Platelet-activating Factor Antagonist Research Articles

Pd(II)-Catalyzed C4-Selective Alkynylation of Indoles by a Transient Directing Group.

With alanine as a transient directing group, Pd-catalyzed regioselective alkynylation at the indole C4-position was successfully established in a good yield. The total synthesis of the PAF antagonist demonstrated the synthetic utility of this protocol. The regioselectivity was explicitly proven by the prepared C4-selective palladacycle intermediate in the catalytic process and the DFT calculation of the energy barriers of C4- and C2-site-selective C-H activation of indole.

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review.

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

Design and Evaluation of Ginkgolides Gastric Floating Controlled Release Tablets Based on Solid Supersaturated Self-nanoemulsifying.

Ginkgolides are receptor antagonist of platelet activating factor with great clinical prospect, but its application is limited by its low solubility, short half-life and poor alkaline environment stability. It is difficult to solve these problems with a single drug delivery system. In this study, supersaturated self-nanoemulsifying gastric floating tablets of ginkgolides were developed through the combination of solid supersaturated self-nanoemulsifying drug delivery system (solid S-SNEDDS) and gastric retentive floating drug delivery system (GFDDS) to solve these problems of ginkgolides. Solid S-SNEDDS was prepared by D-optimal mixture design, normalization method and single factor experiment. The properties of solid-S-SNEDDS were studied by TEM, PXRD, FT-IR, SEM and in vitro drug release profile. Then, the optimal formulation of stomach floating tablet was obtained through single factor experiment and center composite design, followed by the study of in vitro release, model and mechanism of release, in vitro buoyancy and kinetics of erosion and swelling. PXRD and FT-IR showed that the drug in solid S-SNEDDS existed in an amorphous manner and formed hydrogen bond with excipients. The results showed that the cumulative release of GA and GB in the optimal tablets was 96.12% and 92.57% higher than the simple tablets within 12 h. The release mechanism of the tablet was skeleton erosion and drug diffusion. In 12 h, the optimal tablets can float stably in vitro and release the drug at a constant rate, with a cumulative release of more than 80%. In summary, the combination of SNEDDS and GFDDS is a promising means to solve the problems of ginkgolides.

Enhancing both oral bioavailability and anti-ischemic stroke efficacy of ginkgolide B by preparing nanocrystals self-stabilized Pickering nano-emulsion

Ginkgolide B (GB), which has been demonstrated as the most efficacious naturally occurring platelet-activating factor (PAF) antagonist, is extensively utilized for the management of cardiovascular and cerebrovascular ailments. Nevertheless, its limited oral bioavailability is hindered by its low solubility in gastric acid and inadequate stability in intestinal fluid, thereby constraining its practical application. This study aimed to develop GB nanocrystals (GB-NCs) and GB nanocrystals self-stabilized Pickering nano-emulsion (GB-NSSPNE) using a miniaturized wet bead milling method. Comparative evaluations were conducted in vivo and in vitro to assess their effectiveness. The findings revealed that GB-NSSPNE, with its intact nanoparticle slow release and absorption, was more effective in enhancing the oral bioavailability of GB compared to the rapid release and absorption of GB-NCs. This finding suggests a potential novel strategy for the oral delivery of GB.

Biosynthesis of Phomactin Platelet Activating Factor AntagonistRequires a Two-Enzyme Cascade.

Phomactin diterpenoids possess a unique bicyclo[9.3.1]-pentadecane skeleton with multiple oxidative modifications, and are good platelet-activating factor (PAF) antagonists that can inhibit PAF-induced platelet aggregation. In this study, we identified the gene cluster (phm) responsible for the biosynthesis of phomactins from amarine fungus,Phoma sp. ATCC 74077. Despite the complexity of their structures, phomactin biosynthesis only requires two enzymes: a type I diterpene cyclase PhmA and a P450 monooxygenase PhmC. PhmA was found to catalyze the formation of the phomactatriene, while PhmC sequentially catalyzes the oxidation of multiple sites, leading to the generation of structurally diverse phomactins. The rearrangement mechanism of the diterpene scaffold was investigated through isotope labeling experiments. Additionally, we obtained the crystal complex of PhmA with its substrate-analogue FGGPP and elucidated the novel metal ion binding mode and enzymatic mechanism of PhmA through site-directed mutagenesis. This work provides the first insights into the biosynthesis of phomactins, laying the foundation for the efficient production of phomactin natural products using synthetic biology approaches.

