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1.
Gesundheitswesen ; 83(8-09): e41-e48, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34496443

RESUMO

OBJECTIVE: Well-established mortality ratio methodology can contribute to a fuller picture of the SARS-CoV-2/COVID-19 burden of disease by revealing trends and informing mitigation strategies. This work examines respective data from Germany by way of example. METHODS: Using monthly and weekly all-cause mortality data from January 2016 to June 2020 (published by the German Federal Statistical Institute) for all ages,<65 years and≥65 years, and specified for Germany's federal states, we explored mortality as sequela of COVID-19. We analysed standardized mortality ratios (SMRs) comparing 2020 with 2016-2019 as reference years with a focus on trend detection. RESULTS: In Germany as a whole, elevated mortality in April (most pronounced for Bavaria) declined in May. The states of Hamburg and Bremen had increased SMRs in all months under study. In Mecklenburg-Western Pomerania, decreased SMRs in January turned monotonically to increased SMRs by June. Irrespective of age group, this trend was pronounced and significant. CONCLUSIONS: Increased SMRs in Hamburg and Bremen must be interpreted with caution because of potential upward distortions due to a "catchment bias". A pronounced excess mortality in April across Germany was confirmed and a hitherto undetected trend of increasing SMRs for Mecklenburg-Western Pomerania was revealed. To meet the pandemic challenge and to benefit from research based on data collected in standardized ways, national authorities should regularly conduct SMR analyses. For independent analyses, national authorities should also expedite publishing raw mortality and population data, including detailed information on age, sex, and cause of death, in the public domain.


Assuntos
COVID-19 , Idoso , Alemanha/epidemiologia , Humanos , Mortalidade , Pandemias , SARS-CoV-2
3.
J Nat Prod ; 79(4): 732-42, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26894655

RESUMO

A classic withanolide is defined as a highly oxygenated C28 ergostane-type steroid that is characterized by a C22-hydroxy-C26-oic acid δ-lactone in the nine-carbon side chain. Analysis of the reported (13)C NMR data of classic withanolides with hydroxy groups (C-14, C-17, and C-20) revealed that (1) a hydroxy (C-14 or C-17) substituent significantly alters the chemical shifts (C-7, C-9, C-12, and C-21) via the γ-gauche effect; (2) the chemical shift values (C-9, C-12, and C-21) reflect the orientation (α or ß) of the hydroxy moiety (C-14 or C-17); (3) a double-bond positional change in ring A (Δ(2) to Δ(3)), or hydroxylation (C-27), results in a minuscule effect on the chemical shifts of carbons in rings C and D (from C-12 to C-18); and (4) the (13)C NMR γ-gauche effect method is more convenient and reliable than the traditional approach ((1)H NMR shift comparisons in C5D5N versus CDCl3) to probe the orientation of the hydroxy substituent (C-14 and C-17). Utilization of these rules demonstrated that the reported (13)C NMR data of withanolides 1a-29a were inconsistent with their published structures, which were subsequently revised as 1-16 and 12 and 18-29, respectively. When combined, this strongly supports the application of these methods to determine the relative configuration of steroidal substituents.


Assuntos
Vitanolídeos/química , Modelos Moleculares , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Esteroides/química
4.
J Nat Prod ; 78(10): 2488-93, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26492982

RESUMO

Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 µM, respectively.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Physalis/química , Componentes Aéreos da Planta/química , Sacarose/análogos & derivados , Sacarose/isolamento & purificação , Vitanolídeos/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Ésteres , Feminino , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sacarose/química , Sacarose/farmacologia , Vitanolídeos/química , Vitanolídeos/farmacologia
5.
Invest New Drugs ; 32(4): 604-17, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24718901

