1
|
Ngo TTD, Bui NP, Vo TKL, Nguyen TMN, Le HK, Phan TT, Hansen PE, That QT. Miliutine C methyl ester, a new drimane sesquiterpene and bioactive alkaloids from the stems of Miliusa velutina. Nat Prod Res 2024:1-7. [PMID: 38656988 DOI: 10.1080/14786419.2024.2345756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/14/2024] [Indexed: 04/26/2024]
Abstract
Previous results from the our research group have isolated numerous compounds, including novel ones, but the anticancer activity of Miliusa velutina has not been demonstrated. In this study, from the most active ethyl acetate extract of the stems of Miliusa velutina, seven compounds were isolated and determined structures, including a new drimane sesquiterpenoid compound named miliutine C methyl ester (1) and three bioactive alkaloids (5-7). These three alkaloids (5-7) exhibited strong anticancer activities against various cancer cell lines such as MCF-7, HepG2, HeLa, NCI H460 and normal fibroblasts. Especially, on MCF-7 and normal fibroblasts with values of IC50 (μM) in order for compounds 5 (3.38, 31.15), 6 (21.96, 102.00), 7 (7.90, greater than 300), to compare with positive control camptothecin (0.020, 4.51); which is highly noteworthy. These results contribute to elucidating and confirming the value of Miliusa velutina, similar to other published and folkloric findings.
Collapse
Affiliation(s)
- Thi Thuy Duong Ngo
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Ngoc Phuc Bui
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thi Kieu Loan Vo
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thi My Nuong Nguyen
- Vietnam National University, Ho Chi Minh City, Vietnam
- Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam
| | - Hoang Khang Le
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thanh Tung Phan
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Poul Erik Hansen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Quang Ton That
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| |
Collapse
|
2
|
Le HK, Phan TT, Nguyen TMN, Nguyen TC, Tran CL, Hansen PE, That QT. A new sesquiterpene lactone from the leaves of Panax vietnamensis Ha et Grushv. (Vietnamese ginseng). Nat Prod Res 2023; 37:3580-3587. [PMID: 35767319 DOI: 10.1080/14786419.2022.2094374] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/01/2022] [Accepted: 06/16/2022] [Indexed: 12/20/2022]
Abstract
Panax vietnamensis (Vietnamese ginseng, Ngoc Linh ginseng) is an endemic Panax species of Vietnam. From the methanol extract of the leaves of Panax vietnamensis, five compounds (1-5) were isolated, including one new sesquiterpene lactone such as panaxolide (1) and four known compounds. The structures of the compounds (1-5) were elucidated by spectral techniques such as 1 D NMR (1H NMR, 13C NMR), 2 D NMR (COSY, HSQC, HMBC, NOESY) and mass spectrometry. The absolute configuration of 1 was determined based on the Cotton effects in the CD spectrum. All of the five compounds were screened for their in vitro growth inhibitory activities against cancerous cells (HepG2) and normal cells (fibroblast) using the SRB assay. Panaxolide (1) showed the highest potential for the growth inhibition of cancerous cells HepG2 with the IC50 values of 63.8 μM.
Collapse
Affiliation(s)
- Hoang Khang Le
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thanh Tung Phan
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thi My Nuong Nguyen
- Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | | | | | - Poul Erik Hansen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Quang Ton That
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| |
Collapse
|
3
|
Le HK, Phan TT, Loan Vo TK, Duong Ngo TT, Ngo HL, Hansen PE, That QT. Miliutine A acid, a new cyclofarnesane sesquiterpene from the stems of Miliusa velutina. Nat Prod Res 2023:1-8. [PMID: 37599639 DOI: 10.1080/14786419.2023.2248540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 08/02/2023] [Accepted: 08/12/2023] [Indexed: 08/22/2023]
Abstract
Six compounds were isolated from the ethyl acetate extract of the stems of Miliusa velutina, including miliutine A acid (1), a new cyclofarnesane sesquiterpenoid; miliutine B methyl ester (2), a cyclofarnesane sesquiterpenoid which was determined the absolute configuration for the first time and four known phenol derivatives (3-6). NMR spectroscopic and mass spectrometry were used for identifying relative configurations. The assignments of the absolute configurations were determined based on Electronic Circular Dichroism (ECD) and NOESY spectra analysis. All six compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay and they showed weak or none activities.
Collapse
Affiliation(s)
- Hoang Khang Le
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thanh Tung Phan
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thi Kieu Loan Vo
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Thi Thuy Duong Ngo
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Hoang Long Ngo
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
| | - Poul Erik Hansen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Quang Ton That
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| |
Collapse
|
4
|
Shetty G, Wu Z, Lam TNA, Phan TT, Orwig KE, Meistrich ML. Effect of hormone modulations on donor-derived spermatogenesis or colonization after syngeneic and xenotransplantation in mice. Andrology 2018; 7:257-265. [PMID: 30471208 DOI: 10.1111/andr.12571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/15/2018] [Accepted: 11/07/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND Cytotoxic cancer treatments, such as irradiation, can cause permanent sterility in male mammals owing to the loss of spermatogonial stem cells. In animal models, spermatogenesis could be restored from transplanted spermatogonial stem cells. Previously, we showed that transient suppression of FSH, LH, and testosterone in the recipient with a gonadotropin-releasing hormone antagonist (GnRH-ant), given immediately after irradiation, enhanced spermatogenesis from transplanted spermatogonial stem cells in mice and monkeys. OBJECTIVES To explore improvements in the preparation of the recipient for efficient and reliable spermatogenic recovery from spermatogonial stem cell transplantation, so that it can be used effectively in clinical practice. MATERIALS AND METHODS In mouse recipients, we evaluated the effects of hormone suppression given after germ cell depletion was complete, which is a more clinically relevant model, and also the importance of total androgen ablation and maintenance of FSH levels. Three regimens, GnRH-ant, GnRH-ant plus flutamide (androgen receptor antagonist), and GnRH-ant plus FSH, were administered prior to and around the time of transplantation of testis cells from immature mice or from prepubertal monkeys. RESULTS Treatment with GnRH-ant resulted in a fourfold increase in spermatogenic recovery from GFP-marked transplanted mouse cells. Total androgen ablation with the addition of flutamide, started two weeks before transplantation, did not further enhance recovery. Surprisingly, FSH supplementation, started around the time of transplantation, actually reduced spermatogenic recovery from transplanted spermatogonial stem cells in GnRH-ant-treated mice. When prepubertal monkey testicular cells were transplanted into nude mice that were given the same hormone treatments, the numbers of donor-derived colonies were independent of hormone treatment. DISCUSSION AND CONCLUSION The enhancements in spermatogenic recovery may only occur when syngeneic or closely related donor-recipient pairs are used. These results are useful in further investigations in choosing a hormone suppression regimen in combination with spermatogonial transplantation as a treatment to restore fertility in primates after cytotoxic therapy.