Biosynthesis of Phomactin Platelet Activating Factor Antagonist Requires a Two‐Enzyme Cascade

AbstractPhomactin diterpenoids possess a unique bicyclo[9.3.1]pentadecane skeleton with multiple oxidative modifications, and are good platelet‐activating factor (PAF) antagonists that can inhibit PAF‐induced platelet aggregation. In this study, we identified the gene cluster (phm) responsible for the biosynthesis of phomactins from a marine fungus, Phoma sp. ATCC 74077. Despite the complexity of their structures, phomactin biosynthesis only requires two enzymes: a type I diterpene cyclase PhmA and a P450 monooxygenase PhmC. PhmA was found to catalyze the formation of the phomactatriene, while PhmC sequentially catalyzes the oxidation of multiple sites, leading to the generation of structurally diverse phomactins. The rearrangement mechanism of the diterpene scaffold was investigated through isotope labeling experiments. Additionally, we obtained the crystal complex of PhmA with its substrate analogue FGGPP and elucidated the novel metal‐ion‐binding mode and enzymatic mechanism of PhmA through site‐directed mutagenesis. This study provides the first insight into the biosynthesis of phomactins, laying the foundation for the efficient production of phomactin natural products using synthetic biology approaches.

Abstract TP212: Robust Neuroprotection With PAF-R Antagonist Plus AT-NPD1 In Experimental Ischemic Stroke: Dose-response And Therapeutic Window

Objective: We examined the neuroprotective efficacy, including dose-responses and therapeutic window of 1) LAU-0901, receptor antagonist of the bioactive phospholipid mediator platelet-activating factor (PAF-R) that downregulates pro-inflammatory signaling and has been shown efficacy in a stroke model and, 2) AT-NPD1 (Aspirin- triggered NPD1), its synthesis in the brain was discovered upon aspirin + DHA administration (Bazan et al. Exp Neurol., 2012) and induced cell-survival pathways, anti-inflammatory and neuroprotective activity in focal cerebral ischemia. Methods: Male SD rats underwent 2 hours of MCAo. Behavior testing (days 1-7) and ex vivo MRI on day 7 were conducted. In dose-response, rats were treated with LAU-0901 (45 and 60 mg/kg; IP), AT-NPD1 (111, 222, 333 μg/kg; IV), LAU-0901+AT-NPD1 (LAU-0901 at 3h and AT-NPD1 at 3.15h) or vehicle. In the therapeutic window, vehicle LAU-0901 (60 mg/kg), AT-NPD1 (222 μg/kg), and LAU-0901+AT-NPD1 were administered at 3, 4, 5, and 6h after onset of MCAo. Rats were perfused on day 7, and an ex vivo brain MRI was conducted using 11.7 T MRI. Hierarchal region splitting was used to distinguish the core from the penumbra. Results: LAU-0901 and AT-NPD1 treatments alone improved behavior by 40-42% and 20-30%, respectively, and LAU-0901+AT-NPD1 by 40% compared to the vehicle group. T2-weighted imaging (T2WI) volumes were reduced with all doses of LAU-0901 and AT-NPD1 by 73-90% and 67-83% and LAU-0901+AT-NPD1 by 94% compared to vehicle. In the therapeutic window, treatment with LAU-0901 and AT-NPD1 alone, when administered at 3h, improved behavior on day 7 by 35 and 28%. In contrast, LAU-0901+AT-NPD1, when administered at 3, 4, 5, and 6 hours, improved behavior by 50, 56, 33, and 26%. Ischemic core, penumbra, and total lesion volumes were dramatically reduced with LAU-0901+AT-NPD1 when administered at 3, 4, 5, and 6h by 93, 90, 82, and 84% compared to the vehicle. Conclusion: These data suggest that LAU-0901 and AT-NPD1 alone in low doses provide high-grade neuroprotection in the MCAo model. Combination therapy with LAU-0901 and AT-NPD1 is more effective than the single therapy, affording synergistic neuroprotection with improved neurological recovery when administered up to 6 h after focal cerebral ischemia in rats.

