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Naidoo D, van Vuuren SF, van Zyl RL, de Wet H. Plants traditionally used individually and in combination to treat sexually transmitted infections in northern Maputaland, South Africa: antimicrobial activity and cytotoxicity. J Ethnopharmacol 2013; 149:656-667. [PMID: 23880127 DOI: 10.1016/j.jep.2013.07.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 07/06/2013] [Accepted: 07/11/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Although medicinal plants are used extensively to treat sexually transmitted infections (STIs) in rural northern Maputaland, KwaZulu-Natal, the efficacy and safety of these plants have not previously been evaluated. AIM OF STUDY A study was designed to investigate the in vitro antimicrobial activity and cytotoxicity profiles of a selection (individual plants and selected combinations) of traditionally used plants in this study area. MATERIALS AND METHODS Aqueous and organic (dichloromethane: methanol, 1:1) extracts were prepared. Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against the STI associated pathogens; Candida albicans ATCC 10231, Ureaplasma urealyticum clinical strain, Oligella ureolytica ATCC 43534, Trichomonas vaginalis clinical strain, Gardnerella vaginalis ATCC 14018 and Neisseria gonorrhoeae ATCC 19424. For the combination study, interactions were assessed using the fractional inhibitory concentration (ΣFIC). The plant species were assessed for safety using the 3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) cellular viability assay on the human embryonic kidney epithelial (Graham, HEK-293) cell line. RESULTS For the antimicrobial studies, U. urealyticum was the most sensitive of the six test organisms, with the aqueous extract of Ranunculus multifidus (0.02mg/ml) and the organic extract of Peltophorum africanum (0.04mg/ml) being the most antimicrobially active plant species studied. Sclerocarya birrea was found to have the broadest spectrum of activity (mean MIC of 0.89mg/ml). The only plant species to exhibit some degree of cytotoxicity against the kidney epithelial cell line was Kigelia africana (100µg/ml), with 22% and 16% cell death for the aqueous and organic extracts, respectively. Of the 13 combinations studied, several synergistic combinations were evident, the most prominent being the combination of Albizia adianthifolia and Trichilia dregeana (aqueous extract) with an ΣFIC value of 0.15 against O. ureolytica. Synergistic interactions were observed regardless of the ratio of the aqueous mixtures of the two plants. Syzygium cordatum and S. birrea (aqueous extract) was also a combination of interest, demonstrating synergistic (ΣFIC=0.42) interactions against O. ureolytica. This combination, however, also displayed some cytotoxicity towards the human epithelial cell line. CONCLUSION This study demonstrated that anecdotal evidence of plant use does not always correlate with in vitro activity. Furthermore, the toxicological profiling is of utmost importance as if not combined in its correct ratio can lead to potential adverse effects.
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Affiliation(s)
- D Naidoo
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, South Africa
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van der Hagen SJ, van Gemert WG, Soeters PB, de Wet H, Baeten CG. Transvaginal posterior colporrhaphy combined with laparoscopic ventral mesh rectopexy for isolated Grade III rectocele: a prospective study of 27 patients. Colorectal Dis 2012; 14:1398-402. [PMID: 22405411 DOI: 10.1111/j.1463-1318.2012.03023.x] [Citation(s) in RCA: 16] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AIM The aim of this study was to evaluate prospectively transvaginal posterior colporrhaphy (TPC) combined with laparoscopic ventral mesh rectopexy (LVR) in patients with a symptomatic isolated rectocele. METHOD Patients with these complaints underwent dynamic and static MRI. All consecutive patients with a Grade III (4 cm or more) rectocele and without internal/external rectal prolapse, enterocele and external sphincter damage were operated on. The patients completed the Obstructed Defecation Syndrome (ODS) score and the Cleveland Clinic Incontinence Score (CCIS). All tests were repeated after treatment. Dynamic disorders of the pelvic floor detected by MRI were recorded. RESULTS In 27 patients [median age 67 (46-73) years], TPC combined with LVR was feasible. Complications were limited to port site infection in two patients. Sexual discomfort (n = 8) due to prolapse diminished in six (75%) patients and in one (4%) de novo dyspareunia developed after treatment. The median follow-up was 12 (10-18) months. The median CCIS was 12 (10-16) before treatment and 8 (7-10) after (P < 0.0001). The median ODS score was 19 (17-23) before and 6 (3-10) after treatment (P < 0.0001). There was no change in urinary symptoms. CONCLUSION TPC combined with LVR for obstructed defaecation and faecal incontinence in patients with Grade III rectocele significantly relieves the symptoms of these disorders.
