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The tubers of Hydnophytum formicarum Jack. have been used for the treatment of rheumatism, liver and intestinal diseases in the traditional medicine of Vietnam. The 50% ethanolic extract of H. formicarum (EEHF) has been proved anti-inflammatory and analgesic effects as well as hepatoprotective activity at the oral doses of 100 and 200 mg/kg in Swiss albino mice. The aim of this work was to study on the subacute oral toxicity of the EEHF at the doses of 100 and 200 mg/kg for 30 and 60 consecutive days in both sexes of mice. The observations were undertaken on the mortality, the body weights, the toxic signs, hematological and biochemical parameters. At the end of the experiment, the histopathology of liver and kidneys was studied. The results showed that the 100 mg/kg of EEHF did not cause any toxic signs in mice. There was no significant difference of hematological and biochemical parameters between the treated animals and the controls. Histopathological examinations of livers and kidneys showed no significant difference suggesting no morphological disturbances in treated mice. In conclusion, the results indicated that the EEHF did not cause any subacute toxicity in mice at the dose of 100 mg/kg, providing the evidence of the safety of health products from this medicinal plant.

In Vietnamese folk medicine, Bi ky nam (H. formicarum) tuber has been widely used to treat rheumatism, liver and intestinal diseases. This work aimed to study botanical, genetic characteristics and screening of the phytochemical constituents of wild H. formicarum of Phu Quoc Island, Vietnam. Anatomical characteristics of the plant material were described. Fresh leaves were used to analyze DNA barcodes based on rbcL region amplified by PCR. Sequences of DNA products were identified by Sanger method and BioEdit 7.0.5 software, then compared to the control rbcL sequences published in GenBank by BLAST. The tuber powder was studied for pharmacognostic parameters, preliminary phytochemical screening and total phenolic contents by Folin-Ciocalteu method. Results showed that the similarity between the rbcL sequences of H. formicarum leaves collected in Phu Quoc and the control one published in Genbank was 99%. Moisture content, total ash value and acid insoluble ash value of dried tuber powder were 11.06%, 9.60% and 0.70%, respectively. Raw material contained carotenoids, triterpenoids, flavonoids, phenolics, tannins, saponins, reducing substances and amino acids. Total phenolics content was about 58.847 mg pyrrogallol equivalent/g dried powder weight. Our results provided information about botanical, genetic and preliminary phytochemical characteristics of H. formicarum growing on Phu Quoc Island. This could be useful for the authentication of H. formicarum as a medicinal material.

Quantitative kinetic analysis is critical for understanding amyloid mechanisms. Here we demonstrate the application of generic Finke-Watzky (F-W) two-step nucleation-autocatalytic growth model to the concentration-dependent amyloid kinetics of proinflammatory α-helical S100A9 protein at pH 7.4 and at 37 and 42 °C. The model is based on two pseudoelementary reaction steps applied without further analytical constraints, and its treatment of S100A9 amyloid self-assembly demonstrates that initial misfolding and β-sheet formation, defined as "nucleation" step, spontaneously takes place within individual S100A9 molecules at higher rate than the subsequent fibrillar growth. The latter, described as an autocatalytic process, will proceed if misfolded amyloid-prone S100A9 is populated on a macroscopic time scale. Short lengths of S100A9 fibrils are consistent with the F-W model. The analysis of fibrillar length distribution by the Beker-Döring model demonstrates independently that such distribution is solely determined by slow fibril growth and there is no fragmentation or secondary pathways decreasing fibrillar length.

Amyloid cascade and neuroinflammation are hallmarks of neurodegenerative diseases, and pro-inflammatory S100A9 protein is central to both of them. Here, we have shown that NCAM1 peptide constructs carrying polycationic sequences derived from Aβ peptide (KKLVFF) and PrP protein (KKRPKP) significantly promote the S100A9 amyloid self-assembly in a concentration-dependent manner by making transient interactions with individual S100A9 molecules, perturbing its native structure and acting as catalysts. Since the individual molecule misfolding is a rate-limiting step in S100A9 amyloid aggregation, the effects of the NCAM1 construct on the native S100A9 are so critical for its amyloid self-assembly. S100A9 rapid self-assembly into large aggregated clumps may prevent its amyloid tissue propagation, and by modulating S100A9 aggregation as a part of the amyloid cascade, the whole process may be effectively tuned.

Over an extended period, food security in Vietnam has been associated with the availability and supply/demand balance of rice. This paper examines the past, present, and likely future scenario for Vietnam’s ‘rice balance’ and the major policy, investment and other factors contributing to these trends. The focal time period is from 1990 to 2030. With Vietnam moving from a situation of food deficit to food surplus to becoming one of the developing world’s leading exporters of food, the objectives for and modalities to achieve domestic food security policy should now have shifted far beyond the long-standing focus on food availability, generally, and national rice production, specifically. The paper argues Vietnam’s food security challenges now relate more to issues of food affordability (and price volatility), child malnutrition, broader nutritional imbalances, and food safety. While this broader definition of food security has now been embedded in the GoVn’s strategic plans, it has not yet translated over to practice. Major policies and programs continue to place primary emphasis on maintaining or even increasing Vietnam’s rice production (surplus). The paper argues for a more balanced approach, targeting locations and population groups which remain vulnerability to food insecurity, addressing the broader concerns about (mal-)nutrition, and including increased attention to the role which other types of foods and other (non-production centered) instruments can play in meeting the broader objectives associated with food security. Hence, based upon past successes and remaining gaps, it is time to move the goal posts and adjust the on field strategy for realizing food security goals.