Collapse
Affiliation(s)
- G Shetty
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Z Wu
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - T N A Lam
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - T T Phan
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - K E Orwig
- Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - M L Meistrich
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| |
Collapse
|
5
|
Stubbendorff M, Kawalkowska J, Deuse T, Phan TT, Bieback K, Atkinson K, Eiermann T, Reichenspurner H, Robbins RC, Schrepfer S. Immunological and immunomodulatory properties of extra-embryonic tissue-derived mesenchymal stromal cells. Thorac Cardiovasc Surg 2012. [DOI: 10.1055/s-0031-1297633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
6
|
Piya MK, Shivu GN, Tahrani A, Dubb K, Abozguia K, Phan TT, Narendran P, Pop-Busui R, Frenneaux M, Stevens MJ. Abnormal left ventricular torsion and cardiac autonomic dysfunction in subjects with type 1 diabetes mellitus. Metabolism 2011; 60:1115-21. [PMID: 21306747 PMCID: PMC3142285 DOI: 10.1016/j.metabol.2010.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/03/2010] [Accepted: 12/10/2010] [Indexed: 12/16/2022]
Abstract
Left ventricular torsion is increased and cardiac energetics are reduced in uncomplicated type 1 diabetes mellitus (T1DM). Our aim was to determine the relationships of these abnormalities to cardiovascular autonomic neuropathy (CAN) in subjects with T1DM. A cross-sectional study was conducted in 20 subjects with T1DM free of known coronary heart disease attending an outpatient clinic. Cardiovascular autonomic neuropathy was assessed using heart rate variability studies and the continuous wavelet transform method. Left ventricular function was determined by speckle tracking echocardiography. Magnetic resonance spectroscopy and stress magnetic resonance imaging were used to measure cardiac energetics and myocardial perfusion reserve index, respectively. Twenty subjects (age, 35 ± 8 years; diabetes duration, 16 ± 9 years; hemoglobin A(1c), 8.0% ± 1.1%) were recruited. Forty percent of the subjects exhibited definite or borderline CAN. Log peak radial strain was significantly increased in subjects with CAN compared with those without (1.56 ± 0.06 vs 1.43 ± 0.14, respectively; P = .011). Data were adjusted for log duration of diabetes, and log left ventricular torsion correlated (r = 0.593, P = .01) with log low-frequency to high-frequency ratio during the Valsalva maneuver. Log isovolumic relaxation time correlated significantly with log Valsalva ratio and log proportion of differences in consecutive RR intervals of normal beats greater than 50 milliseconds during deep breathing. However, CAN did not correlate with cardiac energetics or myocardial perfusion reserve index. Spectral analysis of low-frequency to high-frequency ratio power during the Valsalva maneuver is associated with altered left ventricular torsion in subjects with T1DM. Parasympathetic dysfunction is closely associated with diastolic deficits. Cardiovascular autonomic neuropathy is not however the principal cause of impaired cardiac energetics. The role of CAN in the development of cardiomyopathy warrants further evaluation.
Collapse
Affiliation(s)
- Milan K Piya
- School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Abozguia K, Elliott P, McKenna W, Phan TT, Nallur-Shivu G, Ahmed I, Maher AR, Ashrafian H, Watkins H, Frenneaux MP. 061 Metabolic alteration in hypertrophic cardiomyopathy (METAL-HCM Study): randomised double blinded placebo controlled trial of perhexiline therapy in patient with hypertrophic cardiomyopathy. Heart 2010. [DOI: 10.1136/hrt.2010.195966.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
8
|
Abstract
OBJECTIVE To investigate the effect of glucose and insulin concentrations on differentiation of umbilical cord lining progenitor cells to adipocyte-like cells (ALCs). METHODS Cord lining mesenchymal cells (CLMCs) were isolated from the explant of human umbilical cord amniotic membrane. CLMCs were subjected to differentiation under various culture conditions for 20 days. Lipid droplets were confirmed with Oil Red O staining. Gene expressions of adipsin and peroxisome proliferator-activated receptor gamma (PPARγ) were analyzed using reverse transcription-PCR. Leptin and adiponectin secretions were detected using enzyme-linked immunosorbent assay kit. RESULTS CLMCs became irregular, cuboidal-shaped cells that resemble adipocytes, and Oil Red O staining showed the presence of lipid droplets. The gene expressions of PPARγ and adipsin were upregulated. Leptin and adiponectin secretions by naive CLMCs were below the limits of detection. Matured ALCs cultured in low-glucose medium significantly secreted leptin and adiponectin, whereas those in high-glucose medium significantly secreted only leptin. Insulin concentration affects leptin but not adiponectin secretion. CONCLUSIONS Under different culture conditions, CLMCs can differentiate into ALCs that resemble adipocytes in either normal-weight or obese individuals. Hence, these ALCs have the potential to be used as an in vitro model to study adipogenesis and obesity, and possibly as a drug discovery model for metabolic disorders.
Collapse
Affiliation(s)
- H H Cheong
- Department of Pharmacy, National University of Singapore, Singapore, Singapore
| | | | | | | |
Collapse
|
9
|
Zeugolis DI, Panengad PP, Yew ESY, Sheppard C, Phan TT, Raghunath M. An in situ and in vitro investigation for the transglutaminase potential in tissue engineering. J Biomed Mater Res A 2010; 92:1310-20. [PMID: 19353617 DOI: 10.1002/jbm.a.32383] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transglutaminases (TGases) constitute a family of enzymes that stabilize protein assemblies by gamma-glutamyl-epsilon-lysine crosslinks. The role of tissue transglutaminase (TGase 2) in several pathophysiologies, wound healing applications, biomaterials functionalization, and drug delivery systems provides grounds for its use in tissue engineering. Herein, we initially studied the endogenous TGase activity and expression under normal (skin, duodenum, colon, and small bowel) and pathophysiological (keloid scar) conditions on cadaveric human tissues. Successful inhibition was achieved using low concentrations of BOC-DON-QIV-OMe (0.1 mM and 1 mM for normal skin and keloid scar, respectively), iodoacetamide (0.1 mM and 1 mM for normal skin and keloid scar, respectively), and cystamine dihydrochloride (1 mM and 10 mM for normal skin and keloid scar, respectively), whilst di-BOC-cystamine was found ineffective even at 100 mM concentration. Secondly, the addition of exogenous guinea pig liver transglutaminase (gpTGase) onto the inhibited tissues and collagen scaffolds was studied, and results presented advocate its use as potential tissue adhesive and drug delivery tool. However, the investigation of its crosslinking extent using second harmonic generation microscopy and differentially scanning calorimetry revealed rather poor stabilization function. Overall, our study indicates that TGase 2 has a role as a biological glue to consolidate various micro-structural components of tissues and biomaterials.
Collapse
Affiliation(s)
- D I Zeugolis
- Tissue Modulation Laboratory, National University of Singapore, Singapore
| | | | | | | | | | | |
Collapse
|
10
|
Shivu GN, Phan TT, Abozguia K, Ahmed I, Wagenmakers A, Henning A, Narendran P, Stevens M, Frenneaux M. Relationship between coronary microvascular dysfunction and cardiac energetics impairment in type 1 diabetes mellitus. Circulation 2010; 121:1209-15. [PMID: 20194884 DOI: 10.1161/circulationaha.109.873273] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Asymptomatic subjects with diabetes mellitus have an impaired cardiac energetics status that may play a significant role in the development of heart failure. In the present study, we assessed the role of microvascular dysfunction in the development of impaired cardiac energetics in subjects with type 1 diabetes mellitus. METHODS AND RESULTS Twenty-five asymptomatic subjects with type 1 diabetes mellitus (mean age +/-1 SD 33+/-8 years) and 26 age-, sex-, and body mass index-matched healthy control subjects (32+/-8 years old) were recruited into the study. The type 1 diabetes mellitus subjects were divided into 2 age-matched groups (newly diagnosed [<5 years] and longer-duration [>10 years] diabetes) to assess the impact of microvascular disease. All subjects had an echocardiogram and an exercise ECG performed, followed by magnetic resonance spectroscopy and stress magnetic resonance imaging. Compared with healthy control subjects, the phosphocreatine/gamma-ATP ratio was reduced significantly both in subjects with longer-term (2.1+/-0.5 versus 1.5+/-0.4, P<0.000) and newly diagnosed (2.1+/-0.5 versus 1.6+/-0.2, P<0.000) diabetes. The phosphocreatine/gamma-ATP ratio was similar in newly diagnosed diabetes subjects and those with longer-term disease (1.6+/-0.2 versus 1.5+/-0.4, P=0.32). The mean myocardial perfusion reserve index in the longer-term type 1 diabetes mellitus subjects was significantly lower than in healthy control subjects (1.7+/-0.6 versus 2.3+/-0.4, P=0.005). On univariate analysis, there was no significant correlation of phosphocreatine/gamma-ATP ratio with myocardial perfusion reserve index (r=0.21, P=0.26). CONCLUSIONS We demonstrate that young subjects with uncomplicated type 1 diabetes mellitus have impaired myocardial energetics irrespective of the duration of diabetes and that the impaired cardiac energetics status is independent of coronary microvascular function. We postulate that impairment of cardiac energetics in these subjects primarily results from metabolic dysfunction rather than microvascular impairment.
