Thiazolidine-2,4-dione derivatives as potential α-glucosidase inhibitors: Synthesis, inhibitory activity, binding interaction and hypoglycemic activity.

In order to find effective α-glucosidase inhibitors, a series of thiazolidine-2,4-dione derivatives (C1 âˆ¼ 36) were synthesized and evaluated for α-glucosidase inhibitory activity. Compared to positive control acarbose (IC50 = 654.35 ± 65.81 µM), all compounds (C1 âˆ¼ 36) showed stronger α-glucosidase inhibitory activity with IC50 values of 0.52 ± 0.06 âˆ¼ 9.31 ± 0.96 µM. Among them, C23 with the best anti-α-glucosidase activity was a reversible mixed-type inhibitor. Fluorescence quenching suggested the binding process of C23 with α-glucosidase in a static process. Fluorescence quenching, CD spectra, and 3D fluorescence spectra results also implied that the binding of C23 with α-glucosidase caused the conformational change of α-glucosidase to inhibit the activity. Molecular docking displayed the binding interaction of C23 with α-glucosidase. Compound C23 (8 âˆ¼ 64 µM) showed no cytotoxicity against LO2 and 293 cells. Moreover, oral administration of C23 (50 mg/kg) could reduce blood glucose and improve glucose tolerance in mice.

Synthesis and biological evaluation of indole derivatives containing thiazolidine-2,4-dione as α-glucosidase inhibitors with antidiabetic activity.

In order to develop potential α-glucosidase inhibitors with antidiabetic activity, twenty-six indole derivatives containing thiazolidine-2,4-dione were synthesized. All compounds presented potential α-glucosidase inhibitory activities with IC50 values ranging from 2.35 ± 0.11 to 24.36 ± 0.79 µM, respectively compared to acarbose (IC50 = 575.02 ± 10.11 µM). Especially, compound IT4 displayed the strongest α-glucosidase inhibitory activity (IC50 = 2.35 ± 0.11 µM). The inhibition mechanism of compound IT4 on α-glucosidase was clarified by the investigation of kinetics studies, fluorescence quenching, CD spectra, 3D fluorescence spectra, and molecular docking. In vivo antidiabetic experiments demonstrated that oral administration of compound IT4 would suppress fasting blood glucose level and ameliorate their glucose tolerance and dyslipidemia in diabetic mice.

Identification of 1,3,4-oxadiazolyl-containing ß-carboline derivatives as novel α-glucosidase inhibitors with antidiabetic activity.

In this study, we designed and synthesized a novel class of 1,3,4-oxadiazolyl-containing ß-carboline derivatives, i.e., compounds f1∼f35 as potential α-glucosidase inhibitors. All the synthesized compounds possessed outstanding α-glucosidase inhibitory activity with the IC50 values in the range of 3.07-15.49 µM, representing that they are 36∼183-fold more active than a positive control, acarbose (IC50 = 564.28 µM). Among them, compound f26 exhibited the highest α-glucosidase inhibitory activity (IC50 = 3.07 µM) and was demonstrated to function as a reversible and noncompetitive inhibitor. Mechanistic studies by means of 3D fluorescence spectra, CD spectra and molecular docking suggested that complexation of compound f26 with α-glucosidase through hydrogen bonds and hydrophobic interactions, led to changes in the conformation and secondary strictures of α-glucosidase and further the inhibition of the enzymatic activity. In vivo results showed that oral administration of compound f26 (50 mg/kg/day) could obviously reduce the levels of fasting blood glucose and improve glucose tolerance and dyslipidemia in diabetic mice. The present findings suggest that compound f26 is exploitable as a potential lead compound for the development of new α-glucosidase inhibitors with antidiabetic activity.

Preparation and Evaluation of Auxiliary Permeable Microneedle Patch Composed of Polyvinyl Alcohol and Eudragit NM30D Aqueous Dispersion.

