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1.
Atherosclerosis ; 392: 117519, 2024 May.
Article in English | MEDLINE | ID: mdl-38581737

ABSTRACT

BACKGROUND AND AIMS: Atherosclerosis is the primary underlying cause of myocardial infarction and stroke, which are the major causes of death globally. Heparanase (Hpse) is a pro-inflammatory extracellular matrix degrading enzyme that has been implicated in atherogenesis. However, to date the precise roles of Hpse in atherosclerosis and its mechanisms of action are not well defined. This study aims to provide new insights into the contribution of Hpse in different stages of atherosclerosis in vivo. METHODS: We generated Hpse gene-deficient mice on the atherosclerosis-prone apolipoprotein E gene knockout (ApoE-/-) background to investigate the impact of Hpse gene deficiency on the initiation and progression of atherosclerosis after 6 and 14 weeks high-fat diet feeding, respectively. Atherosclerotic lesion development, blood serum profiles, lesion composition and aortic immune cell populations were evaluated. RESULTS: Hpse-deficient mice exhibited significantly reduced atherosclerotic lesion burden in the aortic sinus and aorta at both time-points, independent of changes in plasma cholesterol levels. A significant reduction in the necrotic core size and an increase in smooth muscle cell content were also observed in advanced atherosclerotic plaques of Hpse-deficient mice. Additionally, Hpse deficiency reduced circulating and aortic levels of VCAM-1 at the initiation and progression stages of disease and circulating MCP-1 levels in the initiation but not progression stage. Moreover, the aortic levels of total leukocytes and dendritic cells in Hpse-deficient ApoE-/- mice were significantly decreased compared to control ApoE-/-mice at both disease stages. CONCLUSIONS: This study identifies Hpse as a key pro-inflammatory enzyme driving the initiation and progression of atherosclerosis and highlighting the potential of Hpse inhibitors as novel anti-inflammatory treatments for cardiovascular disease.


Subject(s)
Aorta , Atherosclerosis , Disease Models, Animal , Disease Progression , Glucuronidase , Mice, Knockout, ApoE , Plaque, Atherosclerotic , Animals , Atherosclerosis/genetics , Atherosclerosis/pathology , Atherosclerosis/enzymology , Atherosclerosis/metabolism , Glucuronidase/deficiency , Glucuronidase/genetics , Glucuronidase/metabolism , Aorta/pathology , Aorta/metabolism , Aorta/enzymology , Aortic Diseases/pathology , Aortic Diseases/genetics , Aortic Diseases/enzymology , Aortic Diseases/metabolism , Diet, High-Fat , Apolipoproteins E/genetics , Apolipoproteins E/deficiency , Mice, Inbred C57BL , Male , Vascular Cell Adhesion Molecule-1/metabolism , Mice , Mice, Knockout , Sinus of Valsalva/pathology , Necrosis
2.
Med Educ Online ; 29(1): 2330257, 2024 Dec 31.
Article in English | MEDLINE | ID: mdl-38493489

ABSTRACT

Enhancing health professional students' effective learning and collaborative practice requires a deep understanding of strategies for facilitating interprofessional learning. While faculty members and clinical preceptors are recognized as facilitators in interprofessional education (IPE), there is limited knowledge about the impact of student facilitators' engagement in IPE. Accordingly, this study aims to explore the perceptions and experiences of student facilitators in IPE. Thirteen student facilitators were recruited to lead an interprofessional learning program, and they were subsequently invited to participate in one-on-one interviews. An interview guide was developed to explore their motivations, expectations, engagement, effectiveness, and achievements in IPE facilitation. Thematic analysis was conducted using MAXQDA software to analyze the student facilitators' experiences and perceptions. Eight interviewees from various disciplines, including Medicine, Nursing, Pharmacy, Speech and Hearing Sciences, and Social Work, took part in the study. The findings revealed that student facilitators highly valued their IPE facilitation experience, which aligned with their expectations and led to the creation of social networks, increased confidence, improved understanding of other professions, and the development of lifelong skills. Furthermore, the student facilitators demonstrated cognitive and social congruence by establishing a relaxed learning environment, displaying empathetic and supportive behaviors, and using inclusive language to engage IPE learners in group discussions. This study provides a comprehensive understanding of the role of student facilitators in IPE, contributing to the evolving literature on IPE. A conceptual framework was developed to explore the entire facilitation experience, encompassing the motivations and expectations of student facilitators, their engagement and effectiveness, and the observed achievements. These findings can inform the development of peer teaching training in IPE and stimulate further research in identifying relevant facilitator competencies for optimal delivery of IPE.