Ginkgolide B improved postoperative cognitive dysfunction by inhibiting microgliosis-mediated neuroinflammation in the hippocampus of mice

BackgroundPostoperative cognitive dysfunction (POCD) are a common complication of the central nervous system following surgery and anesthesia. The specific pathogenesis and effective therapeutics of POCD need to be further studied. Ginkgolide B (GB), a platelet-activating factor receptor-specific antagonist, has been suggested to have strong anti-inflammatory effects. Here we tested the effects and mechanism of GB on POCD of aged rats.MethodsNeurobehavioral tests were used to investigate the effect of GB pretreatment on POCD. The hippocampus were harvested to test the expression of proinflammatory cytokines by ELISA. The expression of the microglial marker ionized calcium-binding adaptor molecule-1 (Iba-1) in the hippocampus was evaluated by western blot assay and immunohistochemistry. A Nissl staining experiment was used to detect the neuronal numbers in the hippocampus.ResultsSurgery might result in the overexpression of platelet activating factor (PAF) in the plasma and hippocampus and might cause hippocampus-dependent memory impairment. GB pretreatment, inhibited the activation of microglia, reduced the levels of IL-1β and TNF-α, decreased the loss of neurons after surgery, and prevented POCD in aged rats.ConclusionOur findings suggested that PAF was involved in the development of POCD. Improvement of POCD by PAF antagonist GB was associated with the inhibition of microgliosis-mediated neuroinflammation and neuronal apoptosis in aged rats.

Synergistic Neuroprotection by a PAF Antagonist Plus a Docosanoid in Experimental Ischemic Stroke: Dose-Response and Therapeutic Window

ObjectiveWe tested the hypothesis that blocking pro-inflammatory platelet-activating factor receptor (PAFR) with LAU-0901 (LAU) plus administering a selected docosanoid, aspirin-triggered neuroprotectin D1 (AT-NPD1), which activates cell-survival pathways after middle cerebral artery occlusion (MCAo), would lead to neurological recovery. Dose-response and therapeutic window were investigated. Materials and methodsMale SD rats were subjected to 2 hours of MCAo. Behavior testing (days 1-7) and ex vivo MRI on day 7 were conducted. In dose-response, rats were treated with LAU (45 and 60 mg/kg; IP), AT-NPD1 (111, 222, 333 µg/kg; IV), LAU+AT-NPD1 (LAU at 3 hours and AT-NPD1 at 3.15 hours) or vehicle. In the therapeutic window, vehicle, LAU (60 mg/kg), AT-NPD1 (222 µg/kg), and LAU+AT-NPD1 were administered at 3, 4, 5, and 6 hours after onset of MCAo. ResultsLAU and AT-NPD1 treatments alone improved behavior by 40-42% and 20-30%, respectively, and LAU+AT-NPD1 by 40% compared to the vehicle group. T2-weighted imaging (T2WI) volumes were reduced with all doses of LAU and AT-NPD1 by 73-90% and 67-83% and LAU+AT-NPD1 by 94% compared to vehicle. In the therapeutic window, LAU+AT-NPD1, when administered at 3, 4, 5, and 6 hours, improved behavior by 50, 56, 33, and 26% and reduced T2WI volumes by 93, 90, 82, and 84% compared to vehicle. ConclusionsWe have shown here for the first time that LAU plus AT-NPD1 treatment affords high-grade neuroprotection in MCAo, equaling or exceeding that afforded by LAU or AT-NPD1 alone at considerably moderate doses. It has a broad therapeutic window extending to 6 hours after stroke onset.

Plasmalogenic Lipid Analogs as Platelet-Activating Factor Antagonists: A Potential Novel Class of Anti-inflammatory Compounds.

