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1.
Baicalein, a flavonoid originally isolated from the root of Scutellaria baicalensis Georgi, has numerous pharmacological activities. Up to now, several studies regarding the pharmacokinetic profiles of baicalein have been described, while there is no such study reported in monkey, the species which is more similar to human. The purpose of this study was to investigate the pharmacokinetic profiles of baicalein after oral administration in monkeys. After orally administrating three doses of baicalein in monkeys, multi-peaks of the plasma concentration-time curves were observed and the non-linear pharmacokinetics for baicalein and its metabolite baicalin were found at doses of 50-500mg/kg. In order to calculate the absolute bioavailability, the intravenous pharmacokinetic study was also carried out after intravenous administration of 10mg/kg baicalein. The absolute bioavailability of baicalein in different doses was ranged from 13.1% to 23.0%. In this study, baicalein and baicalin were determined by LC-MS method. The chromatographic separation was performed on Agilent Poroshell 120 SB-C18 column (2.7μm, 2.1×50mm). Baicalein and baicalin were detected by single quadrupole mass spectrometer equipment with electrospray ionization interface with the selected ion monitoring mode. The assay was linear for both baicalein and baicalin with the correlation coefficients>0.99. The intra- and inter-day precisions for baicalein and baicalin were all less than 15% by relative standard deviation. The analytes were stable during samples storage and handling, and no matrix effects were observed. The method we developed in this study was sensitive, precise, stable and producible. 相似文献
2.
《Fitoterapia》2014
The current review emphasizes on the herbal bioenhancers which themselves do not possess inherent pharmacological activity of their own but when co-administered with Active Pharmaceutical Ingredients (API), enhances their bioavailability and efficacy. Herbal bioenhancers play a crucial role in enhancing the bioavailability and bioefficacy of different classes of drugs, such as antihypertensives, anticancer, antiviral, antitubercular and antifungal drugs at low doses. This paper highlights various natural compounds that can be utilized as an efficient bioenhancer. Several herbal compounds including piperine, quercetin, genistein, naringin, sinomenine, curcumin, and glycyrrhizin have demonstrated capability to improve the pharmacokinetic parameters of several potent API. This article also focuses on various United States patents on herbal bioenhancers, which has proved to be beneficial in improving oral absorption of nutraceuticals like vitamins, minerals, amino acids and certain herbal compounds. The present paper also describes proposed mechanism of action, which mainly includes absorption process, drug metabolism, and action on drug target. The herbal bioenhancers are easily available, safe, free from side effects, minimizes drug toxicity, shortens the duration of treatment, lowers the drug resistance problems and minimizes the cost of treatment. Inspite of the fact that herbal bioenhancers provide an innovative concept for enhancing the bioavailability of several potent drugs, there are numerous bioenhancers of herbal origin that are yet to be explored in several vital areas. These bioenhancers must also be implied to enhance the bioavailability and bioefficacy through routes other than the oral route of drug delivery. There is a vast array of unexploited plants which can be investigated for their drug bioenhancing potency. The toxicity profiles of these herbal bioenhancers must not be overlooked. Researches must be carried out to solve these issues and to deliver a safe and effective dose of drugs to attain desired pharmacological response. 相似文献
3.
《Fitoterapia》2013
As with many other anti-cancer agents, 20(S)-protopanaxadiol (PPD) has a low oral absorption. In this study, in order to improve the oral bioavailability of PPD, the cubic nanoparticles that it contains were used to enhance absorption. Therefore, the cubic nanoparticle loaded PPD were prepared through the fragmentation of the glyceryl monoolein (GMO)/poloxamer 407 bulk cubic gel and were verified by transmission electron microscope, small angle X-ray scattering and differential scanning calorimetry. The in vitro release of 20(S)-protopanaxadiol from these nanoparticles was less than 5% at 12 h. And then Caco-2 cell monolayer model was used to evaluate the absorption of PPD in vitro. Meanwhile the rat intestinal perfusion model and bioavailability were also estimated in vivo. The results showed that, in the Caco-2 cell model, the PPD-cubosome could increase the permeability values from the apical (AP) to the basolateral (BL) of PPD at 53%. The result showed that the four-site rat intestinal perfusion model was consistent with the Caco-2 cell model. And the result of a pharmacokinetic study in rats showed that the relative bioavailability of the PPD-cubosome (AUC0–∞) compared with the raw PPD (AUC0–∞) was 169%. All the results showed that the PPD-cubosome enhanced bioavailability was likely due to the increased absorption by the cubic nanoparticles rather than by the improved release. Hence, the cubic nanoparticles may be a promising oral carrier for the drugs that have a poor oral absorption. 相似文献
4.
