Pharmacokinetic properties of lansoprazole (30-mg enteric-coated capsules) and its metabolites: A single-dose, open-label study in healthy Chinese male subjects

Cytochrome bc1-aa3 oxidase supercomplex as emerging and potential drug target against tuberculosis

The cytochrome bc1-aa3 supercomplex plays an essential role in the cellular respiratory system of Mycobacterium Tuberculosis. It transfers electrons from menaquinol to cytochrome aa3 (Complex IV) via cytochrome bc1 (Complex III), which reduces the oxygen. The electron transfer from a variety of donors into oxygen through the respiratory electron transport chain is essential to pump protons across the membrane creating an electrochemical transmembrane gradient (proton motive force, PMF) that regulates the synthesis of ATP via the oxidative phosphorylation process. Cytochrome bc1-aa3 supercomplex in M. tuberculosis is, therefore, a major drug target for antibiotic action. In recent years, several respiratory chain components have been targeted for developing new candidate drugs, illustrating the therapeutic potential of obstructing energy conversion of M. tuberculosis. The recently available cryo-EM structure of mycobacterial cytochrome bc1-aa3 supercomplex with open and closed conformations has opened new avenues for understanding its structure and function for developing more effective, new therapeutics against pulmonary tuberculosis. In this review, we discuss the role and function of several components, subunits, and drug targeting elements of the supercomplex cytochrome bc1-aa3, and its potential inhibitors in detail.

Development of Saikosaponin D Liposome Nanocarrier with Increased Hepatoprotective Effect Against Alcoholic Hepatitis Mice

The mortality rate of ethanol induced liver disease has substantially raised to alert level with an increasing use of alcohol, but development of definite hepatoprotective drug is still challenging. The efficacy of Saikosaponin D, one of the natural herbal medicine has been studied in different diseases. Nonetheless, its clinical application is restricted by poor bioavailability, stability and solubility. This study sought to develop a Saikosaponin D loaded liposome via thin film hydration method. The surface morphology, encapsulation efficiency and drug loading capacity were detected with transmission electron microscopy and HPLC, in vitro dissolution was via dialysis method, but efficacy and safety evaluation was through pharmacokinetics, while the assessment of hepatoprotective activity on alcohol induced acute hepatitis mice models was conducted. The optimized liposomes showed significant greater therapeutic effect on liver, through decreased serum levels of alanine transaminase (ALT) and aspartate transaminase (AST), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), total cholesterol (TC) and triglyceride (TG) in liver homogenate. In contrast, levels of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were increased significantly. Pathological study exhibited remarkable alteration of hepatitis liver architecture to almost normal state after administration of Saikosaponin D liposome. The increased hepatoprotective effect of Saikosaponin D liposome was observed during the attenuation of alcoholic hepatitis in mice, which might be ascribable to the anti-oxidative and anti-inflammatory properties of the drug. This study provides a theoretical basis for developing advanced system of Saikosaponin D delivery for the promotion of the therapeutic effects of the liposome against various kinds of diseases.

Application of nanoparticles for oral delivery of acid-labile lansoprazole in the treatment of gastric ulcer: in vitro and in vivo evaluations

The aim of this study was to develop nanoparticles for oral delivery of an acid-labile drug, lansoprazole (LPZ), for gastric ulcer therapy. LPZ-loaded positively charged Eudragit(®) RS100 nanoparticles (ERSNPs-LPZ) and negatively charged poly(lactic-co-glycolic acid) nanoparticles (PLGANPs-LPZ) were prepared. The effect of charge on nanoparticle deposition in ulcerated and non-ulcerated regions of the stomach was investigated. The cellular uptake of nanoparticles in the intestine was evaluated in a Caco-2 cell model. The pharmacokinetic performance and ulcer healing response of LPZ-loaded nanoparticles following oral administration were evaluated in Wistar rats with induced ulcers. The prepared drug-loaded ERSNPs-LPZ and PLGANPs-LPZ possessed opposite surface charge (+38.5±0.3 mV versus -27.3±0.3 mV, respectively) and the particle size was around 200 nm with a narrow size distribution. The negatively charged PLGANPs adhered more readily to the ulcerated region (7.22%±1.21% per cm(2)), whereas the positively charged ERSNPs preferentially distributed in the non-ulcerated region (8.29%±0.35% per cm(2)). Both ERSNPs and PLGANPs were prominent uptake in Caco-2 cells, too. The nanoparticles sustained and prolonged LPZ concentrations up to 24 hours, and the half-life and mean residence time of LPZ were prolonged by 3.5-fold and 4.5-fold, respectively, as compared with LPZ solution. Oral administration of LPZ-loaded nanoparticles healed 92.6%-95.7% of gastric ulcers in Wistar rats within 7 days.