1.PTP1B Inhibitory Activity of Flavonoids from the Roots of Astragalus membranaceus Bunge
Thi Ly PHAM ; Manh Tuan HA ; Byung Sun MIN ; Jeong Ah KIM
Natural Product Sciences 2025;31(1):62-73
The roots of Astragalus membranaceus Bunge have long been used in herbal medicine for their diversebiological activities. Notably, its potential anti-diabetic properties have been extensively studied, highlighting promising therapeutic prospects. In this study, we conducted a comprehensive investigation focusing on flavonoid components from the roots of A. membranaceus and their PTP1B inhibitory activity. As a result, we isolated a total of 24 flavonoids, among which formonentin (1), pratensein (3), and vesticarpan (19) emerged as the most potent inhibitors against PTP1B with IC50 value of 10.9 ± 1.09 μM, 10.0 ± 1.71 μM, and 10.3 ± 1.31 μM, respectively.Additionally, through the enzyme kinetic analysis, the inhibition mode of compound 19 was determined as a competitive inhibitor, with Ki value of 7.6 ± 1.17 μM. Furthermore, the molecular docking simulation elucidated the binding mechanism of compound 19 with PTP1B, mainly through van der Waals forces and hydrogen bonds.This study highlights the PTP1B inhibitory potential of the flavonoid constituents derived from the roots of A. membranaceus. Moreover, discovering vesticarpan (19) as a novel PTP1B inhibitor provides a significant foundation for further investigations to develop innovative therapeutic strategies for diabetes treatment.
2.PTP1B Inhibitory Activity of Flavonoids from the Roots of Astragalus membranaceus Bunge
Thi Ly PHAM ; Manh Tuan HA ; Byung Sun MIN ; Jeong Ah KIM
Natural Product Sciences 2025;31(1):62-73
The roots of Astragalus membranaceus Bunge have long been used in herbal medicine for their diversebiological activities. Notably, its potential anti-diabetic properties have been extensively studied, highlighting promising therapeutic prospects. In this study, we conducted a comprehensive investigation focusing on flavonoid components from the roots of A. membranaceus and their PTP1B inhibitory activity. As a result, we isolated a total of 24 flavonoids, among which formonentin (1), pratensein (3), and vesticarpan (19) emerged as the most potent inhibitors against PTP1B with IC50 value of 10.9 ± 1.09 μM, 10.0 ± 1.71 μM, and 10.3 ± 1.31 μM, respectively.Additionally, through the enzyme kinetic analysis, the inhibition mode of compound 19 was determined as a competitive inhibitor, with Ki value of 7.6 ± 1.17 μM. Furthermore, the molecular docking simulation elucidated the binding mechanism of compound 19 with PTP1B, mainly through van der Waals forces and hydrogen bonds.This study highlights the PTP1B inhibitory potential of the flavonoid constituents derived from the roots of A. membranaceus. Moreover, discovering vesticarpan (19) as a novel PTP1B inhibitor provides a significant foundation for further investigations to develop innovative therapeutic strategies for diabetes treatment.
3.PTP1B Inhibitory Activity of Flavonoids from the Roots of Astragalus membranaceus Bunge
Thi Ly PHAM ; Manh Tuan HA ; Byung Sun MIN ; Jeong Ah KIM
Natural Product Sciences 2025;31(1):62-73
The roots of Astragalus membranaceus Bunge have long been used in herbal medicine for their diversebiological activities. Notably, its potential anti-diabetic properties have been extensively studied, highlighting promising therapeutic prospects. In this study, we conducted a comprehensive investigation focusing on flavonoid components from the roots of A. membranaceus and their PTP1B inhibitory activity. As a result, we isolated a total of 24 flavonoids, among which formonentin (1), pratensein (3), and vesticarpan (19) emerged as the most potent inhibitors against PTP1B with IC50 value of 10.9 ± 1.09 μM, 10.0 ± 1.71 μM, and 10.3 ± 1.31 μM, respectively.Additionally, through the enzyme kinetic analysis, the inhibition mode of compound 19 was determined as a competitive inhibitor, with Ki value of 7.6 ± 1.17 μM. Furthermore, the molecular docking simulation elucidated the binding mechanism of compound 19 with PTP1B, mainly through van der Waals forces and hydrogen bonds.This study highlights the PTP1B inhibitory potential of the flavonoid constituents derived from the roots of A. membranaceus. Moreover, discovering vesticarpan (19) as a novel PTP1B inhibitor provides a significant foundation for further investigations to develop innovative therapeutic strategies for diabetes treatment.
