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The overexpression of antiapoptotic Bcl2 in acute myeloid leukaemia (AML) may contribute to difficulties in eradicating these cells during chemotherapy. In the present study, doxorubicin (Dox) was evaluated for its potential to induce selective apoptotic cell death in AML MOLM13 cells and to modulate autophagy through Bcl2 and Beclin 1 protein expression. Annexin V/propidium iodide and 5(6)carboxyfluorescein diacetate succinimidyl ester (CFSE) flow cytometric analyses were conducted to determine the effects of Dox on cell death and cell proliferation, respectively, following 48 h of coincubation with AML MOLM13 or U937 monocytic cells. The protein expression levels of Bcl2 and Beclin 1 in untreated and treated cells were quantified by western blot analysis. Dox reduced the viability of MOLM13 cells partly by inhibiting cell division and inducing cell apoptosis. Dox demonstrated a level of selectivity in its cytotoxicity against MOLM13 compared to U937 cells (P<0.05). Dox induced a significant decrease in Beclin 1 protein levels in MOLM13 cells without significantly affecting the protein levels in U937 monocytes. A novel Bcl2 1520 kDa (p1520Bcl2) isoform was found to be selectively expressed in AML MOLM13 cells (but absent in the leukaemic cell lines tested, OCIAML2, CML K562 and U937). Dox induced a highly significant inhibition of p1520Bcl2 at concentrations of 0.5, 0.75 and 1 µM (P<0.01). However, the usual 26 kDa Bcl2 (p26Bcl2α) isoform protein expression was not affected by the drug in either the MOLM13 or U937 cells. It was thus postulated that Dox exhibited some selectivity by targeting the p1520Bcl2 isoform in MOLM13 cells and activating Beclin 1 to induce cell death.
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Beclina-1/metabolismo , Doxorrubicina/farmacología , Leucemia Mieloide Aguda/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Doxorrubicina/uso terapéutico , Regulación Leucémica de la Expresión Génica , Humanos , Leucemia Mieloide Aguda/patología , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismoRESUMEN
The strengths and limitations of current approaches to clinical nutrition practice and their underpinning research are explored in this article. It describes how a personalized nutrition practice approach supported by evidence-based pathophysiological reasoning could direct additional research, which could then transform practice and support food industry developments. Current use of the term "personalized nutrition" is reviewed and a definition is provided. Also explored are current approaches to personalized nutrition practice and evidence-based practice in clinical nutrition. Patient-centered practice, which involves individuals in their healthcare decisions, is currently being provided under the name "personalized." An evidence-based personalized practice approach should include the use of robust, standardized, and validated tools that gather a patient's signs and symptoms, health history, family history, genetics, environment, lifestyle, social life, diet, behavior and other factors that have an impact on physiological processes. It should also gather anthropometric measures as well as functional, diagnostic, and prognostic biomarkers for pathophysiological mechanisms. Such tools would pool n = 1 data into a case-by-case evidence base that uses computational network modelling to predict the efficacy of personalized nutrition interventions. Prediction of the efficacy of interventions should also be validated using, when possible, blinded, randomized, controlled, stratified intervention studies. This model would provide practitioners with data that support evidence-based pathophysiological reasoning. It would enable clinicians to prioritize interventions on the basis of the mechanisms of action of interventions and to ameliorate the mechanisms of pathophysiology, which are a priority for the individual. Interventions then may be applied using a patient-centered practice approach. This would transform evidence-based nutrition practice into a P4 medicine approach that is personalized, preventive, predictive, and participatory. Developing pathophysiological mechanistic understanding also provides new opportunities for stakeholders, including the food industry, researchers, healthcare practitioners, and consumers.