Subject(s)
Interprofessional Relations , Students, Health Occupations , Humans , Interprofessional Education , Qualitative Research , Learning , Students, Health Occupations/psychology
3.
Cells ; 11(20)2022 10 12.
Article in English | MEDLINE | ID: mdl-36291066

ABSTRACT

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide, and its management places a huge burden on healthcare systems through hospitalisation and treatment. Atherosclerosis is a chronic inflammatory disease of the arterial wall resulting in the formation of lipid-rich, fibrotic plaques under the subendothelium and is a key contributor to the development of CVD. As such, a detailed understanding of the mechanisms involved in the development of atherosclerosis is urgently required for more effective disease treatment and prevention strategies. Heparanase is the only mammalian enzyme known to cleave heparan sulfate of heparan sulfate proteoglycans, which is a key component of the extracellular matrix and basement membrane. By cleaving heparan sulfate, heparanase contributes to the regulation of numerous physiological and pathological processes such as wound healing, inflammation, tumour angiogenesis, and cell migration. Recent evidence suggests a multifactorial role for heparanase in atherosclerosis by promoting underlying inflammatory processes giving rise to plaque formation, as well as regulating lesion stability. This review provides an up-to-date overview of the role of heparanase in physiological and pathological processes with a focus on the emerging role of the enzyme in atherosclerosis.


Subject(s)
Atherosclerosis , Plaque, Atherosclerotic , Animals , Humans , Heparan Sulfate Proteoglycans , Glucuronidase , Heparitin Sulfate , Atherosclerosis/therapy , Plaque, Atherosclerotic/therapy , Lipids , Mammals
4.
Front Pharmacol ; 13: 981152, 2022.
Article in English | MEDLINE | ID: mdl-36147350

ABSTRACT

Ageing is a risk factor for many degenerative diseases. Cardiovascular diseases (CVDs) are usually big burdens for elderly, caregivers and the health system. During the aging process, normal functions of vascular cells and tissue progressively lost and eventually develop vascular diseases. Endothelial dysfunction, reduced bioavailability of endothelium-derived nitric oxide are usual phenomena observed in patients with cardiovascular diseases. Myriad of studies have been done to investigate to delay the vascular dysfunction or improve the vascular function to prolong the aging process. Tumor suppressor gene p53, also a transcription factor, act as a gatekeeper to regulate a number of genes to maintain normal cell function including but not limited to cell proliferation, cell apoptosis. p53 also crosstalk with other key transcription factors like hypoxia-inducible factor 1 alpha that contribute to the progression of cardiovascular diseases. Therefore, in recent three decades, p53 has drawn scientists' attention on its effects in vascular function. Though the role of tumor suppressor gene p53 is still not clear in vascular function, it is found to play regulatory roles and may involve in vascular remodeling, atherosclerosis or pulmonary hypertension. p53 may have a divergent role in endothelial and vascular muscle cells in those conditions. In this review, we describe the different effects of p53 in cardiovascular physiology. Further studies on the effects of endothelial cell-specific p53 deficiency on atherosclerotic plaque formation in common animal models are required before the therapeutic potential can be realized.

