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The increase of the burden of dengue and chikungunya and the relative failure of traditional vector control strategies have highlighted the need to develop new control methods. RIDL-SIT, a vector control method based on the release of engineered male mosquitoes, has shown promising results from field trials conducted in the Cayman Islands and Brazil. In large scale use, a small proportion of females might be released along with the males. Such females are potential virus vectors; here we investigate the vertical transmission of dengue and chikungunya of homozygous OX513A females.We provided females of OX513A-My1 and a wild type comparator strain with blood meals artificially infected with dengue serotype 1, 2, 3, 4 or chikungunya viruses. For 14 days post-feeding, eggs laid by females were collected. Larvae and their mothers were first tested by qRT-PCR, then by inoculation on cell cultures to search for infectious viral particles. We found no significant difference between the minimum infection rate of OX513A-My1 and wild type females. We also discussed the potential number of females being released, a fraction of the female wild population. Consequently, we conclude that there are no evidence that OX513A-My females, if released into the environment, would cause more harm than their wild counterparts.
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Presence of polyphenolic content in various part of the plant exhibit wide pharmacological activities including antioxidant activity. The present study was designed to evaluate the phenolic contents (total phenols, flavonoid and tannins) and antioxidant properties of ethanolic extracts of flower, leaf, pod, bark and root obtained from Cassia auriculata. Ethanolic extracts of various parts of C. auriculata obtained by sonication extraction techniques are studied for their phenolic contents and DPPH (2,2-diphenyl-1-picrylhydrazine) radical scavenging assay as well as total antioxidant assays using UV visible spectrophotometer. Among the various parts of the plant studied, bark showed significant content of phenolics, flavonoids and tannins followed by the root, leaf, flower and pod. Even bark extract exhibited highest antioxidant capacity in DPPH assay followed by root, leaf, flower and pod with a value of 766.7, 679.3, 644.9, 572.5 and 474.7 mg vitamin C equivalent antioxidant capacity (mg VCEAC)/sample, respectively. In addition, mg VCEAC values obtained from the total antioxidant assay was in the increasing order of bark > root > leaf > flower > pod. Moreover, a strong correlation was also found between phenolic contents and antioxidant values indicating their influence in the found antioxidant activity, hence the bark extract can be employed as an ideal candidate for herbal based pharmaceutical product. Results of the present study also emphasize variation in the chemical composition as well as biological activity ensuring the importance of proper selection of particular part of the plant to evaluate their therapeutic potency.
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Cassia/química , Sequestradores de Radicais Livres/análise , Sequestradores de Radicais Livres/farmacologia , Medicina Tradicional , Fenóis/análise , Fenóis/farmacologia , Estruturas Vegetais/química , Taninos/análise , Taninos/farmacologiaRESUMO
CONTEXT: To date, many findings reveal that most of the modern drugs have the ability to interact with herbal drugs. AIMS: This study was conducted to determine the inhibitory effects of mitragynine on cytochrome P450 2C9, 2D6 and 3A4 activities. METHODS AND MATERIAL: The in vitro study was conducted using a high-throughput luminescence assay. STATISTICAL ANALYSIS: Statistical analysis was conducted using one-way ANOVA and Dunnett's test with P < 0.05 vs. control. The IC50 values were calculated using the GraphPad Prism(®) 5 (Version 5.01, GraphPad Software, Inc., USA). RESULTS: Assessment using recombinant enzymes showed that mitragynine gave the strongest inhibitory effect on CYP2D6 with an IC50 value of 0.45±0.33 mM, followed by CYP2C9 and CYP3A4 with IC50 values of 9.70±4.80 and 41.32±6.74 µM respectively. Positive inhibitors appropriate for CYP2C9, CYP2D6, and CYP3A4 which are sulfaphenazole, quinidine and ketoconazole were used respectively. Vmax values of CYP2C9, CYP2D6 and CYP3A4 were 0.0005, 0.01155 and 0.0137 µM luciferin formed/pmol/min respectively. Km values of CYP2C9, CYP2D6, and CYP3A4 were 32.65, 56.01, and 103.30 µM respectively. Mitragynine noncompetitively inhibits CYP2C9 and CYP2D6 activities with the Ki values of 61.48 and 12.86 µM respectively. On the other hand, mitragynine inhibits CYP3A4 competitively with a Ki value of 379.18 µM. CONCLUSIONS: The findings of this study reveal that mitragynine might inhibit cytochrome P450 enzyme activities, specifically CYP2D6. Therefore, administration of mitragynine together with herbal or modern drugs which follow the same metabolic pathway may contribute to herb-drug interactions.