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Dieta , Dietética/métodos , Práctica Clínica Basada en la Evidencia , Humanos , Estilo de Vida , Estado Nutricional , Nutricionistas , Medicina de PrecisiónRESUMEN
Patients with type 2 diabetes may co-ingest herbal and prescription medicines to control their blood sugar levels. Competitive binding of drug and herb may mutually affect their metabolism. This can alter the level of drug and its kinetics in the body, potentially causing toxicities or loss of efficacy. Understanding how the metabolism of sulfonylureas like glyburide and gliclazide can be affected by the presence of berberine and vice versa can provide valuable information on the possible risk of toxicities caused by co-ingestion of drugs. METHODS: Berberine and sulfonylureas (glyburide and gliclazide) were co-incubated with rat liver microsomes in the presence of a NADPH-regenerating system. The metabolites of berberine and sulfonylureas were analysed using liquid chromatography with high-resolution mass spectrometry in the positive ion mode. The role of individual isozymes in the metabolism of berberine, glyburide and gliclazide was investigated by using specific inhibitors. RESULTS: In vitro metabolism of berberine led to the formation of demethyleneberberine (B1a) and its isomer B1b through demethylenation. Berberrubine (B2a) and its isomer B2b were formed through demethylation. The isozymes CYP3A and CYP2D were found to be involved in the metabolism of berberine. In vitro metabolism of glyburide and gliclazide led to the formation of hydroxylated metabolites. The isozymes CYP3A and CYP2C were found to be involved in the metabolism of glyburide. Gliclazide was metabolised by CYP2C. In vitro co-incubation of glyburide or gliclazide with berberine showed that each drug's metabolism was compromised as they share a common isozyme. A strong negative linear correlation of glyburide or gliclazide metabolite levels and the concentration of berberine confirmed the effect of berberine on the metabolism of sulfonylureas. CONCLUSIONS: The metabolism of sulfonylureas and berberine was affected when these compounds were co-incubated with each other. This may be attributable to competitive binding of the herb and drug to the catalytic sites of the same isozymes.
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Berberina , Compuestos de Sulfonilurea , Animales , Berberina/análisis , Berberina/química , Berberina/farmacocinética , Cromatografía Liquida , Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Gliclazida/análisis , Gliclazida/química , Gliclazida/metabolismo , Gliburida/análisis , Gliburida/química , Gliburida/metabolismo , Interacciones de Hierba-Droga , Masculino , Espectrometría de Masas , Microsomas Hepáticos/metabolismo , Ratas , Compuestos de Sulfonilurea/análisis , Compuestos de Sulfonilurea/química , Compuestos de Sulfonilurea/farmacocinéticaRESUMEN
Inhibitors of the proteasome have found broad therapeutic applications; however, they show severe toxicity due to the abundance of proteasomes in healthy cells. In contrast, inhibitors of the immunoproteasome, which is upregulated during disease states, are less toxic and have increased therapeutic potential including against autoimmune disorders. In this project, we report argyrin B, a natural product cyclic peptide to be a reversible, non-competitive inhibitor of the immunoproteasome. Argyrin B showed selective inhibition of the ß5i and ß1i sites of the immunoproteasome over the ß5c and ß1c sites of the constitutive proteasome with nearly 20-fold selective inhibition of ß1i over the homologous ß1c. Molecular modelling attributes the ß1i over ß1c selectivity to the small hydrophobic S1 pocket of ß1i and ß5i over ß5c to site-specific amino acid variations that enable additional bonding interactions and stabilization of the binding conformation. These findings facilitate the design of immunoproteasome selective and reversible inhibitors that may have a greater therapeutic potential and lower toxicity.
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Oligopéptidos/química , Complejo de la Endopetidasa Proteasomal/química , Inhibidores de Proteasoma/química , Sitios de Unión , HumanosRESUMEN
High-risk human papilloma virus (HPV) infection is directly associated with cervical cancer development. Arsenic trioxide (ATO), despite inducing apoptosis in HPV-infected cervical cancer cells in vitro, has been compromised by toxicity and poor pharmacokinetics in clinical trials. Therefore, to improve ATO's therapeutic profile for HPV-related cancers, this study aims to explore the effects of length of ligand spacers of folate-targeted liposomes on the efficiency of ATO delivery to HPV-infected cells. Fluorescent ATO encapsulated liposomes with folic acid (FA) conjugated to two different PEG lengths (2000 Da and 5000 Da) were synthesised, and their cellular uptake was examined for HPV-positive HeLa and KB and HPV-negative HT-3 cells using confocal microscopy, flow cytometry, and spectrophotometer readings. Cellular arsenic quantification and anti-tumour efficacy was evaluated through inductively coupled plasma-mass spectrometry (ICP-MS) and cytotoxicity studies, respectively. Results showed that liposomes with a longer folic acid-polyethylene glycol (FA-PEG) spacer (5000 Da) displayed a higher efficiency in targeting folate receptor (FR) + HPV-infected cells without increasing any inherent cytotoxicity. Targeted liposomally delivered ATO also displayed superior selectivity and efficiency in inducing higher cell apoptosis in HPV-positive cells per unit of arsenic taken up than free ATO, in contrast to HT-3. These findings may hold promise in improving the management of HPV-associated cancers.
