Polypodium leucotomos targets multiple aspects of oral carcinogenesis and it is a potential antitumor phytotherapy against tongue cancer growth

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Influence of verapamil on the pharmacokinetics and cerebral perfusion of oxcarbazepine and the enantiomers of its metabolite 10- hydroxycarbazepine in healthy volunteers

A oxcarbazepina (OXC) é indicada como terapia adjuvante ou monoterapia no tratamento de crises epilépticas parciais ou crises tônico-clônicas generalizadas em adultos e crianças. A OXC sofre rápida eliminação pré-sistêmica com formação do metabólito ativo 10-hidroxicarbazepina (MHD), o qual possui como enantiômeros o R-(-)- e o S-(+)-MHD. A OXC e o MHD são substratos da glicoproteína-P (P-gp), que pode ser inibida pelo verapamil. O presente estudo avalia a influência do verapamil na farmacocinética e perfusão cerebral da OXC e dos enantiômeros do MHD em voluntários sadios. Os voluntários sadios (n=12) receberam em uma ocasião doses de 300 mg/12h de OXC e em outra ocasião doses de 300 mg/12h de OXC associadas com 80 mg/8h de verapamil. As amostras de sangue foram coletadas no estado de equilíbrio durante 12 horas e a avaliação da perfusão cerebral realizada utilizando a tomografia computadorizada por emissão de fóton único (SPECT) antes do início do tratamento e nos tempos 4, 6 ou 12h após a administração da OXC. As concentrações plasmáticas total e livre da OXC e dos enantiômeros do MHD foram avaliadas por LC-MS/MS. A análise farmacocinética não compartimental foi realizada com o programa WinNonlin e a farmacocinética populacional foi desenvolvida utilizando a modelagem não-linear de efeitos mistos com o programa NONMEM. Os limites de quantificação obtidos foram de 12,5 ng OXC/mL de plasma e 31,25 ng de cada enantiômero MHD/mL de plasma para a análise da concentração total, enquanto foi de 4,0 ng de OXC/mL de plasma e de 20,0 ng de cada enantiômero do MHD/mL de plasma para a determinação da concentração livre. Os coeficientes de variação obtidos nos estudos de precisão e a porcentagem de inexatidão inter e intra-ensaios foram inferiores a 15%, assegurando a reprodutibilidade e repetibilidade dos resultados. A análise farmacocinética não compartimental da OXC em monoterapia resultou nos seguintes parâmetros: concentração plasmática máxima (Cmax) de 1,35 ?g/mL como valor total e 0,32 ?g/mL como concentração livre em 1,0 h, área sob a curva concentração plasmática versus tempo (AUC0-12) de 3,98 ?g.h/mL e meia-vida de eliminação de 2,45 h, volume de distribuição aparente (Vss/F) de 352,17 L e clearance aparente (CLss/F) de 75,58 L/h. A disposição cinética do MHD é enantiosseletiva, com observação de maior proporção para o enantiômero S-(+)-MHD em relação ao R-(-)-MHD (razão AUC0-12 S-(+)/R-(-) de 4,26). A fração livre avaliada no tmax da OXC foi 0,26 para a OXC, 0,42 para o R-(-)-MHD e 0,38 para o S- (+)-MHD, mostrando enantiosseletividade na ligação às proteínas plasmáticas do MHD. O tratamento com o verapamil reduziu o tempo médio de residência (MRT) (4,71 vs 3,83 h) e Cmax como concentração livre (0,32 vs 0,53 ?g/mL) da OXC e aumentou os valores para ambos os enantiômeros do MHD de Cmax como valor total (2,60 vs 3,27 ?g/mL para o R-(-)- e 11,05 vs 11,94 ?g/mL para o S-(+)-MHD), Cmax como concentração livre (3,11 vs 4,14 ?g/mL para o S-(+)-MHD), Cmédia (2,11 vs 2,42 ?g/mL para o R-(-)- e 8,10 vs 9,07 ?g/mL para o S-(+)-MHD) e AUC0-12 (25,36 vs 29,06 ?g.h/mL para o R-(-)- e 97,19 vs 111,37 ?g.h/mL para o S-(+)-MHD). A ii farmacocinética populacional da OXC foi melhor descrita por modelo de dois compartimentos com eliminação de primeira ordem e com um conjunto de três compartimentos de trânsito para descrever o perfil de absorção da OXC. A disposição de ambos os enantiômeros do MHD foi caracterizada por modelo de um compartimento. Os valores de CLss/F estimados na monoterapia foram de 84,9 L/h para a OXC e de 2,0 L/h para ambos enantiômeros do MHD, enquanto os valores de Vss/F foram de 587 L para a OXC, 23,6 L para o R-(-)-MHD e 31,7 L para o S-(+)- MHD. Concluindo, a associação do verapamil aumentou a biodisponibilidade da OXC em 12% (farmacocinética populacional) e aumentou os valores de AUC de ambos os enantiômeros do metabólito MHD (farmacocinética não compartimental), o que está provavelmente relacionado com a inibição da P-gp no trato intestinal. A associação do verapamil aumentou as concentrações cerebrais preditas de ambos os enantiômeros do MHD em maior extensão do que aquelas observadas no plasma. As mudanças no fluxo sanguíneo cerebral (SPECTs realizados 6h após a administração