Schizonepetin, a natural monoterpene from Herba Schizonepetae, is a potential antiviral agent. In this paper, a simple, rapid and sensitive HPLC-UV method was first developed and validated for the determination of schizonepetin in rat plasma and tissue homogenates after oral and intravenous administration. The results showed that schizonepetin was absorbed and eliminated rapidly, and its oral absolute bioavailability in rats achieved about 75%. The drug distributed widely in various tissues of rats, and had no long-term accumulation in vivo. The research provides reliable scientific data for designing drug treatment regimens of schizonepetin. 相似文献
5.
Over the past several years, great advances have been made on development of novel drug delivery systems (NDDS) for plant actives and extracts. The variety of novel herbal formulations like polymeric nanoparticles, nanocapsules, liposomes, phytosomes, nanoemulsions, microsphere, transferosomes, and ethosomes has been reported using bioactive and plant extracts. The novel formulations are reported to have remarkable advantages over conventional formulations of plant actives and extracts which include enhancement of solubility, bioavailability, protection from toxicity, enhancement of pharmacological activity, enhancement of stability, improved tissue macrophages distribution, sustained delivery, and protection from physical and chemical degradation. The present review highlights the current status of the development of novel herbal formulations and summarizes their method of preparation, type of active ingredients, size, entrapment efficiency, route of administration, biological activity and applications of novel formulations. 相似文献
6.
The toxicity depending on both dose and administration route is the major obstacle to the development of brucine, a bioactive alkaloid from Semen Strychni. In this study, the apparent partition coefficient and plasma protein binding extent of brucine were determined. In addition, the dose-dependency of the pharmacokinetics of brucine was investigated. Three intravenous (2.5, 5 and 10 mg/kg) and three oral (10, 20 and 40 mg/kg) doses were administered to rats. After intravenous administration, the systemic clearance was reduced and AUC was nonlinearly increased as a function of dose. Upon oral administration, brucine was rapidly absorbed (Tmax < 0.5 h), which was consistent with previously reported high Caco-2 Papp values. The increase in AUC was proportional to the increase in dose. The oral bioavailability (F) did not vary with the dose (F = 40.31%, 47.15% and 43.02% for 10, 20, 40 mg/kg doses, respectively). However, the dose-proportionality was not observed with Cmax. The values of Cmax/Dose were calculated to be 92.92 ± 45.83, 55.73 ± 24.01 and 36.29 ± 22.44 μg/L for 10, 20 and 40 mg/kg, respectively. The results of dose-dependent pharmacokinetic behavior under different administration routes may account for the significantly different toxicities of brucine between intravenous and oral administration. 相似文献
7.
基于St?ber方法,制备出介孔SiO_2纳米球(MSNs)和树枝状介孔SiO_2纳米球(dMSNs),并以己唑醇(He)为模型农药,通过物理吸附方法分别制备了己唑醇/介孔SiO_2复合纳米球(He/MSNs)和己唑醇/树枝状介孔SiO_2复合纳米球(He/dMSNs)。采用透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FT-IR)对制备的介孔纳米球形貌和结构进行表征;利用Brunauer-Emmett-Teller (BET)气体吸附法对介孔二氧化硅纳米球和树枝状介孔二氧化硅纳米球的孔结构进行表征;通过热重分析(TG)、模拟释放实验和抑菌实验对制备的载药复合纳米球载药量、释药性能及药效进行研究。结果表明,MSNs和d MSNs的平均粒径分别为(210±10)和(235±10) nm,比表面积分别为1 092.867和1 289.110 m^2/g,孔容分别为0.690和0.814 cm^3/g,孔径分别为32.144和32.673?。He/MSNs和He/d MSNs载药率分别达到42%和84%,且缓释作用明显。He/MSNs和He/dMSNs(0.1 mg/m L)对可可毛色二孢菌均表现出良好的抑菌性能。 相似文献
8.