Collapse
Affiliation(s)
- G Nallur Shivu
- Department of Cardiovascular Medicine, University of Birmingham, Edgbaston, Birmingham, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Affiliation(s)
- C T Ong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
The morbidity and mortality of coronary heart disease and of heart failure remain unacceptably high despite major advances in their management. The main focus of treatment has been revascularisation for ischaemic heart disease and neuro-humoral modification for heart failure. There is an urgent need for new modalities of treatment to improve mortality and morbidity. Recently, there has been a great deal of interest in the role of disturbances in cardiac energetics and myocardial metabolism in the pathophysiology of both ischaemic heart disease and heart failure and of therapeutic potential of metabolic modulation. The myocardium is a metabolic omnivore, but mainly uses fatty acids and glucose for generation of Adenosine-5'-triphosphate (ATP). This review focuses on the key changes that occur to the metabolism of the heart in ischaemia and in heart failure and its effects on cardiac energetics.
Collapse
Affiliation(s)
- K Abozguia
- Department of Cardiovascular Medicine, Medical School, University of Birmingham, Edgbaston, Birmingham, UK.
| | | | | | | | | |
Collapse
|
13
|
Ooi BNS, Mukhopadhyay A, Masilamani J, Do DV, Lim CP, Cao XM, Lim IJ, Mao L, Ren HN, Nakamura H, Phan TT. Hepatoma-derived growth factor and its role in keloid pathogenesis. J Cell Mol Med 2009; 14:1328-37. [PMID: 19432814 PMCID: PMC3828849 DOI: 10.1111/j.1582-4934.2009.00779.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Hepatoma-derived growth factor (HDGF) is a novel mitogenic growth factor that has been implicated in many different carcinomas. Its role in keloid biology has not yet been investigated. The present study is aimed at examining the role of HDGF in keloid pathogenesis. Immunohistochemical staining and Western blot analyses were used to examine in vivo localization and expression of HDGF in keloid and normal skin tissue. This was followed by the detection of HDGF expression in fibroblasts cultured in vitro and fibroblasts exposed to serum. To investigate the effect of epithelial–mesenchymal interactions, a two-chamber system was employed in which keratinocytes on membrane inserts were co-cultured with the fibroblasts. HDGF expression levels in all cell extracts and conditioned media were assayed through Western blot analysis. In another set of experiments, the effect of exogenous recombinant HDGF on keloid fibroblasts (KF) and normal fibroblasts (NF) was examined. Cell proliferation was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and by quantifying proliferating cell nuclear antigen (PCNA) expression. Downstream targets of HDGF were identified by detecting their expression through Western blot analysis. Our results indicate that there was an increase in HDGF expression in the dermis of keloid compared with normal skin tissue. The application of serum and epithelial–mesenchymal interactions did not seem to have any effect on intracellular HDGF expression levels. However, co-culturing keloid keratinocytes with KFs resulted in increased HDGF secretion when compared with monoculture or normal controls. Furthermore, treatment with exogenous recombinant HDGF was found to increase the proliferation of KFs, activate the extracellular signal-regulated kinase (ERK) pathway and up-regulate the secretion of vascular endothelial growth factor (VEGF).
Collapse
Affiliation(s)
- B N S Ooi
- Graduate Programme in Bioengineering, National University of Singapore, Singapore, Singapore
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Mukhopadhyay A, Khoo A, Cheong HH, Chan SY, Aalami O, Lim IJ, Phan TT. Targeting of Sp1 transcription factor: a novel therapeutic approach for keloids, an in vitro analysis. Exp Dermatol 2008; 16:1023-31. [PMID: 18031462 DOI: 10.1111/j.1600-0625.2007.00627.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Keloid scars are fibroproliferative disorders characterized by the accumulation of extracellular matrix (ECM) components resulting in a fibrotic condition. Several ECM promoters are regulated by Sp1. Thus, our aim was to investigate the role of Sp1 in keloid pathogenesis and investigate the antiproliferative and antifibrotic effects of Wp631 and mitoxantrone, potent inhibitors of Sp1-activated transcription. An elevated level of Sp1 was observed in tissue extracts obtained from keloid tissue. Serum stimulation elevated Sp1 levels in keloid fibroblasts (KF). Under coculture conditions Sp1 seemed to be downregulated. Wp631 and mitoxanthrone in serum growth factors resulted in a reduced expression of ECM components in KF. Both Wp631 and mitoxanthrone were also able to inhibit the proliferation of normal and keloid keratinocytes and fibroblasts significantly. As Wp631 seems to be potent in downregulating the ECM components in KF and also inhibiting the proliferation of these cells it could be explored as a possible therapeutic agent in the treatment of keloids.
Collapse
Affiliation(s)
- A Mukhopadhyay
- Department of Pharmacy, National University of Singapore, Singapore
| | | | | | | | | | | | | |
Collapse
|
15
|
Chua AWC, Ma DR, Song IC, Phan TT, Lee ST, Song C. In vitro evaluation of fibrin mat and Tegaderm wound dressing for the delivery of keratinocytes--implications of their use to treat burns. Burns 2007; 34:175-80. [PMID: 18029101 DOI: 10.1016/j.burns.2007.07.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 07/24/2007] [Indexed: 10/22/2022]
Abstract
The effectiveness of fibrin mat and Tegaderm delivery systems to maintain clonogenic keratinocytes in culture were evaluated using in vitro methods. A fibrin mat was found to provide a culture environment that is conducive for the proliferation of keratinocytes and supporting their ability to form colonies of good growth potential in vitro. This confirms that the fibrin mat is a good delivery system for cultured epithelial autograft (CEA). In our unit, fibrin-CEA is limited only for the treatment of severe burns due to the high cost of fibrin glue. However, this substrate is able to maintain the regenerative properties of the CEA which is crucial for the treatment of extensive and full thickness burns. Tegaderm, a cost-effective polyurethane wound dressing is able to support keratinocyte cell growth but at a slower rate and with fewer colonies formed compared to the fibrin system. This suggests that Tegaderm can be an alternative approach of delivering autologous cells, limited to treat chronic wounds and less extensive burns. The use of simple and relatively inexpensive bench techniques can potentially serve as a quality control to check for keratinocytes cultured and delivered to every patient in the clinical setting.
Collapse
Affiliation(s)
- A W C Chua
- Skin Bank Unit, Singapore General Hospital, Singapore.
| | | | | | | | | | | |
Collapse
|
16
|
Abstract
Keloid is a dermal fibroproliferative disorder characterized by excessive deposition of extracellular matrix (ECM) components such as collagen, glycoproteins and fibronectin. The mammalian target of rapamycin (mTOR) is a serine/theronine kinase which plays an important role in the regulation of metabolic processes and translation rates. Published reports have shown mTOR as regulator of collagen expression and its inhibition induces a decrease in ECM deposition. Our aim was to investigate the role of mTOR in keloid pathogenesis and investigate the effect of rapamycin on proliferating cell nuclear antigen (PCNA), cyclin D1, collagen, fibronectin and alpha-smooth muscle actin (alpha-SMA) expression in normal fibroblasts (NF) and keloid fibroblasts (KF). Tissue extracts obtained from keloid scar demonstrated elevated expression of mTOR, p70KDa S6 kinase (p70S6K) and their activated forms, suggesting an activated state in keloid scars. Serum stimulation highlighted the heightened responsiveness of KF to mitogens and the importance of mTOR and p70S6K during early phase of wound healing. Application of rapamycin to monoculture NF and KF, dose- and time-dependently downregulates the expression of cytoplasmic PCNA, cyclin D1, fibronectin, collagen and alpha-SMA, demonstrating the anti-proliferative effect and therapeutic potential of rapamycin in the treatment of keloid scars. The inhibitory effect of rapamycin was found to be reversible following recovery in the expression of proteins following the removal of rapamycin from the culture media. These results demonstrate the important role of mTOR in the regulation of cell cycle and the expression of ECM proteins: fibronectin, collagen and alpha-SMA.
