Abstract In this paper, a model of the composite foundation reinforced with geosynthetic encased stone columns was established using the discrete element method, and the characteristics of its action under cyclic loading were studied. The influence of the length and radius of the pile on the settlement of the composite foundation is analyzed. The deformation characteristics of the pile and the stress ratio of pile-soil are studied under different pile lengths and radius. Then, based on this, the analysis of the lateral deformation characteristics of the piles under cyclic loading, the calculation model of the geosynthetic encased pile composite foundation is established. The settlement calculation formula of the composite foundation is solved according to the deformation coordination relationship between the pile and soil, the equilibrium condition, and the boundary condition. The results show that the theoretical value is in good agreement with the simulation value, which verifies the rationality of the theoretical calculation formula.

The novel alkaloid, oleracimine, presented remarkable anti-inflammatory bioactivity, and therefore, its pharmacokinetics was investigated in rat plasma after intravenous and oral administration by using a rapid ultra-high-performance liquid chromatography (UHPLC) method with UV detection at 270 nm. The analysis was performed on a shim-pack ODS column (75 mm×2 mm, 1.6 µm particle size, Shimadzu, Japan) column using isocratic elution with a mobile phase consisting of methanol-water (62:38, v/v) within 3 min. The results indicated that oleracimine was rapidly distributed with Tmax for 11.7 min after oral administration, which presented the double-peak phenomenon in the pharmacokinetic profile with a higher oral absolute bioavailability of 55.1% ± 7.83%.

ABSTRACT Hydroxydihydrobovolide (HDB) was for the first time isolated from Portulaca oleracea L. and then its cytotoxicity against SH-SYTY cells was studied. Moreover, a rapid and sensitive ultra-high performance liquid chromatographic (UHPLC) method with bergapten as internal standard (IS) was developed and validated to investigate the pharmacokinetics of HDB in rats after intravenous and oral administrations of extract (POE). The UHPLC analysis was performed on a Diamonsil C18 analytical column, using acetonitrile-water (35:65, v/v) as the mobile phase with UV detection at 220 nm. The calibration curve was linear over the range of 0.2-25 µg/mL in rat plasma. The average extraction recovery was from 90.1 to 98.9%, and the relative standard deviations (RSDs) of the intra- and inter-day precisions were less than 4.7 and 4.1%, respectively. The results showed that 50 µM HDB had significant cytotoxicity on the SH-SY5Y cells, which was rapidly distributed with a Tmax of 11 min after oral administration and presented a low absolute bioavailability, 4.12%.

O objetivo do presente estudo foi investigar a distribuição tecidual e excreção de cinco componentes de extrato Portulaca oleracea L. (POE) em ratos após administração oral. Um método analítico rápido, sensível e específico para quantificação de cinco componentes de POE (ácido cafeico (CA), ácidop-cumárico (p-CA), ácido ferúlico (FA), quercitrina (QUER) e hesperidina (HP)) por cromatografia líquida de ultra eficiência (UHPLC), empregando puerarina como padrão interno de referência. Os compostos foram quantificados em diferentes tecidos dos animais, sendo eles fígado, intestino, estômago, músculo, coração, pulmão, cérebro, rim e baço, urina e fezes. Os resultados mostraram que apenas p-CA e FA foram encontradas em todos os tecidos com baixas taxas cumulativas e CA apresentou níveis mais altos no intestino e estômago com a taxa cumulativa um pouco mais elevada na urina e nas fezes após 24 h. HP e QUER apresentaram baixas concentrações nos tecidos com baixas taxas cumulativas.