Ajay Semalty Mona Semalty Mohan Singh Maniyari Rawat Federico Franceschi 《Fitoterapia》2010,81(5):306-314
The poor and/or erratic oral bioavailability of polyphenolics can be improved using the PHYTOSOME®1 delivery system, a strategy that enhances the rate and the extent of solubilization into aqueous intestinal fluids and the capacity to cross biomembranes. Phospholipids show affinity for polyphenolics, and form supramolecular adducts having a definite stoichiometry. This article reviews the preparation and characterization of PHYTOSOME® complexes and their activity in various medicinal (cardiovascular, anti-inflammatory, hepatoprotective, anticancer) and cosmetic (skin aging) realms of application. 相似文献
9.
Inoculation trials were set up in fumigated nursery beds for red alder (Alnus rubra Bong.) bare-root seedling production. Frankia inoculum was applied either as nodule homogenate or as pure culture (strain ArI5). The plots were laid out in 4 blocks of 8 treatments consisting of: control, nodule suspension, and three levels each of cell suspension and cells applied with a peat carrier. Numbers, height, and percentage nodulation on the seedlings were determined at mid-season. Numbers, size, dry weights, and degree of nodulation were determined at lifting. The peat inoculum treatment produced larger seedlings than the other treatments, both at mid-season and at lifting. The other treatments had little effect on growth. Size differences paralleled differences in degree of nodulation. Differences in percentage of seedlings nodulated were most pronounced at midseason, indicating that inoculation confered primarily an early-season advantage. 相似文献
10.
The present study is trying to produce a transdermal microemulsion drug delivery system (TMDDS) for Tripterygium Wilfordii Hook f. (TWHF) and attempting to solve male reproductive toxicity problem of TWHF. The formulation was optimized by the central composite design with response surface methodology and was decided as 12% oleic acid, 19.7% Labrasol S, 19.7% ethanol and 19.7% Pharmasolve, and 29% water. TMDDS for TWHF had stronger transdermal ability than free TWHF, and TWHF microemulsion significantly inhibited the adjuvant-induced arthritis and at the same time, had preferable anti-inflammatory effect with the long-time administration. Various pharmacodynamics parameters proved that TWHF microemulsion can reduce the male reproductive toxicity and hepatotoxicity of rats. All these suggested that TMDDS could be a suitable delivery system for TWHF. 相似文献
11.
《Fitoterapia》2014
Mangiferin is an active ingredient of medicinal plant with poor hydrophilicity and lipophilicity. Many reports focused on improving aqueous solubility, but oral bioavailability of mangiferin was still limited. In this study, we intended to increase not only solubility, but also membrane permeability of mangiferin by a phospholipid complexation technique. The new complex's physicochemical properties were characterized in terms of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared absorption spectroscopy (IR), aqueous solubility, oil–water partition coefficient and in vitro dissolution. The intestinal absorption of the complex was studied by the rat in situ intestinal perfusion model. After oral administration of mangiferin–phospholipid complex and crude mangiferin in rats, the concentrations of mangiferin were determined by a validated RP-HPLC method. Results showed that the solubility of the complex in water and in n-octanol was enhanced and the oil–water partition coefficient was improved by 6.2 times and the intestinal permeability in rats was enhanced significantly. Peak plasma concentration and AUC of mangiferin from the complex (Cmax: 377.66 μg/L, AUC: 1039.94 μg/L*h) were higher than crude mangiferin (Cmax: 180 μg/L, AUC: 2355.63 μg/L*h). In view of improved solubility and enhanced permeability, phospholipid complexation technique can increase bioavailability of mangiferin by 2.3 times in comparison to the crude mangiferin. 相似文献
12.
Zhi-peng Chen Jun Sun Hong-xuan Chen Yan-yu Xiao Dan Liu Jun Chen Hao Cai Bao-chang Cai 《Fitoterapia》2010,81(8):1045-1052
The aim of this study was to improve the oral bioavailability of Ginkgo biloba extract (GBE) through preparing G. biloba extract phospholipid complexes (GBP) and G. biloba extract solid dispersions (GBS). Firstly we prepared the GBP and GBS and studied their physicochemical properties by differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and dissolution. Then we studied the pharmacokinetic characteristics and bioavailability in rats. The results showed that the bioavailability of quercetin, kaempferol and isorhamnetin in rats was increased remarkably after oral administration of GBP and GBS comparing with GBE. The bioavailabilities of GBP increased more than that of GBS. 相似文献
13.
