Monoterpene indole N-oxide alkaloids from Tabernaemontana corymbosa and their antimicrobial activity.

Tabernaemontana corymbosa is a traditional folk medicine. In our research, six monoterpene indole N-oxide alkaloids and their parent alkaloids were obtained from the stem bark of T. corymbosa, including seven new alkaloids (1-7) and five known alkaloids (8-12). Their structures and absolute configurations were elucidated by extensive spectroscopy, quantum chemical calculations, and DP4+ probability analyses. The antimicrobial activity of the obtained compounds was evaluated, among which alkaloids 4, 8, 12 showed significant antimicrobial activity against Staphylococcus aureus with an MIC value of 6.25 µg/mL, while alkaloids 11, 12 showed moderate antimicrobial activity against Bacillus subtilis with an MIC value of 25 µg/mL.

Chemotherapeutics for Toxoplasma gondii: Molecular Biotargets, Binding Modes, and Structure-Activity Relationship Investigations.

Toxoplasmosis, an infectious zoonotic disease caused by the apicomplexan parasite Toxoplasma gondii (T. gondii), is a major worldwide health problem. However, there are currently no effective options (chemotherapeutic drugs or prophylactic vaccines) for treating chronic latent toxoplasmosis infection. Accordingly, seeking more effective and safer chemotherapeutics for combating this disease remains a long-term and challenging objective. In this paper, we summarize possible molecular biotargets, with an emphasis on those that are druggable and promising, including, without limitation, calcium-dependent protein kinase 1, bifunctional thymidylate synthase-dihydrofolate reductase, and farnesyl diphosphate synthase. Meanwhile, as important components of medicinal chemistry, the binding modes and structure-activity relationship profiles of the corresponding inhibitors were also illuminated. We anticipate that this information will be helpful for further identification of more effective chemotherapeutic interventions to prevent and treat zoonotic infections caused by T. gondii.

Bone marrow-derived mesenchymal stem cells repair severe acute pancreatitis by secreting miR-181a-5p to target PTEN/Akt/TGF-ß1 signaling.

BACKGROUND: Severe acute pancreatitis (SAP) is associated with high morbidity and mortality. Bone marrow mesenchymal stem cells (BMSCs) have shown obvious protective effect on SAP. However, little is known about the underlying mechanism. The objective of this study is to unravel the role and regulatory mechanism of miR-181a-5p in BMSCs-mediated pancreatic repair. METHODS: BMSCs were isolated from Sprague-Dawley rats and characterized by flow cytometry and Oil Red O staining. Sodium taurocholate- and caerulein-induced models were used as SAP models in vivo and in vitro, respectively. Pancreatic injury were evaluated by H&E and histopathological analysis, as well as by measuring levels of amylase, lipase and cytokines. qRT-PCR and western blotting were performed to detect the level of miR-181a-5p and the protein levels of PTEN/Akt, respectively. ELISA was conducted to detect the levels of TNF-α, IL-1ß, IL-6, angiopoietin, IL-4, IL-10 and TGF-ß1. The apoptotic rate of AR42J cells was quantitated by concurrent staining with Annexin-V-FITC and PI. RESULTS: BMSCs significantly attenuated pancreatic injury in SAP rats by reducing inflammatory infiltration and necrosis, and this effect was abolished by CXCR4 agonist AMD3100. ADM3100 exhibited more severe pancreatic injury and decreased miR-181a-5p levels in the pancreas and serum compared to SAP group. Overexpression of miR-181a-5p in BMSCs (BMSCs-miR-181a-5p) markedly potentiated the protective effect of BMSCs by reducing histological damage and levels of amylase and lipase. Moreover, BMSCs-miR-181a-5p dramatically reduced levels of angiopoietin, TNF-α, IL-1ß and IL-6, but induced the levels of IL-4 and IL-10. In caerulein-treated AR42J cells, co-culturing of BMSCs-miR-181a-5p alleviated caerulein-induced increase of amylase and lipase, and apoptosis via PTEN/Akt/TGF-ß1 signaling. CONCLUSION: BMSCs alleviate SAP and reduce inflammatory responses and apoptosis by secreting miR-181a-5p to target PTEN/Akt/TGF-ß1 signaling. Hence, BMSCs-miR-181a-5p could serve as potential therapeutic target for SAP.

Effect of solid state transition on the physical stability of suspensions containing bupivacaine lipid microparticles.

Bupivacaine lipid microparticles were prepared and evaluated as a parenteral sustained-release dosage form for postoperative pain management. Bupivacaine free base was incorporated into a molten tristearin matrix and lipid micro-particles were subsequently formed from this molten mixture by a spray-congealing process. A 3% injectable bupivacaine lipid microparticle suspension was prepared by dispersing 30% bupivacaine lipid microparticles in an aqueous medium containing carboxymethylcellulose (CMC), mannitol, and Tween 80. Upon room temperature storage, the fluid suspension gradually changed into a nonflowing semisolid (gelation) as a result of crystal growth of bupivacaine. However, suspensions prepared with bupivacaine lipid microparticles that were previously annealed at an elevated temperature remained fluid upon long-term storage. Differential scanning calorimetry (DSC), x-ray powder diffraction (XRPD), and isoperibol solution calorimetry were used to investigate the changes in the solid-state properties of tristearin and bupivacaine in the lipid microparticles before and after the heat treatment. The DSC and XRPD results indicate that after 24 hours of heating at 40 degrees C, tristearin was completely converted from the unstable alpha form to the stable beta form. Using the isoperibol solution calorimetric method, bupivacaine was found to transform into a more stable form after the lipid microparticles were heated at 60 degrees C for 24 hours. The generation of the unstable solid forms of tristearin and bupivacaine was attributed to the resolidification of both components from the molten mixture during the spray-congealing process.