Collapse
Affiliation(s)
- C T Ong
- Department of Surgery, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260
| | | | | | | | | | | | | |
Collapse
|
17
|
Chong EJ, Phan TT, Lim IJ, Zhang YZ, Bay BH, Ramakrishna S, Lim CT. Evaluation of electrospun PCL/gelatin nanofibrous scaffold for wound healing and layered dermal reconstitution. Acta Biomater 2007; 3:321-30. [PMID: 17321811 DOI: 10.1016/j.actbio.2007.01.002] [Citation(s) in RCA: 540] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 01/19/2007] [Accepted: 01/19/2007] [Indexed: 11/19/2022]
Abstract
The current design requirement for a tissue engineering skin substitute is that of a biodegradable scaffold through which fibroblasts can migrate and populate. This artificial "dermal layer" needs to adhere to and integrate with the wound, which is not always successful for the current artificial dermal analogues available. The high cost of these artificial dermal analogues also makes their application prohibitive both to surgeons and patients. We propose a cost-effective composite consisting of a nanofibrous scaffold directly electrospun onto a polyurethane dressing (Tegaderm, 3M Medical) - which we call the Tegaderm-nanofiber (TG-NF) construct - for dermal wound healing. Cell culture is performed on both sides of the nanofibrous scaffold and tested for fibroblast adhesion and proliferation. It is hoped that these studies will result in a fibroblast-populated three-dimensional dermal analogue that is feasible for layered applications to build up thickness of dermis prior to re-epithelialization. Results obtained in this study suggest that both the TG-NF construct and dual-sided fibroblast-populated nanofiber construct achieved significant cell adhesion, growth and proliferation. This is a successful first step for the nanofiber construct in establishing itself as a suitable three-dimensional scaffold for autogenous fibroblast populations, and providing great potential in the treatment of dermal wounds through layered application.
Collapse
Affiliation(s)
- E J Chong
- Nanoscience and Nanotechnology Initiative, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore
| | | | | | | | | | | | | |
Collapse
|
18
|
Ong CT, Khoo YT, Tan EK, Mukhopadhyay A, Do DV, Han HC, Lim IJ, Phan TT. Epithelial-mesenchymal interactions in keloid pathogenesis modulate vascular endothelial growth factor expression and secretion. J Pathol 2007; 211:95-108. [PMID: 17136757 DOI: 10.1002/path.2081] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis during the wound healing process. As epithelial-mesenchymal interactions have been shown to regulate a plethora of genes in wound healing, we hypothesized that these interactions might have a role in modulating VEGF expression and angiogenesis. A two chamber co-culture model was used, wherein normal and keloid keratinocytes and fibroblasts were physically separated by membrane inserts while allowing cytokine diffusion. Cell lysates obtained from keratinocytes co-cultured with fibroblasts demonstrated increased expression of VEGF. An enzyme-linked immunosorbent assay (ELISA) showed significant increase in VEGF expression in co-culture conditioned media compared with controls. Additionally, the conditioned medium from keloid keratinocyte and fibroblast co-cultures increased proliferation and formation of complex three-dimensional capillary-like structures in human umbilical vein endothelial cells, emphasising the importance of epithelial-mesenchymal interactions in the angiogenic process. Immunostaining of keloid tissue localized VEGF in the basal layer of the epidermis and also demonstrated higher blood vessel density than normal skin. Keloid tissue extract also demonstrated increased expression of VEGF compared with normal skin. It is likely that epidermal VEGF exerts significant paracrine control over the dynamics and expression profile of underlying dermal fibroblasts. Addition of the inhibitors WP631, mitoxantrone, and Rapamycin to keloid keratinocyte and fibroblast co-cultures, downregulated secreted VEGF expression in a dose-dependent manner, suggesting therapeutic potential for these compounds in the treatment of keloid scars.
Collapse
Affiliation(s)
- C T Ong
- Department of Surgery, National University of Singapore, Singapore
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
Keloids are proliferative growths of dermal collagen, usually resulting from excessive tissue response during wound healing. There is evidence that keratinocytes may promote keloidogenesis via epithelial-mesenchymal interactions. Metallothioneins (MTs) are known to be involved in the fundamental cellular processes of growth and apoptosis. In this study, we evaluated the expression of MT isoforms in normal and keloid keratinocytes. The expression patterns of ten functional MT isoforms were assessed using real-time RT-PCR in primary cultures of normal and keloid keratinocytes. The MT-2A isoform was the most abundant MT isoform in both normal and keloid keratinocytes while the MT-1B isoform was absent. There was a significant increase in the mRNA expression of four MT isoforms, viz. MT-1A, 1E, 1F and 2A in keloid keratinocytes as compared to normal keratinocytes. Up-regulation of MT-1A, 1E, 1F and 2A isoforms may play a part in the development of keloids by paracrine signaling.
Collapse
Affiliation(s)
- D Lim
- Department of Anatomy, National University of Singapore, Singapore 117597
| | | | | | | |
Collapse
|
20
|
Phan TT, Lim IJ, Aalami O, Lorget F, Khoo A, Tan EK, Mukhopadhyay A, Longaker MT. Smad3 signalling plays an important role in keloid pathogenesis via epithelial-mesenchymal interactions. J Pathol 2005; 207:232-42. [PMID: 16052471 DOI: 10.1002/path.1826] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Smad signalling plays important roles in developmental and cancer biology as well as in fibropathogenesis. Its role in keloid biology is not known. Epithelial-mesenchymal interactions, originally described in normal skin, have recently been established to play a significant role in keloid pathogenesis, and demonstrate the important influence of keratinocyte paracrine factor signalling on fibroblast behaviour. The present study investigated the role of downstream Smad cascade induction in this interaction. Normal fibroblasts (NF) and keloid fibroblasts (KF) were co-cultured in serum-free medium with normal keratinocytes (NK) or keloid keratinocytes (KK) for 5 days, after which fibroblast cell lysates were subjected to western blot and immunoprecipitation analysis to quantify the levels of Smad and Smad2/3/4 binding complex. In another set of experiments, wild-type (wt), Smad2-null (Smad2-/-) and Smad3-null (Smad3-/-) mouse embryonic fibroblasts (MEF) were assayed for cell proliferation and collagen production after serum-free co-culture with KK or exposure to conditioned media collected from serum-free KK/KF co-culture. Compared to normal skin, keloids expressed high basal levels of TGFbetaR1 and TGFbetaR2, Smad2, 3 and 4 and phospho-Smad2. Upregulation of TGFbetaR1 and TGFbetaR2, Smad3 and p-Smad2 was observed in KF co-cultured with KK, together with enhanced Smad3 phosphorylation and Smad2/3/4 binding complex production. When MEF-wt, MEF-Smad2-/- or MEF-Smad3-/- were co-cultured with KK or exposed to KK/KF co-culture conditioned media, enhanced proliferation and collagen production were seen in MEF-wt and MEF-Smad2-/- but not in MEF-Smad3-/- cells. The activation of Smad signalling, importantly that of Smad3, appears to be one facet of the complex epithelial-mesenchymal interactions in keloid pathogenesis, resulting in active KF proliferation and collagen-ECM production in co-culture with KK. This finding suggests the suppression of Smad signalling as a novel approach in keloid therapy.