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We evaluated the phenolic content and antioxidant capacities of pod and seed extracts (in methanol, ethanol, and water) of an underutilized legume, Clitoria fairchildiana (Howard). The antioxidant capacity of the extracts was determined using the ferric reducing antioxidant potential assay, and the free radical-scavenging capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging and ABTS assays. In addition, the total flavonoids, flavonols, and tannin contents were also determined. Overall, the methanol extracts of the pod contained high concentration of phenolics and showed high antioxidant capacities compared to seed extracts. In addition, a positive correlation was found between total phenol and tannin versus antioxidant capacity. Results of the present study indicate pods and seeds of C. fairchildiana to possess rich amount of natural antioxidants, and can be further explored for their possible use as a natural additive in food or in pharmaceutical industries.
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The present study was conducted to examine the effects of sonication treatments (time intervals of 0, 15, 30, 45 and 60 min.) on phenolics and other antioxidant compounds in starfruits extracted in methanol and water. Overall, methanolic extracts exhibited significantly higher extractability, percentage inhibition of DPPH radicals, ferric reducing antioxidant property (FRAP) value, antioxidant capacity, flavonoids, total phenolics and tannins (p < 0.05) compared to control (0 min) and aqueous extracts. Methanolic extract obtained after 30 min of sonication proved to be the best treatment with regard to various parameters evaluated. Results of the present study clearly indicated sonication treatments to be effective in enhancing the antioxidant compounds in starfruit extracts and could be further explored for commercial purposes to benefit the consumers.
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Swietenia mahogani crude methanolic (SMCM) seed extract was investigated for the antifungal activity against Candida albicans which has not been evaluated previously. The antifungal activity was evaluated against C. albicans via disk diffusion, minimum inhibition concentration (MIC), scanning electron microscope (SEM), transmission electron microscope (TEM) and time killing profile. The MIC value of SMCM seed extract is 12.5 mg/ml. The SEM and TEM findings showed there is morphological changes and cytological destruction of C. albicans at the MIC value. Animal model was used to evaluate the in vivo antifungal activity of SMCM seed extract. The colony forming unit (CFU) were calculated per gram of kidney sample and per ml of blood sample respectively for control, curative and ketaconazole treated groups. There was significant reduction for the CFU/ml of blood and CFU/g of kidney. This indicated that the extract was observed to be effective against C. albicans in vitro and in vivo conditions.
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Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Meliaceae/química , Extratos Vegetais/uso terapêutico , Sementes/química , Animais , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Candida albicans/citologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Rim/microbiologia , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Resultado do TratamentoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Mitragyna speciosa Korth (ketum) is widely used in Malaysia as a medicinal agent for treating diarrhea, worm infestations and also acts as an analgesic and antipyretic. AIM: The aim of the study is to determine the acute toxicity of Mitragyna speciosa Korth standardized methanol extract in vivo in 4-weeks-old Sprague-Dawley rats. METHODOLOGY: Rats were orally administrated single dose of 100, 500 and 1000 mg/kg Mitragyna speciosa Korth standardized methanol extract and the control group received 430 mg/kg of morphine orally. There were 10 rats in each group. All animals were sacrificed after 14 days of treatment. Eight parameters were tested: cage side observation, body weight measurement, food and water consumption, blood pressure, absolute and relative organ weight, hematology, biochemical analysis and histopathology, to look for evidence of toxicity. RESULT: No mortality was noted after 14 days of treatment. In general, behavior, food and water consumption, hematological studies and organ weights showed no significant changes. The standardized methanol extraction of Mitragyna speciosa Korth increased rat blood pressure (systolic: 147.4+/-1.01, 131.64+/-4.94 and 137.8+/-4.46) after an hour of 100, 500 and 1000 mg/kg doses, respectively. Biochemical studies showed significant elevation of ALT, AST, albumin, triglycerides, cholesterol and albumin (p>0.05), at all levels of doses. But, nephrotoxicity evidenced by elevated creatinine was seen only at a dose of 1000 mg/kg. Histological examination showed congestion of sinusoids, hemorrhage hepatocytes, fatty change, centrilobular necrosis and increased number of Kuppfer cells in the liver of all Mitragyna speciosa Korth standardized methanol extract treated groups. CONCLUSION: Oral administration of standardized methanolic extraction of Mitragyna speciosa Korth resulted in increasing rat blood pressure after an hour of drug administration. The highest dose of extract also induced acute severe hepatotoxicity and mild nephrotoxicity. However, Mitragyna speciosa Korth shows no effects on body weight, food and water consumption, absolute and relative organ weight and also hematology parameters.