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Affiliation(s)
- S J van der Hagen
- Department of Surgery, Refaja Hospital, Boerhaavestraat 1, Stadskanaal 9501 HE, The Netherlands.
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York T, van Vuuren SF, de Wet H. An antimicrobial evaluation of plants used for the treatment of respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa. J Ethnopharmacol 2012; 144:118-127. [PMID: 22960551 DOI: 10.1016/j.jep.2012.08.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 08/07/2012] [Accepted: 08/25/2012] [Indexed: 06/01/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against respiratory infections. AIM OF THE STUDY This study focussed on determining the antimicrobial efficacies of 30 plant species (independently and in various combinations) used for respiratory related infections in rural Maputaland. MATERIALS AND METHODS In vitro minimum inhibitory concentration (MIC) assays were undertaken on dichloromethane-methanol (CH(2)Cl(2): MeOH) and aqueous extracts, as well as the hydro-distilled essential oils (for aromatic plants). Selected plant parts were assessed for antimicrobial activity against a range of respiratory pathogens i.e. Cryptococcus neoformans (ATCC 14116), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246), Mycobacterium smegmatis (ATCC 14468) and Staphylococcus aureus (ATCC 6538). The sum of the fractional inhibitory concentrations (∑FIC) was determined for plants traditionally used in combination. Isobolograms represent MIC values for a selection of interactions where two plants were combined in various ratios. RESULTS The most antimicrobially active aqueous extracts were that of Ozoroa obovata and Sclerocarya birrea (0.10 mg/ml) while organic extracts from Parinari capensis subsp. incohata and Tetradenia riparia demonstrated the most noteworthy (0.03 mg/ml) activity. Although both Lippia javanica and Eucalyptus grandis were by far the most popular plants traditionally used for respiratory infections, the antimicrobial activity was mostly only moderate. Furthermore, the traditional use in a 1:1 combination did not display strong antimicrobial interactions, but isobolograms demonstrate (against some test organisms) that when combined in various ratios, predominant additive interactions are evident where E. grandis was present in larger proportions. The combination of E. grandis with O. obovata demonstrated synergism against both C. neoformans and K. pneumoniae, with ∑FIC values of 0.34 and 0.28 respectively. Various ratios of these two plants also demonstrated a predominantly synergistic profile. CONCLUSION Although this in vitro study supports the traditional use of some plants independently and in combination for the treatment of respiratory ailments in rural Maputaland, results demonstrate that the traditional selection of plants in higher frequency do not necessarily correlate with higher antimicrobial efficacy.
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Affiliation(s)
- T York
- Department of Botany, University of Zululand, Private Bag 1001, KwaDlangezwa 3886, South Africa
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York T, de Wet H, van Vuuren SF. Plants used for treating respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa. J Ethnopharmacol 2011; 135:696-710. [PMID: 21497646 DOI: 10.1016/j.jep.2011.03.072] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 03/28/2011] [Accepted: 03/31/2011] [Indexed: 05/22/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Traditional remedies are frequently used in treating various respiratory ailments, and are very important in the primary health care of the people living in rural Maputaland, KwaZulu-Natal, South Africa. Novel information gathered from surveys like the present study is important in preserving indigenous knowledge. AIM OF THE STUDY To explore the knowledge that the lay people of a rural community in northern Maputaland have about medicinal plants used in the vicinity to treat respiratory infections. MATERIALS AND METHODS Interviews were conducted among 80 homestead inhabitants, using structured questionnaires where convenience sampling was used. The focus was on plants used in treating respiratory infections. Some of the main topics discussed during the interviews were vernacular plant names, plant parts used, harvested amounts, preparation methods, dosage forms and quantities, use of plants in combination as well as the related symptomatic relief associated with respiratory infections. RESULTS The study documented 30 plant species (18 families) which are used to treat respiratory infections by the rural people in the study area. Decoctions made with these plants are mostly taken orally, combined with the use of steaming. To the best of our knowledge, Acanthospermum glabratum, Aloe marlothii, Krauseola mosambicina, Ozoroa obovata, Parinari capensis and Plectranthus neochilus are recorded for the first time globally as medicinal plants used for treating respiratory infections and related symptoms. The indigenous aromatic shrub, Lippia javanica was by far the most frequently used plant species, followed by Eucalyptus grandis (an exotic), Tetradenia riparia and then Senecio serratulloides. Twenty-four different plant combinations were used where the most frequently used combination encountered was Eucalyptus grandis with Lippia javanica. CONCLUSION The large number of different plant species traditionally used against respiratory infections supports previous research on the importance of traditional medicine in the primary health care of this remote area. The finding of new vernacular plant names and plant uses in the current survey shows the importance of the documentation of such ethnobotanical knowledge.