Plasmalogens and Platelet-Activating Factor (PAF) are both bioactive ether phospholipids. Whereas plasmalogens are recognized for their important antioxidant function and modulatory role in cell membrane structure and dynamics, PAF is a potent pro-inflammatory lipid mediator known to have messenger functions in cell signaling and inflammatory response. The relationship between these two types of lipids has been rarely studied in terms of their metabolic interconversion and reciprocal modulation of the pro-inflammation/anti-inflammation balance. The vinyl-ether bonded plasmalogen lipid can be the lipid sources for the precursor of the biosynthesis of ether-bonded PAF. In this opinion paper, we suggest a potential role of plasmalogenic analogs of PAF as modulators and PAF antagonists (anti-PAF). We discuss that the metabolic interconversion of these two lipid kinds may be explored towards the development of efficient preventive and relief strategies against PAF-mediated pro-inflammation. We propose that plasmalogen analogs, acting as anti-PAF, may be considered as a new class of bioactive anti-inflammatory drugs. Despite of the scarcity of available experimental data, the competition between PAF and its natural plasmalogenic analogs for binding to the PAF receptor (PAF-R) can be proposed as a mechanistic model and potential therapeutic perspective against multiple inflammatory diseases (e.g., cardiovascular and neurodegenerative disorders, diabetes, cancers, and various manifestations in coronavirus infections such as COVID-19).

Role of Platelet-activating factor and HO-1 in mediating the protective effect of rupatadine against 5-fluorouracil-induced hepatotoxicity in rats

5-fluorouracil (5-FU) is a widely used chemotherapeutic drug, but its hepatotoxicity challenges its clinical use. Thus, searching for a hepatoprotective agent is highly required to prevent the accompanied hepatic hazards. The current study aimed to investigate the potential benefit and mechanisms of action of rupatadine (RU), a Platelet-activating factor (PAF) antagonist, in the prevention of 5-FU-related hepatotoxicity in rats. Hepatotoxicity was developed in male albino rats by a single 5-FU (150 mg/kg) intra-peritoneal injection on the 7th day of the experiment. RU (3 mg/kg/day) was orally administrated to the rodents for 10 days. Hepatic toxicity was assessed by measuring both liver and body weights, serum alanine aminotransferase and aspartate aminotransferase (ALT and AST), hepatic oxidative stress parameters (malondialdehyde (MDA), nitric oxide levels (NOx), reduced glutathione (GSH), superoxide dismutase (SOD)), and heme oxygenase-1 (HO-1). Inflammatory markers expressions (inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNFα), interleukins; IL-1B, IL-6), the apoptotic marker (caspase-3), and PAF were measured in the hepatic tissue. 5-FU-induced hepatotoxicity was proved by the biochemical along with histopathological assessments. RU ameliorated 5-FU-induced liver damage as proved by the improved serum ALT, AST, and hepatic oxidative stress parameters, the attenuated expression of hepatic pro-inflammatory cytokines and PAF, and the up-regulation of HO-1. Therefore, it can be concluded that RU pretreatment exerted a hepatoprotective effect against 5-FU-induced liver damage through both its powerful anti-inflammatory, antioxidant, and anti-apoptotic effect.

Molecular Modelling Simulations and Inhibitory Effects of Naturally Derived Flavonoids Targeting Platelet-Activating Factor Receptor (PAFR)

Background:Platelet-activating factor (PAF) is an agonist mediator in the inflammatory process, which interacts with PAF receptor (PAFR) that eventually causes cancers, respiratory and neurodegenerative diseases. This interaction activates the mitogen-activated protein kinase (MAPK) pathway, leading to a pro-inflammatory cascade. The pathophysiological conditions due to activation of inflammatory cascade could be inhibited by PAF antagonists.Objectives:In this study, selected naturally derived flavonoids (flavone, biochanin A, and myricetin) with different functional groups were subjected to molecular modelling and experimental studies to investigate their potential as PAF antagonists.Method:Interactions of flavonoids and PAF were assessed via Autodock Vina for molecular docking and the AMBER program for molecular dynamic simulations. The experimentally antagonistic effects of the flavonoids were also conducted via PAF inhibitory assay to determine the IC50 values.Results:The findings of docking and dynamic simulations have revealed that all selected flavonoids interact with PAFR in the binding site with considerably good binding affinity up to - 9.8 kcal mol-1 as compared to cedrol (- 8.1 kcal mol-1) as a standard natural PAFR antagonist. The PAFR-flavonoid complexes exhibited four conserved active site residues, which included W73, F97, F174, and L279. The stability of all complexes was attained in a 30 ns simulation. The findings of in silico analyses were then compared to the experimental study on PAF inhibitory assay. Inhibitory effects of flavonoids against PAFR showed moderate activities, ranging from 27.8 – 30.8 μgM-1.Conclusion:All studied flavonoids could act as promising PAF antagonists with some enhancement in their structures to exhibit potent antagonistic activity. However, these naturally derived flavonoids demand further investigation at cellular and animal models to develop new PAF antagonist drug candidates for treating PAF-mediated diseases.