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Pressão Sanguínea/efeitos dos fármacos , Creatinina/sangue , Lipídeos/sangue , Fígado/efeitos dos fármacos , Mitragyna/toxicidade , Extratos Vegetais/toxicidade , Albumina Sérica/metabolismo , Administração Oral , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Colesterol/sangue , Fígado/enzimologia , Fígado/patologia , Masculino , Folhas de Planta , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangueRESUMO
AIM: The aim of this study was to prepare a lipid-based self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of a poorly water-soluble compound, buparvaquone (BPQ). METHODS: The solubility of BPQ was determined in various vehicles, and pseudo-ternary phase diagrams were constructed to determine the microemulsion region. A series of formulations with different compositions were selected in the microemulsion region for assessment of self-emulsification time and droplet size. The optimized SMEDDS formulation was used for in vitro dissolution and pharmacokinetic studies in rabbits. RESULTS: The optimum formulation of SMEDDS consisted of Capryol 90 (9.82%), Cremophor EL (70.72%), Labrasol (17.68%), and BPQ (1.78%). Emulsification time and the mean droplet size were found to be 1 minute and 18.0 +/- 0.25 nm, respectively, for the optimum formulation. The cumulative percentage of drug released in 90 minutes was 100% in both SGF and SIF. The calculated absolute oral bioavailability for BPQ was found to be 40.10%. CONCLUSIONS: The optimum SMEDDS formulation was increased the rate and extent of absorption of BPQ. The formulation is suitable for oral administration of BPQ. It would be useful to conduct efficacy studies of BPQ in diseased animal models and subsequently for toxicokinetics studies.
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Sistemas de Liberação de Medicamentos/métodos , Emulsificantes/química , Naftoquinonas/química , Animais , Química Farmacêutica , Avaliação Pré-Clínica de Medicamentos/métodos , Emulsificantes/administração & dosagem , Emulsificantes/sangue , Masculino , Naftoquinonas/administração & dosagem , Naftoquinonas/sangue , CoelhosRESUMO
Cinnomomum iners standardized leaves methanolic extract (CSLE) was subjected to analgesic, toxicity and phytochemical studies. The analgesic activity of CSLE was evaluated using formalin, hot plate and tail flick tests at doses of 100, 200 and 500 mg/kg. CSLE showed significant activity (P < 0.05) in the formalin model (late phase) on the rats at doses of 200 and 500 mg/kg. However, CSLE did not show activity in the hot plate and tail flick tests. The results obtained suggest that CSLE acts peripherally to relieve pain. For the toxicity study, CSLE was orally administered to the Swiss albino mice according to the Organization for Economic Co-Operation and Development (OECD) guideline 423. There was no lethality or toxic symptoms observed for all the tested doses throughout the 14-day period. Phytochemical screening of CSLE showed the presence of cardiac glycoside, flavonoid, polyphenol, saponin, sugar, tannin and terpenoid.