RESUMO

Temozolomide (TMZ) has remained the chemotherapy of choice in patients with glioblastoma multiforme (GBM) primarily due to the lack of more effective drugs. Tumors, however, quickly develop resistance to this line of treatment creating a critical need for alternative approaches and strategies to resensitize the cells. Withaferin A (WA), a steroidal lactone derived from several genera of the Solanaceae plant family has previously demonstrated potent anti-cancer activity in multiple tumor models. Here, we examine the effects of WA against TMZ-resistant GBM cells as a monotherapy and in combination with TMZ. WA prevented GBM cell proliferation by dose-dependent G2/M cell cycle arrest and cell death through both intrinsic and extrinsic apoptotic pathways. This effect correlated with depletion of principle proteins of the Akt/mTOR and MAPK survival and proliferation pathways with diminished phosphorylation of Akt, mTOR, and p70 S6K but compensatory activation of ERK1/2. Depletion of tyrosine kinase cell surface receptors c-Met, EGFR, and Her2 was also observed. WA demonstrated induction of N-acetyl-L-cysteine-repressible oxidative stress as measured directly and through a subsequent heat shock response with HSP32 and HSP70 upregulation and decreased HSF1. Finally, pretreatment of TMZ-resistant GBM cells with WA was associated with O6-methylguanine-DNA methyltransferase (MGMT) depletion which potentiated TMZ-mediated MGMT degradation. Combination treatment with both WA and TMZ resulted in resensitization of MGMT-mediated TMZ-resistance but not resistance through mismatch repair mutations. These studies suggest great clinical potential for the utilization of WA in TMZ-resistant GBM as both a monotherapy and a resensitizer in combination with the standard chemotherapeutic agent TMZ.


Assuntos
Apoptose/efeitos dos fármacos , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Dacarbazina/análogos & derivados , Glioblastoma/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Vitanolídeos/farmacologia , Antineoplásicos/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dacarbazina/farmacologia , Receptores ErbB/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Temozolomida
6.
J Nat Prod ; 77(3): 631-9, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24456028

RESUMO

Nine new withanolides (1-9), withahisolides A-I, were isolated along with nine known compounds (10-18) from the aerial parts of Physalis hispida. The structures of 1-9 were elucidated through a variety of spectroscopic techniques, while the structures of 1 and 2 were confirmed by X-ray crystallographic analysis. Compounds 1-3 are the first withanolides with nonaromatic six-membered ring D moieties. In addition, withanolide 8 represents a novel withanolide skeleton due to the absence of a C-13-C-17 bond within the steroidal nucleus.


Assuntos
Physalis/química , Vitanolídeos/isolamento & purificação , Cristalografia por Raios X , Kansas , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Vitanolídeos/química
7.
World J Surg ; 38(6): 1343-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24763440

RESUMO

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with poor prognosis, as a majority of patients present with advanced disease. Current adjuvant strategies for metastatic patients include mitotane or other cytotoxic agents and carry a significant morbidity as well as a low (<10 %) 5-year survival. Withanolides, including withaferin A, are novel chemotherapeutic agents with potent targeted effects in medullary thyroid cancer and a number of solid malignancies with low toxicity in vivo. We hypothesize that novel naturally derived withanolides will have potent targeted anti-cancer activity against ACCs. METHODS: In vitro cell viability of ACC cell lines (Y1 and SW13) was measured using MTS cell proliferation assay. Cell cycle and apoptotic analysis studied using annexin V/propidium iodide staining on flow cytometry (FC) and targeted molecular mechanisms of withanolide cytotoxicity were assessed using standard Western blot analysis. RESULTS: All the withanolides potently reduced ACC cell viability on MTS assay with 7- to 185-fold higher selectivity than normal fibroblasts. Cell cycle analysis demonstrated a shift in cell cycle arrest from G1/G0 to G2/M with induction of apoptosis at nanomolar concentrations of withanolides. Unlike current ACC therapeutics, withanolides modulated expression of several key oncogenic pathway proteins in ACCs by Western blot, including Jagged 1, MAPK, and Akt/mTOR pathway proteins in a dose-dependent manner after 24 h drug treatment of SW13 cells. CONCLUSION: These results demonstrate the first evidence of the anticancer efficacy of withanolides in ACC cells and provide support for future translational evaluation of these compounds as novel therapeutic agents for ACC patients.