5.
BMC Med Educ ; 22(1): 303, 2022 Apr 21.
Article in English | MEDLINE | ID: mdl-35449047

ABSTRACT

BACKGROUND: The COVID-19 pandemic and the consequent social distancing measures caused unprecedented disruption for medical and healthcare education. This study examined medical teachers' experience with emergency remote teaching during the pandemic and their acceptance of online teaching after the pandemic. METHODS: In this sequential mixed methods study, online surveys were disseminated to teachers (n = 139) at two Asia-Pacific medical schools to evaluate their experience with emergency remote teaching during the pandemic. Subsequently, in-depth interviews were conducted with teachers from both institutions (n = 13). Each interviewee was classified into an adopter category based on Rogers' Diffusion of Innovations Theory. Interview transcripts were analyzed thematically, and the descriptive themes were mapped to broader themes partly based on the Technology Acceptance Model and these included: (i) perceived usefulness of online teaching, (ii) perceived ease of delivering online teaching, (iii) experience with institutional support and (iv) acceptance of online teaching after the pandemic. RESULTS: Our participants described accounts of successes with their emergency remote teaching and difficulties they experienced. In general, most participants found it difficult to deliver clinical skills teaching remotely and manage large groups of students in synchronous online classes. With regards to institutional support, teachers with lower technological literacy required just-in-time technical support, while teachers who were innovative in their online teaching practices found that IT support alone could not fully address their needs. It was also found that teachers' acceptance of online teaching after the pandemic was influenced by their belief about the usefulness of online teaching. CONCLUSIONS: This study demonstrated that our participants managed to adapt to emergency remote teaching during this pandemic, and it also identified a myriad of drivers and blockers to online teaching adoption for medical teachers. It highlights the need for institutes to better support their teaching staff with diverse needs in their online teaching.


Subject(s)
COVID-19 , Education, Distance , Educational Personnel , Students, Medical , COVID-19/epidemiology , Education, Distance/methods , Humans , Pandemics
6.
PLoS One ; 16(10): e0258926, 2021.
Article in English | MEDLINE | ID: mdl-34679098

ABSTRACT

BACKGROUND: Clinical procedural skills are vital components of medical education. Increased student intake and limited capacity of medical schools necessitate more efficient ways to deliver clinical skill teaching. This study employed a flipped classroom, peer-assisted learning approach to deliver clinical skill teaching. It aimed to determine the influence of pre-class demonstration video watching and in-class student-student interactions on clinical skill acquisition. METHODS: In 2017, a cohort of 205 medical students in their penultimate year of undergraduate medical study were recruited, and they learned bag mask ventilation and intravenous cannulation during this study. The participants watched a demonstration video before class, and then underwent self-directed practice as triads. Afterwards, each participant video-recorded their skill performance and completed post-class questionnaires. The videos were evaluated by two blinded assessors. RESULTS: A hundred and thirty-one participants (63.9%) completed the questionnaire. For bag mask ventilation, participants who claimed to have watched the corresponding demonstration video before class achieved higher performance scores (those who watched before class: 7.8 ± 1.0; those who did not: 6.3 ± 1.7; p < 0.01). For intravenous cannulation, while there is no significant difference in performance scores (those who watched before class: 14.3 ± 1.3; those who did not: 14.1 ± 1.4; p = 0.295), those who watched the video before class received less interventions from their peers during triad practice (those who watched before class: 2.9 ± 1.8; those who did not: 4.3 ± 2.9; p < 0.05). The questionnaire results showed that most participants preferred the new approach of clinical skill teaching and perceived it to be useful for skill acquisition. CONCLUSION: The flipped classroom, same-level peer-assisted learning model is potentially an effective way to address the current challenges and improve the efficiency of clinical procedural skill teaching in medical schools.


Subject(s)
Clinical Competence , Education, Medical/methods , Peer Group , Problem-Based Learning , Students, Medical , Educational Measurement , Humans
7.
Free Radic Biol Med ; 166: 255-264, 2021 04.
Article in English | MEDLINE | ID: mdl-33539947

ABSTRACT

During vascular inflammation, the leukocyte-derived enzyme myeloperoxidase (MPO) is transcytosed across the endothelium and into the sub-endothelial extracellular matrix, where it promotes endothelial dysfunction by catalytically consuming nitric oxide (NO) produced by endothelial NO synthase (eNOS). In the presence of chloride ions and hydrogen peroxide (H2O2), MPO forms the oxidant hypochlorous acid (HOCl). Here we examined the short-term implications of HOCl produced by endothelial-transcytosed MPO for eNOS activity. Incubation of MPO with cultured aortic endothelial cells (ECs) resulted in its transport into the sub-endothelium. Exposure of MPO-containing ECs to low micromolar concentrations of H2O2 yielded enhanced rates of H2O2 consumption that correlated with HOCl formation and increased eNOS enzyme activity. The MPO-dependent activation of eNOS occurred despite reduced cellular uptake of the eNOS substrate l-arginine, which involved a decrease in the maximal activity (Vmax), but not substrate affinity (Km), of the major endothelial l-arginine transporter, cationic amino acid transporter-1. Activation of eNOS in MPO-containing ECs exposed to H2O2 involved a rapid elevation in cytosolic calcium and increased eNOS phosphorylation at Ser-1179 and de-phosphorylation at Thr-497. These signaling events were attenuated by intracellular calcium chelation, removal of extracellular calcium and inhibition of phospholipase C. This study shows that stimulation of endothelial-transcytosed MPO activates eNOS by promoting phospholipase C-dependent calcium signaling and altered eNOS phosphorylation at Ser-1179 and Thr-497. This may constitute a compensatory signaling response of ECs aimed at maintaining eNOS activity and NO production in the face of MPO-catalyzed oxidative stress.