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Affiliation(s)
- T York
- Department of Botany, University of Zululand, Private Bag 1001, KwaDlangezwa 3886, South Africa
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de Wet H, Nkwanyana MN, van Vuuren SF. Medicinal plants used for the treatment of diarrhoea in northern Maputaland, KwaZulu-Natal Province, South Africa. J Ethnopharmacol 2010; 130:284-9. [PMID: 20452415 DOI: 10.1016/j.jep.2010.05.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/14/2010] [Accepted: 05/01/2010] [Indexed: 05/20/2023]
Abstract
AIM OF THE STUDY To document the ethnobotanical knowledge on antidiarrhoeal plant use by lay people in a rural community in northern Maputaland. MATERIALS AND METHODS Interviews were conducted amongst homestead inhabitants, using structured questionnaires. The focus was on the medicinal plants which are growing in and around the immediate vicinity of the homesteads. RESULTS Twenty-three plant species are used in the study area to treat diarrhoea. Four plants (Acacia burkei, Brachylaena transvaalensis, Cissampelos hirta and Sarcostemma viminale) are recorded for the first time globally as an antidiarrhoel. The three antidiarrhoeal plants most frequently used in the study area are Psidium guajava, Catharanthus roseus and Melia azedarach (all three are exotic to South Africa), followed by Sclerocarya birrea and Strychnos madagascariensis which are indigenous. Seven of the 23 plant species are used in five different plant combinations for increased antidiarrhoeal efficacy. CONCLUSION The wide variety of plants that are used to treat diarrhoea in this area supports the traditional value that medicinal plants have in the primary health care system of the rural people in northern Maputaland, KwaZulu-Natal.
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Affiliation(s)
- H de Wet
- Department of Botany, University of Zululand, KwaDlangezwa, South Africa.
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Abstract
Skeletal mass is maintained by a balance between formation and resorption, cell proliferation and apoptosis. In vitro, glucocorticoids (GCs) decrease extracellular signal-regulated kinases (ERK) activation by mitogens, thus inhibiting osteoblast proliferation. Both ERK activity and proliferation are restored by co-treatment with the protein tyrosine phosphatase inhibitor, vanadate. Since ERK signalling may also be anti-apoptotic, we explored the effects of vanadate on GC-induced apoptosis in vitro and in vivo. Apoptosis in MBA-15.4 pre-osteoblasts increased from 6 h and remained up to eightfold higher through 6 days of 10(- 6) M dexamethasone (Dex) treatment. Co-incubation with 10(- 7) M vanadate markedly reduced apoptosis at all time points. Vanadate also prevented GC-induced poly-ADP-ribose polymerase cleavage. We assessed the transcriptional profiles of seven anti-apoptotic proteins (Bcl-2, Bcl-X(L), inhibitors of apoptosis protein-1 (IAP-1), IAP-2, X-linked IAP (XIAP), Fas-associated death-domain-like IL-1beta-converting enzyme-inhibitory protein (FLIP(Long)) and FLIP(Short)) in osteoblasts subjected to various stimuli using real-time quantitative PCR. Although these anti-apoptotic genes responded to different mitogenic conditions, Dex failed to repress their expression, and in fact significantly up-regulated Bcl-X(L), IAP-2 and XIAP. Dex may therefore induce apoptosis by up-regulating pro-apoptotic gene expression. We have previously demonstrated that rats treated with GC develop low formation osteoporosis (bone histomorphometry and DEXA) and skeletal fragility (breaking strength) that were largely prevented by co-treatment with vanadate. We report here that vertebrae from rats treated with 3.5 mg/kg per day methylprednisolone for 9 weeks showed increased incidence of terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end-labelling-positive apoptotic osteocytes, which was reduced by vanadate co-treatment. We conclude that vanadate prevents GC-induced apoptosis of pre-osteoblasts in vitro and osteocytes in vivo, and this may contribute to its bone-sparing effects in vivo.
