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McLaughlin DK, Hoffmann C, Sasaki M, Li F, Ma J, Cui X, Sutliff RL, Brewster LP. Comparison of arterial storage conditions for delayed arterial ring testing. JVS Vasc Sci 2023; 4:100122. [PMID: 37649473 PMCID: PMC10463248 DOI: 10.1016/j.jvssci.2023.100122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/12/2023] [Indexed: 09/01/2023] Open
Abstract
Objective Arterial ring testing is the gold standard for measuring arterial function. Increased arterial tone through arterial contraction and impaired endothelial relaxation (endothelial dysfunction) are key metrics of impaired arterial health in peripheral arterial disease (PAD). To allow for comparative testing of arteries during standard laboratory hours, storage buffers and conditions have been used to extend the functional life of arteries. Various storage conditions have been compared, but there has not been a robust comparison or validation in human arteries. The objective of this work is to optimize storage of arterial segments for endothelial cell (EC) testing in a murine model and to test EC function in human PAD arteries. We hypothesized that certain storage conditions would be superior to others. Methods Healthy murine aortas were harvested from 10- to 14-week-old C57/Bl6J male and female mice and compared under different storage protocols (24 hours) to immediate arterial testing. The storage conditions tested were: Opti-MEM (37°C or 4°C), Krebs-HEPES with 1.8 mmol/L or 2.5 mmol/L calcium (4°C), or Wisconsin (WI) solution at 4°C. Vascular function was evaluated by isometric force testing. Endothelium-dependent and -independent relaxation were measured after precontraction with addition of methacholine or sodium nitroprusside, respectively. Arterial contraction was stimulated with potassium chloride or phenylephrine. Analysis of variance was used to determine significance compared with immediate testing with P < .05. Under institutional review board approval, 28 PAD arteries were collected at amputation and underwent vascular function testing as described. Disturbed flow conditions were determined by indirect (upstream occlusion) flow to the harvested tibial arteries. Stable flow arteries had in-line flow. Arterial calcification was quantified manually as present or not present. Results We found that 4°C WI and 37°C Opti-MEM best preserved endothelium-dependent relaxation and performed similarly to immediately testing aortas (termed fresh for freshly tested) (P > .95). Other storage conditions were inferior to freshly tested aortas (P < .05). Vascular smooth muscle function was tested by endothelial-independent relaxation and contractility. All storage conditions preserved endothelial-independent relaxation and contractility similar to freshly tested arteries. However, 4°C WI and 37°C Opti-MEM storage conditions most closely approximated the maximum force of contraction of freshly tested arteries in response to potassium chloride (P > .39). For human arterial testing, 28 tibial arteries were tested for relaxation and contraction with 16 arteries with peripheral artery occlusive disease (PAD with disturbed flow) and 12 without peripheral artery occlusive disease (PAD with stable flow), of which 14 were calcified and 14 were noncalcified. Endothelial-dependent relaxation data was measurable in 9 arteries and arterial contraction data was measurable in 14 arteries. When comparing flow conditions, arteries exposed to disturbed flow (n = 4) had significantly less relaxation (2% vs 59%; P = .03) compared with stable flow conditions (n = 5). In contrast, presence the (n = 6) or absence of calcification (n = 3) did not impact arterial relaxation. Arterial contraction was not different between groups in either comparison by flow (n = 9 disturbed; n = 5 stable) or calcification (n = 6 present; n = 8 absent). Conclusions In healthy murine aortas, arterial storage for 24 hours in 4°C WI or 37°C Opti-MEM both preserved endothelium-dependent relaxation and maximum force of contraction. In human PAD arteries stored in 4° WI, flow conditions before arterial harvest, but not arterial calcification, led to differences in arterial relaxation in human PAD arteries. Arterial contractility was more robust (11/28 arteries) compared with arterial relaxation (7/28 arteries), but was not significantly different under flow or calcification parameters. This work defines ideal storage conditions for arterial ring testing and identifies that EC dysfunction from disturbed flow may persist in delayed ex vivo arterial testing.