Collapse
Affiliation(s)
- T T Phan
- Department of Surgery, National University of Singapore, Singapore.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Phan TT, Lim IJ, Tan EK, Bay BH, Lee ST. Evaluation of cell culture on the polyurethane-based membrane (TegadermTM): implication for tissue engineering of skin. Cell Tissue Bank 2005; 6:91-7. [PMID: 15909096 DOI: 10.1007/s10561-004-3904-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Accepted: 09/27/2004] [Indexed: 11/26/2022]
Abstract
BACKGROUND The use of polymer-based delivery systems, on which cells are cultured and transferred, improves the ease of handling and transfer of the keratinocytes. A transparent polymer also allows observation of cell growth prior to grafting as well as re-epithelialization after grafting to the wound. We have developed techniques for cultured keratinocytes on Tegaderm (3M), an inexpensive and easily available polyurethane-based wound dressing, for treatment of burn and chronic wounds. In this study, we evaluate cell culture characteristics of three different cell types, human epidermal keratinocytes, human dermal fibroblasts and pig bone marrow mesenchymal stem cells on Tegaderm membrane. METHODS Cells were isolated from human skin or pig bone marrow and cultured on membranes for a period of five days. Cell proliferation was assessed by colorimetric assay (MTT) and scanning electron microscopy. RESULTS AND CONCLUSIONS This study confirms that Tegaderm membranes support attachment and growths for these cell types, with those growth characteristics are similar, if not as good as that of optimal condition of tissue culture plastics. Data from our study suggest that Tegaderm membranes can be used, modified and developed further as an economical and easily available material for tissue engineered skin.
Collapse
Affiliation(s)
- T T Phan
- Department of Plastic Surgery, Singapore General Hospital, Republic of Singapore.
| | | | | | | | | |
Collapse
|
22
|
Mukhopadhyay A, Tan EKJ, Khoo YTA, Chan SY, Lim IJ, Phan TT. Conditioned medium from keloid keratinocyte/keloid fibroblast coculture induces contraction of fibroblast-populated collagen lattices. Br J Dermatol 2005; 152:639-45. [PMID: 15840092 DOI: 10.1111/j.1365-2133.2005.06545.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Keloid scars represent a pathological response to cutaneous injury. Overproliferation of fibroblasts and overproduction of collagen characterize these abnormal scars. The pathology of these scars remains poorly understood. The role of epithelial-mesenchymal interactions in keloid pathogenesis and scar contracture has recently been explored. OBJECTIVES To test our hypothesis that epithelial-mesenchymal interactions play a major role in modulating keloid scar contracture. METHODS A coculture model was employed wherein keloid and normal keratinocytes were cocultured with keloid or normal fibroblasts, and the conditioned media from day 5 cocultures were collected to study the effect of the paracrine secretions on contraction of an in vitro fibroblast-populated collagen lattice (FPCL) model. RESULTS Keloid keratinocyte/keloid fibroblast coculture conditioned media brought about increased contraction of the collagen lattice compared with non-cocultured conditioned media. When keloid fibroblasts populated the collagen lattice, significantly increased lattice contraction was induced compared with lattices populated by normal fibroblasts. The addition of antitransforming growth factor (TGF)-beta neutralizing antibody to the conditioned media produced an attenuation of the contraction of the FPCLs. When keloid and normal fibroblasts were cultured on chamber slides and treated with conditioned media from coculture and non-coculture series, immunohistochemical analysis demonstrated an increased expression of alpha-smooth muscle actin (a marker for fibroblast differentiation into myofibroblasts) in fibroblasts exposed to conditioned media from coculture. CONCLUSIONS These data indicate that epithelial-mesenchymal interactions are likely to play a major role in scar contracture and scar pathogenesis, and underscore the role of TGF-beta1 as a key player in keloid pathogenesis.
Collapse
Affiliation(s)
- A Mukhopadhyay
- Department of Surgery, The National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260
| | | | | | | | | | | |
Collapse
|
23
|
Cherry GW, Parish J, Hu D, Jia C, Phan TT, Hughes MA. Pharmacological and Mechanical Effects on Collagen Lattice Contraction - the Oxford Experience. Wound Repair Regen 2005. [DOI: 10.1111/j.1067-1927.2005.130117n.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
24
|
Ang LPK, Tan DTH, Cajucom-Uy H, Phan TT, Beuerman RW, Lavker RM. Reconstruction of the ocular surface by transplantation of a serum free cultivated conjunctival tissue equivalent. Ann Acad Med Singap 2004; 33:S55-6. [PMID: 15651209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- L P K Ang
- Department of Ophthalmology, National University of Singapore, Singapore
| | | | | | | | | | | |
Collapse
|
25
|
Phan TT, Lim IJ, Sun L, Chan SY, Bay BH, Tan EK, Lee ST. Quercetin inhibits fibronectin production by keloid-derived fibroblasts. Implication for the treatment of excessive scars. J Dermatol Sci 2004; 33:192-4. [PMID: 14643528 DOI: 10.1016/j.jdermsci.2003.08.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
26
|
Allen J, Phan TT, Hughes MA, Cherry GW, Wojnarowska F. The cellular origins of the linear IgA disease target antigens: an indirect immunofluorescence study using cultured human keratinocytes and fibroblasts. Br J Dermatol 2003; 148:945-53. [PMID: 12786825 DOI: 10.1046/j.1365-2133.2003.05313.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Linear IgA disease (LAD) is an IgA-mediated subepidermal immunobullous disease of adults and children, with heterogeneous immunopathology. Objectives To investigate to what extent the cellular origins of the target antigens account for the heterogeneity of the immune response in LAD. METHODS Forty-nine adult and 33 childhood LAD sera were studied. Immunofluorescence was carried out to determine the expression of the LAD antigens by normal human keratinocytes, fibroblasts and mixed cultures of keratinocytes and fibroblasts. Immunoblotting was performed to determine the localization of the LAD target antigens in tissue extracts (48 adult and 31 childhood sera) and cell extracts (21 adult and 10 childhood sera). RESULTS Thirty-one adult and 13 childhood LAD sera bound proteins expressed by human keratinocytes; of these sera, 15 adult and four childhood LAD sera also recognized proteins expressed by fibroblasts. A single adult serum was positive on fibroblasts alone. Seventeen adult and 20 childhood sera were negative on both cell types. There was a modest increase (9%) in the detection of the IgA autoantibodies on keratinocytes and fibroblasts grown together in mixed culture. Immunoblotting showed that the LAD target antigens could be detected in cell as well as in tissue extracts. CONCLUSIONS Our results have shown that normal human keratinocytes and fibroblasts in culture express the LAD target antigens. LAD sera (with a single exception) bound antigens expressed by keratinocytes alone or by both keratinocytes and fibroblasts. The principal pattern of expression in keratinocytes was cytoplasmic, similar to that demonstrated by polyclonal antibodies to the 180-kDa bullous pemphigoid antigen (BP180). This reflects the pivotal role of BP180 in LAD. The finding that LAD antigens are expressed by both human keratinocytes and fibroblasts in culture may explain the heterogeneity of the target antigens, and may be a contributory factor in the immunopathology of the disease.
Collapse
Affiliation(s)
- J Allen
- Department of Dermatology and The Wound Healing Institute, The Oxford Radcliffe Hospital, Oxford OX3 7LJ, UK
| | | | | | | | | |
Collapse
|
27
|
Chaw CS, Yang YY, Lim IJ, Phan TT. Water-soluble betamethasone-loaded poly(lactide-co-glycolide) hollow microparticles as a sustained release dosage form. J Microencapsul 2003; 20:349-59. [PMID: 12881115 DOI: 10.1080/0265204021000058447] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
In this study, betamethasone disodium phosphate-loaded microparticles were fabricated for sustained release using poly(lactide-co-glycolide) (PLGA) by spray drying and emulsion solvent evaporation/extraction techniques. Encapsulation efficiencies ranged from 59-80% using a water-in-oil-in-oil (W/O/O) double emulsion technique and more than 90% for a spray-drying method were obtained. This was a significant improvement compared to fabrication by a water-in-oil-in-water (W/O/W) double emulsion process, which had an encapsulation efficiency of less than 15%. Multiple-phase and biphasic release profiles were observed for microparticles of PLGA 50/50 and PLGA of higher lactide contents, respectively. The PLGA 50/50 hollow microparticles fabricated using the W/O/O double emulsion technique provided a sustained release of betamethasone disodium phosphate over 3 weeks.