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Affiliation(s)
- M M Conradie
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - H de Wet
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - D D R Kotze
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - J M Burrin
- Department of Endocrinology, St Bart's Hospital, University of LondonLondonUK
| | - F S Hough
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - P A Hulley
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
- Institute of Musculoskeletal Sciences, Botnar Research Centre, Nuffield Orthopaedic Centre, University of OxfordHeadington, Oxford OX3 7LDUK
- (Correspondence should be addressed to P A Hulley; )
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Shimomura K, Hörster F, de Wet H, Flanagan SE, Ellard S, Hattersley AT, Wolf NI, Ashcroft F, Ebinger F. A novel mutation causing DEND syndrome: a treatable channelopathy of pancreas and brain. Neurology 2007; 69:1342-9. [PMID: 17652641 DOI: 10.1212/01.wnl.0000268488.51776.53] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES Activating mutations in the human KCNJ11 gene, encoding the pore-forming subunit (Kir6.2) of the ATP-sensitive potassium (K(ATP)) channel, are one cause of neonatal diabetes mellitus. In a few patients, KCNJ11 mutations cause a triad of developmental delay, epilepsy, and neonatal diabetes (DEND syndrome). The aim of this study was to determine the clinical effects, functional cause, and sensitivity to sulfonylurea treatment of a novel KCNJ11 mutation producing DEND syndrome. METHODS We screened the DNA of a 3-year-old patient with neonatal diabetes, severe developmental delay, and therapy-resistant epilepsy for mutations in KCNJ11. We carried out electrophysiologic analysis of wild-type and mutant K(ATP) channels heterologously expressed in Xenopus oocytes. RESULTS We identified a novel Kir6.2 mutation (I167L) causing DEND syndrome. Functional analysis showed both homomeric and heterozygous mutant channels were less inhibited by MgATP leading to an increase in whole-cell K(ATP) currents. This effect was due to an increase in the intrinsic open probability. Heterozygous channels were strongly inhibited by the sulfonylurea tolbutamide. Treatment of the patient with the sulfonylurea glibenclamide not only enabled insulin therapy to be stopped, but also resulted in improvement in epilepsy and psychomotor abilities. CONCLUSIONS We report a case of developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome that shows neurologic improvement with sulfonylurea therapy. Early recognition of patients with DEND syndrome may have considerable therapeutic benefit for the patient.
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Affiliation(s)
- K Shimomura
- University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK
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Engelbrecht Y, de Wet H, Horsch K, Langeveldt CR, Hough FS, Hulley PA. Glucocorticoids induce rapid up-regulation of mitogen-activated protein kinase phosphatase-1 and dephosphorylation of extracellular signal-regulated kinase and impair proliferation in human and mouse osteoblast cell lines. Endocrinology 2003; 144:412-22. [PMID: 12538600 PMCID: PMC2820733 DOI: 10.1210/en.2002-220769] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A central feature of glucocorticoid (GC)-induced osteoporosis is decreased bone formation, secondary to decreased numbers of functional osteoblasts. We find that ERK activity is essential for serum-induced osteoblast proliferation in vitro because inhibition of MAPK/ERK kinase activity by U0126 completely abolished both serum-induced activation of ERK and proliferation of mouse (MBA-15.4) and human (MG-63) osteoblast cell lines. Dexamethasone (Dex) rapidly (<2 h) inhibits the sustained phase of ERK activation, required for nuclear shift and mitogenesis. This inhibition is reversed by cotreatment with the protein synthesis inhibitor, cycloheximide, and by the GC receptor antagonist, RU486, suggesting a classical transcriptional mechanism. Phosphatase activity was up-regulated by Dex treatment, and inhibition of ERK activity by Dex was also reversed by the protein tyrosine phosphatase inhibitor, vanadate. Coupled with the rapidity of Dex action, this indicates immediate-early gene phosphatase involvement, and we therefore used quantitative, real-time PCR to examine expression profiles of the dual-specificity MAPK phosphatases, MKP-1 and MKP-3. MKP-1, but not MKP-3, mRNA expression was 10-fold up-regulated in both mouse and human osteoblast cell lines within 30 min of Dex treatment and remained elevated for 24 h. MKP-1 protein was also markedly up-regulated following 1-8 h of Dex treatment, and this correlated precisely with dephosphorylation of ERK. Cell proliferation was impaired by Dex treatment, and this was reversed by both RU486 and vanadate. Therefore, MKP-1 up-regulation provides a novel and rapid mechanism, whereby GCs inhibit osteoblast proliferation.