Poor transdermal permeability limits the possibility of most drug delivery through the skin. Auxiliary permeable microneedles (AP-MNs) with a three-dimensional network structure can effectively break the skin stratum corneum barrier and assist in the transdermal delivery of active ingredients. Herein, we propose a simple method for preparing AP-MNs using polyvinyl alcohol and Eudragit NM30D for the first time. To optimize the formulation of microneedles, the characteristics of swelling properties, skin insertion, solution viscosity, and needle integrity were systematically examined. Additionally, the morphology, mechanical strength, formation mechanism, skin permeability, swelling performance, biocompatibility, and in vitro transdermal drug delivery of AP-MNs were evaluated. The results indicated that the microneedles exhibited excellent mechanical-strength and hydrogel-forming properties after swelling. Further, it proved that a continuous and unblockable network channel was created based on physical entanglement and encapsulation of two materials. The 24 h cumulative permeation of acidic and alkaline model drugs, azelaic acid and matrine, were 51.73 ± 2.61% and 54.02 ± 2.85%, respectively, significantly enhancing the transdermal permeability of the two drugs. In summary, the novel auxiliary permeable microneedles prepared through a simple blending route of two materials was a promising and valuable way to improve drug permeation efficiency.

JLX001 attenuates blood-brain barrier dysfunction in MCAO/R rats via activating the Wnt/ß-catenin signaling pathway.

JLX001, a new dihydrochloride of Cyclovirobuxine D (CVB-D), has bioactivities against ischemia injury. The blood-brain barrier (BBB) disruption is involved in the pathogeneses of ischemic stroke. This study was designed to explore the effect and potential mechanism of JLX001 on the BBB after ischemic stroke. Rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) to mimic cerebral ischemia in vivo. In vitro, rat primary brain microvascular endothelial cells (PBMECs) were cultured and exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). Posttreatment of JLX001 for 15 days after MCAO/R improved the behavior, learning and memory ability. Pretreatment of JLX001 for 3 days significantly attenuated infarct volume, lessened brain edema, mitigated BBB disruption and decreased the neurological deficit score in MCAO/R rats. Moreover, JLX001 increased cell viability and reduced sodium fluorescein leakage after OGD/R injury. In addition, JLX001 increased the expressions of Claudin-5 and Occludin, decreased the expression of MMP-9 both in vivo and in vitro. Moreover, immunofluorescence staining and western immunoblotting results showed that JLX001 increased the expressions of tight junction proteins via activating Wnt/ß-catenin signal pathway in vivo and in vitro, which may be associated with the activation of PI3K/Akt signaling. Besides, XAV939 (an inhibitor of the Wnt/ß-catenin pathway) proved the connection of JLX001 and Wnt/ß-catenin pathway. These results suggest that JLX001 alleviates BBB disruption after MCAO/R and OGD/R possibly by alleviating MMP-9 and activating the Wnt/ß-catenin signaling pathway.

JLX001 improves myocardial ischemia-reperfusion injury by activating Jak2-Stat3 pathway.

AIMS: To investigate the preclinical pharmacodynamics and mechanism of JLX001 against myocardial ischemia reperfusion (MI/R) for clinical application. MATERIALS AND METHODS: In vivo, SD rats were given intragastric administration for 5 days, and the MI/R model was established by ligating/releasing the left anterior descending coronary artery. In vitro, the oxygen-glucose deprivation/reperfusion (OGD/R) model was established after the drug was pre-incubated for 24 h in H9C2 cells. The infract size was determined by TTC staining. Left ventricular function of MI/R rats was detected by echocardiography. The level of histopathological score was determined by hematoxylin-eosin (HE) staining. The level of superoxide dismutase (SOD), malondialdehyde (MDA), creatine kinase (CK), lactic dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) were determined by relevant kits. The level of apoptosis was measured by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Hoechst staining. The expression of p-Jak2, p-Stat3, Bax, Bcl-2, TNF-α, IL-1ß protein were determined by western blot. KEY FINDINGS: JLX001 can significantly improve left ventricular function, reduce myocardial infract size, histopathological score, the level of MDA, CK, LDH, TNF-α, IL-1ß and the expression of Bax protein, significantly increase the activity of SOD, Bcl-2 protein expression, p-Jak2 protein expression, p-Stat3 protein expression in rat heart tissues and H9C2 cells. These effects can be reversed by AG490 which is a specific inhibitor of Jak2-Stat3 pathway. SIGNIFICANCE: JLX001 can alleviate MI/R injury by inhibiting myocardial apoptosis, inflammation, and oxidative stress via Jak2-Stat3 pathway in vivo and in vitro.