Subject(s)
Nitric Oxide Synthase Type III , Peroxidase , Calcium/metabolism , Calcium Signaling , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Hydrogen Peroxide/metabolism , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Peroxidase/metabolism , Type C Phospholipases/metabolism
8.
Pharmacol Ther ; 221: 107711, 2021 05.
Article in English | MEDLINE | ID: mdl-33137376

ABSTRACT

Myeloperoxidase (MPO) is a prominent mammalian heme peroxidase and a fundamental component of the innate immune response against microbial pathogens. In recent times, MPO has received considerable attention as a key oxidative enzyme capable of impairing the bioactivity of nitric oxide (NO) and promoting endothelial dysfunction; a clinically relevant event that manifests throughout the development of inflammatory cardiovascular disease. Increasing evidence indicates that during cardiovascular disease, MPO is released intravascularly by activated leukocytes resulting in its transport and sequestration within the vascular endothelium. At this site, MPO catalyzes various oxidative reactions that are capable of promoting vascular inflammation and impairing NO bioactivity and endothelial function. In particular, MPO catalyzes the production of the potent oxidant hypochlorous acid (HOCl) and the catalytic consumption of NO via the enzyme's NO oxidase activity. An emerging paradigm is the ability of MPO to also influence endothelial function via non-catalytic, cytokine-like activities. In this review article we discuss the implications of our increasing knowledge of the versatility of MPO's actions as a mediator of cardiovascular disease and endothelial dysfunction for the development of new pharmacological agents capable of effectively combating MPO's pathogenic activities. More specifically, we will (i) discuss the various transport mechanisms by which MPO accumulates into the endothelium of inflamed or diseased arteries, (ii) detail the clinical and basic scientific evidence identifying MPO as a significant cause of endothelial dysfunction and cardiovascular disease, (iii) provide an up-to-date coverage on the different oxidative mechanisms by which MPO can impair endothelial function during cardiovascular disease including an evaluation of the contributions of MPO-catalyzed HOCl production and NO oxidation, and (iv) outline the novel non-enzymatic mechanisms of MPO and their potential contribution to endothelial dysfunction. Finally, we deliver a detailed appraisal of the different pharmacological strategies available for targeting the catalytic and non-catalytic modes-of-action of MPO in order to protect against endothelial dysfunction in cardiovascular disease.


Subject(s)
Cardiovascular Diseases , Peroxidase , Vascular Diseases , Animals , Cardiovascular Diseases/drug therapy , Endothelium, Vascular/metabolism , Humans , Hypochlorous Acid/metabolism , Nitric Oxide/metabolism , Oxidation-Reduction , Peroxidase/metabolism , Peroxidase/pharmacology , Vascular Diseases/metabolism
9.
Sci Adv ; 6(31): eaaz7815, 2020 07.
Article in English | MEDLINE | ID: mdl-32923607

ABSTRACT

Vascular permeability and angiogenesis underpin neovascular age-related macular degeneration and diabetic retinopathy. While anti-VEGF therapies are widely used clinically, many patients do not respond optimally, or at all, and small-molecule therapies are lacking. Here, we identified a dibenzoxazepinone BT2 that inhibits endothelial cell proliferation, migration, wound repair in vitro, network formation, and angiogenesis in mice bearing Matrigel plugs. BT2 interacts with MEK1 and inhibits ERK phosphorylation and the expression of FosB/ΔFosB, VCAM-1, and many genes involved in proliferation, migration, angiogenesis, and inflammation. BT2 reduced retinal vascular leakage following rat choroidal laser trauma and rabbit intravitreal VEGF-A165 administration. BT2 suppressed retinal CD31, pERK, VCAM-1, and VEGF-A165 expression. BT2 reduced retinal leakage in rats at least as effectively as aflibercept, a first-line therapy for nAMD/DR. BT2 withstands boiling or autoclaving and several months' storage at 22°C. BT2 is a new small-molecule inhibitor of vascular permeability and angiogenesis.