Assuntos
Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Vitanolídeos/farmacologia , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/cirurgia , Carcinoma Adrenocortical/tratamento farmacológico , Carcinoma Adrenocortical/cirurgia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Sensibilidade e Especificidade , Células Tumorais Cultivadas/efeitos dos fármacos
8.
Invest New Drugs ; 31(3): 545-57, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23129310

RESUMO

Withaferin A (WA), a steroidal lactone derived from the plant Vassobia breviflora, has been reported to have anti-proliferative, pro-apoptotic, and anti-angiogenic properties against cancer growth. In this study, we identified several key underlying mechanisms of anticancer action of WA in glioblastoma cells. WA was found to inhibit proliferation by inducing a dose-dependent G2/M cell cycle arrest and promoting cell death through both intrinsic and extrinsic apoptotic pathways. This was accompanied by an inhibitory shift in the Akt/mTOR signaling pathway which included diminished expression and/or phosphorylation of Akt, mTOR, p70 S6K, and p85 S6K with increased activation of AMPKα and the tumor suppressor tuberin/TSC2. Alterations in proteins of the MAPK pathway and cell surface receptors like EGFR, Her2/ErbB2, and c-Met were also observed. WA induced an N-acetyl-L-cysteine-repressible enhancement in cellular oxidative potential/stress with subsequent induction of a heat shock stress response primarily through HSP70, HSP32, and HSP27 upregulation and HSF1 downregulation. Taken together, we suggest that WA may represent a promising chemotherapeutic candidate in glioblastoma therapy warranting further translational evaluation.


Assuntos
Antineoplásicos/farmacologia , Glioblastoma/metabolismo , Vitanolídeos/farmacologia , Animais , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA , Fatores de Transcrição de Choque Térmico , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Humanos , Camundongos , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição
9.
J Nat Prod ; 76(11): 2040-6, 2013 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-24152046

RESUMO

Methanol solutions of the main withanolides (6-8) naturally present in Physalis longifolia yielded five artificial withanolides (1-5), including three new compounds (1-3). Withanolides 1 and 2 were identified as intramolecular Michael addition derivatives, while withanolides 3-5 were the result of intermolecular Michael addition. A comprehensive literature investigation was conducted to identify potential withanolide Michael addition artifacts isolated from Solanaceous species to date.


Assuntos
Metanol/química , Physalis/química , Vitanolídeos/química , Ergosterol/análogos & derivados , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Vitanolídeos/isolamento & purificação
10.
J Nat Prod ; 76(3): 316-21, 2013 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-23145932

RESUMO

Effects of curcuminoids on breast cancer cell secretion of the bone-resorptive peptide parathyroid hormone-related protein (PTHrP) and on lytic breast cancer bone metastasis were evaluated. In vitro, transforming growth factor (TGF)-ß-stimulated PTHrP secretion was inhibited by curcuminoids (IC50 = 24 µM) in MDA-MB-231 human breast cancer cells independent of effects on cell growth inhibition. Effects on TGF-ß signaling revealed decreases in phospho-Smad2/3 and Ets-1 protein levels with no effect on p-38 MAPK-mediated TGF-ß signaling. In vivo, mice were inoculated with MDA-MB-231 cells into the left cardiac ventricle and treated ip every other day with curcuminoids (25 or 50 mg/kg) for 21 days. Osteolytic bone lesion area was reduced up to 51% (p < 0.01). Consistent with specific effects on bone osteolysis, osteoclast number at the bone-tumor interface was reduced up to 53% (p < 0.05), while tumor area within bone was unaltered. In a separate study, tumor mass in orthotopic mammary xenografts was also unaltered by treatment. These data suggest that curcuminoids prevent TGF-ß induction of PTHrP and reduce osteolytic bone destruction by blockade of Smad signaling in breast cancer cells.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Curcumina/análogos & derivados , Curcumina/farmacologia , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Curcumina/química , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Estrutura Molecular , Osteólise/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/fisiologia
11.
J Nat Prod ; 76(3): 445-9, 2013 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-23252848