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Antineoplásicos/toxicidad , Trióxido de Arsénico/toxicidad , Ácido Fólico/análogos & derivados , Liposomas/química , Neoplasias del Cuello Uterino/metabolismo , Apoptosis/efectos de los fármacos , Femenino , Células HeLa , Humanos , Papillomaviridae , Polietilenglicoles/química , Neoplasias del Cuello Uterino/virologíaRESUMEN
Despite the success of arsenic trioxide (ATO) in treating haematological malignancies, its potential to treat solid tumours has not been fully exploited, owing to its dose-limiting toxicity and poor pharmacokinetics. In order to overcome this hurdle, liposomal encapsulation of the drug with different surface charges (neutral, negative, and positive) and sizes (100, 200 and 400 nm) were synthesised and tested on human papilloma virus (HPV)-positive HeLa and HPV-negative HT-3 cervical cancer cell lines. Two epithelial cell lines-human keratinocytes (HK) and human colon cells (CRL-1790)-were used as controls. The synthesised liposomes were tested for their physico-chemical characteristics, drug loading efficiency, and toxicity on the studied cell lines. Neutral liposomes of 100 nm in size were the chosen formulation for delivering ATO into the studied cells, as they showed the least intrinsic cytotoxicity and the highest loading efficiency. The findings demonstrated that the optimised formulation of liposomes was an effective drug delivery method for HPV-infected cervical cancer cells. Furthermore, the toxicity vs. uptake ratio was highest for HeLa cells, while a reduced or minimal toxic effect was observed for non-HPV-infected cervical cancer cells and control cells. These findings may provide a promising therapeutic strategy for effectively managing cervical cancers.
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Antineoplásicos/administración & dosificación , Arsenicales/administración & dosificación , Sistemas de Liberación de Medicamentos , Liposomas , Óxidos/administración & dosificación , Antineoplásicos/química , Trióxido de Arsénico , Arsenicales/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Composición de Medicamentos , Femenino , Humanos , Óxidos/química , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/virología , Tamaño de la Partícula , Electricidad Estática , Neoplasias del Cuello Uterino/etiologíaRESUMEN
Baicalein (BL), a potential cancer chemopreventative flavone, has been reported to inhibit cancer cell growth by inducing apoptosis and causing cell cycle arrest in various human cancer cell models. Delivery of BL via nanoliposomes has been shown to improve its oral bioavailability and longcirculating property in vivo. However, the role of BL in the inhibition of human chronic myeloid leukemia (CML) K562 cell growth and its underlying mechanisms has yet to be elucidated. In the present study, BL was formulated into liposomes with different sizes to improve its solubility and stability. The cytotoxic and proapoptotic effects of free BL and liposomal BL were also evaluated. The results demonstrated that 100 nm liposomes were the most stable formulation when compared with 200 and 400 nm liposomes. Liposomal BL inhibited K562 cell growth as efficiently as free BL (prepared in DMSO), indicating that the liposome may be a potential vehicle to deliver BL for the treatment of CML. Flow cytometry analysis showed that there was significant (P<0.005) cell cycle arrest in the subG1 phase (compared with vehicle control), indicating cell apoptosis following 20 µM liposomal BL or free BL treatment of K562 cells for 48 h. The induction of cell apoptosis by all BL preparations was further confirmed through the staining of treated cells with Annexin Vfluorescein isothiocyanate/propidium iodide. A significant increase in reactive oxygen species (ROS) gene-ration was observed in free BL and liposomal BL treated cells, with a higher level of ROS produced from those treated with free BL. This indicated that cell apoptosis induced by BL may be via ROS generation and liposome delivery may further extend the effect through its longcirculating property.