da OXC) associadas à coadministração de verapamil provavelmente foram causadas pelo aumento dos níveis cerebrais de ambos os enantiômeros do MHD. A confirmação dessa observação requer um braço experimental adicional com SPECTs realizados também após a administração do verapamil em monoterapia.Oxcarbazepine (OXC) is indicated as adjunctive therapy or monotherapy for the treatment of partial or generalized tonic-clonic seizures in adults and children. OXC undergoes rapid pre-systemic reduction with formation of the active metabolite 10- hydroxycarbazepine (MHD), which has the enantiomers R-(-)- and S-(+)-MHD. OXC and MHD are substrates of P-glycoprotein (P-gp), which can be inhibited by verapamil. The present study evaluates the influence of verapamil on the pharmacokinetics and cerebral perfusion of OXC and the MHD enantiomers in healthy volunteers. The healthy volunteers (n=12) received on one occasion doses of 300 mg/12h OXC and on another occasion they received doses of 300 mg/12h OXC associated with 80 mg/8h of verapamil. Blood samples were collected at steady state for 12 hours and the assessment of cerebral perfusion was performed using a single-photon emission computed tomography (SPECT) before the beginning of treatment and at times 4, 6 or 12 hours after OXC administration. The total and free plasma concentrations of OXC and MHD enantiomers were assessed by LC-MS/MS. The non-compartmental pharmacokinetics analysis was performed using the WinNonlin program, and population pharmacokinetics was developed using nonlinear mixed effects modelling with NONMEM.The limits of quantification obtained were 12.5 ng/mL plasma for OXC and 31.25 ng of each MHD enantiomer/mL plasma for total concentration analysis, while it was 4.0 ng OXC/mL plasma and 20.0 ng of each MHD enantiomer/mL plasma for the free concentration determination. The coefficients of variation obtained in studies of accuracy and the percentage of inaccuracy inter and intra-assay were less than 15%, ensuring the result reproducibility and repeatability. The non-compartmental pharmacokinetic analysis of OXC in monotherapy treatment, resulted in the following parameters: maximum plasma concentration (Cmax) of 1.35 ?g/mL as total concentration and 0.32 mg/mL as free concentration in 1.0 h, area under the plasma concentration vs time curve (AUC0-12) was 3.98 ?g.h/mL, half-life of 2.45 h, apparent volume of distribution (Vss/F) of 352.17 L and the apparent clearance (CLSS/F) of 75.58 L/h. The MHD kinetic disposition is enantioselective, with observation of a greater proportion of the S-(+)-MHD enantiomer compared to R-(-)-MHD (ratio AUC0-12 S-(+)/R-(-) of 4.26). The free fraction measured in the tmax of OXC was 0.26 for OXC, 0.42 for R-(-)-MHD and 0.38 for S-(+)-MHD, showing enantioselectivity in the plasma protein binding of MHD. Verapamil treatment reduced the mean residence time (MRT) (4.71 vs 3.83 h) and Cmax (0.26 vs 0.31 ?g/mL) as free concentration for OXC and increased the both MHD enantiomers values of Cmax (2.60 vs 3.27 ?g/mL for R-(-)- and 11.94 vs 11.05 ?g/mL for S-(+)-MHD) as total concentration, Cmax (3.11 vs 4,14 ?g/mL for S- (+)-MHD) as free concentration, Cavg (2.11 vs 2.42 ?g/mL for R-(-)- and 8.10 vs 9.07 ?g/mL for S-(+)-MHD) and AUC0-12 (25.36 vs 29.06 ?g.h/mL for R-(-)- and 97.19 vs 111.37 ?g.h/mL for S-(+)-MHD). The population pharmacokinetics of oxcarbazepine was best described by a two-compartment model with first-order elimination and a iv set of three transit compartments to describe the absorption profile of the parent compound. The disposition of both MHD enantiomers was characterised by onecompartment model. The CLss/F estimates in monotherapy were 84.9 L/h for OXC and 2.0 L/h for both MHD enantiomers, whereas the values of Vss/F were 587 L for OXC, 23.6 L for R-(-)-MHD and 31.7 L for S-(+)-MHD. In conclusion, verapamil coadministration increased the OXC bioavailability in 12% (population pharmacokinetics) and increased the AUC of both metabolite MHD enantiomers (non-compartmental pharmacokinetics), which is probably related to the inhibition of P-gp in the intestinal tract. Verapamil co-administration increased the predicted brain concentrations of both MHD enantiomers in a greater extent than those observed in plasma. Changes in cerebral blood flow (SPECTs performed 6h after administration of OXC) associated with co-administration of verapamil were probably caused by an increase in brain levels of both MHD enantiomers. Confirmation of this observation requires additional experimental arm with SPECTs also performed after administration of verapamil in monotherapy