4.PTP1B Inhibitory Activity of Flavonoids from the Roots of Astragalus membranaceus Bunge
Thi Ly PHAM ; Manh Tuan HA ; Byung Sun MIN ; Jeong Ah KIM
Natural Product Sciences 2025;31(1):62-73
The roots of Astragalus membranaceus Bunge have long been used in herbal medicine for their diversebiological activities. Notably, its potential anti-diabetic properties have been extensively studied, highlighting promising therapeutic prospects. In this study, we conducted a comprehensive investigation focusing on flavonoid components from the roots of A. membranaceus and their PTP1B inhibitory activity. As a result, we isolated a total of 24 flavonoids, among which formonentin (1), pratensein (3), and vesticarpan (19) emerged as the most potent inhibitors against PTP1B with IC50 value of 10.9 ± 1.09 μM, 10.0 ± 1.71 μM, and 10.3 ± 1.31 μM, respectively.Additionally, through the enzyme kinetic analysis, the inhibition mode of compound 19 was determined as a competitive inhibitor, with Ki value of 7.6 ± 1.17 μM. Furthermore, the molecular docking simulation elucidated the binding mechanism of compound 19 with PTP1B, mainly through van der Waals forces and hydrogen bonds.This study highlights the PTP1B inhibitory potential of the flavonoid constituents derived from the roots of A. membranaceus. Moreover, discovering vesticarpan (19) as a novel PTP1B inhibitor provides a significant foundation for further investigations to develop innovative therapeutic strategies for diabetes treatment.
5.PTP1B Inhibitory Activity of Flavonoids from the Roots of Astragalus membranaceus Bunge
Thi Ly PHAM ; Manh Tuan HA ; Byung Sun MIN ; Jeong Ah KIM
Natural Product Sciences 2025;31(1):62-73
The roots of Astragalus membranaceus Bunge have long been used in herbal medicine for their diversebiological activities. Notably, its potential anti-diabetic properties have been extensively studied, highlighting promising therapeutic prospects. In this study, we conducted a comprehensive investigation focusing on flavonoid components from the roots of A. membranaceus and their PTP1B inhibitory activity. As a result, we isolated a total of 24 flavonoids, among which formonentin (1), pratensein (3), and vesticarpan (19) emerged as the most potent inhibitors against PTP1B with IC50 value of 10.9 ± 1.09 μM, 10.0 ± 1.71 μM, and 10.3 ± 1.31 μM, respectively.Additionally, through the enzyme kinetic analysis, the inhibition mode of compound 19 was determined as a competitive inhibitor, with Ki value of 7.6 ± 1.17 μM. Furthermore, the molecular docking simulation elucidated the binding mechanism of compound 19 with PTP1B, mainly through van der Waals forces and hydrogen bonds.This study highlights the PTP1B inhibitory potential of the flavonoid constituents derived from the roots of A. membranaceus. Moreover, discovering vesticarpan (19) as a novel PTP1B inhibitor provides a significant foundation for further investigations to develop innovative therapeutic strategies for diabetes treatment.
6.Isolation and toxicity of Xanthomonas oryzae pv. oryzae in rice and a collection of phages against the pathogen
Ngoc Quynh Anh Pham ; Vo Thanh Phuc ; Pham Do Tra My ; Le Thi My Duyen ; To Hue Ngoc ; Nguyen Minh Thien ; Nguyen Hai Duong ; Le Thi Thuy Tien ; Le Phi Nga ; Hoang Anh Hoang
Malaysian Journal of Microbiology 2024;20(no.1):15-23
Aims:
The objective of the study was to isolate bacteriophages and conduct a comprehensive analysis of their potential against Xanthomonas oryzae pv. oryzae (Xoo) strains in the Mekong Delta, Vietnam.