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Affiliation(s)
- Y Engelbrecht
- Endocrinology and Metabolism Unit, Department of Internal Medicine, University of Stellenbosch, Tygerberg 7505, Cape Town, South Africa
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Di Pietro A, Conseil G, Pérez-Victoria JM, Dayan G, Baubichon-Cortay H, Trompier D, Steinfels E, Jault JM, de Wet H, Maitrejean M, Comte G, Boumendjel A, Mariotte AM, Dumontet C, McIntosh DB, Goffeau A, Castanys S, Gamarro F, Barron D. Modulation by flavonoids of cell multidrug resistance mediated by P-glycoprotein and related ABC transporters. Cell Mol Life Sci 2002; 59:307-22. [PMID: 11915946 DOI: 10.1007/s00018-002-8424-8] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.5] [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: 10/27/2022]
Abstract
Cancer cell resistance to chemotherapy is often mediated by overexpression of P-glycoprotein, a plasma membrane ABC (ATP-binding cassette) transporter which extrudes cytotoxic drugs at the expense of ATP hydrolysis. P-glycoprotein (ABCB1, according to the human gene nomenclature committee) consists of two homologous halves each containing a transmembrane domain (TMD) involved in drug binding and efflux, and a cytosolic nucleotide-binding domain (NBD) involved in ATP binding and hydrolysis, with an overall (TMD-NBD)2 domain topology. Homologous ABC multidrug transporters, from the same ABCB family, are found in many species such as Plasmodiumfalciparum and Leishmania spp. protozoa, where they induce resistance to antiparasitic drugs. In yeasts, some ABC transporters involved in resistance to fungicides, such as Saccharomyces cerevisiae Pdr5p and Snq2p, display a different (NBD-TMD)2 domain topology and are classified in another family, ABCG. Much effort has been spent to modulate multidrug resistance in the different species by using specific inhibitors, but generally with little success due to additional cellular targets and/or extrusion of the potential inhibitors. This review shows that due to similarities in function and maybe in three-dimensional organization of the different transporters, common potential modulators have been found. An in vitro 'rational screening' was performed among the large flavonoid family using a four-step procedure: (i) direct binding to purified recombinant cytosolic NBD and/or full-length transporter, (ii) inhibition of ATP hydrolysis and energy-dependent drug interaction with transporter-enriched membranes, (iii) inhibition of cell transporter activity monitored by flow cytometry and (iv) chemosensitization of cell growth. The results indicate that prenylated flavonoids bind with high affinity, and strongly inhibit drug interaction and nucleotide hydrolysis. As such, they constitute promising potential modulators of multidrug resistance.
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Affiliation(s)
- A Di Pietro
- Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS/Université Claude Bernard-Lyon I, Passage du Vercors, Lyon, France
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de Wet H, McIntosh DB, Conseil G, Baubichon-Cortay H, Krell T, Jault JM, Daskiewicz JB, Barron D, Di Pietro A. Sequence requirements of the ATP-binding site within the C-terminal nucleotide-binding domain of mouse P-glycoprotein: structure-activity relationships for flavonoid binding. Biochemistry 2001; 40:10382-91. [PMID: 11513617 DOI: 10.1021/bi010657c] [Citation(s) in RCA: 33] [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: 11/28/2022]
Abstract
Sequence requirements of the ATP-binding site within the C-terminal nucleotide-binding domain (NBD2) of mouse P-glycoprotein were investigated by using two recombinantly expressed soluble proteins of different lengths and photoactive ATP analogues, 8-azidoadenosine triphosphate (8N(3)-ATP) and 2',3',4'-O-(2,4,6-trinitrophenyl)-8-azidoadenosine triphosphate (TNP-8N(3)-ATP). The two proteins, Thr(1044)-Thr(1224) (NBD2(short)) and Lys(1025)-Ser(1276) (NBD2(long)), both incorporated the four consensus sequences of ABC (ATP-binding cassette) transporters, Walker A and B motifs, the Q-loop, and the ABC signature, while differing in N-terminal and C-terminal extensions. Radioactive photolabeling of both proteins was characterized by hyperbolic dependence on nucleotide concentration and high-affinity binding with K(0.5)(8N(3)-ATP) = 36-37 microM and K(0.5)(TNP-8N(3)-ATP) = 0.8-2.6 microM and was maximal at acidic pH. Photolabeling was strongly inhibited by TNP-ATP (K(D) = 0.1-5 microM) and ATP (K(D) = 0.5-2.7 mM). Since flavonoids display bifunctional interactions at the ATP-binding site and a vicinal steroid-interacting hydrophobic sequence [Conseil, G., Baubichon-Cortay, H., Dayan, G., Jault, J.-M., Barron, D., and Di Pietro, A. (1998) Proc. Natl. Acad. Sci. U.S.A. 95, 9831-9836], a series of 30 flavonoids from different classes were investigated for structure-activity relationships toward binding to the ATP site, monitored by protection against photolabeling. The 3-OH and aromaticity of conjugated rings A and C appeared important, whereas opening of ring C abolished the binding in all but one case. It can be concluded that the benzopyrone portion of the flavonoids binds at the adenyl site and the phenyl ring B at the ribosyl site. The Walker A and B motifs, intervening sequences, and small segments on both sides are sufficient to constitute the ATP site.