Therapeutic effects of JLX-001 on ischemic stroke by inducing autophagy via AMPK-ULK1 signaling pathway in rats.

(3ß,5α,16α,20S)-4,4,14-trimethyl-3,20-bis(methylamino)-9,19-cyclopregnan-16-ol-dihydrochloride (JLX-001), a structural analogue of cyclovirobuxine D (CVB-D), is a novel compound from synthesis. This study aims to confirm the therapeutic effects of JLX001 on ischemic stroke (IS) and research its induction of autophagy function via 5'-AMP-activated protein kinase (AMPK)-Human Serine/threonine-protein kinase (ULK1) signaling pathway activation. The therapeutic effects of JLX001 were evaluated by infarct sizes, brain edema, neurological scores and proportion of apoptotic neurons in Sprague-Dawley (SD) rats with middle cerebral artery occlusion/reperfusion (MCAO/R). The number of autophagosomes was obtained by transmission electron microscopy. The expression of LC3-II was measured by immunofluorescence. p-AMPK and activated ULK1 were detected by western blots. Results showed that JLX001 treatment markedly alleviated cerebral infarcts, edema, neurological scores and proportion of apoptotic neurons in MCAO/R rats. The number of autophagosomes was increased, accompanying with the increased expressions of LC3-II, p-AMPK and ULK1. In summary, JLX001 attenuates cerebral ischemia injury and the underlying mechanisms may relate to inducing autophagy via AMPK-ULK1 signaling pathway activation.

JLX001 Ameliorates Ischemia/Reperfusion Injury by Reducing Neuronal Apoptosis via Down-Regulating JNK Signaling Pathway.

JLX001, a novel compound with similar structure with cyclovirobuxine D (CVB-D), has been proved to exert therapeutical effects on permanent focal cerebral ischemia. However, the protective effects of JLX001 on cerebral ischemia/reperfusion (I/R) injury and its anti-apoptotic effects have not been reported. We investigated the efficacy of JLX001 in two pharmacodynamic tests (pre-treatment test and post-treatment) with rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The pharmacodynamic tests demonstrated that JLX001 ameliorated I/R injury by reducing infarct sizes and brain edema. The results of Morris water maze, neurological scores, cylinder test and posture reflex test implied that JLX001 improved the learning, memory and motor ability after MCAO/R in the long term. Anti-apoptotic effects of JLX001 and its regulation of cytosolic c-Jun N-terminal Kinases (JNKs) signal pathway were confirmed in vivo by co-immunofluorescence staining and western immunoblotting. Furthermore, primary cortical neuron cultures were prepared and exposed to oxygen glucose deprivation/reoxygenation (OGD/R) for in vitro studies. Cytotoxicity test and mitochondrial membrane potential (MMP) test showed that JLX001 enhanced cell survival rate and maintained MMP. Flow cytometry and TdT-mediated dUTP-X nick end labeling (TUNEL) staining demonstrated the anti-apoptotic effects of JLX001 in vitro. Likewise, JLX001 regulated JNK signal pathway in vivo, which was also confirmed by western immunoblotting. Collectively, this study presents the first evidence that JLX001 exerted protective effects against I/R injury by reducing neuronal apoptosis via down-regulating JNK signaling pathway.

JLX001 Modulated the Inflammatory Reaction and Oxidative Stress in pMCAO Rats via Inhibiting the TLR2/4-NF-κB Signaling Pathway.