Subject(s)
Capillary Permeability , Vascular Cell Adhesion Molecule-1 , Angiogenesis Inhibitors/pharmacology , Animals , Humans , Mice , Neovascularization, Pathologic/drug therapy , Neovascularization, Pathologic/genetics , Proto-Oncogene Proteins c-fos/metabolism , Rabbits , Rats , Vascular Cell Adhesion Molecule-1/metabolism , Vascular Cell Adhesion Molecule-1/pharmacology , Vascular Endothelial Growth Factor A/metabolism
10.
MedEdPublish (2016) ; 9: 212, 2020.
Article in English | MEDLINE | ID: mdl-38073842

ABSTRACT

This article was migrated. The article was marked as recommended. Education in Hong Kong was shifted online on an abrupt and massive scale as the city faced unprecedented disruptions, first from social unrest in 2019 and then again with the COVID-19 pandemic. Concurrent modernization initiatives since early 2019 in The University of Hong Kong's Medical Faculty (HKUMed), conferred a fortuitous head start for this rapid change. Pre-clinical and clinical teaching were restructured for online delivery through e-learning solutions for didactic teaching, and new innovative approaches were developed to convert bedside to"webside" teaching. E-learning in the current circumstances provided necessary social distancing while being pedagogically sound. Students were also able to develop key communication and collaboration skills via online platforms, developing digital skills critical to their future profession. However, unforeseen issues including socioeconomic inequality, privacy concerns, and social isolation became apparent and should be addressed as medical education progresses further down the digital path. The goal must entail a sustainable and scholarly approach towards optimizing medical education in an increasingly online environment. This will help safeguard the medical curriculum against disruption and empower future medical professionals for tomorrow's practice. Here, we share experiences and perspectives from educators in a global city characterised by land scarcity and income inequality.

11.
Pharmaceutics ; 11(5)2019 May 01.
Article in English | MEDLINE | ID: mdl-31052466

ABSTRACT

PURPOSE: This study describes the development and characterization of glucagon dry powder inhaler (DPI) formulation for pulmonary delivery. Lactose monohydrate, as a carrier, and L-leucine and magnesium stearate (MgSt) were used as dispersibility enhancers for this formulation. METHODS: Using Fourier-transform infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), and Raman confocal microscopy, the interactions between glucagon and all excipients were characterized. The fine particle fractions (FPFs) of glucagon in different formulations were determined by a twin stage impinger (TSI) using a 2.5% glucagon mixture, and the glucagon concentration was measured by a validated LC-MS/MS method. RESULTS: The FPF of the glucagon was 6.4%, which increased six-fold from the formulations with excipients. The highest FPF (36%) was observed for the formulation containing MgSt and large carrier lactose. The FTIR, Raman, and DSC data showed remarkable physical interactions of glucagon with leucine and a minor interaction with lactose; however, there were no interactions with MgSt alone or mixed with lactose. CONCLUSION: Due to the interaction between L-leucine and glucagon, leucine was not a suitable excipient for glucagon formulation. In contrast, the use of lactose and MgSt could be considered to prepare an efficient DPI formulation for the pulmonary delivery of glucagon.

12.
Singapore Med J ; 58(7): 408-410, 2017 07.
Article in English | MEDLINE | ID: mdl-28740998

ABSTRACT

Therapeutic temperature management (TTM) was strongly recommended by the 2015 International Liaison Committee on Resuscitation as a component of post-resuscitation care. It has been known to be effective in improving the survival rate and neurologic functional outcome of patients after cardiac arrest. In an effort to increase local adoption of TTM as a standard of post-resuscitation care, this paper discusses and makes recommendations on the treatment for local providers.