The effect of Ginkgo biloba EGb 761 on intestinal anastomotic healing in rats with ischemia-reperfusion induced in the lower extremities

Background/Aim: Remote ischemia-reperfusion (I-R) injury for anastomotic healing is a newly identified risk factor and there is a wide array of studies being conducted. This study aimed to reveal the negative effects of lower I-R on the colonic anastomotic healing process and examine the effects of Ginkgo biloba EGb 761 treatment, a platelet activating factor (PAF) antagonist, on anastomotic healing through the inhibition of pathological mechanisms of mediators causing these negative effects. Methods: Thirty-six Wistar-Albino rats were divided into sham, I-R and I-R+EGb 761 groups, each consisting of 12 rats. In the subjects in the sham group, an end-to-end anastomosis was performed by transecting the descending colon following midline laparotomy. In the I-R group, unilateral lower extremity ischemia was created by occluding the femoral artery and collaterals using a tourniquet from the most proximal segment of the left extremity. Then, the descending colon was transected, anastomosis was performed, and reperfusion was created by a tourniquet application at the 30th minute of ischemia. Different from the I-R (control) group, the subjects in the I-R+EGb 761 group were given two equal doses of 64 mg/kg/d Ginkgo biloba EGb 761 by the orogastric route until 10 days after surgery. After all subjects were sacrificed on the 10th day of surgery, the descending colon segment containing the anastomosis area was resected and samples were taken for bursting pressure and hydroxyproline measurements. Results: In the I-R group, anastomotic bursting pressure and perianastomotic hydroxyproline values were significantly lower compared to the sham group and the I-R+EGb 761 group. However, there was no statistically significant difference in these parameters between the sham and the I-R+EGb 761 groups. Conclusion: Colonic anastomotic bursting pressure and peri-anastomotic hydroxyproline values in the sham group were significantly decreased by lower extremity I-R, and this change was prevented with the use of EGb 761.

Effect of Ginkgolide in Ischemic Stroke patients with large Artery Atherosclerosis: Results from a randomized trial.

BackgroundDual antiplatelet therapy is considered beneficial in acute ischemic stroke (AIS) patients with intracranial artery stenosis (ICAS), with more bleeding events. Ginkgolide is shown to reduce platelet activation after infarction, which might be of benefit in AIS. We aimed to explore the effect of Ginkgolide in AIS patients with ICAS.MethodsThis was a randomized, double‐blinded, placebo‐controlled trial conducted at 61 centers in China. Within 72 h after onset, consecutive patients diagnosed as AIS with ICAS were randomized to either Ginkgolide or placebo treatment. The primary outcome was the composite of mortality and recurrent stroke (ischemic or hemorrhagic) during first 4 weeks in an intention‐to‐treat analysis. Secondary functional outcome was assessed by modified Rankin Scale and improvement of stroke severity was assessed by National Institution of Health Stroke Scale at day 28. Safety outcome was measured by the rate of severe adverse event (SAE).ResultsThere were 936 patients randomized to either Ginkgolide or placebo treatment. Their average age was 64.2 ± 10.4 years old and 36.0% of the patients were female. The composite index event occurred in six patients in placebo group, and none occurred in Ginkgolide group (risk ratio 1.01; 95% CI 1.00–1.02). There were more patients who achieved favorable outcome in Ginkgolide group, compared with that of the placebo group (OR 2.16, 95%CI 1.37–3.41). SAE occurred in five (1.1%) patients in the Ginkgolide group and three (0.6%) in the placebo group (OR0.60, 95CI% 0.14–2.53). Intracranial hemorrhage occurred in 1/473 (0.2%) in the placebo group.ConclusionsGinkgolide, working as PAF antagonist, may reduce recurrent stroke in AIS with ICAS patients within 72 hours after onset. It might be an optional treatment in moderate‐to‐severe AIS patients with ICAS. (http://www.chictr.org.cn Number as ChiCTR‐IPR‐17012310).