RESUMO

A new withanolide, named withawrightolide (1), and four known withanolides (2-5) were isolated from the aerial parts of Datura wrightii. The structure of compound 1 was elucidated through 2D NMR and other spectroscopic techniques. In addition, the structure of withametelin L (2) was confirmed by X-ray crystallographic analysis. Using MTS viability assays, withanolides 1-5 showed antiproliferative activities against human glioblastoma (U251 and U87), head and neck squamous cell carcinoma (MDA-1986), and normal fetal lung fibroblast (MRC-5) cells with IC50 values in the range between 0.56 and 5.6 µM.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Datura/química , Vitanolídeos/isolamento & purificação , Vitanolídeos/farmacologia , Antineoplásicos Fitogênicos/química , Carcinoma de Células Escamosas/tratamento farmacológico , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Fibroblastos/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Humanos , Concentração Inibidora 50 , Kansas , Pulmão/citologia , Pulmão/efeitos dos fármacos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Vitanolídeos/química
12.
Toxicol Appl Pharmacol ; 258(2): 268-74, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22178739

RESUMO

Farnesoid X receptor (FXR) is a ligand-activated nuclear receptor and serves as a key regulator to maintain health of the liver and intestine. Bile acids are endogenous ligands of FXR, and there are increasing efforts to identify FXR modulators to serve as biological probes and/or pharmaceutical agents. Natural FXR ligands isolated from plants may serve as models to synthesize novel FXR modulators. In this study, we demonstrated that epigallocatechin-3-gallate (EGCG), a major tea catechin, specifically and dose-dependently activates FXR. In addition, EGCG induced FXR target gene expression in vitro. Surprisingly, in a co-activator (SRC2) recruitment assay, we found that EGCG does not recruit SRC2 to FXR, but it dose-dependently inhibits recruitment of SRC2 to FXR (IC(50), 1µM) by GW6064, which is a potent FXR synthetic ligand. In addition, EGCG suppressed FXR target gene expression induced by either GW4064 or chenodeoxycholic acid in vitro. Furthermore, wild-type and FXR knockout mice treated with an acute dose of EGCG had induced mRNA expression in a subset of FXR target genes in the intestine but not in the liver. In conclusion, EGCG is a unique modulator of FXR in the intestine and may serve as an important model for future development of FXR modulators.


Assuntos
Catequina/análogos & derivados , Regulação da Expressão Gênica/efeitos dos fármacos , Coativador 2 de Receptor Nuclear/metabolismo , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Chá/química , Animais , Catequina/administração & dosagem , Catequina/farmacologia , Células Cultivadas , Ácido Quenodesoxicólico/farmacologia , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Concentração Inibidora 50 , Isoxazóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/genética
13.
Tumour Biol ; 33(4): 1179-89, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22477711

RESUMO

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. While effective therapy exists for the primary tumor, there is a lack of effective treatment for metastatic disease currently. Natural withanolide withaferin A (WA) has shown efficacy in cancers demonstrating upregulation of pro-survival pathways. The purpose of the present study is to investigate the effect of WA as a potential therapeutic agent for UM in vitro as well as in vivo. UM cells were treated with WA and several cell-based assays, such as MTS, trypan blue exclusion assay, clonogenic, wound healing, cell cycle shift, annexin V/propidium iodide, and Western blot, were performed. In vivo experiments utilized the 92.1 cells in a xenograft murine model. WA inhibits cell proliferation of uveal melanoma cells with an IC50 of 0.90, 1.66, and 2.42 µM for OMM2.3, 92.1, and MEL290 cells, respectively. Flow cytometry analysis demonstrates G2/M cell cycle arrest and apoptosis at 1 µM WA in treated cells. WA induced apoptosis partly through the suppression of c-Met, Akt, and Raf-1 signaling activation. In vivo studies using WA reduced tumor growth in 100% of animals (p = 0.015). Our observation indicates that WA is a potent drug that inhibits cell proliferation, shifts cell cycle arrest, and induces apoptosis in multiple UM cell lines in vitro. WA-mediated apoptosis in UM cells is partly mediated though the suppression of c-Met and Akt activation. WA significantly decreases UM tumor growth in vivo and justifies further evaluation of this drug for the treatment of metastatic uveal melanoma.