Percentage survival in aqueous suspensions and infectivity of six Egyptian entomopathogenic nematode isolates from the genus Heterorhabditis varied during the hot period of the year with daily temperature range from 18 to 24?°C. The isolate designated as AS1 had the highest mean of survival (87?%) and infectivity to Galleria mellonella larvae (90?%) after 10 days. When the nematodes coexisted with cytoplasmic polyhedrosis virus of 100 × 106 polyhedra inclusion bodies/ml, which was reproduced within and killed Rhynchophorus ferrugineus larvae, the nematode survival was adversely and progressively affected by the increase in the viral suspension. Among tested concentrations, a viral suspension equal to one-fifth size of the nematode and virus suspension is the best for nematode activity in integrated control against the red palm weevil. 相似文献
14.
The clinical application of salvianolic acid B (Sal B), a potential therapeutic agent for cardiovascular diseases isolated from Salvia miltiorrhiza, is greatly restricted by its short half-life and low bioavailability. To improve therapeutic effects and prolong the systemic circulation time of Sal B, liposomes, composed of soybean phosphatidylcholine and cholesterol were prepared by reverse-phase evaporation method. In addition, polyethylene glycol 2000-disteroylphosphoethanolamine (PEG-DSPE 2000) was included to give steric barrier to liposomes. A central composite design was employed to optimize liposomal formulation with high encapsulation efficiency and small particle size. Physicochemical characteristics such as particle size, zeta potential, encapsulation efficiency and in vitro release were investigated. In vivo pharmacokinetic properties of Sal B in beagle dogs and the effect of PEG on the blood circulation time of Sal B-loaded liposomes were also evaluated. An optimized formulation with encapsulation efficiency of 73.68% and mean particle size of 136.6nm were developed. Encapsulation of Sal B into conventional and PEGylated liposomes could prolong the half-life of Sal B by 5.8- and 17.5-fold and enhance the AUC(0-t) of Sal B by 6.7- and 13.3-fold compared with free Sal B, respectively. Therefore, the use of PEGylated liposomes could prolong the circulation time in blood and longevity effect of liposomes on Sal B was increased by PEG. 相似文献
15.
Extracts from hawthorn leafs and flowers (Crataegus sp., Rosaceae) are widely used as a rational based phytomedicine for declining cardiac performance. According to present literature C-glycosylated flavones and oligomeric procyanidins are considered to be the active ingredients, despite the fact that no systematic data are available on systemic bioavailability of proanthocyanidins after oral intake. The present study aims to review the actual state of literature in this field and to investigate the intestinal absorption mechanisms of defined hawthorn PAs with different degrees of polymerization by validated in vitro Caco-2 monolayer permeation system. Hawthorn OPCs with DP 2 to 6 were isolated as defined clusters. Procyanidin B2 and the procyanidin clusters DP 4, 5 and 6 had very low P(app) values between 0.6 and 6×10(-7)cm/s for apical to basolateral permeation. The higher the molecular weight the lower permeation coefficients were calculated. The observed low-level transport was mainly due to passive paracellular permeation. Additionally cellular uptake of OPCs by transcellular permeation was possible; on the other side procyanidins were shown to be p-glycoprotein substrates, which leads to subsequent excretion of PAs by the efflux pump to the apical side. Mixtures of the different OPCs did not have an increased permeation. Transport experiments of complex OPC mixtures together with hawthorn flavonoids did not indicate any improved permeation or synergistic effects. In principle this raises the question if systemic pharmacological activities of hawthorn extracts, can really be attributed to OPCs with very low systemic bioavailability. 相似文献
16.
17.
We determined how age of embryogenic cell suspensions affects somaclonal variation in five F1 hybrids of Coffea arabica L. Batches of plants were produced either directly from embryogenic callus, or after 3, 6, 9 and 12 months of embryogenic cell suspension culture. Seven phenotypic variants were characterized. Based on vigor and productivity of the regenerated plants, we classified the variants in order of increasing severity of physiological disorders as: Juvenile leaf color, Giant, Dwarf, Thick leaf (Bullata), Variegata, Angustifolia, and Multi-stem. The Dwarf, Angustifolia and Multi-stem variants were the most frequent among the regenerated plants (1.4, 4.8 and 2.9%, respectively). The frequency (f) of variants increased exponentially with the age (t) of the embryogenic suspension, in accordance with the function f = 0.99e(0.267t). For all genotypes, somaclonal variation was low (1.3%) in plants produced from embryogenic callus or 3-month-old cell suspensions and increased in frequency with increasing suspension age (6, 10 and 25% in plants produced from cell suspensions aged 6, 9 and 12 months, respectively). Large differences in somaclonal variation among genotypes were found only in plants produced from 12-month-old cell suspensions. For two genotypes, the oldest suspensions produced a majority of somaclonal variants (80-90%), whereas somaclonal variation ranged between 8 and 18% in the other genotypes. Cell suspension age and genotype also affected the type of variant produced. The severity of somaclonal variations increased with cell suspension age. For all genotypes combined, the Angustifolia variant was the most common. The other somaclonal variations were specific to certain genotypes or distributed randomly among the genotypes. 相似文献
18.