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Affiliation(s)
- Dylan K. McLaughlin
- Division of Vascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
- Surgical and Research Services, Atlanta VA Medical Center, Decatur, GA
| | - Carson Hoffmann
- Division of Vascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
- Surgical and Research Services, Atlanta VA Medical Center, Decatur, GA
| | - Maiko Sasaki
- Division of Vascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
- Surgical and Research Services, Atlanta VA Medical Center, Decatur, GA
| | - Feifei Li
- Division of Vascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
- Surgical and Research Services, Atlanta VA Medical Center, Decatur, GA
| | - Jing Ma
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Xiangqin Cui
- Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA
| | - Roy L. Sutliff
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Luke P. Brewster
- Division of Vascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
- Surgical and Research Services, Atlanta VA Medical Center, Decatur, GA
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Goh BH, Cheng HS, Alexandra PTAA, Ting KN, Palanisamy UD, Tan JBL. Geraniin Ameliorates Hypertensive Vascular Remodelling in a Diet-Induced Obese Animal Model through Antioxidant and Anti-Inflammatory Effects. Nutrients 2023; 15:2696. [PMID: 37375598 DOI: 10.3390/nu15122696] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
Geraniin, an ellagitannin, has shown a potent blood pressure-lowering effect in vivo. Therefore, this study aims to further characterize the ability of geraniin to attenuate hypertensive vascular dysfunction, a key feature of cardiovascular disease (CVD) development. Hypertension was induced in male Sprague-Dawley rats through feeding a high-fat diet (HFD) for eight weeks, followed by oral administration of 25 mg/kg/day geraniin for four weeks. The parameters of vascular dysfunction such as the structure and function of blood vessels as well as the vascular oxidative stress and inflammation were evaluated. The outcomes of geraniin-treated rats were compared with those of untreated rats on either a normal diet (ND) or HFD and with HFD-fed rats treated with captopril (40 mg/kg/day). We found that geraniin supplementation effectively ameliorated HFD-induced hypertension and abnormal remodelling of the thoracic aorta by suppressing excessive vascular superoxide (O2-) radical generation and overexpression of pro-inflammatory mediators in the circulating leukocytes. Furthermore, compared to the ND-fed rats, geraniin also independently promoted the significant enlargement of the thoracic aortic lumen for blood pressure reduction. Notably, the vascular benefits of geraniin were comparable to that of captopril. Collectively, these data suggest that geraniin can mitigate hypertensive vascular remodelling caused by overnutrition, which potentially abrogates the further development of CVDs.
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Affiliation(s)
- Boon Hee Goh
- School of Science, Monash University Malaysia, Bandar Sunway 47500, Malaysia
| | - Hong Sheng Cheng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 637551, Singapore
| | | | - Kang-Nee Ting
- School of Pharmacy, University of Nottingham Malaysia Campus, Semenyih 43500, Malaysia
| | - Uma Devi Palanisamy
- Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Subang Jaya 47500, Malaysia
| | - Joash Ban Lee Tan
- School of Science, Monash University Malaysia, Bandar Sunway 47500, Malaysia
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Mak YY, Loong BJ, Millns P, Bauer CC, Bon RS, Mbaki Y, Lee FK, Lim KH, Kong C, Then SM, Ting KN. Schwarzinicine A inhibits transient receptor potential canonical channels and exhibits overt vasorelaxation effects. Phytother Res 2022; 36:2952-2963. [PMID: 35537691 PMCID: PMC9544403 DOI: 10.1002/ptr.7489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 04/10/2022] [Accepted: 04/19/2022] [Indexed: 11/15/2022]
Abstract
This study investigated the vasorelaxant effects of schwarzinicine A, an alkaloid recently reported from Ficus schwarzii Koord. Regulation of calcium homeostasis in vascular smooth muscle cells (VSMC) is viewed as one of the main mechanisms for controlling blood pressure. L‐type voltage‐gated calcium channel (VGCC) blockers are commonly used for controlling hypertension. Recently, the transient receptor potential canonical (TRPC) channels were found in blood vessels of different animal species with evidence of their roles in the regulation of vascular contractility. In this study, we studied the mechanism of actions of schwarzinicine A focusing on its regulation of L‐type VGCC and TRPC channels. Schwarzinicine A exhibited the highest vasorelaxant effect (123.1%) compared to other calcium channel blockers. It also overtly attenuated calcium‐induced contractions of the rat isolated aortae in a calcium‐free environment showing its mechanism to inhibit calcium influx. Fluorometric intracellular calcium recordings confirmed its inhibition of hTRPC3‐, hTRPC4‐, hTRPC5‐ and hTRPC6‐mediated calcium influx into HEK cells with IC50 values of 3, 17, 19 and 7 μM, respectively. The evidence gathered in this study suggests that schwarzinicine A blocks multiple TRPC channels and L‐type VGCC to exert a significant vascular relaxation response.
