Latest ArticlesA droplet microfluidic chip system was developed for drug screening against Candida albicans. The microfluidic chip was designed and prepared for the formation of droplets. Alamar blue was selected as an indicator for its characteristic of fluorescence mission in live cells. Four antifungal drugs (amphotericin B, caspofungin, 5-fluorocytosine, terbinafine) and a new drug (iodiconazole) were selected as model drugs to test the microfluidic chip approach. At the same time, 96-well microplate method was performed to verify the applicability of the chip method. The results showed that the developed droplet microfluidic chip platform was able to complete the antifungal susceptibility test within 2 h. In comparison with the 96-well microplate method, the microfluidic chip method showed a consistence of 100% with regard to the minimum inhibition concentrations and less reagent consumption. The new droplet microfluidic chip method is simple, rapid and suitable for rapid screening of antifungal drugs.
A series of ursolic acid derivatives were synthesized by the introduction of 4-chloroindole compounds at A ring and esterification and amidation at C-28 position, which structures were characterized by 1H NMR, MS and etc. The cytotoxic activity of derivatives was evaluated against HepG2 and SGC7901 cells in vitro by MTT assay, in which paclitaxel and adriamycin were used as a positive control. The results indicated that all of derivatives can inhibit cell proliferation in HepG2 and SGC7901 cells with a better activity than ursolic acid. Especially, the compounds 6 and 12 showed significant antitumor activity comparable to the paclitaxel. The compounds are worthy to be studied further.
Interleukin-6 (IL-6)/signal transducers and activators of transcription (STAT) signaling pathway is closely related to the development and progression of atherosclerosis (AS). Taking Chinese natural product berberine (BBR) as the leading compound, a series of novel BBR analogues defined on different types of substituents on position 3 or/and 9 were designed, synthesized and evaluated for their inhibitory activities on phosphorylation of STAT-1 and STAT-3 induced by IL-6. The structure-activity relationship indicated that introduction of rigid fragment on position 3 or 9 was beneficial for enhancing their activities. Among them, compounds 2b and 9 exhibited the most satisfactory potency. The study revealed that the compounds 2b and 9 exhibit anti-inflammatory potencies via activating AMPK, and down-regulation of phosphorylation of STAT1 and STAT3 induced by IL-6 in HUVEC cells. These results suggest that BBR derivatives may inhibit the inflammatory response mediated by the IL-6/STAT signaling pathway through regulation of AMPK, which provides useful insight into the development of BBR derivatives for treatment of atherosclerosis.
The quality of Scutellaria baicalensis Georgi has a close relationship to the harvest time. With the annual and biennial Scutellaria baicalensis Georgi in different harvest periods as samples, we detected the dynamic changes of chemical compositions in their contents by UHPLC-MS/MS metabolomics technology, then identified the biomarkers of different harvest periods and analyzed their changes in content, finally analyzed the correlation among different metabolites. The results showed that chemical compositions of different harvest periods were obviously different, and showed regular changes. According to the results, if the flavonoid aglycones are chosen as the target components, the proposed harvest time could be May. If flavonoid glycosides, the time is from July to August. Plant metabolomics methodology based on UHPLC-MS/MS can be used to detect the chemical compositions of Scutellaria baicalensis Georgi in different harvest periods, which provide a reference to the optimum harvest period of Scutellaria baicalensis Georgi, and also provide a new method of quality evaluation of traditional Chinese medicinal materials.
