RESUMO
Abstract Poorly water-soluble drugs, such as the antifungal drug griseofulvin (GF), exhibit limited bioavailability, despite their high membrane permeability. Several technological approaches have been proposed to enhance the water solubility and bioavailability of GF, including micellar solubilization. Poloxamers are amphiphilic block copolymers that increase drug solubility by forming micelles and supra-micellar structures via molecular self-association. In this regard, the aim of this study was to evaluate the water solubility increment of GF by poloxamer 407 (P407) and its effect on the antifungal activity against three Trichophyton mentagrophytes and two T. rubrum isolates. The GF water solubility profile with P407 revealed a non-linear behavior, well-fitted by the sigmoid model of Morgan-Mercer-Flodin. The polymer promoted an 8-fold increase in GF water solubility. Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and 2D nuclear magnetic resonance (NMR Roesy) spectroscopy suggested a GF-P407 interaction, which occurs in the GF cyclohexene ring. These results were supported by an increase in the water solubility of the GF impurities with the same molecular structure. The MIC values recorded for GF ranged from 0.0028 to 0.0172 mM, except for T. Mentagrophytes TME34. Notably, the micellar solubilization of GF did not increase its antifungal activity, which could be related to the high binding constant between GF and P407.
Assuntos
Solubilidade , Análise Espectral/métodos , Trichophyton/classificação , Poloxâmero/análogos & derivados , Griseofulvina/agonistas , Preparações Farmacêuticas/administração & dosagem , Disponibilidade Biológica , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Antifúngicos/administração & dosagemRESUMO
The biological properties of Achyrocline satureioides have been mostly ascribed to its major flavonoids quercetin (QCT), luteolin (LUT), and 3-O-methylquercetin (3OMQ). The present study aimed to optimize the extraction by dynamic maceration of the major phenolic compounds in order to obtain in a subsequent step a flavonoid-enriched fraction (FEF) using high performance countercurrent chromatography (HPCCC). A 3-level Box-Behnken design (BBD) was applied to maximize the extraction of the substances, using the plantâ:âsolvent ratio (X1 ), extraction time (X2 ), and ethanol concentration (X3 ) as factors. One-step HPCCC semipreparative separation with a solvent system composed of hexaneâ:âethyl acetateâ:âmethanolâ:âwater (0.9â:â0.9â:â0.8â:â1.0, v/v) was employed to obtain the FEF. The second-order polynomial model was able to fit the experimental data adequately. The linear and quadratic terms of X3 were the most significant factors that affected all the responses. The positive linear term of X3 indicated a substantial increase in extraction yield, while the negative quadratic term showed a nonlinear tendency. Linear terms of X1 suggested a tendency to solvent saturation, except for QCT. The terms of X2 did not affect the responses substantially. The HPCCC method was found to be efficient and rapid for separating the FEF with 71% (w/w) flavonoid content. Overall, the developed extraction procedure coupled with HPCCC proved to be efficient for obtaining an enriched fraction with a very high content of flavonoids from A. satureioides.
Assuntos
Achyrocline/química , Distribuição Contracorrente/métodos , Flavonoides/isolamento & purificação , Extratos Vegetais/isolamento & purificaçãoRESUMO
ABSTRACT Griseofulvin (GF) and terbinafine (TF) are commonly used drugs to treat dermatophytosis, a fungal infection of the skin. Today there is an increase in drug resistance to these antifungals which highlight the need for alternative synergistic therapies. Minimum Inhibitory Concentration (MIC) of GF and TF were determined against fungi clinical isolates from local hospitals with values ranging 0.03-2.0 µg mL-1 and 0.24-4.0 µg mL-1, respectively. A checkboard test was used to determine the combination of GF:TF which could induce an additive effect against the fungi isolates Multidrug-resistant isolates showed susceptibility after treatment with 16:2 µg mL-1 GF:TF. An MTT assay further verified that GF and TF combinations have greater additive effect against pathological and multidrug-resistant isolates than antifungals alone. Herein we disclose GF:TF combinations that could constitute as a possible new anti-dermatophyte therapy.