Collapse
Affiliation(s)
- C S Chaw
- Institute of Materials Research & Engineering, No.3, Research Link, Singapore 117602.
| | | | | | | |
Collapse
|
28
|
Phan TT, See P, Tran E, Nguyen TTT, Chan SY, Lee ST, Huynh H. Suppression of insulin-like growth factor signalling pathway and collagen expression in keloid-derived fibroblasts by quercetin: its therapeutic potential use in the treatment and/or prevention of keloids. Br J Dermatol 2003; 148:544-52. [PMID: 12653748 DOI: 10.1046/j.1365-2133.2003.05174.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Keloids are characterized by abnormal proliferation of fibroblasts and overproduction of collagen. Insulin-like growth factor (IGF)-I is mitogenic for fibroblasts and a stimulatory factor for collagen synthesis. OBJECTIVES We have assessed the in vitro effects of quercetin on proliferation, collagen synthesis and the expression of the IGF system in keloid-derived fibroblasts. METHODS Fibroblasts were isolated from earlobe keloids and exposed to quercetin at different concentrations. The inhibitory effects of quercetin on fibroblast proliferation were assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Western and Northern blot analyses. RESULTS Quercetin inhibited keloid fibroblast (KF) proliferation in a dose-dependent manner. Significant growth inhibition was observed on day 2 of culture. The dose required for 50% growth inhibition was approximately 25 microg mL-1. Collagen 1 expression was significantly decreased while collagen 3 was almost undetectable following quercetin treatment. Basal levels of IGF-I receptor (IGF-IR) beta subunits, p85 subunit of phosphatidylinositol 3-kinase, c-Raf, phospho-Raf-1, phospho-MEK 1/2, phospho-mitogen-activated protein kinase, phospho-Elk-1 and phospho-Akt-1 were significantly reduced when KF cells were exposed to quercetin for 24 h. Blocking IGF-IR activity with IGF-IR antibody or neutralizing endogenous IGF-I activity with IGF-I antibody led to significant growth inhibition suggesting the role of IGF-I in regulation of KF proliferation. CONCLUSIONS Because the IGF system plays an important part in fibroblast cell proliferation and collagen production, the described activities of quercetin on the IGF system and collagen expression may provide a novel approach for the use of quercetin in treatment and/or prevention of hypertrophic scar and keloid.
Collapse
Affiliation(s)
- T T Phan
- Department of Plastic Surgery, Singapore General Hospital, Singapore
| | | | | | | | | | | | | |
Collapse
|
29
|
Phan TT, Wang L, See P, Grayer RJ, Chan SY, Lee ST. Phenolic compounds of Chromolaena odorata protect cultured skin cells from oxidative damage: implication for cutaneous wound healing. Biol Pharm Bull 2001; 24:1373-9. [PMID: 11767105 DOI: 10.1248/bpb.24.1373] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Extracts from the leaves of Chromolaena odorata have been shown to be beneficial for treatment of wounds. The crude ethanol extract of the plant had been demonstrated to be a powerful antioxidant to protect fibroblasts and keratinocytes in vitro. In this study, the most active compounds were fractionated and identified from the crude extract using liquid chromatography coupled with UV spectroscopy and mass spectrometry. The antioxidant effects of purified fractions on cultured fibroblasts and keratinocytes were investigated using colorimetric and lactate hydrogenase release assay. The results showed that the phenolic acids present (protocatechuic, p-hydroxybenzoic, p-coumaric, ferulic and vanillic acids) and complex mixtures of lipophilic flavonoid aglycones (flavanones, flavonols, flavones and chalcones) were major and powerful antioxidants to protect cultured skin cells against oxidative damage. In conclusion, the extract from C odorata contains a mixture of powerful antioxidant compounds that may be one of potential mechanism contributing to enhanced wound healing.
Collapse
Affiliation(s)
- T T Phan
- Department of Plastic Surgery, Singapore General Hospital, Republic of Singapore.
| | | | | | | | | | | |
Collapse
|
30
|
Phan TT, See P, Lee ST, Chan SY. Protective effects of curcumin against oxidative damage on skin cells in vitro: its implication for wound healing. J Trauma 2001; 51:927-31. [PMID: 11706342 DOI: 10.1097/00005373-200111000-00017] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Curcumin, isolated from turmeric, has been known to possess many pharmacologic properties. It has been proven to exhibit remarkable anticarcinogenic, anti-inflammatory, and antioxidant properties. Turmeric curcumin may be a good potential agent for wound healing. METHODS To further understand its therapeutic mechanisms on wound healing, the antioxidant effects of curcumin on hydrogen peroxide (H2O2) and hypoxanthine-xanthine oxidase induced damage to cultured human keratinocytes and fibroblasts were investigated. Cell viability was assessed by colorimetric assay and quantification of lactate dehydrogenase release. RESULTS Exposure of human keratinocytes to curcumin at 10 microg/mL showed significant protective effect against hydrogen peroxide. Interestingly, exposure of human dermal fibroblasts to curcumin at 2.5 microg/mL showed significant protective effects against hydrogen peroxide. No protective effects of curcumin on either fibroblasts or keratinocytes against hypoxanthine-xanthine oxidase induced damage were found in our present studies. CONCLUSION The findings indicate that curcumin indeed possessed powerful inhibition against hydrogen peroxide damage in human keratinocytes and fibroblasts.
Collapse
Affiliation(s)
- T T Phan
- Department of Plastic Surgery/National Burns Centre, Singapore General Hospital.
| | | | | | | |
Collapse
|
31
|
Ng KW, Hutmacher DW, Schantz JT, Ng CS, Too HP, Lim TC, Phan TT, Teoh SH. Evaluation of ultra-thin poly(epsilon-caprolactone) films for tissue-engineered skin. Tissue Eng 2001; 7:441-55. [PMID: 11506733 DOI: 10.1089/10763270152436490] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Various natural and synthetic polymeric materials have been used as scaffold matrices for tissue-engineered skin. However, the commercially available skin replacement products pose problems of poor mechanical properties and immunological rejection. We have thus developed a film of 5 microm thickness, via biaxial stretching of poly(epsilon-caprolactone) (PCL), as a potential matrix for living skin replacements. The aim of this study was to evaluate the feasibility of using biaxially stretched PCL films as matrices for culturing human dermal fibroblasts. For this purpose, we cultured human dermal fibroblasts for 7 days on the films. Glass cover slips and polyurethane (PU) sheets were used as controls. The data from phase contrast light, confocal laser, and scanning electron microscopy suggested that biaxially stretched PCL films support the attachment and proliferation of human dermal fibroblasts. Thymidine-labeling results showed quantitatively that cell proliferation on the PCL films was superior to that on the PU samples. These results indicated that biaxially stretched PCL films supported the growth of human dermal fibroblasts and might have potential to be applied in tissue engineering a dermal equivalent or skin graft.
Collapse
Affiliation(s)
- K W Ng
- Laboratory for Biomedical Engineering (LBME), Department of Mechanical Engineering, National University of Singapore, Singapore
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Phan TT, Hughes MA, Cherry GW. Effects of an aqueous extract from the leaves of Chromolaena odorata (Eupolin) on the proliferation of human keratinocytes and on their migration in an in vitro model of reepithelialization. Wound Repair Regen 2001; 9:305-13. [PMID: 11679139 DOI: 10.1046/j.1524-475x.2001.00305.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Eupolin ointment, prepared from the leaves of Chromolaena odorata, has been shown to promote the healing of soft tissue wounds and burns in Vietnam. However, the mechanism by which this agent affects cells involved in the wound healing process is unknown. Cultured human keratinocytes were used in this study to investigate the effects of the Eupolin extract in vitro on processes involved in wound reepithelialization. Keratinocyte proliferation was monitored by a colorimetric assay and migration by the closure of a denuded area scratched in a confluent monolayer. Human keratinocyte proliferation was stimulated by low concentrations of the extract (from 0.1 to 5 microg/ml), cell differentiation by higher concentrations (50 to 300 microg/ml), and migration by intermediate concentrations (5 to 60 microg/ml). The increased proliferation and migration of human keratinocytes observed in vitro might explain, in part, the beneficial effects that have been observed in the clinic.
