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Thavorn K, Wolfe D, Faust L, Shorr R, Akkawi M, Isaranuwatchai W, Klinger C, Chai-Adisaksopa C, Tanvejsilp P, Nochaiwong S, Straus SE, Hutton B. A systematic review of the efficacy and safety of turmeric in the treatment of digestive disorders. Phytother Res 2024. [PMID: 38503513 DOI: 10.1002/ptr.8189] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 02/24/2024] [Accepted: 03/02/2024] [Indexed: 03/21/2024]
Abstract
Turmeric has been gaining popularity as a treatment option for digestive disorders, although a rigorous synthesis of efficacy has not been conducted. This study aimed to summarize the evidence for the efficacy and safety of turmeric in the treatment of digestive disorders, including inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), dyspepsia, gastroesophageal reflux disease, and peptic ulcers. Literature searches were conducted in Medline, EMBASE, AMED, the Cochrane Central Register of Control Trials, and Dissertation Abstracts from inception to November 15, 2021. Dual independent screening of citations and full texts was conducted and studies meeting inclusion criteria were retained: randomized controlled trials (RCT) and comparative observational studies evaluating turmeric use in people of any age with one of the digestive disorders of interest. Extraction of relevant data and risk of bias assessments were performed by two reviewers independently. Meta-analysis was not conducted due to high heterogeneity. From 1136 citations screened, 26 eligible studies were retained. Most studies were assessed to have a high risk of bias, and many had methodological limitations. Descriptive summaries suggest that turmeric is safe, with possible efficacy in patients with IBD or IBS, but its effects were inconsistent for other conditions. The efficacy of turmeric in digestive disorders remains unclear due to the high risk of bias and methodological limitations of the included studies. Future studies should be designed to include larger sample sizes, use rigorous statistical methods, employ core outcome sets, and adhere to reporting guidance for RCTs of herbal interventions to facilitate more meaningful comparisons and robust conclusions.
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Affiliation(s)
- Kednapa Thavorn
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
- Pharmacoepidemiology and Statistics Research Center (PESRC), Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
| | - Dianna Wolfe
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Lena Faust
- McGill International Tuberculosis Centre, McGill University, Montreal, Canada
| | - Risa Shorr
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Maya Akkawi
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Wanrudee Isaranuwatchai
- Health Intervention and Technology Assessment Program, Ministry of Public Health, Bangkok, Thailand
- Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada
| | - Christopher Klinger
- Department of Family Medicine, McMaster University, Hamilton, Canada
- Institute for Life Course and Aging, University of Toronto, Toronto, Canada
- National Initiative for the Care of the Elderly (NICE), Toronto, Canada
| | | | - Pimwara Tanvejsilp
- Department of Social Administrative Pharmacy, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, Thailand
| | - Surapon Nochaiwong
- Pharmacoepidemiology and Statistics Research Center (PESRC), Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
| | - Sharon E Straus
- Knowledge Translation Program, St. Michael's Hospital, Toronto, Canada
- Department of Medicine, University of Toronto, Toronto, Canada
| | - Brian Hutton
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
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Khattari Z, Brotons G, Akkawi M, Arbely E, Arkin IT, Salditt T. SARS coronavirus E protein in phospholipid bilayers: an x-ray study. Biophys J 2006; 90:2038-50. [PMID: 16361349 PMCID: PMC1386782 DOI: 10.1529/biophysj.105.072892] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Accepted: 11/21/2005] [Indexed: 11/18/2022] Open
Abstract
We investigated the structure of the hydrophobic domain of the severe acute respiratory syndrome E protein in model lipid membranes by x-ray reflectivity and x-ray scattering. In particular, we used x-ray reflectivity to study the location of an iodine-labeled residue within the lipid bilayer. The label imposes spatial constraints on the protein topology. Experimental data taken as a function of protein/lipid ratio P/L and different swelling states support the hairpin conformation of severe acute respiratory syndrome E protein reported previously. Changes in the bilayer thickness and acyl-chain ordering are presented as a function of P/L, and discussed in view of different structural models.
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Affiliation(s)
- Z Khattari
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
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Abstract
It is shown that alcohol-water mixtures (e.g., 43 wt% ethanol) provide a suitable medium for the efficient production in high yield of beta-hematin from ferriprotoporphyrin IX (FP), as measured by infrared spectroscopy. Previous and present light-absorption data of FP, obtained under specific acid conditions in an ethanol-water medium, suggest the presence of FP monomers, which are considered to promote the reaction leading to beta-hematin. Other aspects of the mechanism of reaction are discussed.