Assuntos
Técnicas In Vitro/métodos , Combinação de Medicamentos , Griseofulvina/análise , Tinha/patologia , Testes de Sensibilidade Microbiana/instrumentação , Dermatomicoses/classificação , Arthrodermataceae/classificação , Antifúngicos/análiseRESUMO
CONTEXT: Uncaria tomentosa D.C. (Rubiaceae) has several biological activities, including activity against resistant Candida strains. The synergistic interaction with terbinafine or fluconazole can be an important alternative to overcome this resistance. OBJECTIVES: The potential synergy between a water insoluble fraction (WIF) from Uncaria tomentosa bark and the antifungals terbinafine (TRB) and fluconazole (FLZ) against non-Candida albicans resistant strains was investigated. MATERIALS AND METHODS: TRB and FLZ, alone and combined with WIF, were tested by the checkerboard procedure using the micro-dilution technique against seven isolates of Candida glabrata and C. krusei. The molecular interactions occurring outside the cell wall were evaluated by scanning electron microscopy, Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) analysis. RESULTS: The checkerboard inhibitory assay demonstrated synergy for WIF:TRB and WIF:FLZ combinations, respectively. The best synergistic cell damage was demonstrated unequivocally for the associations of WIF and TRB (1.95:4.0 µg/mL) and WIF and FLZ (1.95:8.0 µg/mL). The comparison of the FT-IR spectra of the antifungal alone, and in combination with WIF, allows recognizing clear differences in 3000, 1600, 1400, and 700-800 cm-1 bands. Additionally, modifications on TRB and FLZ thermograms were clearly noticed after their combination with WIF. CONCLUSIONS: DSC and infrared analysis demonstrated intermolecular interactions between WIF and either TRB or FLZ. Hence, quite likely the synergistic effect is related to interaction events occurring outside the cell wall between antifungal and cat's claw proanthocyanidins. A direct action on the cell wall is suggested, without connection with the ABC efflux pump mechanism.
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Unha-de-Gato/química , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Naftalenos/farmacologia , Extratos Vegetais/farmacologia , Antifúngicos/isolamento & purificação , Varredura Diferencial de Calorimetria , Candida/crescimento & desenvolvimento , Candida/ultraestrutura , Parede Celular/efeitos dos fármacos , Parede Celular/ultraestrutura , Sinergismo Farmacológico , Microscopia Eletrônica de Varredura , Fitoterapia , Casca de Planta , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Terbinafina , Água/químicaRESUMO
Uncaria tomentosa is widely used in folk medicine for the treatment of numerous diseases, such as urinary tract disease. Hemorrhagic cystitis (HE) is an inflammatory condition of the bladder associated with the use of anticancer drugs such as cyclophosphamide (CYP). Sodium 2-mercaptoethanesulfonate (Mesna) has been used to prevent the occurrence of HE, although this compound is not effective in established lesions. It has been demonstrated that the purinergic system is involved in several pathophysiological events. Among purinergic receptors, P2X7 deserves attention because it is involved in HE induced by CYP and, therefore, can be considered a therapeutic target. The objective of this study was to investigate the potential therapeutic effect of the quinovic acid glycosides purified fraction (QAPF) from U. tomentosa in the mouse model of CYP-induced HE. Pretreatment with QAPF not only had a protective effect on HE-induced urothelial damage (edema, hemorrhage and bladder wet weight) but was also able to control visceral pain, decrease IL-1ß levels and down-regulates P2X7 receptors, most likely by inhibit the neutrophils migration to the bladder. This research clearly demonstrates the promising anti-inflammatory properties of QAPF, supporting its use as complementary therapy. QAPF represents a promising therapeutic option for this pathological condition.
