Catalpol stimulates VEGF production via the JAK2/STAT3 pathway to improve angiogenesis in rats' stroke model.

ETHNOBOTANICAL RELEVANCE: Catalpol is the main active component of the radix from Rehmannia glutinosa Libosch, which has pleiotropic protective effects in neurodegenerative diseases, ischemic stroke, metabolic disorders and others AIM: Catalpol has been shown to have neuroprotective, neurorepair, and angiogenesis effects following ischemic brain injury. However, its molecular mechanisms are still poorly understood. In previous studies, the JAK2/STAT3 signaling pathway was found to play a role in neuroprotection and angiogenesis. This study investigated the role of catalpol in stimulating angiogenesis via the JAK2/STAT3 pathway after permanent focal cerebral ischemia (pMCAO). METHODS: Rats were subjected to right middle cerebral artery occlusion through electrocoagulation and were treated with catalpol (5mg/kg), AG490 was also used to inhibit STAT3 phosphorylation (pSTAT3). RESULTS: Following stroke, Catalpol improved the neuroethology deficit, increased the cerebral blood flow (CBF) of infarcted brain and upregulated EPO and EPOR. AG490 suppressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3), ultimately inhibited VEGF mRNA expression, which reduced VEGF protein expression and inhibited stroke-induced angiogenesis. However, Catalpol enhanced stroke-induced STAT3 activation and subsequently restored STAT3 activity through the recovery of STAT3 binding to VEGF. Moreover, Catalpol reversed the effect of AG490 on STAT3 activation and nuclear translocation, restored the transcriptional activity of the VEGF promoter by recruiting STAT3 to the VEGF promoter, improved VEGF mRNA and protein expression, increased angiogenesis, reduced the difference in CBF between the infarcted and intact brain and ameliorated the neuroethology behaviors after stroke. CONCLUSION: Catalpol affects neuroprotection and angiogenesis via the JAK2/STAT3 signaling pathway, which is mediated by STAT3 activation and VEGF expression. Catalpol may be used as a potential therapeutic drug for stroke.

Review of Catalpol’s pleiotropic signaling pathways / 中国药理学通报

Catalpol is a kind of iridoid,which has wide pharma-cological activities,including anti-cerebral ischemia,improving senile dementia,anti-inflammation,inhibiting capillary permea-bility,relieving pain,anti-tumor,antidiarrheal,reducing blood sugar level,protecting liver,and anti-aging.The mechanisms of Catalpol effects have been well studied.Signaling pathways in-clude NF-κB signaling pathway,PI3K/AKT signaling pathway, BDNF /TrkB signaling pathway,JAK2 /STAT3 /angiogenesis sig-naling pathway,MAPK signaling pathway,TGF-β/Smad signa-ling pathway,and ACh signaling pathway.We reviewed related signaling pathways of Catalpol effects,in order to broaden the understanding of molecular mechanism and signaling pathways of Catalpol,to know the status of catalpol,and to provide new di-rection to study Catalpol.

CSK-conjugated PLGA nanoparticles enhance oral delivery of insulin / 中国生化药物杂志

Objective To investigate the effects of CSK-conjugated PLGA nanoparticles on oral delivery of insulin in vitro and in vivo.Method CSK-INS-NPs were prepared by double-emulsion. Nanoparticle size、zeta potential and entrapment efficiency were measured. The efficiency of cellular uptake on Caco-2 cells in vitro was evaluated. The hypoglycemic effects were evaluated by monitoring the glucose levels in diabetic rats. Results The average sizes was(134. 4 ± 15)nm and their PDI values were less than 0.3.The insulin entrapment efifciency was around 71%. The cellular uptake of CSK-INS-NPs by Caco-2 cells was 2.8 times higher than INS-NPs. The CSK-INS-NPs transferred more insulin across the Caco-2 cell monolayer than INS-NPs and insulin solution did. In vivo experiments,the CSK-INS-NPs could reduce the blood glucose level of diabetic rats after oral administration in 10 h.Conclusion Compared with insulin solution,CSK-INS-NPs enhanced the insulin through Caco-2 cell monolayer by transcellular pathway and may be a potential delivery system for Oral Delivery of Insulin.

