analyze for six POPs, including hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), heptachlor, aldrin, dieldrin, and polychlorinated biphenyl (PCBs). The averaged concentrations of the respective POPs in water samples were 0.07, 0.1, 0.01, 0.03, 0.001, and 0.2 µg L-1 and in sediment samples were 2.6, 3.1, 0.9, 0.2, 0.2, and 121 µg kg-1. Of the six POPs examined, the concentration of DDTs in sediment samples and PCBs in water samples was significantly affected by the interactive effect of the two examined factors. The concentrations of HCHs, DDTs, heptachlor, and aldrin in water samples and of HCHs in sediment samples were significantly higher in the rainy season than in the dry season. Sediment samples collected from the inner position had a significantly higher concentration of HCHs and PCBs than in the outer position. Some mechanisms possibly influenced the varying POP concentration could include (1) greater riverine discharge in the rainy season and (2) the sea dilution effect in the outer position. Therefore, the concentration of the individual examined POPs in water and sediment in the Cua Dai estuary significantly depended on either the season, estuary position, or their combination.