Subject(s)
Heart Arrest/therapy , Hyperthermia, Induced , Adult , Body Temperature , Cardiopulmonary Resuscitation , Heart Arrest/physiopathology , Humans , Hyperthermia, Induced/adverse effects , Hyperthermia, Induced/methods
13.
Clin Exp Pharmacol Physiol ; 39(10): 894-6, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22823573

ABSTRACT

1. It is well documented that both acetylcholine (ACh)-evoked arterial relaxation and brachial artery flow-mediated vasodilatation are blunted in hypercholesterolaemic patients. However, there are no simple diagnostic methods to detect the pathology of blood vessels of patients. 2. To establish the use of serum nitric oxide synthase (NOS) activity as a diagnostic parameter for impaired vasorelaxation, animals with different levels of vascular healthiness were made by feeding Sprague-Dawley rats a normal diet, a high-cholesterol diet (HCD) or an HCD supplemented with 10 mg/kg per day, p.o., simvastatin, a cholesterol-lowering drug, for 30 days. Serum total cholesterol levels, serum NOS activity and ACh-induced vasorelaxation of the isolated aorta were determined at the end of the experiment. 3. Consumption of HCD for 30 days resulted in an increase in serum total cholesterol, attenuated ACh-induced nitric oxide/endothelium-dependent aortic relaxation and decreased NOS activity. Concomitant administration of simvastatin lowered the elevated blood cholesterol levels with complete reversal of the attenuated ACh-induced aortic relaxation and serum NOS activity. An attempt was made to correlate serum NOS activity and the magnitude of ACh-elicited vascular relaxation among the different groups. A positive correlation (r = 0.8329; P < 0.001; n = 30) was found between serum NOS activity and vascular relaxation. 4. This finding is a good foundation for the development of a simple and low-cost alternative for diagnosing vascular diseases and evaluating the effectiveness of drugs on the vascular system in patients.


Subject(s)
Aorta/enzymology , Endothelium, Vascular/drug effects , Nitric Oxide Synthase/blood , Vasodilation/physiology , Acetylcholine/pharmacology , Animals , Aorta/drug effects , Aorta/metabolism , Cholesterol/blood , Diet, High-Fat , Endothelium, Vascular/enzymology , Endothelium, Vascular/metabolism , Endothelium, Vascular/physiology , Hypolipidemic Agents/pharmacology , Male , Nitric Oxide/metabolism , Rats , Rats, Sprague-Dawley , Vasodilation/drug effects
14.
Inflammopharmacology ; 20(6): 307-14, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22189914

ABSTRACT

The anticancer effects of traditional Chinese medicine (TCM) have attracted the attention of the public vis-à-vis existing cancer therapies with various side effects. Lycium barbarum fruit, commonly known as Gou Qi Zi in China, is a potential anticancer agent/adjuvant. Its major active ingredients, L. barbarum polysaccharides (LBP), scopoletin and 2-O-ß-D-glucopyranosyl-L-ascorbic acid (AA-2ßG), are found to have apoptotic and antiproliferative effects on cancer cell lines. Moreover, LBP also contributes to body's immunomodulatory effects and enhances effects of other cancer therapies. It is not known whether there are any undesirable effects. Further studies on its pharmacological mechanisms and toxicology could facilitate a safe usage of this TCM herb.


Subject(s)
Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Fruit/chemistry , Immunologic Factors/pharmacology , Immunologic Factors/therapeutic use , Lycium/chemistry , Plant Preparations/pharmacology , Plant Preparations/therapeutic use , Animals , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Humans
15.
Am J Chin Med ; 39(4): 693-704, 2011.
Article in English | MEDLINE | ID: mdl-21721150

ABSTRACT

Ischemic heart disease is a major cause of death in the world. Common therapies, such as primary coronary angioplasty and thrombolysis, are applied to restore blood supply to the heart, limit infarct size and reduce mortality. However, the restoration of blood supply would generate reactive oxygen species in damaged sites of the myocardium, intensifying the damage to the cardiac tissues. Radix Scutellariae baicalensis (Huangqin) is a well-known herb in traditional Chinese medicine with high antioxidant power. In this study, extract of the dry root of Scutellaria baicalensis Georgi (Sb) was confirmed to have a high content of flavonoids and phenolic compounds. The cardioprotective effects of the Sb extracts (3, 30 and 300 mg/kg) were evaluated in myocardial ischemia-reperfusion injuried rats. The results showed that animals that had received five-day pretreatment of the Sb extract (30 mg/kg) had a significant reduction in myocardial infarct size and a marked increase in the activity of catalase in the liver. The Sb extract could additionally enhance acetylcholine-induced vasorelaxation. It was proposed that the Sb extract exerted its cardioprotection by stimulating the catalase activity and improving vascular elasticity.