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Affiliation(s)
- H de Wet
- Department of Chemical Pathology, University of Cape Town Medical School, Observatory 7925, Cape Town, South Africa
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Decottignies A, Grant AM, Nichols JW, de Wet H, McIntosh DB, Goffeau A. ATPase and multidrug transport activities of the overexpressed yeast ABC protein Yor1p. J Biol Chem 1998; 273:12612-22. [PMID: 9575223 DOI: 10.1074/jbc.273.20.12612] [Citation(s) in RCA: 303] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae genome encodes 15 full-size ATP binding cassette transporters (ABC), of which PDR5, SNQ2, and YOR1 are known to be regulated by the transcription factors Pdr1p and Pdr3p (pleiotropic drug resistance). We have identified two new ABC transporter-encoding genes, PDR10 and PDR15, which were up-regulated by the PDR1-3 mutation. These genes, as well as four other ABC transporter-encoding genes, were deleted in order to study the properties of Yor1p. The PDR1-3 gain-of-function mutant was then used to overproduce Yor1p up to 10% of the total plasma membrane proteins. Overexpressed Yor1p was photolabeled by [gamma-32P]2', 3'-O-(2,4,6-trinitrophenyl)-8-azido-ATP (K0.5 = 45 microM) and inhibited by ATP (KD = 0.3 mM) in plasma membranes. Solubilization and partial purification on sucrose gradient allowed to detect significant Yor1p ATP hydrolysis activity (approximately 100 nmol of Pi.min-1.mg-1). This activity was phospholipid-dependent and sensitive to low concentrations of vanadate (I50 = 0.3 microM) and oligomycin (I50 = 8.5 microg/ml). In vivo, we observed a correlation between the amount of Yor1p in the plasma membrane and the level of resistance to oligomycin. We also demonstrated that Yor1p drives an energy-dependent, proton uncoupler-insensitive, cellular extrusion of rhodamine B. Furthermore, cells lacking both Yor1p and Pdr5p (but not Snq2p) showed increased accumulation of the fluorescent derivative of 1-myristoyl-2-[6-(NBD)aminocaproyl]phosphatidylethanolamine. Despite their different topologies, both Yor1p and Pdr5p mediated the ATP-dependent translocation of similar drugs and phospholipids across the yeast cell membrane. Both ABC transporters exhibit ATP hydrolysis in vitro, but Pdr5p ATPase activity is about 15 times higher than that of Yor1p, which may indicate mechanistic or regulatory differences between the two enzymes.
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Affiliation(s)
- A Decottignies
- Unité de Biochimie Physiologique, Université Catholique de Louvain, Place Croix du Sud 2-20, B-1348 Louvain-la-Neuve, Belgium
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Pattinson RC, de Jonge E, Pistorius LR, Howarth GR, de Wet H, Bremer P, Hay IT, Delport S. Practical application of data obtained from a Perinatal Problem Identification Programme. S Afr Med J 1995; 85:131-2. [PMID: 7777952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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Fayman M, Hugo B, de Wet H. Simultaneous dislocation of all five carpometacarpal joints. Plast Reconstr Surg 1988; 82:151-4. [PMID: 3380904] [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: 01/05/2023]
Abstract
A case of unique combination of simultaneous dislocation of all five carpometacarpal joints is presented. The mechanism of injury in this case seems to be some manner of punching with a closed fist rather than direct violence. Satisfactory results were achieved using simple principles of manipulation under anesthesia, open reduction, and skeletal fixation, followed by intensive physiotherapy.
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Affiliation(s)
- M Fayman
- Department of Surgery, University of the Witwatersrand, Johannesburg, South Africa
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de Wet H. [Safety belts]. S Afr Med J 1968; 42:708. [PMID: 5673822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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