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Affiliation(s)
- G Blauer
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
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Blauer G, Akkawi M. On the preparation of beta-haematin. Biochem J 2000; 346 Pt 2:249-50. [PMID: 10677340 PMCID: PMC1220847] [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: 02/15/2023]
Abstract
Synthetic beta-haematin is considered to be identical, or at least very similar to, purified malaria pigment. Methods for its preparation use ferriprotoporphyrin IX at acid pH in the presence of acetic acid at different concentrations and degrees of ionization, elevated temperatures and long reaction times. Here we show that certain widely used reaction conditions, involving very high concentrations of acetic acid/acetate mixtures, do not produce substantial amounts of polymeric beta-haematin on immediate isolation of the reaction products, but only during prolonged drying of the products at 37 degrees C after washing with water. Alternative, more convenient methods of preparation of pure beta-haematin are suggested.
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Affiliation(s)
- G Blauer
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Abstract
The preparation from ferriprotoporphyrin IX (FP) in aqueous acid medium of the related pigments beta- and B-hematin [see G. Blauer and M. Akkawi, Biochem. Mol. Biol. Int. 35, 231 (1995)] is presented under different conditions. Both pigments are characterized by infrared spectra which differ in the range of 1600-1700 cm-1 in their strong bands with absorption peaks measured at 1648 +/- 2 cm-1 for B-hematin and at 1663 +/- 1 cm-1 for beta-hematin. The pH dependence of B-hematin formation at 37 degrees C and at different concentrations of acetic acid and FP exhibits a maximum yield near pH 4. The formation of beta-hematin at 70 degrees C shows high yield in 6 M acetic acid or in the presence of 0.028 M trichloroacetate at pH 4.6. The dependence of the yield of the pigments on the time and temperature of incubation, concentration of FP, and the presence of different electrolytes was investigated. Both B- and beta-hematin are either insoluble or very slightly soluble in different solvents at room temperature, and appear to dissociate into regular FP in strongly alkaline aqueous medium. In the presence of different quinoline-based drugs, the formation of both B- and beta-hematin at pH 4-5 is inhibited. Under certain conditions, the effect of added carboxylic acids on pigment formation is suggested to be due, at least in part, to the prevention of initial hydrogen bonding among FP carboxyl groups. For both B- and beta-hematin, branched and cyclic macromolecular structures are proposed involving linkages between an FP iron and a side-chain carboxylate group of another FP, in addition to hydrogen bonds between FP carboxyl groups. B- and beta-hematin are assumed to differ in molecular weight and the extent of bond formation. Possible mechanisms for beta-hematin production from B-hematin and certain relations between the synthetic pigments and the malaria pigment are suggested.
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Affiliation(s)
- G Blauer
- Department of Biological Chemistry, Hebrew University, Jerusalem, Israel
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Blauer G, Akkawi M. B-hematin. Biochem Mol Biol Int 1995; 35:231-235. [PMID: 7663376] [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: 05/21/2023]
Abstract
Very rapid production in vitro of a particular type of hematin (B-hematin) with high yield at physiological pH and temperature is presently reported, using a simple chemical system including an organic acid in the absence of any enzyme. B-hematin is characterized by infrared spectra and solubility properties. The antimalarial drug chloroquine practically prevents formation of this hematin under the conditions used. It has recently been suggested that the purified malaria pigment hemozoin is identical with beta-hematin, a form of ferriprotoporphyrin IX sparingly soluble in different solvents which is prepared under non-physiological conditions. Relations between B- and beta-hematin and possible mechanisms of hemozoin formation and antimalarial drug action, are discussed.
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Affiliation(s)
- G Blauer
- Department of Biological Chemistry, Hebrew University, Jerusalem, Israel
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Abstract
Evidence for complex formation of the antimalarial drug amodiaquine (AD) with ferriprotoporphyrin IX (FP) in aqueous medium is presented, in addition to previous preliminary data. A mole ratio of one between the complex components is determined for the insoluble complex at pH 6.7-6.8. Mössbauer data obtained at pH 7-8 and at higher concentrations in the millimolar range confirm the interactions existing between the complex components. These data are considered to aid in removing previous objections to a mechanism of antimalarial action involving complexes of FP with AD and related drugs.
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Affiliation(s)
- G Blauer
- Department of Biological Chemistry, Hebrew University of Jerusalem, Israel
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