Assuntos
Apoptose/efeitos dos fármacos , Melanoma/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Neoplasias Uveais/tratamento farmacológico , Vitanolídeos/farmacologia , Animais , Western Blotting , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Concentração Inibidora 50 , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Camundongos SCID , Estrutura Molecular , Fatores de Tempo , Carga Tumoral/efeitos dos fármacos , Neoplasias Uveais/metabolismo , Neoplasias Uveais/patologia , Vitanolídeos/química , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Gynecol Oncol ; 124(3): 606-12, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22188785

RESUMO

OBJECTIVE: Withaferin A, a natural withanolide, has shown anti-cancer properties in various cancers including breast cancer, but its effects in ovarian cancer remain unexplored. Notch 1 and Notch3 are critically involved in ovarian cancer progression. We decided to examine the effects of Withaferin A in ovarian carcinoma cell lines and its molecular mechanism of action including its regulation of Notch. METHODS: The effects of Withaferin A were examined in CaOV3 and SKOV3 ovarian carcinoma cell lines using MTS assay, clonogenic assay, annexin V/propidium iodide flow cytometry, and cell cycle analysis. Western analysis was conducted to examine the molecular mechanisms of action. RESULTS: Withaferin A inhibited the growth and colony formation of CaOV3 and SKOV3 cells by inducing apoptosis and cell cycle arrest. These changes correlated with down-regulation of Notch1, Notch3, cdc25C, total and phosphorylated Akt, and bcl-2 proteins. CONCLUSIONS: Withaferin A inhibits CaOV3 and SKOV3 ovarian carcinoma cell growth, at least in part by targeting Notch1 and Notch3.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Ovarianas/tratamento farmacológico , Vitanolídeos/farmacologia , Processos de Crescimento Celular/efeitos dos fármacos , Regulação para Baixo , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Proteína Oncogênica v-akt/antagonistas & inibidores , Proteína Oncogênica v-akt/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/metabolismo , Receptor Notch3 , Receptores Notch/antagonistas & inibidores , Receptores Notch/metabolismo , Fosfatases cdc25/metabolismo
15.
Pure Appl Chem ; 84(6): 1353-1367, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-24098060

RESUMO

As part of our search for bioactive compounds from plant biodiversity, 29 withanolides (1, 3-6, 9, 12-18, and 20-35) were recently isolated from three members of the Solanaceae: Physalis longifolia, Vassobia breviflora, and Withania somnifera. Six derivatives (2, 7, 8, 10, 11, and 19) were prepared from these naturally occurring withanolides. All compounds (1-35) were evaluated for in vitro anti-proliferative activity against an array of cell lines [melanoma cell lines (B16F10, SKMEL28); human head and neck squamous cell carcinomas (HNSCC) cell lines (JMAR, MDA1986, DR081-1); breast cancer cell line (Hs578T), and non-malignant human cell line (MRC5)]. This led to the discovery of 15 withanolides, with IC50 values in the range of 0.067-17.4 µM, including withaferin A 1, withaferin A 4,27-diacetate 2, 27-O-glucopyranosylwithaferin A 3, withalongolide H 4, withalongolide C 5, withalongolide A 6, withalongolide A 4,27-diacetate 7, withalongolide A 4,19,27-triacetate 8, withalongolide B 9, withalongolide B 4-acetate 10, withalongolide B 4,19-diacetate 11, withalongolide D 16, withalongolide E 17, withalongolide G 21, and 2,3-dihydrowithaferin A 3-O-sulfate 22). In order to update the growing literature on withanolides and their activities, we summarized the distribution, structural types and anti-proliferative activities for all published withanolides to date. The structure-activity relationship analysis (SARA) confirmed the importance of the presence of a Δ2-1-oxo- functionality in ring A, a 5ß,6ß-epoxy or 5α-chloro-6ß-hydroxy groupings in ring B, and nine carbon side chain with a lactone moiety for cytotoxic activity. Conversely, the SARA indicated that the -OH or -OR groups at C-4, 7, 11, 12, 14, 15, 16, 17, 18, 19, 20, 23, 24, 27, 28 were not contributors to the observed anti-proliferative activity within the systems analyzed.