The purpose of this article was to study the pharmacokinetic characteristics of YZG-331, plasma protein binding and metabolic stability in vivo and in vitro. Plasma and tissue concentrations of YZG-331 were determined in mice and rats after administration by LC-MS/MS analysis orally or intravenously. The plasma protein binding of YZG-331 with human, dog, monkey, rat and mouse were measured by ultrafiltration method. The stability of YZG-331 in animal and human plasma, liver microsomes, intestinal bacteria and artificial gastrointestinal fluid was also investigated in vitro. The results show that YZG-331 was absorbed rapidly in both mice and rats after oral administration, while the absorption and elimination saturation YZG-331 were also observed. The bioavailability of YZG-331 was much higher in male mice (51.2%) than that in female mice (27.7%), however, the bioavailability in male rats (27.1%) was lower than that in female rats (78.7%). YZG-331 was widely distributed in different tissues of mice, especially in certain regains of brain, including thalamus, hippocampi, cortical and striatal. YZG-331 was found to bind to human, dog, monkey, rat and mouse plasma protein in vitro (93.3%-98.9%) without significant concentration dependences and species differences. YZG-331 was stable in animal and human plasma, simulated gastric/intestinal fluid and liver microsomal incubations, except rat liver microsomes and intestinal flora. Therefore, we concluded that:the pharmacokinetics of YZG-331 in mice and rats have gender and species differences; YZG-331 was widely distributed in vivo including brain, the targets of the agent; YZG-331 had a high affinity to plasma protein and was metabolized by rat liver microsomes and intestinal flora.
Nimodipine is a selective calcium channel antagonist of cerebral vessels smooth muscle and also has polymorphs. It hasn't been reported that different crystal forms influence the metabolism process in huge animals like rhesus monkeys in vivo. This article may provide reference in the control of the quality of nimodipine and quality consistency evaluation. The powder X-ray diffraction (PXRD) method was used to identify different crystal forms and the dissolution test in vitro was used to detect the dissolution. The LC-MS method of assay nimodipine in rhesus monkey plasm was established to determine pharmacokinetics characters of different tablets from different crystal forms in rhesus monkey in vivo. As a result, the tablets inherit difference crystal forms and the dissolution of reference tablets is 1.3% higher than crystal tablets. However, the maximal blood concentration (Cmax) of crystal tablet was 37.3% higher than reference tablet and AUC of crystal tablet was 29.8% higher than reference tablet. After administrated 2.5 mg·kg-1 orally, calculated pharmacokinetics characters were observed as following:Cmax was 381.4 ±327.3 and 178.0 ±214.8 μg·L-1; AUC0-t was 853.1 ±500.7 and 646.5 ±430.3 μg·L-1·h respectively. The serum concentration result of different nimodipine tablets in rhesus monkeys in vivo suggests that polymorphs has a significantly distinction, which points out that controlling the crystal forms of nimodipine is essential to ensure the therapeutic efficacy. It is essential to execute quality consistency evaluation.
The aim of this study is to establish the in vitro methods for the study of induction and inhibition on CYP450 by drugs, and to validate the analytical method and incubation system. A method for the simultaneous determination of eight metabolites of seven subtypes of CYP450 enzymes probe substrates in human liver microsomes (HLM) was established and validated. The incubation system was optimized to confirm the incubation time and protein concentration of HLM, the enzyme activity of seven subtypes of CYP450 enzymes in HLM was determined, and the inhibition effects on each CYP450s were checked by positive controls. The method for the simultaneous determination of three metabolites of subtypes of CYP450 enzymes was established and validated in human primary cultured hepatocytes (HPCH) using the incubation medium. The enzyme activity of three subtypes of CYP450 enzymes in HPCH was determined, and the total RNA was extracted from HPCH after incubation. The expression of CYP450 enzymes were measured by Taqman fluorescence probe method. The induction effects on each CYP450s were examined using the positive controls. The established methods for the determination of metabolites of probe substrates were fully validated, and the results were conformed to the requirements of bioanalytical method validation. The induction and inhibition effects on each CYP450s were checked by positive controls. The established in vitro methods for the study of drug induction and inhibition on CYP450 were simple and reliable, which could be used in the investigation of enzyme induction or inhibition properties of new drug candidates and to evaluation the metabolic interactions of concomitant medication in clinical.