Influence of gestational Diabetes mellitus on the enantioselective kinetic disposition and metabolism of metoprolol in hypertensive parturients

O metoprolol, um fármaco aceito no tratamento da hipertensão durante a gestação, está disponível na clínica como mistura racêmica dos enantiômeros S-(-) e R-(+), embora o S-(-)-metoprolol seja considerado o eutômero em termos do bloqueio do receptor 1 adrenérgico. O presente estudo avalia a influência do Diabetes mellitus gestacional na disposição cinética e no metabolismo enantiosseletivos do metoprolol em parturientes hipertensas. As parturientes hipertensas investigadas (n=35) com idade gestacional de 35-42 semanas e fenotipadas como metabolizadoras extensivas tipo metoprolol, foram distribuídas nos grupos controle (n=24) ou portadoras de Diabetes mellitus gestacional (n=11). As parturientes foram tratadas com dose única oral de 100 mg de tartarato de metoprolol racêmico 1-11 h antes do parto. Foram coletadas amostras seriadas de sangue materno (0-24h) e no momento do parto foram coletados simultaneamente sangue materno, sangue do cordão umbilical e líquido amniótico. Os enantiômeros do metoprolol e seus metabólitos foram quantificados por LC-MS/MS ou por detecção por fluorescência. A disposição cinética do metoprolol é enantiosseletiva em parturientes hipertensas com observação de maiores concentrações plasmáticas (AUC0- 113,42 vs 62,65 ng.h/mL) e menor clearance total aparente (344,21 vs 623,14 L/h) para o eutômero S-(-)-metoprolol. A formação do metabólito -hidroximetoprolol também é estereosseletiva com favorecimento do novo centro quiral 1R (AUC0- 1R/1S=2,84). O favorecimento da formação do R-(+)-ácido O-desmetilmetoprolóico (AUC0- 2,77 vs 2,66 g.h/mL) explica o acúmulo plasmático do S-(-)-metoprolol. O Diabetes mellitus gestacional compensado prolonga o tmax para ambos os enantiômeros do metoprolol (1,5 vs 2,5 h) e ácido O-desmetilmetoprolóico (2,0 vs 3,5 h) e para todos os isômeros do -hidroximetoprolol (2,0 vs 3,0 h). O Diabetes mellitus gestacional compensado não altera as razões isoméricas de concentrações plasmáticas do metoprolol, -hidroximetoprolol e ácido O-desmetilmetoprolóico. As razões de concentrações líquido amniótico/plasma materno obtidas para ambos os enantiômeros do metoprolol (3,0 para o R-(+)-metoprolol e 3,2 para o S-(-)-metoprolol) e para os isômeros do -hidroximetoprolol (5,1 para o 1\'S,2R; 4,0 para o 1\'S,2S; 1,6 para o 1\'R,2R e 2,3 para o 1\'R,2S) evidenciam maiores concentrações dos fármacos no líquido amniótico do que no plasma materno. No entanto, os enantiômeros do ácido O-desmetilmetoprolóico atingem menores concentrações no líquido amniótico do que no plasma materno das parturientes hipertensas (líquido amniótico/plasma materno = 0,29 e 0,37 respectivamente para os enantiômeros R-(+)- e S-(-)). A distribuição transplacentária é próxima a 1 para ambos os enantiômeros do metoprolol e para todos os isômeros do -hidroximetoprolol e próxima a 0,8 para ambos os enantiômeros do ácido O-desmetilmetoprolóico em parturientes hipertensas. O Diabetes mellitus gestacional compensado reduz em aproximadamente 20% a