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Apoptosis/efectos de los fármacos , Flavanonas/farmacología , Liposomas/química , Especies Reactivas de Oxígeno/metabolismo , Proliferación Celular/efectos de los fármacos , Flavanonas/química , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Células K562RESUMEN
Practitioners of traditional Chinese medicine (TCM) commonly prescribe medicinal formulations relying on the purported synergism of a combination of plant species, sometimes incorporating animal parts and minerals. Bear bile, obtained from either wild or farmed bears, is a commonly used constituent of traditional medicine formulations. With several bear species now listed under Convention on International Trade in Endangered Species of Wild Fauna and Flora as threatened with extinction and with bear farming being actively campaigned against on ethical grounds, it is important to seek and promote alternatives to the use of bear bile as medicine. This chapter describes and evaluates the scientific data relating to the efficacy of bear bile and potential alternatives to its use, including the use of bile from other animal species, the use of synthetic chemical alternatives, and the use of herbal substitutes. Scientific studies have confirmed the efficacy of bear bile as an antiinflammatory and a hepatoprotective agent. Ursodeoxycholic acid (UDCA), the active component of bear bile is used in a synthetic form in Western medicine and can serve as an alternative to bear bile in the treatment and management of certain cholestatic liver conditions. In TCM practice, bile from domesticated animal species (such as cattle, chicken, and pig) has been used as a substitute for bear bile. Following evaluation of TCM literature and pharmacological/clinical data, the authors propose six plant species, either as single herbs or in combination, Gardenia jasminoides (zhi zi; ), Scutellaria baicalensis (huáng qín; ), Coptis chinensis (huáng lián, ), Phellodendron amurense (huáng bai; ), Andrographis paniculata (chuan xin lian; ), and Rheum palmatum (dà huang; ), two medicinal Kampo formulations, Orengedokuto, Dia-Orengedokuto (which originated from traditional Chinese herbal formula Huanglian Jiedu Tang, ), and two individual phytochemicals (berberine and andrographolide) as alternatives to bear bile. The proposed herbal alternatives are frequently found listed in traditional formulations also containing bear bile, usually with different therapeutic roles ascribed to them. The existing evidence base for the effectiveness of herbal alternatives is sufficiently strong for TCM practitioners and consumers to consider using these without the addition of bear bile. This consideration is driven by the imperative to protect populations of bears from overexploitation in the wild and when farmed. However, for the identified alternatives to be accepted by users, it is essential that researchers and TCM practitioners collaborate effectively to initiate consumer behavior change.
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Antiinflamatorios/uso terapéutico , Bilis/química , Inflamación/tratamiento farmacológico , Medicina Tradicional China/métodos , Plantas Medicinales , Ursidae/metabolismo , Animales , Bilis/metabolismo , Humanos , Plantas Medicinales/químicaRESUMEN
Advances in scientific research and targeted treatment regimes have improved survival rates for many cancers over the past few decades. However, for some types of leukemia, including acute lymphoblastic and acute myeloid leukemia, mortality rates have continued to rise, with chemoresistance in leukemic stem cells (LSCs) being a major contributing factor. Most cancer drug therapies act by inducing apoptosis in dividing cells but are ineffective in targeting quiescent LSCs. Niches in the bone marrow, known as leukemic niches, behave as "sanctuaries" where LSCs acquire drug resistance. This review explores the role of the bone marrow environment in the maintenance of LSCs and its contribution to chemoresistance and considers current research on the potential use of phytochemicals to overcome chemoresistance through the modulation of signaling pathways involved in the survival and death of leukemic clonal cells and/or leukemic stem cells. Phytochemicals from traditional Chinese medicine, namely baicalein, chrysin, wogonin (constituents of Scutellaria baicalensis; huáng qín; ), curcumin (a constituent of Curcuma longa, jiang huáng, ), and resveratrol (a constituent of Polygonum cuspidatum; hu zhàng, ) have been shown to induce apoptosis in leukemic cell lines, with curcumin and resveratrol also causing cell death via the induction of autophagy (a nonapoptotic pathway). In order to be effective in eliminating LSCs, it is important to target signaling pathways (such as Wnt/ß-catenin, Notch, and Hedgehog). Resveratrol has been reported to induce apoptosis in leukemic cells through the inhibition of the Notch and Sonic hedgehog signaling pathways, therefore showing potential to affect LSCs. While these findings are of interest, there is a lack of reported research on the modulatory effect of phytochemicals on the autophagic cell death pathway in leukemia, and on the signaling pathways involved in the maintenance of LSCs, highlighting the need for further work in these areas.
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Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Leucemia/tratamiento farmacológico , Fitoquímicos/uso terapéutico , Animales , Médula Ósea/anatomía & histología , Humanos , Nicho de Células MadreRESUMEN
Since arsenic trioxide was first approved as the front line therapy for acute promyelocytic leukemia 25 years ago, its anti-cancer properties for various malignancies have been under intense investigation. However, the clinical successes of arsenic trioxide in treating hematological cancers have not been translated to solid cancers. This is due to arsenic's rapid clearance by the body's immune system before reaching the tumor site. Several attempts have henceforth been made to increase its bioavailability toward solid cancers without increasing its dosage albeit without much success. This review summarizes the past and current utilization of arsenic trioxide in the medical field with primary focus on the implementation of nanotechnology for arsenic trioxide delivery to solid cancer cells. Different approaches that have been employed to increase arsenic's efficacy, specificity and bioavailability to solid cancer cells were evaluated and compared. The potential of combining different approaches or tailoring delivery vehicles to target specific types of solid cancers according to individual cancer characteristics and arsenic chemistry is proposed and discussed.