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Affiliation(s)
- Yin-Ying Mak
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Bi-Juin Loong
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Paul Millns
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Claudia C Bauer
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Robin S Bon
- Department of Discovery and Translational Science, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Yvonne Mbaki
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Fong-Kai Lee
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Kuan-Hon Lim
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Cin Kong
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Sue-Mian Then
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Kang-Nee Ting
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Malaysia
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Xu T, Fan X, Zhao M, Wu M, Li H, Ji B, Zhu X, Li L, Ding H, Sun M, Xu Z, Gao Q. DNA Methylation-Reprogrammed Ang II (Angiotensin II) Type 1 Receptor-Early Growth Response Gene 1-Protein Kinase C ε Axis Underlies Vascular Hypercontractility in Antenatal Hypoxic Offspring. Hypertension 2020; 77:491-506. [PMID: 33342239 DOI: 10.1161/hypertensionaha.120.16247] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As the most common clinical stress during mid and late pregnancy, antenatal hypoxia has profound adverse effects on individual's vascular health later in life, but the underlying mechanisms are still not understood. The purpose of this study was to reveal the mechanisms of the acquired vascular dysfunction in offspring imposed by antenatal hypoxia. Pregnant rats were housed in a normoxic or hypoxic (10.5% oxygen) chamber from gestation day 10 to 21. Male offspring were euthanized at gestational day 21 (fetus) or postnatal 16 weeks old (adult offspring). Mesenteric arteries were collected for examining Ang II (angiotensin II)-mediated vascular contractility, gene expression, and promoter methylation. Antenatal hypoxia increased vascular sensitivity to Ang II, which was resulted by an upregulated AT1R (angiotensin II type 1 receptor). The increased AT1R was correlated with a hypomethylation-mediated activated transcription of Agtr1a (alpha subtype of AT1R). In addition, we presented evidences that there was an AT1R-Egr1 (early growth response gene 1)-PKCε (ε isoform of protein kinase C) axis in vasculature; AT1R could modulate PKCε expression via upregulating Egr1; Egr1 mediated transcription activation of PKCε via Egr1 binding sites in PKCε gene promoter. Overall, antenatal hypoxia activated AT1R-Egr1-PKCε axis in vasculature, eventually predisposed offspring to vascular hypercontractility. This is the first description that antenatal hypoxia resulted in vascular adverse outcomes in postnatal offspring, was strongly associated with reprogrammed gene expression via a DNA methylation-mediated epigenetic mechanism, advancing understanding toward the influence of adverse antenatal factors in early life on long-term vascular health.
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Affiliation(s)
- Ting Xu
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Xiaorong Fan
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (X.F.)
| | - Meng Zhao
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Meng Wu
- Institutes of Biological and Medical Sciences, Soochow University Medical School, Suzhou, China (M.W.)
| | - Huan Li
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Bingyu Ji
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Xiaolin Zhu
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Lingjun Li
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Hongmei Ding
- Department of Obstetrics and Gynecology (H.D.), First Hospital of Soochow University, Suzhou, China
| | - Miao Sun
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Zhice Xu
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
| | - Qinqin Gao
- From the Institute for Fetology (T.X., M.Z., H.L., B.J., X.Z., L.L., M.S., Z.X., Q.G.), First Hospital of Soochow University, Suzhou, China
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Krishnan P, Lee FK, Yap VA, Low YY, Kam TS, Yong KT, Ting KN, Lim KH. Schwarzinicines A-G, 1,4-Diarylbutanoid-Phenethylamine Conjugates from the Leaves of Ficus schwarzii. JOURNAL OF NATURAL PRODUCTS 2020; 83:152-158. [PMID: 31935094 DOI: 10.1021/acs.jnatprod.9b01160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Schwarzinicines A-G (1-7), representing the first examples of 1,4-diarylbutanoid-phenethylamine conjugates, were isolated from the leaves of Ficus schwarzii. The structures of these compounds were determined by detailed analysis of their MS, 1D and 2D NMR data. Compounds 1-4 exhibited pronounced vasorelaxant effects in the rat isolated aorta (Emax 106-120%; EC50 0.96-2.10 μM). However, compounds 1 and 2 showed no cytotoxic effects against A549, MCF-7, and HCT 116 human cancer cells (IC50 > 10 μM).