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AIM: This study was designed to evaluate the phenolic content and antioxidant activity of ethanolic extracts from T. catappa leaves obtained by different intervals of sonication. METHODS: Three commonly used methods were followed to evaluate phenolic content and four in vitro methods like 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assay, ferric reducing antioxidant potency (FRAP), and total antioxidant capacity assays for measuring the antioxidant activities. Antioxidant values of these assays were expressed in terms of milligrams vitamin C equivalent (VCE) antioxidant activities. RESULTS: This study showed that extract obtained with 40 minutes of sonication possessed significant (P < 0.05) polyphenolic contents compared to 20 and 60 minutes sonication and control (24 hour maceration). Moreover, sonication of T. catappa leaf above 40 minutes was found to be unsuitable for extracting out phenolic contents. Even the results of antioxidant assays showed that 40 minutes of the sonicated extract exhibited significant (P < 0.05) VCE values compared to extracts obtained at different intervals of sonication and control. CONCLUSIONS: In sonication extraction method 40 minutes is an ideal time to obtain extract enriched with high polyphenolic content with good antioxidant activity from T. catappa leaves.
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AIM OF THE STUDY: Typhonium flagelliforme is an indigenous plant of Malaysia and is used by the local communities to treat cancer. This study aims to identify the chemical constituents of Typhonium flagelliforme particularly those which have antiproliferative properties towards human cancer cell lines. MATERIALS AND METHODS: Purification of the chemical constituents by various chromatographic procedures was guided by the antiproliferative activity. Identification of the chemical constituents was carried out by various spectroscopic techniques including high resolution MS and NMR. The antiproliferative activity was assayed using MTT on NCI-H23 (lung cancer) and HS578T (breast cancer) cell lines. Microscopic observation and DeadEnd colourimetric TUNEL assay was used to identify the apoptotic mode of cell death. RESULTS AND CONCLUSION: Four pheophorbide related compounds, namely pheophorbide-a, pheophorbide-a', pyropheophorbide-a and methyl pyropheophorbide-a were identified in the most active fraction, D/F19. These constituents exhibited antiproliferative activity against cancer cells and the activity increased following photoactivation. However, the greater antiproliferative activity exhibited by D/F19 itself compared to the pheophorbides and its other subfractions suggests some form of synergistic action between the constituents. The inhibitory effect of D/F19 and the pheophorbides was apoptotic in the absence of light. Other chemical constituents that have been identified in this study include hexadecanoic acid, oleic acid, linoleic acid, linolenic acid, campesterol, stigmasterol and beta-sitosterol. Most of the chemical constituents identified in this plant have not been reported previously.
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Antineoplásicos Fitogênicos/química , Araceae , Extratos Vegetais/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular Tumoral , Humanos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologiaRESUMO
Clitoria ternatea is known for its antimicrobial activity but the antifungal effects of leaf extract on growth and morphogenesis of Aspergillus niger have not been observed. The extract showed a favorable antifungal activity against A. niger with a minimum inhibition concentration 0.8 mg/mL and minimum fungicidal concentration 1.6 mg/mL, respectively. The leaf extract exhibited considerable antifungal activity against filamentous fungi in a dose-dependent manner with 0.4 mg/mL IC50 value on hyphal growth of A. niger. The main changes observed under scanning electron microscopy after C. ternatea extract treatment were loss of cytoplasm in fungal hyphae and the hyphal wall and its diameter became markedly thinner, distorted, and resulted in cell wall disruption. In addition, conidiophore alterations were also observed when A. niger was treated with C. ternatea leaf extract.