Assuntos
Unha-de-Gato/química , Ciclofosfamida/efeitos adversos , Cistite/complicações , Cistite/tratamento farmacológico , Glicosídeos/uso terapêutico , Hemorragia/tratamento farmacológico , Triterpenos/uso terapêutico , Animais , Comportamento Animal , Cistite/induzido quimicamente , Cistite/fisiopatologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Hemorragia/induzido quimicamente , Hemorragia/complicações , Hemorragia/fisiopatologia , Interleucina-1beta/metabolismo , Masculino , Camundongos , Nociceptividade/efeitos dos fármacos , Peroxidase/metabolismo , Substâncias Protetoras/farmacologia , Substâncias Protetoras/uso terapêutico , Receptores Purinérgicos P2X7/metabolismo , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Bexiga Urinária/efeitos dos fármacos , Vísceras/efeitos dos fármacosRESUMO
Bladder cancer is the second most prevalent malignancy in the genitourinary tract and remains a therapeutic challenge. In the search for new treatments, researchers have attempted to find compounds with low toxicity. With this goal in mind, Uncaria tomentosa is noteworthy because the bark and root of this species are widely used in traditional medicine and in adjuvant therapy for the treatment of numerous diseases. The objective of this study was to investigate the antitumor effect of one purified bioactive fraction of U.tomentosa bark on cell proliferation in two human bladder cancer cell lines, T24 and RT4. Quinovic acid glycosides purified fraction (QAPF) of U.tomentosa decreased the growth and viability of both T24 and RT4 cell lines. In T24 cells, QAPF induced apoptosis by activating caspase-3 and NF-κB. Further study showed that this fraction does not induce cell cycle arrest and does not alter PTEN and ERK levels. In conclusion, we demonstrated that QAPF of U.tomentosa has a potent inhibitory effect on the growth of human bladder cancer cell lines by inducing apoptosis through modulation of NF-κB, and we suggest that QAPF may become a potential therapeutic agent for the prevention and/or treatment of this cancer.
Assuntos
Apoptose/efeitos dos fármacos , Unha-de-Gato/química , Glicosídeos/farmacologia , Triterpenos/farmacologia , Neoplasias da Bexiga Urinária/patologia , Linhagem Celular Tumoral , Humanos , Triterpenos/químicaRESUMO
Uncaria tomentosa have been used to treat viral diseases such as herpes due to multiple pharmacological effects, but its therapeutic efficacy against this virus have not been reported yet. Thus, in vitro antiherpetic activity of hydroethanolic extract from barks, purified fractions of quinovic acid glycosides and oxindole alkaloids was evaluated by plaque reduction assay, including mechanistic studies (virucidal, attachment and penetration action). Once exposure to physical agents might lead to reactivation of the herpetic infection, antimutagenic effect (pre-, simultaneous and post-treatment protocols) was also evaluated by Comet assay. The antiherpetic activity from the samples under investigation seemed to be associated with the presence of polyphenols or their synergistic effect with oxindole alkaloids or quinovic acid glycosides, once both purified fractions did not present activity when evaluated alone. Inhibition of viral attachment in the host cells was the main mechanism of antiviral activity. Although both purified fractions displayed the lowest antimutagenic activity in pre and simultaneous treatment, they provided a similar effect to that of cat's claw hydroethanolic extract in post-treatment. Given that purified fractions may result in a reduced antiherpetic activity, the use of cat's claw hydroethanolic extract from barks should be prioritized in order to obtain a synergistic effect.
Assuntos
Antimutagênicos/farmacologia , Antivirais/farmacologia , Unha-de-Gato/química , Herpesviridae/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Chlorocebus aethiops , Herpesviridae/crescimento & desenvolvimento , Células Vero , Ensaio de Placa ViralRESUMO
The antitumor activity of Uncaria tomentosa, a native vine from the Amazonian rainforest, has been ascribed to pentacyclic oxindole alkaloids occurring in its bark. Former studies have shown that this activity, as well as its intensity, depends on whether cat's claw alkaloids occur as original compounds or isomerized derivatives. This work addresses this aspect, using T24 and RT4 human bladder cancer cell lines for that purpose. Bark samples were extracted by dynamic maceration, prepurified with cross-linked polyvinylpyrrolidone and properly fractioned by an ion exchange process to obtain an oxindole alkaloid purified fraction. Alkaloid isomerization was induced by heating it under reflux at 85 °C. Samples collected after 5, 15, and 45 min of heating were analyzed by HPLC-PDA, freeze-dried at once, and separately assayed using the non-isomerized purified fraction for comparison purposes. The latter showed significant and dose-dependent cytotoxic activity against both T24 and RT4 cancer cell lines (IC50: 164.13 and 137.23 µg/mL, respectively). However, results for both cell lines were equivalent to those observed for isomerized samples (p > 0.05). The alkaloid isomerization induced by the incubation conditions (buffered medium pH 7.4 and temperature 37 °C) helps to explain the similar results obtained from non-isomerized and isomerized samples. Mitraphylline, speciophylline, uncarine F, and, to a lesser degree, pteropodine were more susceptible to isomerization under the incubation conditions. Thus, the alkaloid profile of all fractions and their cytotoxic activities against T24 and RT4 human bladder cancer cell lines are determined to a large extent by the incubation conditions.