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Affiliation(s)
- Premanand Krishnan
- School of Pharmacy , University of Nottingham Malaysia , Jalan Broga , 43500 Semenyih , Selangor , Malaysia
| | - Fong-Kai Lee
- School of Pharmacy , University of Nottingham Malaysia , Jalan Broga , 43500 Semenyih , Selangor , Malaysia
| | - Veronica Alicia Yap
- School of Pharmacy , University of Nottingham Malaysia , Jalan Broga , 43500 Semenyih , Selangor , Malaysia
| | - Yun-Yee Low
- Department of Chemistry, Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia
| | - Toh-Seok Kam
- Department of Chemistry, Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia
| | - Kien-Thai Yong
- Institute of Biological Sciences, Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia
| | - Kang-Nee Ting
- School of Pharmacy , University of Nottingham Malaysia , Jalan Broga , 43500 Semenyih , Selangor , Malaysia
| | - Kuan-Hon Lim
- School of Pharmacy , University of Nottingham Malaysia , Jalan Broga , 43500 Semenyih , Selangor , Malaysia
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Chai BK, Lau YS, Loong BJ, Rais MM, Ting KN, Dharmani DM, Mohankumar SK. Co-administration of conjugated linoleic acid and rosiglitazone increases atherogenic co-efficient and alters isoprenaline-induced vasodilatation in rats fed high fat diet. Physiol Res 2018; 67:729-740. [PMID: 29750886 DOI: 10.33549/physiolres.933706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The cis(c)-9, trans(t)-11 (c9,t11) and t10,c12 isomers of conjugated linoleic acid (CLA) have been reported as agonists of peroxisome proliferator-activated receptor (PPAR) and beneficial in lipidemia and glycemia. However, it is unclear whether CLA isomers enhance or antagonize effects of conventional drugs targeting PPAR. Male Sprague-Dawley rats were fed high fat diet (HFD) for 8 weeks and treated without or with CLA, rosiglitazone or both for 4 weeks. Oral glucose tolerance and surrogate markers of insulin resistance were not significantly different for all treatments compared to untreated normal diet (ND) or HFD group, except lipoprotein levels. The combination of CLA and rosiglitazone had suppressed levels of low and high density lipoproteins (46 % and 25 %, respectively), compared to HFD-alone. Conversely, the atherogenic co-efficient of the animals received HFD or HFD+rosiglitazone+CLA was 2-folds higher than ND, HFD+rosiglitazone or HFD+CLA. Isolated aortic rings from the combined CLA and rosiglitazone treated animals were less sensitive to isoprenaline-induced relaxation among endothelium-denuded aortas with a decreased efficacy and potency (R(max)=53+/-4.7 %; pEC50=6+/-0.2) compared to endothelium-intact aortas (R(max)=100+/-9.9 %; pEC50=7+/-0.2). Our findings illustrate that the combination of CLA and rosiglitazone precede the atherogenic state with impaired endothelium-independent vasodilatation before the onset of HFD-induced insulin resistance.
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Affiliation(s)
- B K Chai
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia. TIFAC CORE Herbal Drugs JSS College of Pharmacy, Jagadguru Sri Shivrathreeshwara University, Mysuru, India. or
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Lee MK, Li X, Yap ACS, Cheung PCK, Tan CS, Ng ST, Roberts R, Ting KN, Fung SY. Airway Relaxation Effects of Water-Soluble Sclerotial Extract From Lignosus rhinocerotis. Front Pharmacol 2018; 9:461. [PMID: 29867469 PMCID: PMC5949369 DOI: 10.3389/fphar.2018.00461] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/19/2018] [Indexed: 12/28/2022] Open
Abstract
Lignosus rhinocerotis has a long history of use by the indigenous community within East Asia to treat a range of health conditions including asthma and chronic cough. To date, there is limited scientific evidence to support its therapeutic effects in relieving these airways conditions. In this study, we examined the effects of the different molecular weight fractions [high-molecular-weight (HMW), medium-molecular-weight (MMW), and low-molecular-weight (LMW)] obtained from the cold water sclerotial extract (CWE) of L. rhinocerotis on airways patency using airway segments isolated from Sprague Dawley rat in an organ bath set-up. It is demonstrated that the HMW and MMW fractions exhibited higher efficacy in relaxing the pre-contracted airways when compared to the CWE and LMW fraction. In addition, the HMW fraction markedly supressed carbachol-, 5-hydroxytrptamine-, and calcium-induced airway contractions. CWE demonstrated a lower efficacy than the HMW fraction but it also significantly attenuated carbachol- and calcium-induced airway contractions. Results showed that the bronchorelaxation effect of CWE and fractions is mediated via blockade of extracellular Ca2+ influx. The composition analysis revealed the following parts of carbohydrate and proteins, respectively: HMW fraction: 71 and 4%; MMW fraction: 35 and 1%; and LMW fraction: 22 and 0.3%. Our results strongly suggest that the polysaccharide–protein complex or proteins found in the HMW and MMW fractions is likely to contribute to the bronchorelaxation effect of CWE.