distribuição transplacentária dos isômeros 1S,2S; 1R,2R; e 1R,2S--hidroximetoprolol mas não altera a distribuição dos enantiômeros do metoprolol.Metoprolol is a drug accepted in the treatment of hypertension during pregnancy and it is clinically available as a racemic mixture of its enantiomers S-(-) and R-(+) metoprolol, although S-(-)-metoprolol is considered the eutomer responsible for 1 adrenergic receptor blockade.This study evaluates the influence of gestational Diabetes mellitus on the kinetic disposition and metabolism of metoprolol enantiomers in hypertensive parturients. The investigated parturients (n=35) presented gestational age within 35 to 42 weeks, were phenotyped as extensive metabolizers of metoprolol and were distributed in the control group (n=24) or in the gestational Diabetes mellitus group (n =11). The parturients were treated with single oral dose of 100 mg racemic metoprolol tartrate 1-11 h before delivery. Maternal blood samples were collected until 24h after drug administration, whereas maternal blood, umbilical cord blood and amniotic fluid were simultaneously collected at delivery. Metoprolol enantiomers and its metabolites were quantified by LC-MS/MS or by fluorescence detection. Kinetic disposition of metoprolol is enantioselective in hypertensive parturients with observation of higher plasma concentrations (AUC0- 113.42 vs 62.65 ng.h/mL) and lower apparent total clearance (344.21 vs 623.14 L/h) for the S-(-)-metoprolol eutomer. The formation of -hydroxymetoprolol metabolite is also stereoselective in favor of the new chiral center 1\'R (AUC0- 1\'R/1\'S = 2.84). The formation in favor of R-(+)-metoprolol acid metabolite (AUC0- 2.77 vs 2.66 g.h/mL) explains the plasma accumulation of S-(-)-metoprolol. Gestational Diabetes mellitus prolongs tmax for both metoprolol enantiomers (1.5 vs 2.5 h), metoprolol acid metabolite (2.0 vs 3.5 h) and for all -hydroxymetoprolol isomers (2.0 vs 3.0 h). Gestational Diabetes mellitus does not alter the isomeric ratios of plasma concentrations of metoprolol, -hydroxymetoprolol and metoprolol acid metabolite. The concentrations of both metoprolol enantiomers (amniotic fluid/maternal plasma = 3.0 for R-(+)-metoprolol and 3.2 for the S-(-)-metoprolol) and -hydroxymetoprolol isomers (liquid amniotic fluid/maternal plasma = 5.1 for 1\'S,2R; 4.0 for 1\'S,2S; 1.6 for 1\'R,2R and 2.3 for 1\'R,2S) are higher in amniotic fluid than in maternal plasma. However, metoprolol acid metabolite enantiomers reach lower concentrations in amniotic fluid than in maternal plasma of hypertensive parturients (amniotic fluid/maternal plasma = 0.29 and 0.37 respectively for the R-(+)- and S-(-)- enantiomers). The transplacental distribution is approximately 1 for both enantiomers of metoprolol and all isomers of -hydroxymetoprolol and approximately 0.8 for both metoprolol acid metabolite enantiomers in hypertensive parturients. Gestational Diabetes mellitus reduces in approximately 20% the transplacental distribution of the isomers 1\'S,2S; 1\'R,2R and 1\'R,2S--hidroximetoprolol but does not alter the transplacental distribution of both metoprolol enantiomers