Assuntos
Antineoplásicos Fitogênicos/química , Unha-de-Gato/química , Alcaloides Indólicos/química , Indóis/química , Fitoterapia , Extratos Vegetais/química , Neoplasias da Bexiga Urinária/tratamento farmacológico , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Tumoral , Temperatura Alta , Humanos , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/uso terapêutico , Indóis/isolamento & purificação , Indóis/uso terapêutico , Isomerismo , Oxindóis , Casca de Planta , Extratos Vegetais/uso terapêuticoRESUMO
The triterpene chikusetsusaponin IVa was isolated from the fruit of Ilex paraguariensis. Using biochemical and pharmacological methods, we demonstrated that chikusetsusaponin IVa (1) prolongs the recalcification time, prothrombin time, activated partial thromboplastin time, and thrombin time of normal human plasma in a dose-dependent manner, (2) inhibits the amidolytic activity of thrombin and factor Xa upon synthetic substrates S2238 and S2222, (3) inhibits thrombin-induced fibrinogen clotting (50% inhibition concentration, 199.4 ± 9.1 µM), and (4) inhibits thrombin- and collagen-induced platelet aggregation. The results also indicate that chikusetsusaponin IVa preferentially inhibits thrombin in a competitive manner (K(i)=219.6 µM). Furthermore, when administered intravenously to rats, chikusetsusaponin IVa inhibited thrombus formation in a stasis model of venous thrombosis, although it did not induce a significant bleeding effect. Chikusetsusaponin IVa also prolonged the ex vivo activated partial thromboplastin time. Altogether, these data suggest that chikusetsusaponin IVa exerts antithrombotic effects, including minor hemorrhagic events. This appears to be important for the development of new therapeutic agents.
Assuntos
Fibrinolíticos/farmacologia , Ilex paraguariensis/química , Ácido Oleanólico/análogos & derivados , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Animais , Tempo de Sangramento , Coagulação Sanguínea/efeitos dos fármacos , Fator Xa/metabolismo , Inibidores do Fator Xa , Hemostasia/efeitos dos fármacos , Humanos , Modelos Lineares , Masculino , Ácido Oleanólico/farmacologia , Tempo de Tromboplastina Parcial , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Ratos , Ratos Wistar , Trombina/antagonistas & inibidores , Trombina/metabolismo , Tempo de TrombinaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Ilex paraguariensis A. St. Hilaire (mate) has traditionally been used in several South American countries to prepare tea-like beverages having stimulant effects on the CNS and appetite. In recent years, however, mate preparations have been recommended putatively as an appetite suppressant and slimming remedy. Moreover, studies carried out on either normal or diet-induced obese rats treated with mate extracts revealed anti-obesity and satiety effects, thus refuting ethnopharmacological data. In this work, the effect of mate on the intra-abdominal and epididymal fat, and glucose oxidation levels after oral administration in male Wistar rats, was studied using crude extract from leaves, unripe fruits, and a chemically well-defined purified saponin fraction (MSF). MATERIAL AND METHODS: Saponin, polyphenol and methylxanthine contents in MSF were analyzed by HPLC-PDA and UPLC/Q-TOF-MS. Crude extracts from mate leaves (LAE) and unripe fruits (FHE) were assayed for comparison purposes. Male Wistar rats fed with standard diet and water ad libitum were used as the control group. RESULTS: The fat weight and both liver and adipose glucose oxidation were reduced significantly by MSF (35, 90 and 60%, respectively), while LAE and FHE were less active. Also, a significant lowering of the blood triglycerides level was observed in rats treated with MSF and LAE. All creatinine, urea, and transaminase plasma levels remained unaffected no matter what mate preparation was considered. It is also worth pointing out that the glucose blood level was increased after treatment with FHE. This finding did not correlate either with the content of methylxanthines, polyphenols or saponins. CONCLUSION: A reduction in both visceral fat weight and glucose oxidation of hepatic and adipose tissue in healthy rats fed with a standard diet could be ascribed to a purified mate saponin fraction from unripe fruits. These findings agree with former studies carried out with crude mate extracts and also suggest their potential use as an anti-obesity preparation. Nonetheless, further in vivo experiments are still required to corroborate its effect on human beings.