Collapse
Affiliation(s)
- T T Phan
- Wound Healing Institute, The Churchill Hospital, Oxford, United Kingdom
| | | | | |
Collapse
|
33
|
Lim IJ, Phan TT, Song C, Tan WT, Longaker MT. Investigation of the influence of keloid-derived keratinocytes on fibroblast growth and proliferation in vitro. Plast Reconstr Surg 2001; 107:797-808. [PMID: 11304607 DOI: 10.1097/00006534-200103000-00022] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Keloids are disfiguring, proliferative scars that represent a pathological response to cutaneous injury. The overabundant extracellular matrix formation, largely from collagen deposition, is characteristic of these lesions and has led to investigations into the role of the fibroblast in its pathogenesis. Curiously, the role of the epidermis in extracellular matrix collagen deposition of normal skin has been established, but a similar hypothesis in keloids has not been investigated. The aim of this study was to investigate the influence of keloid epithelial keratinocytes on the growth and proliferation of normal fibroblasts in an in vitro serum-free co-culture system. A permeable membrane separated two chambers; the upper chamber contained a fully differentiated stratified epithelium derived from the skin of excised earlobe keloid specimens, whereas the lower chamber contained a monolayer of normal or keloid fibroblasts. Both cell types were nourished by serum-free medium from the lower chamber. Epithelial keratinocytes from five separate earlobe keloid specimens were investigated. Four sets of quadruplicates were performed for each specimen co-cultured with normal fibroblasts or keloid-derived fibroblasts. Controls consisted of (1) normal keratinocytes co-cultured with normal fibroblasts, and (2) fibroblasts grown in serum-free media in the absence of keratinocytes in the upper chamber. Fibroblasts were indirectly quantified by 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay, with results confirmed by DNA content measurement, at days 1 and 5 after the co- culture initiation.Significantly, increased proliferation was seen in fibroblasts co-cultured with keloid keratinocytes, as compared with the normal keratinocyte controls at day 5 (analysis of variance, p < 0.001). These results strongly suggest that the overlying epidermal keratinocytes of the keloid may have an important, previously unappreciated role in keloid pathogenesis using paracrine or epithelial-mesenchymal signaling.
Collapse
Affiliation(s)
- I J Lim
- Division of Plastic Surgery, the Department of Surgery, National University Hospital, National University of Singapore, Singapore.
| | | | | | | | | |
Collapse
|
34
|
See P, Phan TT, Chua JJ, Song C, Tan KC, Lee ST. Our Clinical Experience using Cryopreserved Cadaveric Allograft for the Management of Severe Burns. Cell Tissue Bank 2001; 2:113-7. [PMID: 15256922 DOI: 10.1023/a:1014344327544] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Human cadaveric allograft is the most commonly used alternative wound closure material for excised burn wounds when limited donor sites or the overall patient condition does not permit immediate grafting with autologous skin.The Skin Bank in Singapore has supplied a total of 33,000 cm(2) of cryopreserved cadaveric allograft to the Burns Centre in Singapore for the early post-burn treatment of 17 severely burned patients with body surface area (BSA) burn wounds averaging 58% (range 33-90). An average of 13% (range 3-30%) cadaveric allograft was transplanted on 17 patients. Seven patients had recovered from their burn injuries and ten patients died of multiple complications related to their burn injuries. Our clinical observation has shown good adherence of cadaveric allograft when applied on clean and debrided wound bed after 4-7 days of post-operation.The availability of cadaveric allograft permits early excision and wound coverage before the patients' condition is further compromised. Our clinical experience using cryopreserved cadaveric allograft is proving to be indispensable in the management of patients with severe burns.
Collapse
Affiliation(s)
- P See
- Department of Plastic Surgery/Burns Centre, Singapore General Hospital, Outram Road, 169608 Republic of Singapore
| | | | | | | | | | | |
Collapse
|
35
|
Phan TT, Allen J, Hughes MA, Cherry G, Wojnarowska F. Upregulation of adhesion complex proteins and fibronectin by human keratinocytes treated with an aqueous extract from the leaves of Chromolaena odorata (Eupolin). Eur J Dermatol 2000; 10:522. [PMID: 11056422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The fresh leaves and extract of the plant Chromolaena odorata are a traditional herbal treatment in developing countries for burns, soft tissue wounds and skin infections. We have previously shown that the extract had an effect on the growth and proliferation of keratinocytes and fibroblasts in culture. This study has demonstrated that Eupolin extract increased expression of several components of the adhesion complex and fibronectin by human keratinocytes. Using indirect immunofluorescence we found increased expression (dose-dependent) of laminin 5, laminin 1, collagen IV, and fibronectin. The expression of the b1 and b4 integrins was upregulated by the extract at low concentrations (0.1 and 1 microg/ml), but the expression was decreased at higher doses of Eupolin (10 microg-150 microg/ml). A number of clinical studies carried out by Vietnamese and international medical investigators have demonstrated the efficacy of this extract on the wound healing process. In this study we have shown that Eupolin stimulated the expression of many proteins of the adhesion complex and fibronectin by human keratinocytes. The adhesion complex proteins are essential to stabilise epithelium and this effect could contribute to the clinical efficacy of Eupolin in healing.
Collapse
Affiliation(s)
- T T Phan
- Department of Dermatology, The Churchill, The Oxford Radcliffe Hospital, Headington, OX3 7LS Oxford, UK
| | | | | | | | | |
Collapse
|
36
|
Townsend KM, Hanh TX, O'Boyle D, Wilkie I, Phan TT, Wijewardana TG, Trung NT, Frost AJ. PCR detection and analysis of Pasteurella multocida from the tonsils of slaughtered pigs in Vietnam. Vet Microbiol 2000; 72:69-78. [PMID: 10699504 DOI: 10.1016/s0378-1135(99)00188-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the abattoirs in Can tho and Tien giang provinces of Southern Vietnam. The presence of Pasteurella multocida in these samples was detected by the combination of direct cultivation and isolation, mouse inoculation and the polymerase chain reaction (PM-PCR). P. multocida was detected in 16 samples by PCR, with 17 strains ultimately isolated. All samples were negative for serogroup B by HSB-PCR and conventional serotyping, with isolates identified as A:3, D:1 or D:3. In addition, all samples were determined to be negative for the P. multocida toxin (PMT). Characterisation of isolated P. multocida by REP-PCR and biotyping revealed nine distinct REP profiles and seven biotypes among the 17 isolates. Some correlation was seen with P. multocida isolated from a previous Australian outbreak of acute swine pasteurellosis, and those isolated from fowl cholera outbreaks in Vietnamese poultry.
Collapse
Affiliation(s)
- K M Townsend
- Veterinary Pathology and Anatomy, University of Queensland, Brisbane, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Phan TT, Lee ST, Chan SY, Hughes MA, Cherry GW. Investigating plant-based medicines for wound healing with the use of cell culture technologies and in vitro models: a review. Ann Acad Med Singap 2000; 29:27-36. [PMID: 10748961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
INTRODUCTION Cell culture and molecular technologies are basic yet sophisticated research tool used to investigate plant-based medicine for wound healing. METHODS Cell viability and proliferation assay is used to determine whether there are any positive effects and to discover what is the limiting cytotoxic concentration in vitro. The scratch technique, fibroblast-populated collagen lattices and aortic rings embedded gels are used as the in-vitro models of wound re-epithelialization, contraction and angiogenesis. The immunofluorescence, immunoblotting and organotypic culture can be used to detect expression of specific proteins that are modulated by plant extracts during the wound healing process. MAIN FINDINGS Given the dynamics of the wound healing process, cell culture and molecular technologies are advantageous in providing us with detailed studies and analysis of each intricate process. CONCLUSION The scientific approaches for the study of traditional plant-based remedies for wound healing will provide us an important platform for rigorous testing and evaluation of their clinical efficacy based on accepted rules of evidence.