The aim of the present study was to investigate the tissue distribution and excretion of five components of Portulaca oleracea L. extract (POE) in rat following oral administration. A rapid, sensitive and specific ultra-high performance liquid chromatography (UHPLC) method with puerarin as the internal standard was used for the quantitative analysis of five components of POE, including caffeic acid (CA), p-coumaric acid (p-CA), ferulic acid (FA), quercitrin (QUER) and hesperidin (HP) in rat tissues including the liver, intestine, stomach, muscle, heart, lung, brain, kidney and spleen, urine and feces. The results show that onlyp-CA and FA were found in nearly all tissues with low cumulative ratios, and CA was higher in the intestine and stomach with a slightly higher cumulative ratio in the urine and feces after 24 h. HP and QUER were found at low levels in the tissues with low cumulative ratios.

O objetivo deste estudo é desenvolver um método simples e específico de HPLC usando vitexina como padrão interno para investigar a farmacocinética do isoquercitrina (ISOQ) após três doses diferentes administradas por via intravenosa a ratos. Os parâmetros farmacocinéticos foram calculados pelas abordagens compartimental e não compartimental. Os resultados mostraram que ISOQ se encaixa no modelo de três compartimentos. Os valores de AUC aumentaram proporcionalmente na faixa de 5-10 mg·kg-1. Além disso, a meia-vida, b meia-vida, ªCL, MRT0-t and MRT0→∞ de ISOQ em ratos mostraram diferenças significativas entre 20 mg·kg-1 e outras doses, o que significa que ISOQ apresenta farmacocinética dose-dependente no intervalo de 5-10 mg·kg-1 e farmacocinética não linear em doses mais elevadas.

The aim of this study is to develop a simple and specific HPLC method using vitexin as the internal standard to investigate the pharmacokinetics of isoquercitrin (ISOQ) after three different doses administrated intravenously to rats. The pharmacokinetic parameters were calculated by both compartmental and non-compartmental approaches. The results showed that ISOQ fitted a three-compartment open model. The values of AUC increased proportionally within the range of 5-10 mg·kg-1. Moreover, a half-life, b half-life, ªCL, MRT0-t and MRT0→∞ of ISOQ in rats showed significant differences between 20 mg·kg-1 and other doses, indicating that ISOQ presented dose-dependent pharmacokinetics in the range of 5-10 mg·kg-1 and non-linear pharmacokinetics at higher doses.

O objetivo do estudo foi desenvolver um método simples e específico de HPLC para a determinação simultânea de hesperidina (HP), ácido caféico (CA), ácido ferúlico (FA) e ácido p-cumárico (p-CA) em plasma de rato após a administração intravenosa de extrato Portulaca oleracea L. (POE) empregando hyperosídeo como padrão interno de referência. Metanol foi empregado para os analitos em plasma (0,2 mL). A fase móvel isocrática foi composta por metanol-acetonitrila-tetraidrofurano-0,5% ácido acético glacial (5:3:18:74, v/v/v/v). Curvas de calibração foram lineares na faixa de concentração de 0,1-25 µg mL-1, 0,1-25 µg mL-1, 0,1-25 µg mL-1 e 0,015-3 µg mL-1 para HP, CA, FA e p-CA, respectivamente. O método desenvolvido foi adequado para estudo farmacocinético de HP, CA, FA e p-CA em ratos após a administração intravenosa de POE.

The objective of the present study was to develop a simple and selective HPLC method for the simultaneous determination of hesperidin (HP), caffeic acid (CA), ferulic acid (FA) and p-coumaric acid (p-CA) in rat plasma after intravenous administration of Portulaca oleracea L. extract (POE). With the hyperoside as the internal standard, the sample pretreatment procedure involved simple single-step extraction with methanol of 0.2 mL plasma. The mobile phase consisted of methanol-acetonitrile-tetrahydrofuran-0.5% glacial acetic acid (5:3:18:74, v/v/v/v). The calibration curves were linear over the range of 0.1-25 µg mL-1, 0.1-25 µg mL-1, 0.1-25 µg mL-1and 0.015-3 µg mL-1 for HP, CA, FA and p-CA, respectively. The method developed was suitable for the pharmacokinetic study of HP, CA, FA and p-CA in rats after intravenous administration of POE.