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Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Clitoria/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Folhas de Planta/química , Aspergillus niger/citologia , Aspergillus niger/crescimento & desenvolvimento , Divisão Celular/efeitos dos fármacos , Citoplasma/ultraestrutura , Hifas/ultraestrutura , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Morfogênese/efeitos dos fármacosRESUMO
With the expanded use of the combination of artesunate (AS) and amodiaquine (AQ) for the treatment of falciparum malaria and the abundance of products on the market, comes the need for rapid and reliable bioanalytical methods for the determination of the parent compounds and their metabolites. While the existing methods were developed for the determination of either AS or AQ in biological fluids, the current validated method allows simultaneous extraction and determination of AS and AQ in human plasma. Extraction is carried out on Supelclean LC-18 extraction cartridges where AS, its metabolite dihydroartemisinin (DHA) and the internal standard artemisinin (QHS) are separated from AQ, its metabolite desethylamodiaquine (DeAQ) and the internal standard, an isobutyl analogue of desethylamodiaquine (IB-DeAQ). AS, DHA and QHS are then analysed using Hypersil C4 column with acetonitrile-acetic acid (0.05M adjusted to pH 5.2 with 1.00M NaOH) (42:58, v/v) as mobile phase at flow rate 1.50ml/min. The analytes are detected with an electrochemical detector operating in the reductive mode. Chromatography of AQ, DeAQ and IB-DeAQ is carried out on an Inertsil C4 column with acetonitrile-KH(2)PO(4) (pH 4.0, 0.05M) (11:89, v/v) as mobile phase at flow rate 1.00ml/min. The analytes are detected by an electrochemical detector operating in the oxidative mode. The recoveries of AS, DHA, AQ and DeAQ vary between 79.1% and 104.0% over the concentration range of 50-1400ng/ml plasma. The accuracies of the determination of all the analytes are 96.8-103.9%, while the variation for within-day and day-to-day analysis are <15%. The lower limit of quantification for all the analytes is 20ng/ml and limit of detection is 8ng/ml. The method is sensitive, selective, accurate, reproducible and suited particularly for pharmacokinetic study of AS-AQ drug combination and can also be used to compare the bioavailability of different formulations, including a fixed-dose AS-AQ co-formulation.
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Amodiaquina/análogos & derivados , Artemisininas/sangue , Artemisininas/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Extração em Fase Sólida/métodos , Administração Oral , Amodiaquina/administração & dosagem , Amodiaquina/sangue , Amodiaquina/farmacocinética , Amodiaquina/farmacologia , Antimaláricos/administração & dosagem , Antimaláricos/sangue , Antimaláricos/farmacocinética , Artemisininas/administração & dosagem , Artemisininas/farmacocinética , Artesunato , Combinação de Medicamentos , Estabilidade de Medicamentos , HumanosRESUMO
The present study was designed to evaluate the antibacterial activities of Swietenia mahagoni crude methanolic (SMCM) seed extract. The antimicrobial activity of the oily extract against Gram-positive, Gram-negative, yeast and fungus strains was evaluated based on the inhibition zone using disc diffusion assay, minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) values. The crude extract was subjected to various phytochemicals analysis. The demonstrated qualitative phytochemical tests exhibited the presences of common phytocompounds including alkaloids, terpenoids, antraquinones, cardiac glycosides, saponins, and volatile oils as major active constituents. The SMCM seed extract had inhibitory effects on the growth of Candida albicans, Staphylococcus aureus, Pseudomonas aeroginosa, Streptococcus faecalis and Proteus mirabillase and illustrated MIC and MBC values ranging from 25 mg/ml to 50 mg/ml.
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Antibacterianos , Antifúngicos , Meliaceae/química , Extratos Vegetais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Descoberta de Drogas , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Controle Biológico de Vetores , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Sementes/químicaRESUMO
Copolyesters of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) were produced by Cupriavidus sp. (USMAA2-4) (DSM 19379) from carbon sources of 1,4-butanediol and gamma-butyrolactone. The composition of copolyesters produced varied from 0 to 45 mol% 4HB, depending on the combination of carbon sources supplied. The P(3HB-co-4HB) films containing Mitragyna speciosa crude extract were prepared with the ratio varying from 10 to 40% (w/w). The in vitro crude extract release of the films was studied in 0.1M phosphate buffer (pH 7.4) at 37 degrees C. Although the release rate was slow, it was maintained at a constant rate. This suggests that the crude extract release was due to the polymer degradation because the amount of crude extract released was consistent. The amount of degradation was based on the films' dry weight loss, decrease in molecular weight and surface morphology changes. The degradation rate increased with the 4HB content. This showed that the polymer degradation is dependant on the molecular weight, crystallinity, thermal properties and water permeability. The different drug loading ratio which led to surface morphology changes also gave an effect on polymer degradation.
