Two-step emulsification for the fabrication of homogeneous PCL microspheres encapsulating geniposidic acid with antioxidant properties

The mortality rate of neurological disorders is increasing globally,and natural antioxidant geniposidic acid(GPA)holds great potential in the treatment of neuronal oxidative damage.Nevertheless,its inherent instability constrains its pragmatic utilization.Herein,we introduced a drug delivery system capable of protecting unstable natural active compounds from degradation.Among the various methods for preparing drug-loaded microspheres,the emulsification-solvent evaporation technique is one of the most commonly employed due to its efficiency and simplicity.Nevertheless,this method results in microspheres with heterogeneous particle sizes.To address this limitation,we developed a two-step emulsification method involving stirring and homogenization.Using the biocompatible,synthetic,biodegradable polymer polycaprolactone(PCL)as the drug delivery carrier,we prepared GPA-loaded PCL microspheres via the two-step emulsification method.The results demonstrated that the microspheres possessed uniform particle size(polydispersity index=0.12),excellent drug loading capacity(∼4.86%),sustained drug release profiles(∼68.55%in 264 h),and biocompatibility(cell viability>85%).The in vitro tests showed that the microspheres exerted antioxidant effects by scavenging reactive oxygen species(ROS)induced by oxidative stress,thereby protecting neuronal cells from oxidative damage.This work presents a promising new approach for the treatment of neuronal oxidative damage.

Development of HPLC Method to Evaluate Drug-processing Technique of Eucommiae Cortex

Objective To establish a RP-HPLC method investigate the processing technique and mechanism of Eucommiae Cortex.Methods The RP-HPLC method was applied to simultaneously determining six ingredients,geniposidic acid,geniposide,genipin,chlorogenic acid,(+)-pinoresinol-di-β-D-glucopyranoside,and(+)-syringaresinol-di-β-D-glucopyranoside,in the different processed barks of Eucommia ulmoides.Results The valid method with good accuracy could be well used to study the processing technique of E.ulmoides;Besides,target ingredients in E.ulmoide were decreased within 6 h when they were processed.Conclusion Established RP-HPLC is a reliable method which could be used to research the processing technique of the barks of E.ulmoides.Moreover,the result of this study could be provided with significant evidence of processed barks of E.ulmoides.

Protein Tyrosine Phosphatase 1B Inhibitors from Plantago asiatica

Objective To identify the active compounds for protein tyrosine phosphatase 1B(PTP1B) from the seeds of Plantago asiatica.Methods Bioassay-guided fractionation resulted in the isolation of iridoid glucosides(1-5) with PTP1B inhibitory activity.Results Five compounds were identified as desacetylhookerioside(1),melittoside(2),geniposidic acid(3),10-O-acetyl-geniposidic acid(4),and alpinoside(5).Conclusion Isolated compounds 35 inhibit PTP1B with IC50 values ranged from(16.3 ± 1.1) to(19.8 ± 1.2) μmol/L.