Progress in studies of pharmacological action and mechanisms of catalpol on brain diease / 中国中药杂志

Catalpol is a effective components of rehmannia root, it have many pharmacological actions, such as anti-brain ischemia, anti-senile dementia, promoting neuro-remodeling and reducing capillary permeability and so on.

HPLC determination of catalpol in cerebrospinal fluid of rats / 中国中药杂志

<p><b>OBJECTIVE</b>To establish an HPLC method for determination of catalpol in CSF (cerebrospinal fluid) of rats.</p><p><b>METHOD</b>Rats were intravenously injected 1.0 g x L(-1) catalpol physiological saline, and the sample of CSF from subarachnoid space of the cerebrum 40 minutes of injection. The sample of CSF from normal rats was used for blank control, the all samples were preserved in a refrigerator of - 20 degrees C, and use HPLC was employed to determine the catalpol content. The separation of catalpol was performed on Hypersil C18 reversion phase chromatographic column. The mobile phase consisted of water-acetonitrile (99.5: 0.5) with a flow rate of 1.0 mL x min(-1) and detection wavelength of 210 nm.</p><p><b>RESULT</b>The linear range of catalpol in CSF was 0.5-40 mg x L(-1) (r = 0.999 7). The absolute recoveries were (90.2 +/- 1.71)%, (89.1 +/- 1.17)% and (86.9 +/- 0.98)%; and the methodological recoveries were (99.8 +/- 1.98)%, (101.1 +/- 3.04)%, (100.1 +/- 2.30)% respectively. The within-day and between-day derivation RSD were less than 4%. Catalpol was stable in a refrigerator of -20 degrees C for 15 days.</p><p><b>CONCLUSION</b>The method is simple and accurate for the determination of the content of catalpol in CSF.</p>

Construction, expression and in vitro biological effects of idiotype Ig Fab fragment of B-chronic lymphocytic leukemia / 华中科技大学学报（医学）（英德文版）

The purpose of this study was to construct expression vectors of idiotype (Id) SmIg in patients with B-chronic lymphocytic leukemia and to express them in E.coli to obtain recombinant Id, and to investigate the effect of the protein on the proliferation and secretion of IL-2 and IFN-gamma of stimulated peripheral blood mononuclear cells (PBMC) in vitro. Light chain gene and Fd fragment of heavy chain gene were inserted into fd-tet-DOG2 vector to construct fd-tet-DOG2-Fab. Fab gene was further cloned into expression vector pHEN2 to construct the soluble expression vector pHEN2-Fab. After induction by IPTG, Fab protein was purified by Ni-NTA-chromatography. MTT was used to determine the effects of purified protein on the proliferation of stimulated PBMC in vitro and the concentrations of IL-2 and IFN-gamma in the culture supernatants were detected by ELISA. The results showed that recombinant pHEN2-Fab expression vector was constructed successfully. Fab protein was expressed in positive clone after induced by IPTG and two specific bands at 24-25 kD position were observed by SDS-PAGE electrophoresis. Proliferation of PBMC could be induced by purified Fab and the concentrations of IL-2 and IFN-gamma in culture supernatants were increased significantly after induction. It was suggested that the expression vector of SmIg Fab fragment was constructed successfully, and expressed and secreted from E. coli. The Fab protein could induce proliferation of PBMC and promote secretion of IL-2 and IFN-gamma.

Quality Standard Study on Danqi Tablets / 浙江中医药大学学报

[Objective] To set up standard method of quality to Danqi Tablets.[Method] Take HPLC to make nature authentication,take reverse HPLC to test the content of salvianolc acid B in the preparation.[Result] The authentication is strong in attribute and has good repetition,the measurement has good linear relation,the recycle rate is 101.7%,RSD 1.77%.[Conclusion] The quality standard can effectively control the quality of Danqi Tablets.