Collapse
Affiliation(s)
- T T Phan
- Department of Plastic Surgery/National Burns Centre, Singapore General Hospital, Singapore.
| | | | | | | | | |
Collapse
|
38
|
Abstract
Sixteen isolates of Pasteurella multocida were cultured from cases diagnosed as acute septicaemic pasteurellosis in Vietnamese pigs. The HSB-PCR assay provided rapid presumptive determination of 10 isolates of P. multocida identified as haemorrhagic septicaemia (HS) causing type B cultures (B:2, B:5, B:2,5). Serological designation using the Carter and Heddleston typing systems confirmed these findings, and identified the six HSB-PCR negative cultures as either A:1, A:3 or D:3,4. Biochemical fermentation and REP-PCR revealed phenotypic and genotypic identity between P. multocida type A:1 isolated from Vietnamese pigs and poultry. Marked homogeneity was also demonstrated among HSB-PCR positive swine isolates, which were shown to possess genotypic identity with P. multocida type B:2 from buffaloes diagnosed with HS.
Collapse
Affiliation(s)
- K M Townsend
- Division of Veterinary Pathology and Anatomy, University of Queensland, Brisbane, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
Oedema is considered a key pathogenic factor in the development of venous leg ulcers. The purpose of this study was to determine the localization of oedema in legs with ulcers. Twelve patients with 13 venous leg ulcers (one bilateral), with a duration of 7-18 months, were examined by high-frequency B-mode ultrasound scanner. This was performed at three sites in the leg (low, middle and upper sites of the lower leg). In the same group of patients, the legs without ulcers were used as controls. The echogenicity and the thickness of the whole dermis were quantified by digital image analysis; the echogenicities of the upper (papillary) and lower portions of the dermis were measured. In the upper site no significant difference was found between the legs with ulcers and controls. In the middle and low sites of legs with ulcers, the dermal echogenicities were 34% and 64% (P < 0.01) less than those in controls, and the dermal thicknesses were 0.4 mm and 0.8 mm (P < 0.01) thicker than those in controls, respectively. This indicated intradermal oedema existing in the lower part (gaiter area) of the legs with ulcers. The ratios of low echogenic pixels in the upper and lower portions of the dermis, in the middle and low sites of legs with ulcers, were 0.5 and 0.9 (P < 0.05 and P < 0.01), respectively, higher than those in controls, suggesting the papillary dermis as a preferential site of oedema formation. The present study demonstrates that in the low sites of legs with ulcers, a marked increase in oedema was seen in the papillary dermis. This may add to the understanding of the origin of leg ulcers in the gaiter area of the leg.
Collapse
Affiliation(s)
- D Hu
- Department of Dermatology, Churchill Hospital, Oxford, U.K
| | | | | | | |
Collapse
|
40
|
Phan TT, Hughes MA, Cherry GW. Enhanced proliferation of fibroblasts and endothelial cells treated with an extract of the leaves of Chromolaena odorata (Eupolin), an herbal remedy for treating wounds. Plast Reconstr Surg 1998; 101:756-65. [PMID: 9500394 DOI: 10.1097/00006534-199803000-00027] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Burns are a major problem in many developing countries. Eupolin ointment is a topical agent used in the treatment of soft-tissue wounds and burns in Vietnam and is made from an aqueous extract of the leaves of Chromolaena odorata (formerly Eupatorium odoratum). Clinical studies using this extract have shown antimicrobial and anticoagulation effects as well as the promotion of tissue remodeling in the wound healing process. However, the mechanism by which this agent affects cells involved in the wound healing process is unknown. In our research, fibroblasts and endothelial cells, two cell types that play a crucial role in wound healing, were used to investigate some of the effects of Eupolin extract in vitro. Cell growth was estimated by a colorimetric assay at different time intervals. Enhanced growth of fibroblasts and endothelial cells was found at concentrations of 10 microg/ml and 100 microg/ml of Eupolin extract. This was particularly evident in medium supplemented with only 0.5% fetal calf serum where the cells were quiescent. Toxicity of the extract to fibroblasts was observed at 250 microg/ml in Dulbecco's modified Eagle's medium/0.5% fetal calf serum, but there was no significant damage at this dose to the endothelial cells. The results of the study demonstrated that Eupolin extract increased fibroblast and endothelial cell growth, and this could explain in part the beneficial clinical effects that have been observed.
Collapse
Affiliation(s)
- T T Phan
- Wound Healing Institute, Headington, Oxford, United Kingdom
| | | | | |
Collapse
|
41
|
Phan TT, Hughes MA, Cherry GW, Le TT, Pham HM. An aqueous extract of the leaves of Chromolaena odorata (formerly Eupatorium odoratum) (Eupolin) inhibits hydrated collagen lattice contraction by normal human dermal fibroblasts. J Altern Complement Med 1997; 2:335-43. [PMID: 9395667 DOI: 10.1089/acm.1996.2.335] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Chromolaena odorata (formerly Eupatorium odoratum) is used as a traditional medicine in Vietnam (Nghiem, 1992), where its Vietnamese common name is "co hoi." While it has been widely considered a weed by agriculturalists (Holm et al., 1991), the aqueous extract and the decoction from the leaves of this plant have been used throughout Vietnam for the treatment of soft tissue wounds, burn wounds, and skin infections. A number of clinical studies done by Vietnamese as well as foreign medical workers has demonstrated the efficacy of this extract on the wound-healing process. In this article, the effect of the Eupolin extract on hydrated collagen lattice contraction by human dermal fibroblasts, an in vitro model of wound contraction, is described. The significant inhibition of collagen gel contraction by Eupolin extract at 50 to 200 micrograms/ml is demonstrated in various concentrations of collagen. When the extract at 50 to 150 micrograms/ml was washed out of the lattices and replaced by fresh medium without Eupolin, the contraction of collagen by cells was resumed. The visualization of cells in the lattices by incubation in a tetrazolium salt for 2 h showed live cells at 50 to 150 micrograms/ml of extract. In contrast, all cells were killed in the higher extract doses of 300 or 400 micrograms/ml. These preliminary results showing the inhibitory effect of Eupolin extract on collagen contraction suggest that a clinical evaluation of its effect on wound contraction and scar quality should be made. This work illustrates that traditional remedies that are used by folk practitioners to improve healing can be examined in a scientific manner using in vitro wound-healing models. It could be that the synergistic properties of components of the natural extract contribute to the positive effects demonstrated on various wound-healing mechanisms.
Collapse
Affiliation(s)
- T T Phan
- Wound Healing Institute, Churchill, Oxford, U.K
| | | | | | | | | |
Collapse
|
42
|
Phan TT, Reifler BV. Psychiatric disorders among nursing home residents. Depression, anxiety, and paranoia. Clin Geriatr Med 1988; 4:601-11. [PMID: 3044560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The number of people in nursing homes is growing at a rapid rate as the population includes greater numbers of elderly Americans. Psychiatric disorders, including depression, anxiety, and paranoia, are commonly seen among this group. Recognition and treatment of these disorders by health care professionals can improve the quality of care and quality of life for elderly nursing home residents.
Collapse
Affiliation(s)
- T T Phan
- Department of Psychiatry and Behavioral Medicine, Bowman Gray School of Medicine, Winston-Salem, North Carolina
| | | |
Collapse
|