《林业研究》2017,(5)
Nitraria sibirica Pall.is a shrub that grows in saline-alkali soil and has traditional medicinal value and potential commercial value.The objectives of this study include induction and multiplication of callus,establishment of a suspension cell line,and isolation of protoplasts from cell suspensions.Murashige and Skoog(MS) medium was used for callus induction from mature seeds of N.sibirica.Seed-derived calluses were further multiplied on MS medium augmented with 0.5 mgL~(-1) 6-benzylaminopurine(6-BA) and 1.0 mgL~(-1) 2,4-dichlorophenoxy(2,4-D) acetic acid.Suspension cultures of N.sibirica were initiated by transferring friable calli to the same liquid multiplication medium.Characterization of the suspension culture was assessed based on fresh mass,dry mass,cell viability and p H value of the culture.A typical growth curve was observed after inoculating 1.5 g of callus in 40 mL liquid medium,including a lag phase,an exponential growth phase,a stationary phase,and a negative acceleration phase.The effect of factors such as pre-plasmolysis,enzyme combination,enzymolysis time and mannitol concentration,on the isolation of cell-derived protoplasts were evaluated to determine the usefulness of suspension cultures.The maximum yield(9.79 9 106 cells/g) and highest viability(79.97%) of protoplast were reached when approximately 1 g of cell suspension(cultured for 6 days) was inoculated for 12 h in cell and protoplast washing solution made of 0.8 molL~(-1) mannitol mixture solution,cellulose onozuka R-10 2%(w/v),hemicellulose 0.2%,macerozyme R-10 1%,and pectolyase Y-23 0.5%.Protoplast yield was significantly influenced by pre-plasmolysis and cellulose onozuka R-10(P0.05). 相似文献
19.
Radix scutellariae was used alone or in combination with other medicinal herbs in the treatment of type 2 diabetes mellitus in China. At present, the pharmacokinetics of baicalin in type 2 diabetic rats following oral administration of Radix scutellariae extract was investigated. The results showed that the pharmacokinetics (especially AUC) of baicalin in type 2 diabetic rats after oral administration of Radix scutellariae extract was remarkably different from that in normal rats. Then the mechanism which resulted in the increased AUC of baicalin in diabetic rats was investigated from system clearance and presystemic metabolism. And it was found that the increased AUC of baicalin in diabetic rats at least partly resulted from higher production of baicalein in the intestinal tract of type 2 diabetic rats. Moreover, the activity of β-glucuronidase in intestinal mucosa of type 2 diabetic rats was demonstrated to be higher than that in normal rats, which confirmed the results above. In conclusion, the pharmacokinetic behavior of baicalin was significantly altered in type 2 diabetic rats after orally administrated Radix scutellariae extract, which may partly result from the increased activity of intestinal β-glucuronidase under the pathological state of type 2 diabetes mellitus. 相似文献
20.
拟南芥悬浮细胞生长特性及其继代培养条件 总被引：2，自引：1，他引：1
研究了拟南芥悬浮细胞的生长特性及其继代培养条件。结果表明:在每个7d一次的继代周期中,拟南芥悬浮细胞的生长表现出明显的S型生长曲线。正常培养条件下,继代后2-4 d出现快速生长,此后生长量迅速下降,但接种量不同,其继代后悬浮细胞生物量及快速增长发生时期不同。维持7 d继代周期的理想接种量为起始悬浮液按10 mL／50 mL稀释。接种量小,生长迟缓,甚至不能增殖。培养基中不同激素及不同蔗糖含量均会对其生长产生极明显的影响,在B5 0．2 mg／L NAA条件下反复继代后的细胞,再加入外源NAA时,反而会抑制其生长。蔗糖含量以30 g／L最好,蔗糖含量低,悬浮生物量及细胞活性明显下降。 相似文献