Subject(s)
Cardiotonic Agents/therapeutic use , Myocardial Reperfusion Injury/prevention & control , Phytotherapy , Plant Extracts/therapeutic use , Polyphenols/therapeutic use , Vasodilation/drug effects , Acetylcholine/pharmacology , Animals , Cardiotonic Agents/analysis , Cardiotonic Agents/pharmacology , Catalase/metabolism , Liver/metabolism , Male , Myocardial Infarction/etiology , Myocardial Infarction/prevention & control , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/pathology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Roots , Polyphenols/analysis , Polyphenols/pharmacology , Rats , Rats, Sprague-Dawley , Scutellaria baicalensis/chemistry
16.
Pharm Biol ; 49(11): 1114-20, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21595572

ABSTRACT

CONTEXT: Grifola frondosa (Polyporaceae), maitake, is a widely consumed edible mushroom in some Asian countries. The fruit bodies and mycelia of maitake have shown different bioactive compounds with anticancer and other therapeutic properties. OBJECTIVE: This study evaluated three chemically modified maitake polysaccharide-peptides' (MPSP) adjuvant effect (in vivo) and anticancer activity (in vitro growth inhibitory effect) compared with crude MPSP from G. frondosa. MATERIALS AND METHODS: We investigated the possibility of enhancing the adjuvant effect and anticancer effect of crude MPSP by using simple chemical modification methods to convert crude MPSP to phosphorylated, acetylated or esterified MPSPs. The adjuvant effect and growth inhibitory effect were evaluated by C6 cell inoculated rat model with cyclophosphamide (CPA) treatment and in vitro cell viability assay, respectively. RESULTS: All four tested MPSPs showed significant adjuvant effect to CPA treatment on rats inoculated with C6 cancer cells. In addition, an obvious growth inhibitory effect was observed in C6 cancer cells but not in normal brain cells treated with various forms of MPSPs. Only phosphorylation could significantly (p < 0.05) improve the adjuvant effect (in vivo) and growth inhibitory effect. A same rank order (phosphorylated MPSP > esterified MPSP ≥ acetylated MPSP ≥ crude MPSP) of efficacy was observed in both the in vivo and in vitro assays. DISCUSSION AND CONCLUSION: This study showed chemical phosphorylation could markedly enhance both adjuvant effects and growth inhibitory effects. This study demonstrated the feasibility of enhancing the efficacy of MPSP by using a simple chemical modification method, and this provides a foundation for future study in this area.


Subject(s)
Antineoplastic Agents/pharmacology , Brain Neoplasms/drug therapy , Glioma/drug therapy , Grifola , Proteoglycans/pharmacology , Acetylation , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/isolation & purification , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Design , Esterification , Glioma/pathology , Grifola/chemistry , Male , Molecular Structure , Phosphorylation , Proteoglycans/chemical synthesis , Proteoglycans/isolation & purification , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
17.
Inflammopharmacology ; 19(5): 245-54, 2011 Oct.
Article in English | MEDLINE | ID: mdl-20981575

ABSTRACT

Arctium lappa, commonly known as burdock, is being promoted/recommended as a healthy and nutritive food in Chinese societies. Burdock has been used therapeutically in Europe, North America and Asia for hundreds of years. The roots, seeds and leaves of burdock have been investigated in view of its popular uses in traditional Chinese medicine (TCM). In this review, the reported therapeutic effects of the active compounds present in the different botanical parts of burdock are summarized. In the root, the active ingredients have been found to "detoxify" blood in terms of TCM and promote blood circulation to the skin surface, improving the skin quality/texture and curing skin diseases like eczema. Antioxidants and antidiabetic compounds have also been found in the root. In the seeds, some active compounds possess anti-inflammatory effects and potent inhibitory effects on the growth of tumors such as pancreatic carcinoma. In the leaf extract, the active compounds isolated can inhibit the growth of micro-organisms in the oral cavity. The medicinal uses of burdock in treating chronic diseases such as cancers, diabetes and AIDS have been reported. However, it is also essential to be aware of the side effects of burdock including contact dermatitis and other allergic/inflammatory responses that might be evoked by burdock.