Methodology and results:
Twelve Xoo strains were isolated from rice fields located in the Mekong Delta, Vietnam. Among these strains, three strains Xoo L019, L020 and L024, showed the highest disease index of bacterial blight. Four
phages specific to Xoo were isolated from soil, water and leaf samples, and their morphologies were determined. In a test against 12 Xoo strains, phage L541, MLA23 or W41 could infect 10 of the 12 Xoo strains, while phage LBH01 could infect 8 of the 12 Xoo strains. The stability of the phages to pH, organic solvents, UV-A and UV-B was also evaluated.
Conclusion, significance and impact of study
The initial characterization of the phages indicates their potential as biocontrol agents against bacterial blight in rice. The study is one of the very first studies about Xoo phages in rice in Vietnam.
7.Prevalence and risk factors for human papillomavirus infection among female sex workers in Hanoi and Ho Chi Minh City, Viet Nam: a cross-sectional study
Quang Duy Pham ; Kiesha Prem ; Tuan Anh Le ; Nguyen Van Trang ; Mark Jit ; Tuan Anh Nguyen ; Van Cao ; Tam-Duong Le-Ha ; Mai Thi Ngoc Chu ; Ly Thi Khanh Le ; Zheng Quan Toh ; Marc Brisson ; Suzanne Garland ; Gerald Murray ; Kathryn Bright ; Duc Anh Dang ; Hau Phuc Trana ; Edward Kim Mulholland
Western Pacific Surveillance and Response 2022;13(4):1-11
Objective:
Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infections and cervical cancer due to their high number of sexual partners. The objectives of this study were to determine the prevalence of HPV and identify risk factors for high-risk HPV infection among FSWs in Hanoi and Ho Chi Minh City (HCMC), Viet Nam.
Methods:
A cross-sectional study was conducted in Hanoi and HCMC between December 2017 and May 2018. We surveyed and screened 699 FSWs aged ≥18 years for HPV infection and abnormal cytology. A multivariable modified Cox regression model was used to determine risk factors for high-risk HPV infection.
Results
The overall prevalence of any HPV, high-risk HPV and HPV-16/18 infection in the 699 FSWs was 26.3%, 17.6% and 4.0%, respectively, and were similar in both cities. Multiple infections were identified in 127 participants (69.0%).HPV-52 was the most prevalent (7%), followed by HPV-58 (6%). Abnormal cytology was detected in 91 participants (13.0%). FSWs who are divorced (adjusted prevalence ratio [aPR]: 1.96, 95% confidence interval [CI]: 1.01–3.81), widowed (aPR: 3.26, 95% CI: 1.49–7.12) or living alone (aPR: 1.85, 95% CI: 1.01–3.39) were associated with a higher prevalence of high-risk HPV infection.
8.Melanin-embedded materials effectively remove hexavalent chromium (Cr) from aqueous solution.
An Manh CUONG ; Nguyen Thi LE NA ; Pham Nhat THANG ; Trinh Ngoc DIEP ; Ly Bich THUY ; Nguyen Lai THANH ; Nguyen Dinh THANG
Environmental Health and Preventive Medicine 2018;23(1):9-9
BACKGROUND:
Currently, it is recognized that water polluted with toxic heavy metal ions may cause serious effects on human health. Therefore, the development of new materials for effective removal of heavy metal ions from water is still a widely important area. Melanin is being considered as a potential material for removal of heavy metal from water.
METHODS:
In this study, we synthesized two melanin-embedded beads from two different melanin powder sources and named IMB (Isolated Melanin Bead originated from squid ink sac) and CMB (Commercial Melanin Bead originated from sesame seeds). These beads were of globular shape and 2-3 mm in diameter. We investigated and compared the sorption abilities of these two bead materials toward hexavalent-chromium (Cr) in water. The isotherm sorption curves were established using Langmuir and Freundlich models in the optimized conditions of pH, sorption time, solid/liquid ratio, and initial concentration of Cr. The FITR analysis was also carried out to show the differences in surface properties of these two beads.
