Protease-activated receptor-1 (PAR1), a G-protein-coupled receptor, plays a critical role in thrombin-mediated platelet aggregation. It is regarded as a promising antithrombosis target that is unlikely to result in bleeding. Here, we describe the synthesis of a series of novel PAR1 antagonists by borrowing the chiral fragment of andrographolide, an easily accessible natural molecule from Andrographis paniculata, to produce natural product/synthesis hybrids. An in vitro PAR1 inhibition assay and an in vivo pharmacokinetic profile led to the identification of compound 39 as the best PAR1 inhibitor. The further in vitro and ex vivo antiplatelet aggregation assays of compound 39 indicated that compound 39 was a potent antiplatelet agent. In addition, this compound is metabolically stable and displays a favorable pharmacokinetic profile with an elimination half-life of 3.1 h, which could be treated as a promising candidate for further clinical development.

Stichopus japonicus Polysaccharide (SJP) is a sulfated polysaccharide from the body wall of the sea cucumber, Stichopus japonicus. Fucoidan is a heparinoid compound that belongs to a family of sulfated polyfucose polysaccharides. Heparin is a glycosaminoglycan. SJP, fucoidan, and heparin profoundly promoted stromal cell-derived factor 1 alpha (SDF-1α)-induced neural stem cell (NSC) migration in a concentration-dependent manner. In addition, the basal migration capacity of cells was significantly promoted after incubation with SJP, fucoidan, or heparin. Interaction of SJP, fucoidan, or heparin with SDF-1α efficiently showed additive effects on the promotion of cell migration from the neurosphere. SJP, fucoidan, or heparin interaction with SDF-1α treatment could increase Nestin expression. SDF-1α modulated by SJP, fucoidan, or heparin activated the CXCR4 receptor and directed cellular migration via the activation of the PI3K/Akt/FOXO3a signaling pathway. Moreover, interaction of SJP, fucoidan, or heparin with SDF-1α effectively promoted NSC migration and induced SDF-1α and CXCR4 expressions. Results suggested that SJP, fucoidan, and heparin might be good candidates for alleviating injury-initiated signals to which NSCs respond.

In this report, the sulfated polysaccharide (SJP) isolated from the sea cucumber Stichopus japonicus can protect PC12 from Na2S2O4-induced hypoxia/reoxygenation (H/R) injury. SJP effectively improves cell viability and reduces extracellular LDH release in PC12 cells after H/R. Moreover, SJP significantly increases SOD activity but decreases MDA levels. Our experiments showed that SJP could significantly reduce cell apoptosis caused by H/R. Our current results demonstrate that SJP suppressed the activation of MAPKs, resulting in a significant decrease in Bax/Bcl-2 ratio, cleaved caspase-3/caspase-3, p53 phosphorylation, and cytochrome c release in a concentration-dependent manner. MAPK is closely related to H/R injury. SJP inhibited JNK1/2 and p38 MAPK activation but did not affect the increased ERK1/2 expression. These results suggested that JNK1/2 and p38 MAPK pathways could be involved in SJP-mediated attenuation of PC12 H/R injury. SJP prevented PC12 H/R injury in a dose-dependent manner, indicating that SJP may be developed as a candidate drug to prevent or treat cerebral ischemia–reperfusion injury.

Two-factor and three-level fractional factorial design was employed for evaluation of the effect of Glycine and Triton X-100 on the secretion and expression of ZZ–EGFP fusion proteins. Varying contents of glycine (0%, 1%, 2%) and Triton X-100 (0%, 1%, 2%) were added into shaking flasks, respectively, and supplied with appropriate volume of ampicillin (total 9 combinations; group at concentration zero serving as control) to promote more ZZ–EGFP diffuse into liquid culture medium. Fluorescent intensity in the culture supernatant was detected. A standard curve could be generated on the basis of fluorescent intensity and protein concentration. The expression level of ZZ–EGFP fusion proteins was estimated by checking the protein standard curve concentration fluorescene intensity. Results show that when the culture medium contains 2% Glycine and 1% Triton X-100, the expression level of ZZ–EGFP was able to be greatly increased. Further experiments revealed that absorbance value (A600) in the experiment group, whose culture medium contains 2% Glycine and 2% Triton X-100, is significantly lower than other groups in the present experiment. These results indicate that the culture medium containing appropriate quantity of Glycine and Triton X-100 is favourable to the secretion and expression level of ZZ–EGFP in gene-engineering bacteria Escherichia coli HB101.

The neuronal damage following cerebral ischemia is a serious risk to stroke patients. The aim of this study was to investigate the neuroprotective effects of alkaloid extract from Leonurus heterophyllus (LHAE) on cerebral ischemic injury. After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), some rats were intraperitoneally administered different doses of LHAE (3.6, 7.2, 14.4 mg/kg, respectively). Neurological examination was measured in all animals. Infarct volume, myeloperoxidase (MPO) activity, levels of nitrate/nitrite metabolite (NO) and apoptosis ratio of nerve fiber in brain were determined. The results showed that LHAE at 7.2 mg/kg or 14.4 mg/kg exerted significantly decreasing neurological deficit scores and reducing the infarct volume on rats with focal cerebral ischemic injury (p < 0.05). At those dose, the MPO content were significantly decreased in ischemic brain as compared with model group (p < 0.05). LHAE at 14.4 mg/kg significantly decreased the NO level compared with the model group (p < 0.05). In addition, LHAE significantly decreased the apoptosis ratio of nerve fiber compared with the model group (p < 0.05). This study suggests that LHAE may be used for treatment of ischemic stroke as a neuroprotective agent. Further studies are warranted to assess the efficacy and safety of LHAE in patients.