16.
J Nat Prod ; 75(3): 400-7, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22316168

RESUMO

Phytochemical investigation of the dried biomass of Asclepias syriaca afforded five new compounds (1-5), along with 19 known structures. Overall, the secondary metabolites isolated and identified from this plant showed a wide structural diversity including pentacyclic triterpenes, cardiac glycosides, flavonoid glycosides, lignans, a phenylethanoid, and a glycosylated megastigmane. In addition, the isolates were tested against the cancer breast cell line Hs578T, and those showing IC(50) values lower than 50 µM (1 and 6-9) were further investigated in three additional breast cancer cell lines (MCF-7, T47D, and Sk-Br-3) and the normal breast cell line Hs578Bst.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Asclepias/química , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Antineoplásicos Fitogênicos/química , Glicosídeos Cardíacos/química , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Triterpenos/química
17.
Chem Pharm Bull (Tokyo) ; 60(10): 1234-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23036966

RESUMO

In our recent publication on bioactive guided isolation of compounds from Physalis longifolia (Solanaceae) novel anti-proliferative agents withalongolides A (4) and B (5), and their highly cytotoxic analogues, withalongolide A 4,19,27-triacetate (4a) and withalongolide B 4,19-diacetate (5a) were elucidated. In this study, the two lead compounds (4, 5) were re-isolated in gram quantities for the purpose of further analogue preparation and in vivo testing that would continue to probe structure-activity relationships. During this process, two additional withanolides, named withalongolides O (1) and P (2), were elucidated. Their structures were determined by spectroscopic techniques with 1 being subsequently confirmed by X-ray crystallographic analysis. Utilizing a MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] viability assay, withalongolide O (1) and its 4,7-diaceatate (1a), both containing the functionalities of Δ(2)-1-oxo- in A ring, a 5ß,6ß-epoxy in B ring, and a lactone ring in the nine-carbon side chain, exhibited potent cytotoxicity against human head and neck squamous cell carcinoma (JMAR and MDA-1986), melanoma (B16F10 and SKMEL-28), and normal fetal lung fibroblast (MRC-5) cells with IC(50) values in the range between 0.15 and 2.95 µM. In addition, the previously reported α orientation of 7-acetate group in acnistins C and D should be revised to the ß orientation on the basis of NMR data comparison.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Physalis/química , Vitanolídeos/química , Vitanolídeos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Melanoma/tratamento farmacológico , Modelos Moleculares , Carcinoma de Células Escamosas de Cabeça e Pescoço , Relação Estrutura-Atividade , Vitanolídeos/isolamento & purificação
18.
Nutrients ; 14(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558560

RESUMO

Treatment regimens for head and neck squamous cell carcinoma (HNSCC) typically include cisplatin and radiotherapy and are limited by toxicities. We have identified naturally derived withalongolide A triacetate (WGA-TA) from Physalis longifolia as a lead compound for targeting HNSCC. We hypothesized that combining WGA-TA with cisplatin may allow for lower, less toxic cisplatin doses. HNSCC cell lines were treated with WGA-TA and cisplatin. After treatment with the drugs, the cell viability was determined by MTS assay. The combination index was calculated using CompuSyn. The expression of proteins involved in the targeting of translational initiation complex, epithelial to mesenchymal transition (EMT), and apoptosis were measured by western blot. Invasion and migration were measured using the Boyden-chamber assay. Treatment of MDA-1986 and UMSCC-22B cell lines with either WGA-TA or cisplatin alone for 72 h resulted in a dose dependent decrease in cell viability. Cisplatin in combination with WGA-TA resulted in significant synergistic cell death starting from 1.25 µM cisplatin. Combination treatment with WGA-TA resulted in lower cisplatin dosing while maintaining the downregulation of translational initiation complex proteins, the induction of apoptosis, and the blockade of migration, invasion, and EMT transition. These results suggest that combining a low concentration of cisplatin with WGA-TA may provide a safer, more effective therapeutic option for HNSCC that warrants translational validation.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Cisplatino/farmacologia , Transição Epitelial-Mesenquimal , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Linhagem Celular Tumoral , Apoptose
19.
J Pharmacol Exp Ther ; 339(2): 624-32, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21846839