Inflammatory reactions and oxidative stress play critical roles in cerebral ischemic injuries. Microglia are activated after ischemic injury. Activated microglia produce neurotoxic proinflammatory factors and reactive oxygen species (ROS), which have been demonstrated closely related TLR2/4-NF-κB signal pathways. This study was to evaluate the effect of JLX001 against ischemic injury and investigate the mechanisms. The permanent middle cerebral artery occlusion (pMCAO) model was employed in rats. The neurobehavioral score, brain infarction rate, brain water content, pathological changes, immunohistochemical staining, biochemical index (T-AOC, SOD, and MDA), proinflammatory factors (IL-1ß, TNF-α, and NO), expression of TLR2/4 and nuclear translocation of NF-κB p65 were determined. To explore probable underlying mechanism of the neuroprotective effect of JLX001, BV-2 cells were exposed to in oxygen-glucose deprivation (OGD) for 4 h to mimic ischemic injury in vitro. The result showed that JLX001 significantly decreased neurological deficit score, infarct size, and brain edema, attenuated pathological changes, inhibited the activation of microglia, improved the process of oxidative stress, reduced the release of proinflammatory cytokines and downregulated TLR2/4-NF-κB signal pathway. Moreover, OGD reduced BV2 cell viability, induced oxidative damage, increased the release of proinflammatory factors and activated TLR2/4-NF-κB signal pathway, which was significantly reversed by the intervention of JLX001. This study demonstrates that JLX001 is effective in protecting the brain from ischemic injury, which may be mediated by regulating oxidative stress, inflammation and inhibiting TLR2/4-NFκB signal pathway.

Therapeutic effects of JLX001 on cerebral ischemia through inhibiting platelet activation and thrombus formation in rats.

(3ß,5α,16α,20S)-4,4,14-trimethyl-3,20-bis(methylamino)-9,19-cyclopregnan-16-ol-dihydrochloride (JLX001), a derivative of cyclovirobuxine D (CVB-D), is a novel compound from synthesis. This study aims to confirm the therapeutic effect of JLX001 on cerebral ischemia and researchits antiplatelet and antithrombosis activities via thromboxane (TXA2)/phospholipase C-ß-3(PLCß3)/protein kinase C (PKC) pathway suppression. The therapeutic effects of JLX001 was evaluated by infarct sizes, brain edema and neurological scores in Sprague-Dawley (SD) rats with middle cerebral artery occlusion (MCAO). Brain TXA2 and prostacyclin (PGI2) were measured by enzyme-linked immunosorbentassay (ELISA). P-PLCß3and activated PKC were detected by immunohistochemical method. Adenosine diphosphate (ADP) or 9, 11-dieoxy-11α, 9α-epoxymethanoeprostaglandin F2α (U46619) was used as platelet agonist in the in vivo and in vitro platelet aggregation experiments. Clotting time and bleeding time were determined. Besides, two whole-animal experiments including arteriovenous shunt thrombosis and pulmonary thromboembolism model were conducted. Results showed that JLX001 treatment markedly alleviated cerebral infarcts, edema, and neurological scores in permanent middle cerebral artery occlusion (pMCAO) rats. Brain TXA2 level, p-PLCß3and activated PKC were decreased, while PGI2level had no significant change. Besides, JLX001 inhibited platelet aggregation induced by ADP or U46619 and exhibited anti-coagulation effects with a minor bleeding risk. In the two whole-animal experiments, JLX001 inhibited thrombus formation. In summary, JLX001 attenuates cerebral ischemia injury and the underlying mechanisms relate to inhibiting platelet activation and thrombus formation via TXA2/PLCß3/PKC pathway suppression.

[Studies on pharmacokinetics of artemether patch in mice].

OBJECTIVE: To establish a HPLC-MS-MS determination method of artemether (ARM) and active derivatives DHA, and compare the pharmacokinetic parameters of ARM after transdermal and oral administration. METHOD: The mice were divided two groups (transdermal and oral) by parallel design. ARM and active derivatives DHA in plasma of mice at different sampling time were determined. The pharmacokinetic parameters were calculated by DAS 2.0 and by statistic analysis. RESULT: compare oral administration, the pharmacokinetic parameters of ARM after transdermal, Cmax Tmax , AUC(0-t) MRT, had significant difference (P < 0.05). CONCLUSION: The artemether patch has long-releasing property.