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Hidroxibutiratos/química , Mitragyna/química , Extratos Vegetais/metabolismo , Poliésteres/química , Cristalização , Peso Molecular , Permeabilidade , Temperatura , Água/metabolismoRESUMO
AIM OF THE STUDY: Typhonium flagelliforme (Lodd.) Blume (Araceae) is a Malaysian plant used locally to combat cancer. In order to evaluate its antiproliferative activity in vitro and to possibly identify the active chemical constituents, a bioactivity guided study was conducted on the extracts of this plant. MATERIALS AND METHODS: The active extracts of Typhonium flagelliforme were fractionated by flash column chromatography and each fraction was evaluated for antiproliferative activity using MTT assay. The apoptotic effect of the active fraction was determined microscopically and by using TUNEL colorimetric assay. GC-MS and NMR were used to determine the chemical constituents of this active fraction. RESULTS: Several fractions of the hexane and dichloromethane extracts were found to inhibit the growth of NCI-H23 non-small cell lung carcinoma cell line significantly, with IC(50)<15 microg/ml. However, most of these active fractions were also found to inhibit the growth of non-tumorigenic BALB/c 3T3 mouse fibroblast cell line except for fraction 21 of the dichloromethane extract (D/F21). This particular fraction was not only less cytotoxic to the non-tumorigenic cells, where the IC(50) was 48.6 microg/ml compared to IC(50) 7.5 microg/ml for NCI-H23, but it was also found to induce apoptosis in the cancer cell line. GC-MS analysis revealed that D/F21 contains hexadecanoic acid, 1-hexadecene, phytol and a derivative of phytol. The presence of non-saturated fatty acids in this fraction was confirmed by nuclear magnetic resonance spectroscopy. CONCLUSIONS: D/F21 was found to be the active and cancer cell line specific fraction of Typhonium flagelliforme. Its major chemical constituents had been determined spectroscopically.
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Antineoplásicos Fitogênicos/farmacologia , Araceae/química , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Células 3T3 BALB , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Malásia , Medicina Tradicional do Leste Asiático , Camundongos , Extratos Vegetais/administração & dosagemRESUMO
A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 microL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient>or=0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ.
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Cromatografia Líquida de Alta Pressão/métodos , Naftoquinonas/sangue , Naftoquinonas/farmacocinética , Extração em Fase Sólida/métodos , Espectrofotometria Ultravioleta/métodos , Animais , Antiprotozoários/sangue , Antiprotozoários/química , Antiprotozoários/farmacocinética , Humanos , Estrutura Molecular , Naftoquinonas/química , Coelhos , Reprodutibilidade dos TestesRESUMO
The combination of two sensitive, selective and reproducible reversed phase liquid chromatographic (RP-HPLC) methods was developed for the determination of artesunate (AS), its active metabolite dihydroartemisinin (DHA) and mefloquine (MQ) in human plasma. Solid phase extraction (SPE) of the plasma samples was carried out on Supelclean LC-18 extraction cartridges. Chromatographic separation of AS, DHA and the internal standard, artemisinin (QHS) was obtained on a Hypersil C4 column with mobile phase consisting of acetonitrile-0.05 M acetic acid adjusted to pH 5.2 with 1.0M NaOH (42:58, v/v) at the flow rate of 1.50 ml/min. The analytes were detected using an electrochemical detector operating in the reductive mode. Chromatography of MQ and the internal standard, chlorpromazine hydrochloride (CPM) was carried out on an Inertsil C8-3 column using methanol-acetonitrile-0.05 M potassium dihydrogen phosphate adjusted to pH 3.9 with 0.5% orthophosphoric acid (50:8:42, v/v/v) at a flow rate of 1.00 ml/min with ultraviolet detection at 284 nm. The mean recoveries of AS and DHA over a concentration range of 30-750 ng/0.5 ml plasma and MQ over a concentration of 75-1500 ng/0.5 ml plasma were above 80% and the accuracy ranged from 91.1 to 103.5%. The within-day coefficients of variation were 1.0-1.4% for AS, 0.4-3.4% for DHA and 0.7-1.5% for MQ. The day-to-day coefficients of variation were 1.3-7.6%, 1.8-7.8% and 2.0-3.4%, respectively. Both the lower limit of quantifications for AS and DHA were at 10 ng/0.5 ml and the lower limit of quantification for MQ was at 25 ng/0.5 ml. The limit of detections were 4 ng/0.5 ml for AS and DHA and 15 ng/0.5 ml for MQ. The method was found to be suitable for use in clinical pharmacological studies.