Subject(s)
Arctium , Drugs, Chinese Herbal/pharmacology , Phytotherapy , Plant Extracts/pharmacology , Anti-Infective Agents/adverse effects , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Anti-Inflammatory Agents/adverse effects , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Drugs, Chinese Herbal/adverse effects , Drugs, Chinese Herbal/therapeutic use , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Medicine, Chinese Traditional , Neoplasms/drug therapy , Plant Extracts/adverse effects , Plant Extracts/therapeutic use
18.
Am J Chin Med ; 38(4): 815-27, 2010.
Article in English | MEDLINE | ID: mdl-20626065

ABSTRACT

In Chinese communities, regular consumption of Chinese-medicated diets (CMD) (usually in the form of soup) is a traditional practice to promote health and prevent disease development. The overall improvement of health conditions is believed to be correlated with the anti-oxidant potentials of these herbs. Huangqin, roots of Scutellaria baicalensis Georgi (Lamiaceae), is one of the herbs commonly used in CMD. In this study, the anti-oxidant capacities of Huangqin extracts (water, ethanol and ether extracts) were evaluated and compared to commonly used CMD herbs, Heshouwu, roots of Polygonum multiflorum Thunb (Polygonaceae) and Renshen (or Ginseng), roots of Panax ginseng CA Meyer (Araliaceae). The anti-oxidant capacities were measured by using both cell-free assay [ferric reducing/anti-oxidant power (FRAP)] and biological methods [2,2'-azobis-(2-amidinopropane) (AAPH)-induced haemolysis assay and H(2)O(2)-induced cell damage on H9C2 cells]. Additionally, the total phenolic content was measured using Folin-Ciocalteu methods. Water extract of Huangqin has the highest anti-oxidant activities compared to the ethanol and ether extracts. A positive relationship between the anti-oxidant effects and total phenolic contents of extracts was demonstrated. This shows that Huangqin could be an effective dietary anti-oxidant that can be consumed regularly as a functional food for the prevention of oxidant/free radical-related diseases.


Subject(s)
Antioxidants/pharmacology , Drugs, Chinese Herbal/pharmacology , Panax/chemistry , Phenols/pharmacology , Polygonum/chemistry , Scutellaria baicalensis/chemistry , Cell Line , Drugs, Chinese Herbal/chemistry , Hydrogen Peroxide , Phenols/analysis , Plant Roots
19.
Bioorg Med Chem ; 15(12): 4091-7, 2007 Jun 15.
Article in English | MEDLINE | ID: mdl-17420133

ABSTRACT

In search of new oligodeoxynucleotide (ODN) delivery agents, we evaluated novel peptides derived from core peptide H-GLRILLLKV-OH (CP). CP is a fragment designed from the T-cell antigen receptor (TCR) alpha-chain transmembrane sequence. CP was able to enter cells including T-cells and inhibited interleukin-2 (IL-2) production. To examine the effect of increased lipophilicity on cellular uptake and activity of CP, a lipoamino acid (2-aminododecanoic acid) was incorporated into peptide CP resulting in 2-aminodecanoyl-CP (LP). The toxicity of CP and LP was assessed by measuring the haemolytic activity. Neither compound caused any haemolysis of red blood cells. We have also compared the biological activities of the CP and LP. Using a T-cell antigen presentation assay, the more lipophilic LP caused greater inhibition of IL-2 production than the parent CP in the antigen stimulated T-cells. The LP also showed increased permeability than CP in the Caco-2 cell assay. We utilised the enhanced cell permeability property of LP in oligodeoxynucleotide ODN1 delivery. Isothermal titration calorimetry (ITC) suggested that CP and LP complex with ODN1 in a 12:1 (CP:ODN1) and 15:1 (LP:ODN1) ratio. These complexes were then transfected into human retinal pigment epithelial cells. The level of transfection was measured by the decreased production of the protein human vascular endothelial growth factor (hVEGF). The results revealed greater transfection efficiency for both CP and LP (47%, 55% more inhibition) compared to commercially available transfection agent cytofectin GSV. These results suggested that the CP and particularly its lipophilic analogue LP have the potential to be used as oligodeoxynucleotide delivery systems.


Subject(s)
Oligonucleotides/administration & dosage , Peptides/administration & dosage , Base Sequence , Caco-2 Cells , Calorimetry , Cations , Hemolysis/drug effects , Humans , Interleukin-2/biosynthesis , Peptides/chemistry , Peptides/pharmacology , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism
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