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Arsenic trioxide (ATO) has been used successfully to treat acute promyelocytic leukaemia, and since this discovery, it has also been researched as a possible treatment for other haematological and solid cancers. Even though many positive results have been found in the laboratory, wider clinical use of ATO has been compromised by its toxicity at higher concentrations. The aim of this study was to explore an improved method for delivering ATO using liposomal nanotechnology to evaluate whether this could reduce drug toxicity and improve the efficacy of ATO in treating human papillomavirus (HPV)-associated cancers. HeLa, C33a, and human keratinocytes were exposed to 5 µm of ATO in both free and liposomal forms for 48 h. The stability of the prepared samples was tested using inductively coupled plasma optical emission spectrometer (ICP-OES) to measure the intracellular arsenic concentrations after treatment. Fluorescent double-immunocytochemical staining was carried out to evaluate the protein expression levels of HPV-E6 oncogene and caspase-3. Cell apoptosis was analysed by flow cytometry. Results showed that liposomal ATO was more effective than free ATO in reducing protein levels of HPV-E6 and inducing cell apoptosis in HeLa cells. Moreover, lower toxicity was observed when liposomal-delivered ATO was used. This could be explained by lower intracellular concentrations of arsenic. The slowly accumulated intracellular ATO through liposomal delivery might act as a reservoir which releases ATO gradually to maintain its anti-HPV effects. To conclude, liposome-delivered ATO could protect cells from the direct toxic effects induced by higher concentrations of intracellular ATO. Different pathways may be involved in this process, depending on local architecture of the tissues and HPV status.
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OBJECTIVE: To investigate the biochemical relationship between follicular/oocyte maturity and follicular inhibins and activin levels. DESIGN: Prospective study. SETTING: Research laboratory in university hospital. PATIENT(S): Thirty-five women undertook IVF/ICSI program. INTERVENTION(S): Individual follicular fluid aspirations, oocyte isolation, follicular fluid storage. MAIN OUTCOME MEASURE(S): Inhibin A, inhibin B, and activin A concentrations, oocyte retrieval, and fertility outcome. RESULT(S): Inhibin A, inhibin B, and activin A concentrations varied from 7.9 to 436 ng/mL, 9.7 to 786 ng/mL, and 1.7 to 267.9 ng/mL, respectively. There was no change of inhibin A concentrations, whereas inhibin B and activin A concentrations dropped dramatically as the follicles enlarged. Total follicular content of inhibin A and activin A increased, and inhibin B remained constant. Both inhibin A and inhibin B levels were significantly higher in those follicles from which an oocyte could be recovered, but they did not differ with respect to subsequent oocyte fertilization. CONCLUSION(S): Inhibin A is actively produced throughout follicular growth to retain a set concentration. In contrast, inhibin B appears not to be actively produced, and the concentration drops as follicles enlarge. Activin A concentrations also decrease, but there is some extra synthesis. Higher levels of inhibin A and B are associated with oocyte presence but not with fertilization rates.
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Activinas/análisis , Fertilización In Vitro/estadística & datos numéricos , Líquido Folicular/química , Infertilidad/diagnóstico , Infertilidad/epidemiología , Subunidades beta de Inhibinas/análisis , Inhibinas/análisis , Evaluación de Resultado en la Atención de Salud/métodos , Folículo Ovárico/citología , Adulto , Biomarcadores/análisis , Femenino , Humanos , Infertilidad/terapia , Pronóstico , Reino Unido/epidemiologíaRESUMEN
Oxidative damage is implicated in the pathogenesis of a number of diseases. Scientific research shows positive links between accumulated free-radical damage and age-related diseases such as atherosclerosis, Alzheimer, and osteoarthritis. There are reports that plant-derived phenolic compounds such as flavonoids have antioxidant properties capable of reducing the risk of developing these diseases. This work aims to evaluate the antioxidant activity of selected medicinal plants traditionally used by herbalists, in particular for the treatment of arthritis, with a view to developing a formula for treating age and age-related diseases. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses of each plant confirmed the presence of a number of flavonoids reported in the literature, as well as unidentified compounds. The antioxidant activities of these plants were determined by DPPH (= '1,1-diphenyl-2-picryl-hydrazyl') radical scavenging, and by inhibition of linoleic acid peroxidation. All the crude plant extracts showed marked antioxidant activities in both assays. The extracts' inhibitory effects on linoleic acid peroxidation was concentration-dependent, with the highest activity shown at 0.1% (w/v). These results suggest that the phenolic compounds, particularly the flavonoids, may, in part, be responsible for the antioxidant activity of traditional plant extracts.