In this study, we used low molecular weight heparin (LH) as hydrophilic sides, doxorubicin (DOX) as hydrophobic sides, and indocyanine green (ICG) as a photosensitive drug to prepare pH-sensitive self-assembled polymeric micelles (LH-DOX/ICG). The micelles were prepared by dialysis, and evaluated for stability, pH sensibility in vitro, hemolytic test and photo-thermal effect. Wound healing test was used to evaluate the anti-metastatic effects. MTT assay and apoptosis detection kit were used to evaluate the cytotoxicity of micelles against melanoma B16F10 cells. The size of the micelles was (148.7 ±2.1) nm and the zeta potential was (-30.7 ±1.1) mV. The drug-loading content of DOX and ICG were 11.82% and 5.59%, respectively. The micelles exhibited spherical in shape, fairly uniform size. The micelles were stable within 48 h in 50% fetal bovine serum phosphate buffer. The release of DOX was pH-sensitive, while the release of ICG was sustained. The micelles were biocompatible and safe as indicated by the hemolytic test. In vitro photo-thermal effect indicated LH-DOX/ICG micelles had similar photo-thermal effect to the free ICG. Wound healing test showed that the micelles had a good ability to inhibit tumor migration with laser irradiation. MTT assay and cell apoptosis assay indicated that LH-DOX/ICG micelles displayed more efficient anti-tumor effect after near infrared laser compared to LH-DOX micelles. LH-DOX/ICG micelles are promising for the therapeutic effect of phototherapy and chemotherapy in combination for melanoma.
Photo-sensitive reactive oxygen species (ROS) responsive liposomes loaded with 1, 4, 8, 11, 15, 18, 22, 25-octabutoxypalladium phthalocyanine[PdPC(OBu)8] and doxorubicin hydrochloride (DOX) (LPD) were prepared by (NH4)2SO4-gradient method. LPD was characterized with transmission electron microscopy (TEM), dynamic light scattering particle size, zeta potentials, photo-sensitive ROS-responsive DOX release behaviors and the serum stability in vitro. LPD cytotoxicity, DOX uptake and singlet oxygen production in MCF-7 cells were evaluated. The results showed that the particle size of LPD was (169.3 ±1.2) nm, PDI of LPD was 0.198 ±0.003 and zeta potentials of LPD was (-39.8 ±0.8) mV. The accumulated release of DOX reached 95.5% in 5 min under 730 nm laser irradiation (300 mW·cm-2). The DOX uptake of liposome was increased and 1O2 was generated. The half inhibition concentration (IC50) of DOX in LPD with irradiation group was decreased by 85.7% and no irradiation group was decreased by 67.9% compared with free DOX group in MCF-7 cells. Therefore, photo-sensitive ROS-responsive liposomes would be a promising drug delivery system for tumor therapy.
Calcium signaling plays a critical role in response to various abiotic and biotic stresses in plants. Preliminarily evidence showed that calcium signaling perceived and transduced the harmful signaling generated from continuous cropping stress in R. glutinosa. To investigate the roles of calcium signaling in continuous cropping injury formation, the key genes involved in calcium signaling transduction were identified in R. glutinosa transcriptome through bioinformatic methods. Furthermore, the calcium ion concentration in both normal and continuous cropping R. glutinosa root cells were measured by potassium pyroantimonate precipitation and calcium fluorescence method. As a result, a set of 84 calcium signaling-related genes, including 5 CaMs, 12 CBLs, 21 CDPKs, 21 CIPKs, 16 CMLs, and 9 CRKs were captured in R. glutinosa transcriptome. The analysis of expression profile in continuous cropping compared to normal growth R. glutinosa indicated that continuous cropping stress significantly increased the expression of calcium signaling-related genes in continuous cropping R. glutinosa. At the same time, the abundance levels of 12 calcium signaling-related genes quantified by qPCR further validated the high expression of calcium signaling-related genes presented in continous cropping R. glutinosa. In addition, the continuous cropping condition significantly promoted the accumulation of intracellular calcium ions in R. glutinosa based on two methods of potassium pyroantimonate precipitation and calcium fluorescence. This study verified the possible roles of calcium signaling in the formation of continuous cropping injury on molecular and cellular level, which lays a solid foundation for illuminating formation mechanism of continuous cropping injury on molecular level.
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