RESUMO

Organic anion-transporting polypeptides 1B1 and 1B3 (OATP1B1 and OATP1B3) are liver-specific transporters that mediate the uptake of a broad range of drugs into hepatocytes, including statins, antibiotics, and many anticancer drugs. Compounds that alter transport by one or both of these OATPs could potentially be used to target drugs to hepatocytes or improve the bioavailability of drugs that are cleared by the liver. In this study, we applied a bioassay-guided isolation approach to identify such compounds from the organic extract of Rollinia emarginata Schlecht (Annonaceae). Fractions of the plant extract were screened for effects on OATP1B1- and OATP1B3-mediated transport of the model substrates estradiol-17ß-glucuronide and estrone-3-sulfate. We isolated three compounds, ursolic acid, oleanolic acid, and 8-trans-p-coumaroyloxy-α-terpineol, which inhibited estradiol-17ß-glucuronide uptake by OATP1B1 but not OATP1B3. In addition, a rare compound, quercetin 3-O-α-l-arabinopyranosyl(1→2) α-L-rhamnopyranoside, was identified that had distinct effects on each OATP. OATP1B1 was strongly inhibited, as was OATP1B3-mediated transport of estradiol-17ß-glucuronide. However, OATP1B3-mediated uptake of estrone-3-sulfate was stimulated 4- to 5-fold. Kinetic analysis of this stimulation revealed that the apparent affinity for estrone-3-sulfate was increased (decreased K(m)), whereas the maximal rate of transport (V(max)) was significantly reduced. These results demonstrate a mechanism through which the hepatic uptake of drug OATP substrates could be stimulated.


Assuntos
Hepatócitos/metabolismo , Fígado/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Rollinia , Terpenos/isolamento & purificação , Terpenos/farmacologia , Animais , Células CHO , Cricetinae , Cricetulus , Descoberta de Drogas , Estradiol/análogos & derivados , Estradiol/metabolismo , Estrona/análogos & derivados , Estrona/metabolismo , Cinética , Fígado/efeitos dos fármacos , Transportador 1 de Ânion Orgânico Específico do Fígado , Terapia de Alvo Molecular , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Casca de Planta , Extratos Vegetais/química , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto , Terpenos/química , Triterpenos/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Ácido Ursólico
20.
Drug Metab Dispos ; 39(5): 920-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21278283

RESUMO

Organic anion-transporting polypeptides (OATPs) are multispecific transporters that mediate the uptake of numerous drugs and xenobiotics into cells. Here, we examined the effect of green tea (Camellia sinensis) catechins on the function of the four OATPs expressed in human enterocytes and hepatocytes. Uptake of the model substrate estrone-3-sulfate by cells expressing OATP1A2, OATP1B1, OATP1B3, or OATP2B1 was measured in the absence and presence of the four most abundant flavonols found in green tea. Uptake by OATP1A2, OATP1B1, and OATP2B1 was inhibited by epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) in a concentration-dependent way. In contrast, OATP1B3-mediated uptake of estrone-3-sulfate was strongly stimulated by EGCG at low substrate concentrations. The effect of EGCG on OATP1B3 was also studied with additional substrates: uptake of estradiol-17ß-glucuronide was unchanged, whereas uptake of Fluo-3 was noncompetitively inhibited. Both ECG and EGCG were found to be substrates of OATP1A2 (K(m) values of 10.4 and 18.8 µM, respectively) and OATP1B3 (34.1 and 13.2 µM, respectively) but not of OATP1B1 or OATP2B1. These results indicate that two of the major flavonols found in green tea have a substantial effect on the function of OATPs expressed in enterocytes and hepatocytes and can potentially alter the pharmacokinetics of drugs and other OATP substrates. In addition, the diverse effects of EGCG on the transport of other OATP1B3 substrates suggest that different transport/binding sites are involved.


Assuntos
Antioxidantes/metabolismo , Camellia sinensis , Hepatócitos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Compostos de Anilina/metabolismo , Animais , Transporte Biológico , Células CHO , Catequina/análogos & derivados , Catequina/metabolismo , Linhagem Celular , Cricetinae , Cricetulus , Interações Medicamentosas , Enterócitos/metabolismo , Estradiol/análogos & derivados , Estradiol/metabolismo , Estrona/análogos & derivados , Estrona/metabolismo , Corantes Fluorescentes/metabolismo , Humanos , Chá , Xantenos/metabolismo
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