Evaluation of folic acid supplementation by concomitant administration of ethinyl estradiol plus levonorgestrel in healthy female subjects

Objectives: Folic acid supplementation prevents 50 - 75% of cases of neural tube defects. This study evaluated the folic acid supplementation after oral administration of the ethinyl estradiol 0.02 mg + levonorgestrel 0.10 mg + folic acid 0.4 mg coated tablet as well as its safety and tolerability in healthy female subjects. Materials and methods: 36 healthy female subjects received 1 coated tablet of the test product - ethinyl estradiol 0.02 mg + levonorgestrel 0.10 mg + folic acid 0.4 mg for 21 days and a placebo coated tablet containing folic acid 0.4 mg only on the last 7 days of the cycle, in 3 cycles. Blood samples were collected to quantify folate by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The safety was assessed by recording adverse events, monitoring of vital signs, and the evaluation of laboratory tests and ECG. Results: The mean whole blood level of folic acid at baseline (1st day of 1St cycle) was 42.7 +/- 22.2 ng/mL, while on the 28th day of the 3rd cycle it was 47.6 +/- 20.1 ng/mL, with a variation of 11.32%. The subjects tolerated the clinical protocol well and reported no clinically significant adverse effects. Conclusion: Oral contraceptives may be a good vehicle for folate supplementation in women of reproductive age.576290297FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2016/22506-

Effect of Type 2 Diabetes Mellitus on the Pharmacokinetics of Metformin in Obese Pregnant Women

Background and Objective The use of metformin throughout gestation by women with polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus (T2DM) significantly reduces the number of first-trimester spontaneous abortions and the rate of occurrence of gestational diabetes and hypertensive syndromes. Metformin is taken up into renal tubular cells by organic cation transport 2 (OCT2) and eliminated unchanged into the urine. The objective of this study was to analyse the influence of T2DM on the pharmacokinetics of metformin in obese pregnant women and in a control group of non-diabetic obese pregnant women with PCOS. Methods Eight non-diabetic obese pregnant women with PCOS and nine obese pregnant women with T2DM taking oral metformin 850 mg every 12 h were evaluated throughout gestation. Serial blood samples were collected over a 12-h period during the third trimester of pregnancy. Steady-state plasma concentrations of metformin were determined by high-performance liquid chromatography with a UV detector. The pharmacokinetic results of the two groups, reported as median and 25th and 75th percentile, were compared statistically using the Mann Whitney test, with the level of significance set at p < 0.05. Results The pharmacokinetic parameters detected for PCOS versus T2DM patients, reported as median, were, respectively: elimination half-life 3.75 versus 4.00 h; time to maximum concentration 2.00 versus 3.00 h; maximum concentration 1.42 versus 1.21 mu g/mL; mean concentration 0.53 versus 0.56 mu g/mL; area under the plasma concentration time curve from time zero to 12 h 6.42 versus 6.73 mu g.h/mL; apparent total oral clearance 105.39 versus 98.38 L/h; apparent volume of distribution after oral administration 550.51 versus 490.98 L; and fluctuation (maximum minimum concentration variation) of 179.56 versus 181.73%. No significant differences in pharmacokinetic parameters were observed between the groups. Conclusion T2DM in the presence of insulin use does not influence the pharmacokinetics of metformin in pregnant patients, demonstrating the absence of a need to increase the dose, and consequently does not influence the OCT2-mediated transport in pregnant women with PCOS.Foundation for Research Support of Sao Paulo (FAPESP)Foundation for Research Support of Sao Paulo (FAPESP)National Council for Scientific and Technological Development (CNPq), BrazilNational Council for Scientific and Technological Development (CNPq), Brazi

