1.Establishment of LC-MS/MS method for the determination of forsklin in rat plasma and its pharmacokinetics
Dianwei SONG ; Decai WANG ; Zhiyun MENG ; Ruolan GU ; Meihui SHI ; Zhuona WU ; Jingze WANG ; Guifang DOU
Journal of International Pharmaceutical Research 2012;(2):149-153
Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1% formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4% and RE values between -3.5 % and 3.8%.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.
2.Determination of aconitine in dog tissue homogenates by HPLC-MS/MS and its application to in vitro metabolic stability study
Cuiping YANG ; Sha LIAO ; Tianhong ZHANG ; Jinglai LI ; Xiaoying WANG ; Jinxiu RUAN ; Zhenqing ZHANG
Journal of International Pharmaceutical Research 2012;(3):256-260
Objective To develop a HPLC-MS/MS method for the determination of aconitine and study thein vitro metabolic stability of aconitine in dog tissue homogenates.Methods The chromatographic separation was performed on a C18 column.The mobile phase consisted of acetonitrile and water with 0.2% formic acid and 5 mmol/L ammonium acetate.A triple quadrupole tandem mass spectrometer equipped with an electrospray ionization interface source was used for the quantitative determination in the positive selective reaction monitor mode.Aconitine was incubated with dog tissue homogenates and samples were withdrawn at different time points and precipitated by acetonitrile with internal standards citalopram.Results Aconitine showed good linear relationship over the range from 5 to 500 ng/ml.The recoveries of aconitine were between 85.73% and 92.12% at three QC concentration levels.The intra- and inter-day precisions were 5.32% - 8.95% and 5.45% - 8.86%,respectively.After incubation,about 20% of aconitine were cleared in the liver and small intestine,and t1/2 were 460.6 and 521.3 min,respectively.But none was metabolized in the stomach and kidney.Conclusion These results demonstrated that aconitine was mainly metabolized in the liver and small intestine at a slow rate.
3.Competitiveα-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid receptor antagonists:research advances
Dian XIAO ; Lingxiao WANG ; Xinbo ZHOU ; Song LI
Journal of International Pharmaceutical Research 2014;(4):407-412
α-Amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA) receptor, a subtype of ionotropic glutamate receptors widely distributed in the central nervous system, mediates the fast excitatory neurotransmission. Meanwhile more and more evidence indicates that AMPA receptor plays an important role in synaptic plasticity as well as central sensitization, and it also has close relationships with nervous system diseases. Over stimulation of AMPA receptor would produce excitotoxicity, leading to neuronal damage and finally resulting in a multitude of nervous system diseases, such as epilepsy, amyotrophic lateral scelerosis,Parkinson′s dis-ease. Competitive AMPA receptor antagonists that downregulate AMPA receptor′s function are of great importance in the prevention and treatment of nervous system diseases. This article reviews the research advances of competitive AMPA receptor antagonists.
4.Overviews and analysis of the U.S. FDA′s new approvals in 2014 first half year
Journal of International Pharmaceutical Research 2014;(4):493-502
In the first half of 2014, the U.S. Food and Drug Administration (FDA) approved 46 new drugs, including 10 new molecular entities and 10 new biologic license applications. According to the prescription information for professionals, this article introduces the description, mechanism of action and clinical studies, briefly describs the box warning, indications and usage, dosage and administration, dosage form and strength, contraindications, warning and precautions, adverse reactions, drug interaction and use in special population of these new drugs. In addition, the “first events” in the history of new drug research, development and approval are also discussed.
5.Galloyl glucosidic constituents of Choerospondias axillaries and their in vitro anti-tumor, anti-hypoxia and anti-bacteria activities
Changwei LI ; Chengbin CUI ; Bing CAI ; Bing HAN ; Mingming LI ; Ming FAN
Journal of International Pharmaceutical Research 2014;(4):449-455
Objective To investigate gallic acid-derived chemical constituents of Choerospondias axillaries (Roxb.) Burtt. et Hill., and evaluate their in vitro anti-tumor, anti-hypoxia and anti-bacteria activities. Methods The aimed chemical constituents were isolated by various chromatographic means, and their structures were identified by physicochemical and spectroscopic data. MTT method was employed to evaluate anti-tumor and anti-hypoxia activities. Antibacterial activities were tested by paper disc method. Results Seven compounds 1-7 were isolated from the stem barks of Choerospondias axillaries (Roxb.) Burtt. et Hill. and identified as gallic acid(1), gallic acid ethyl ether(2), 1-O-galloyl-β-D-glucose(3), 1,6-di-O-galloyl-β-D-glucose(4), 1,4-di-O-galloyl-β-D-glucose(5), 1,4,6-tri-O-galloyl-β-D-glucose(6), and 1,3,4,6-tetra-O-galloyl-β-D-glucose(7). Compounds 1, 2 and 4-6 significantly inhibited K562 cells with the IC50 values of 2.9, 14.6, 39.1, 40.2, 41.2 μg/ml, respectively, and 3 and 7 also showed a slight inhibition of the K562 cells with the inhibition rate of 20.8% and 30.1% at 100 μg/ml respectively. Compounds 1-7 showed protective effects on anoxia-induced injury in cultured ECV304 and PC12 cells at the concentrations showing no significant cytotoxicity, and 5-7 also showed an antibacterial effect on Staphylococcus aureus ATCC6538 to a certain extent. Conclusion Compounds 2-7 were isolated from the genus Choerospondias for the first time. It was the first time to report 1-7 as anti-tumor and anti-hypoxia constituents of Choerospondias axillaries, and the anti-hypoxia activity for 1-7 was also recorded for the first time in the present study.