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Affiliation(s)
- Mei Kee Lee
- Department of Biomedical Science, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Xiaojie Li
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
| | - Alvin Chee Sum Yap
- Medicinal Mushroom Research Group, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Szu Ting Ng
- LiGNO Biotech Sdn Bhd, Balakong Jaya, Malaysia
| | - Richard Roberts
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| | - Kang Nee Ting
- Department of Biomedical Science, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Shin Yee Fung
- Medicinal Mushroom Research Group, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Center for Natural Products Research and Drug Discovery, University of Malaya, Kuala Lumpur, Malaysia
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Lee MK, Lim KH, Millns P, Mohankumar SK, Ng ST, Tan CS, Then SM, Mbaki Y, Ting KN. Bronchodilator effects of Lignosus rhinocerotis extract on rat isolated airways is linked to the blockage of calcium entry. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2018; 42:172-179. [PMID: 29655683 DOI: 10.1016/j.phymed.2018.03.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 02/02/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Lignosus rhinocerotis (Cooke) Ryvarden is a popular medicinal mushroom used for centuries in Southeast Asia to treat asthma and chronic cough. The present study aimed to investigate the effect of this mushroom on airways patency. MATERIALS AND METHODS The composition of L. rhinocerotis TM02 cultivar was analyzed. Organ bath experiment was employed to study the bronchodilator effect of Lignosus rhinocerotis cold water extract (CWE) on rat isolated airways. Trachea and bronchus were removed from male Sprague-Dawley rats, cut into rings of 2 mm, pre-contracted with carbachol before adding CWE into the bath in increasing concentrations. To investigate the influence of incubation time, tissues were exposed to intervals of 5, 15 and 30 min between CWE concentrations after pre-contraction with carbachol in subsequent protocol. Next, tissues were pre-incubated with CWE before the addition of different contractile agents, carbachol and 5-hydroxytrptamine (5-HT). The bronchodilator effect of CWE was compared with salmeterol and ipratropium. In order to uncover the mechanism of action of CWE, the role of beta-adrenoceptor, potassium and calcium channels was investigated. RESULTS Composition analysis of TM02 cultivar revealed the presence of β-glucans and derivatives of adenosine. The extract fully relaxed the trachea at 3.75 mg/ml (p < 0.0001) and bronchus at 2.5 mg/ml (p < 0.0001). It was observed that lower concentrations of CWE were able to fully relax both trachea and bronchus but at a longer incubation interval between concentrations. CWE pre-incubation significantly reduced the maximum responses of carbachol-induced contractions (in both trachea, p = 0.0012 and bronchus, p = 0.001), and 5-HT-induced contractions (in trachea, p = 0.0048 and bronchus, p = 0.0014). Ipratropium has demonstrated a significant relaxation effect in both trachea (p = 0.0004) and bronchus (p = 0.0031), whereas salmeterol has only affected the bronchus (p = 0.0104). The involvement of β2-adrenoceptor and potassium channel in CWE-mediated airway relaxation is ruled out, but the bronchodilator effect was unequivocally affected by influx of calcium. CONCLUSIONS The bronchodilator effect of L. rhinocerotis on airways is mediated by calcium signalling pathway downstream of Gαq-coupled protein receptors. The airway relaxation effect is both concentration- and incubation time-dependent. Our findings provide unequivocal evidence to support its traditional use to relieve asthma and cough.
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Affiliation(s)
- Mei-Kee Lee
- Department of Biomedical Sciences, University of Nottingham Malaysia Campus, Semenyih 43500, Malaysia
| | - Kuan-Hon Lim
- School of Pharmacy, University of Nottingham Malaysia Campus, Semenyih 43500, Malaysia
| | - Paul Millns
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Suresh Kumar Mohankumar
- JSS College of Pharmacy, Rocklands, Ootacamund-643001, Tamil Nadu, India; a constituent college of JSS Academy of Higher Education & Research, Mysuru, Karnataka, India
| | - Szu-Ting Ng
- LiGNO Biotech Sdn Bhd, Balakong Jaya 43300, Malaysia
| | - Chon-Seng Tan
- LiGNO Biotech Sdn Bhd, Balakong Jaya 43300, Malaysia
| | - Sue-Mian Then
- Department of Biomedical Sciences, University of Nottingham Malaysia Campus, Semenyih 43500, Malaysia
| | - Yvonne Mbaki
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Kang-Nee Ting
- Department of Biomedical Sciences, University of Nottingham Malaysia Campus, Semenyih 43500, Malaysia.
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