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Antimaláricos/sangue , Antimaláricos/isolamento & purificação , Técnicas de Química Analítica/métodos , Administração Oral , Adulto , Antimaláricos/administração & dosagem , Antimaláricos/farmacocinética , Artemisininas/administração & dosagem , Artemisininas/sangue , Artemisininas/isolamento & purificação , Artemisininas/farmacocinética , Artesunato , Cromatografia Líquida de Alta Pressão , Combinação de Medicamentos , Estabilidade de Medicamentos , Feminino , Congelamento , Humanos , Masculino , Mefloquina/administração & dosagem , Mefloquina/sangue , Mefloquina/isolamento & purificação , Mefloquina/farmacocinética , Reprodutibilidade dos Testes , Sesquiterpenos/administração & dosagem , Sesquiterpenos/sangue , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacocinética , Fatores de TempoRESUMO
A simple and sensitive RP-HPLC-UV method was developed and validated for simultaneous determination of atenolol and propranolol and subsequently applied to investigate the effect of dimethyl sulfoxide in rat in situ intestinal permeability studies. Atenolol (400 microm) and propranolol (100 microm) were perfused in the small intestine of anaesthetized (pentobarbitone sodium 60 mg/kg, i.p.) male Sprague-Dawley rats either in the presence (1, 3 and 5%) or in the absence of dimethyl sulfoxide. There was no significant alteration (p > 0.05) in the permeability of atenolol and propranolol, which indicated there was no effect of various concentrations of dimethyl sulfoxide (1-5%) on the membrane integrity of the rat intestinal tissues. The analytical method was validated on a C(4) column with a mobile phase comprising ammonium acetate buffer (pH 3.5, 0.02 m) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 mL/min. The validated method was found to be accurate and precise and stability studies were carried out at different storage conditions and both analytes were found to be stable. These findings are applicable for determining the absorbability of water-insoluble drugs and new chemical entities for the purpose of classifying them in the biopharmaceutical classification system.
Assuntos
Antagonistas Adrenérgicos beta/farmacocinética , Atenolol/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Dimetil Sulfóxido/química , Mucosa Intestinal/metabolismo , Propranolol/farmacocinética , Espectrofotometria Ultravioleta/métodos , Animais , Masculino , Perfusão , Permeabilidade , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos TestesRESUMO
A simple, sensitive and specific reversed phase high performance liquid chromatographic (RP-HPLC) method with UV detection at 251 nm was developed for simultaneous quantitation of buparvaquone (BPQ), atenolol, propranolol, quinidine and verapamil. The method was applicable in rat in situ intestinal permeability study to assess intestinal permeability of BPQ, a promising lead compound for Leishmania donovani infections. The method was validated on a C-4 column with mobile phase comprising ammonium acetate buffer (0.02 M, pH 3.5) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 ml/min. The retention times for atenolol, quinidine, propranolol, verapamil and BPQ were 4.30, 5.96, 6.55, 7.98 and 8.54 min, respectively. The calibration curves were linear (correlation coefficient > or =0.996) in the selected range of each analyte. The method is specific and sensitive with limit of quantitation of 15 microg/ml for atenolol, 0.8 microg/ml for quinidine, 5 microg/ml for propranolol, 10 microg/ml for verapamil and 200 ng/ml for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and all the analytes were found to be stable. This method is simple, reliable and can be routinely used for accurate permeability characterization.