Trace Metal Element Analysis in Some Seafood in the Coastal Zone of the Red River (Ba Lat Estuary, Vietnam) by Green Sample Preparation and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).

Fisheries and aquaculture production in the coastal zone of Vietnam contribute significantly to the national economy. However, seafood quality and safety, especially in terms of metal contents, are of increasing concern, for both domestic and international markets. This paper presents the results of an investigation in some trace metal elements (iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), arsenic (As), cadmium (Cd), and mercury (Hg)) concentrations in some fishes, crustaceans, and molluscs in the coastal zone of the Red River (in the Ba Lat estuary in Thai Binh and Nam Dinh provinces) during four sampling campaigns in 2020. All samples were treated by a green sample preparation using microwave digestion and then analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the trace metal element concentrations in fish, crustacean, and mollusc samples decreased in the following order: Fe > Zn > Mn > Cu > As > Cd ∼ Hg. In more details, the ranges of trace metal elements in seafood samples were 13.13-202.73; 7.63-82.71; 0.48-22.73; 0.72-15.58; 0.18-5.12; 0.001-1.114; and 0.001-0.923 mg·kg-1 for Fe, Zn, Mn, Cu, As, Cd, and Hg, respectively. The research results contribute to the dataset of the seafood (both fishery and aquacultural seafood) quality in the Red River coastal zone. Although the mean values of different trace metal elements observed in this study were lower than the allowed values of Vietnam's or European's threshold for food safety, some high concentrations were detected. The survey results suggest the need to expand the monitoring scope (frequency of monitoring, number of samples, and observed variables) for obtaining a fully comprehensive assessment of seafood quality in this region. Our results also indicate that it is necessary to manage water quality in coastal areas, especially where aquaculture activities are carried out.

Hypoglycemic property of triterpenoid saponin PFS isolated from Polyscias fruticosa leaves.

This paper evaluated the inhibitory effect of 3-O-[ß-d-glucopyranosyl-(1→4)-ß-d-glucuronopyranosyl] oleanolic acid 28-O-ß-d-glucopyranosyl ester (PFS), a major saponin isolated from Polyscias fruticosa leaves, on α-amylase and α-glucosidase, and its potential for reducing the postprandial blood glucose level in mice. In enzyme inhibition assays, PFS strongly inhibited porcine pancreas α-amylase and yeast α-glucosidase. Using the Lineweaver-Burk equation, we found that PFS inhibited porcine pancreas α-amylase in a mixed noncompetitive mode, and yeast α-glucosidase via noncompetitive inhibition. In the sucrose tolerance test, PFS at 100 mg/kg body weight significantly decreased the postprandial blood glucose level in mice fed a high-sucrose diet. These findings suggest that P. fruticosa leaves and their major saponin PFS can be used to prevent and treat diabetes and its complications.

Sanggenon C and O inhibit NO production, iNOS expression and NF-κB activation in LPS-induced RAW264.7 cells.

OBJECTIVE: The NO production through the iNOS induction by activation of nuclear factor (NF-κB) is known to involve in various inflammatory conditions. Sanggenon C and O, two Diels-Alder type adducts isolated from Morus alba, a plant has been used for the anti-inflammatory purpose in the Oriental medicine, were investigated for their effect on the NO production, iNOS expression and NF-κB activity. METHODS: The inhibitory effects of sanggenon C and O on the NF-κB activity were investigated in LPS-stimulated RAW264.7 cells by SEAP reporter assay. The regulation of the iNOS expression and IκBα activation by two compounds was also evaluated by Western blot. RESULTS: Both compounds strongly inhibited NO production and NF-κB activation in a dose-dependent manner. The expression of the iNOS protein was also suppressed by treatment of the compounds (10 and 1 µM). Sanggenon O showed stronger inhibition than the diastereomer sanggenon C. Both compounds prevented the phosphorylation and degradation of IκBα protein. CONCLUSION: We demonstrated that sanggenon C and O inhibited NO production and iNOS expression by suppressing NF-κB activity and IκBα activation.

Cytotoxic prenylated flavonoids from Morus alba.

A phytochemical fractionation of the methanol extract of the Morus alba leaves led to the isolation of eleven flavonoids (1-11). The structure of the new 3'-geranyl-3-prenyl-2',4',5,7-tetrahydroxyflavone (1) was elucidated by means of spectroscopic methods. The cytotoxicity of the isolated compounds against human cervical carcinoma HeLa, human breast carcinoma MCF-7, and human hepatocarcinoma Hep3B cells was evaluated. Of note, morusin (9) was the most potent with an IC(50) value of 0.64 µM against HeLa cells.