Metformin pharmacokinetics in nondiabetic pregnant women with polycystic ovary syndrome

The use of metformin throughout gestation by pregnant women with polycystic ovary syndrome (PCOS) significantly reduces the number of first trimester spontaneous abortions and the rate of occurrence of gestational diabetes. The objective of this study was to investigate the pharmacokinetics and the placental transfer of metformin in pregnant women with PCOS. Eight pregnant women with PCOS taking 850 mg metformin every 12 h during the third trimester of pregnancy were evaluated. Maternal blood samples were collected at steady state during the dose interval (0-12 h). Maternal and umbilical cord blood samples were also obtained at delivery. Metformin plasma concentrations were analyzed by high-performance liquid chromatography, and pharmacokinetic parameters were determined using a non-compartmental model. Data are reported as median and minimum and maximum values. Metformin pharmacokinetic parameters were: t(A1/2), 3.8 (2.8-5.4) h; t(max), 2.0 (0.5-3.0) h; C(max), 1.4 (0.5-2.1) mg/L; C(mean), 0.5 (0.2-0.9) mg/L; AUC(0-12), 6.4 (1.1-9.2) mg h/L; Cl/f, 105 (60-274) L/h; Vd/f, 551 (385-1173) L; median fluctuation, 89 (79-95)%. Umbilical/maternal metformin plasma concentration ratios were 0.7 (0.4-1.3). Metformin oral clearance (Cl/f) had increased in our patients relative to nonpregnant healthy volunteers or diabetic patients. Therefore, lower plasma metformin concentrations were observed for nondiabetic pregnant women with PCOS. Future studies should be conducted to demonstrate the therapeutic efficacy of metformin during pregnancy. Caution is warranted as umbilical/maternal metformin plasma concentrations ratios of around 0.7 require metformin dosage adjustment.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Apoio a Pesquisa e Assistencia do HCFMRP-USP (FAEPA)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq

Comparative bioavailability of two zolpidem hemitartrate formulations in healthy human Brazilian volunteers using high-performance liquid chromatography coupled to tandem mass spectrometry

To assess the bioequivalence of two zolpidem hemitartrate formulations in 30 healthy volunteers. Plasma samples were obtained over a 24 h period. Plasma concentrations of zolpidem were analyzed by liquid chromatography coupled to tandem mass spectrometry with positive ion electrospray ionization using multiple reaction monitoring. Values of peak concentration (C-max), area under curve (AUC), half-life, elimination constant, volume of distribution and clearance showed statistically significant differences when comparing women (604.34 ng h/ml, 127.36 ng/ml, 4.4 h, 0.18 1/h, 50.56 L and 8.55 L/h, respectively) and men (276.1 ng h/ml, 70.9 ng/ml, 3.3 h, 0.26 1/h, 91.42 L and 24.34 L/h, respectively), receiving the same dose (5 mg), respectively. The geometric means with corresponding 90% confidence interval for Test/Reference percentage ratios were 99.73% (CI 93.69-106.16) for C-max,C- 97.44% (90% CI = 91.85-103.37%) for area under curve of plasma concentration until the last concentration observed (AUC(last)) and 98.30% (90% CI = 92.48-104.49) for the area under curve between the first sample (pre-dosage) and infinity (AUC(0-inf)). Since the 90% CI for AUC(last), AUC(0-inf) and C-max ratios were within the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that zolpidem hemitartrate formulation (5 mg orodispersible tablet) is bioequivalent to the zolpidem hemitartrate formulation (Patz SL 5 mg sublingual tablet) with regard to both the rate and the extent of absorption. A new formulation of zolpidem 2.5 mg may be useful in women for the same clinical benefits as the 5 mg formulation in men