6.Main biologics for anti-autoimmune disease:research advances
Weihua HOU ; Wei MO ; Min YU
Journal of International Pharmaceutical Research 2014;(4):424-428
Immune system is a security guard to help human body repel or remove bacteria, viruses, parasites and other fore-ign invaders .But when some tissue components or the immune system itself become abnormal, it can not distinguish friend from foe accurately and may attack our own tissue then cause some clinical symptoms, leading to autoimmune diseases. Nearly 5 % of the world's population suffer from various autoimmune diseases. By now in addition to control the formation of autoantigens such as infection,tiredness, the main biologics used in clinic are immunoregulators to block pathological autoimmune response and then to create a new proper immune response. Recently, new biologics to treat autoimmune disease come into being one after another, and this article gives a brief overview about research progress in anti-autoimmune disease biologics.
7.Physicochemical properties of a polysaccharide RAP-B-1 from Rubus amabilis and its immunomodulating effects
Yulin DIAO ; Hao MA ; Jinwei REN ; Guiqiang ZHANG ; Shuai LI ; Junjie SHAN ; Bin LIU
Journal of International Pharmaceutical Research 2014;(4):461-467
Objective To investigate the physicochemica l properties and immunobiological activity of a polysaccharide (RAP-B-1) from stems of Rubus amabilis. Methods The crude polysaccharide (RAP) was obtained successively by boiling, ethanol precipitating and dialyzing. RAP was isolated with DEAE-cellulose and Sephadex G-100 to obtain a polysaccharide RAP-B-1. The physicochemical properties of RAP-B-1 were studied by hydrolysis, periodate oxidation, Smith degradation and methylation, CE, IR, NMR and GC-MS. The immunobiological activities were estimated by the proliferative activity of spleen lymphocytes and phagocytic activity of peritoneal macrophages in mice. Results The molecular weight of RAP-B-1 was 4.80×104 with specific optical rotation value [α] 20D+68.3 (c=1,H2O), and was composed of eight monosaccharides. The molar ratios were as Xyl: Ara: Glc: Rha:Gal: Man: GlcA: GalA = 1.0:6.9:0.8:1.1:6.9:0.3:0.5:3.3. RAP-B-1 was an arabinogalactan. The linkages of arabinose were →1) Ara (2,3→,→1) Ara(5→and→1) Ara, and the linkages of galactose were→1) Gal(4→,→1) Gal(6→and→1) Gal. RAP-B-1 could improve the proliferative activity of spleen T cells(P<0.05) and booste phagocytic activity of peritoneal macrophages at 50μg/ml concentration(P<0.01). Conclusion RAP-B-1 is an arabinogalactan and has immunobiological activity.
8.Thrombolysis of plasmin and its derivatives:research advances
Rongzeng LIU ; Wei MO ; Min YU
Journal of International Pharmaceutical Research 2014;(3):296-300
All of the thrombolytic agents currently approved for use in humans are plasminogen activators, the application of which is limited by bleeding complications at vascular injury sites and plasminogen content in the thrombus. Plasmin is rapidly neutral-ized in the circulation by α2-antiplasmin and tolerated without bleeding. With the application of catheter-based delivery, the unique bio-chemical properties of plasmin make it a safe and effective direct fibrinolytics. Plasmin derivatives, including miniplasmin,Δ-plasmin and microplsmin, display more thrombolysis efficacy and better hemostatic safety in preclinical study and clinical trials. This review sum-marizes the current information on plasmin and its derivatives, including the advances on biochemical properties, preclinical and clinical trials.
9.PD-1/PD-L1 signaling pathway and its application in tumor
Shi WANG ; Longlong LUO ; Ming LV ; Yuanfang MA
Journal of International Pharmaceutical Research 2015;(2):143-147
PD-1/PD-L1 signaling pathway as a T cell immune response co-stimulatory signaling pathway plays an important role in adaptive immunity. PD-1 is a major co-receptor expressing on T cells, binding with its ligands(PD-L1 and PD-L2), PD-1 can inhibit T cell activation and protect the body against the attacks from its own immune system. In addition to adjusting and maintaining autoimmune tolerance, in tumor cells PD-L1 expression is up-regulated, while in the virus-infected T cells PD-L1 expression is also upregulated. PD-1 / PD-L1 are involved in the tumor and infectious pathogen immune evasion, thus blocking the PD-1 / PD-L1 signaling pathway has become a hot research of cancer and chronic diseases. Currently, there are several anti-PD-1 or PD-L1 monoclonal antibodies approved by the FDA to enter clinical studies, which have shown significant anti-cancer effect.
10.Pulsatile delivery pellets:research advances
Hang FENG ; Ying LI ; Xingguo MEI
Journal of International Pharmaceutical Research 2015;(4):483-487
Under physiological conditions, many vital functions of the body are controlled by transient release of bioactive substances at a specific time and site. Based on the circadian rhythm character of disease and chronotherapeutic conceptions, pulsatile delivery system has been designed to achieve optimal therapeutic effect and reduce the toxic and side-effect. In recent years, more and more studies are focused on the pulsatile multiparticulate drug delivery system. Pulsatile multiparticulate system possesses many benefits, such as no risk of dose dumping, predictable gastric emptying, flexible release patterns and increased bioavailability. Based on these premises, the aim of this review is to summarize the major design methods of pulsatile multiparticulate and the research progress.