RESULTS:
The optimized conditions for isotherm sorption of Cr on IMB/CMB were set at pH values of 2/2, sorption times of 90/300 min, and solid-liquid ratios of 10/20 mg/mL. The maximum sorption capacities calculated based on the Langmuir model were 19.60 and 6.24 for IMB and CMB, respectively. However, the adsorption kinetic of Cr on the beads fitted the Freundlich model with R values of 0.992 for IMB and 0.989 for CMB. The deduced Freundlich constant, 1/n, in the range of 0.2-0.8 indicated that these beads are good adsorption materials. In addition, structure analysis data revealed great differences in physical and chemical properties between IMB and CMB. Interestingly, FTIR analysis results showed strong signals of -OH (3295.35 cm) and -C=O (1608.63 cm) groups harboring on the IMB but not CMB. Moreover, loading of Cr on the IMB caused a shift of broad peaks from 3295.35 cm and 1608.63 cm to 3354.21 cm and 1597.06 cm, respectively, due to -OH and -C=O stretching.
CONCLUSIONS
Taken together, our study suggests that IMB has great potential as a bead material for the elimination of Cr from aqueous solutions and may be highly useful for water treatment applications.
Adsorption
;
Chromium
;
chemistry
;
Kinetics
;
Melanins
;
chemistry
;
Waste Disposal, Fluid
;
methods
;
Water Pollutants, Chemical
;
chemistry
;
Water Pollution, Chemical
;
prevention & control
;
Water Purification
;
methods
9. Ethanol extracts of Scutellaria baicalensis protect against lipopolysaccharideinduced acute liver injury in mice
Hai Nguyen THANH ; Tuan Anh LE ; Huong Duong Thi LY ; Tung Nguyen HUU ; Loi Vu DUC ; Thu Dang KIM ; Tung Bui THANH ; Hue Pham Thi MINH
Asian Pacific Journal of Tropical Biomedicine 2015;5(9):761-767
Objective: To investigated the protective potential of ethanol extracts of Scutellaria baicalensis (S. baicalensis) against lipopolysaccharide (LPS)-induced liver injury. Methods: Dried roots of S. baicalensis were extracted with ethanol and concentrated to yield a dry residue. Mice were administered 200 mg/kg of the ethanol extracts orally once daily for one week. Animals were subsequently administered a single dose of LPS (5 mg/kg of body weight, intraperitoneal injection). Both protein and mRNA levels of cytokines, such as tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in liver tissues were evaluated by ELISA assay and quantitative PCR. Cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-kB protein levels in liver tissues were analyzed by western blotting. Results: Liver injury induced by LPS significantly increased necrosis factor alpha, interleukin-1β, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB in liver tissues. Treatment with ethanol extracts of S. baicalensis prevented all of these observed changes associated with LPS-induced injury in liver mice. Conclusions: Our study showed that S. baicalensis is potentially protective against LPSinduced liver injury in mice.
10.Application of microplate almar blue assay for rapid detection of drug resistance of M. tuberculosis strains
Ly Minh Ho ; Hoa Thanh Tran ; Lien Kim Pham ; Hung Van Nguyen ; Phuong Thi Hoang ; Sy Ngoc Dinh
Journal of Preventive Medicine 2008;0(3):60-66
Background: Recently, microplate almar blue assay has been used commonly in detecting gen related to tuberculosis drug resistance, which provides results after 5-7 days with lower cost compared to traditional methods. Objective: To evaluate the application of microplate almar blue assay for rapid detection of drug resistance of M. tuberculosis strains. Subject and Method: A microplate-based assay which uses Alamar blue reagent - an oxidation reduction dye (MABA), was used for the determination of the anti-tuberculosis drug (isoniazid-INH, rifampicine-RIF, streptomycine-STR and ethabuton=EMB) resistance of 96 M. tuberculosis strains isolated from Vietnamese patients in comparison to those obtained by conversional method. Result: MABA showed to have high sensitivity and specificity in testing the sensitivity to individual anti-tuberculosis drugs (from 82.4% for STR to 93.3% for - INH and from 82.5% for EMB to 98.4% for STR; respectively), as well as for the multi-drug resistant M.tuberculosis (86.4% of sensitivity), highly correlated with the result determined by proportion method. Conclusion: MABA reveals the advantage in shortening test time, in simple performance and lower cost compared with the conversional culture based methods.
Microplate almar blue assay
;
M. tuberculosis
;
drug resistance


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