Antithrombotic properties of differently fed farmed gilthead sea bream: In vitro and in vivo studies

Background and Aims: During the last years, the replacement of fish oil, by plant oils in compounded fish feeds, is under investigation. Platelet-Activating Factor (PAF) is a potent inflammatory mediator implicated in atherosclerosis. PAF antagonists exist in olive oil by-products (OOP), and inhibit the development of atherosclerosis in animal models. Present work aims to evaluate the in vitro and in vivo antithrombotic properties of sea bream fed with the polar lipid extract from OOP enriched-diet (enriched fish; EF) versus sea bream fed with fish oil diet (conventional fish; CF).

Molecular Docking, Drug likeness Studies and ADMET prediction of Flavonoids as Platelet-Activating Factor (PAF) Receptor Binding

Studies and scientific research indicate that the platelet-activating factor (PAF) is a major pro-inflammatory mediator in the initiation and development of cancer. There is also evidence confirming that PAF is an integral part of suppressing the immune system and promoting the appearance of a malignant tumor. For this reason, it is useful to analyze the molecular docking data of eleven flavonoids derivatives isolated from the active leaf extracted from chromolaena odorata with their anti-PAF activity. As a result, it is evident that the natural product of flavonoids may have a positive effect in the development of both therapeutic and preventive agents for platelet activating factor (PAF) antagonist and suggests potential guidelines for the design of PAF inhibitors. Based on the docking score analysis, drug likeness study, and ADMET prediction. We found that six compounds respect all drug-likeness rules and can be used as a potent molecule for inhibition of platelet activating factor (PAF).

Replacement of L-amino acid peptides with D-amino acid peptides mitigates anti-PEG antibody generation against polymer-peptide conjugates in mice

The generation of anti-PEG antibodies in response to PEGylated proteins, peptides, and carriers significantly limits their clinical applicability. IgM antibodies mediate the clearance of these therapeutics upon repeat injection, resulting in toxicity and hindered therapeutic efficacy. We observed this phenomenon in our polymer platform, virus-inspired polymer for endosomal release (VIPER), which employs pH-sensitive triggered display of a lytic peptide, melittin, to facilitate endosomal escape. While the polymer-peptide conjugate was well tolerated after a single injection, we observed unexpected mortality upon repeat injection. Thus, the goal of this work was to enhance the safety and tolerability of VIPER for frequent dosing. Based on previous reports on anti-PEG antibodies and the adjuvant activity of melittin, we characterized the antibody response to polymer, peptide, and polymer-peptide conjugates after repeat-dosing and measured high IgM titers that bound PEG. By substituting the L-amino acid peptide for its D-amino acid enantiomer, we significantly attenuated the anti-PEG antibody generation and toxicity, permitting repeat-injections. We attempted to rescue mice from L-melittin induced toxicity by prophylactic injection of platelet activating factor (PAF) antagonist CV-6209, but observed minimal effect, suggesting that PAF is not the primary mediator of the observed hypersensitivity response. Overall, we demonstrated that the D-amino acid polymer-peptide conjugates, unlike L-amino acid polymer-peptide conjugates, exhibit good tolerability in vivo, even upon repeat administration, and do not elicit the generation of anti-PEG antibodies.

Detection of Lipase Activity in Cells by a Fluorescent Probe Based on Formation of Self-Assembled Micelles.

SummaryReliable and sensitive detection of lipase activity is essential for the early diagnosis and monitoring of acute pancreatitis or progression of digestive diseases. However, the available fluorescent probes for detection of lipase activity are only implemented in a hexane-water two-phase system due to the nature of heterogeneous catalysis of lipase, thus limiting their applications in direct imaging of lipase activity in living cells and tissues. Here we designed and synthesized a “turn on” fluorescent probe CPP based on self-assembled micelles for hydrolysis of lipase. The CPP probe exhibits high selectivity and excellent sensitivity for the detection of lipase in such a homogeneous system and is successfully applied for monitoring lipase activity in pancreatic AR42J cells, tissues, and serums. Taken together, the fluorescent CPP probe not only provides a tool for diagnostic potential in pancreatic disease but also demonstrates an application potential for micelle self-assembly-based development of biological probes.

Rupatadine, a dual antagonist of histamine and platelet-activating factor (PAF), attenuates experimentally induced diabetic nephropathy in rats.

The role of histamine and platelet activating factor (PAF) as involved mediators in the pathophysiology of diabetic complications, in particular diabetic nephropathy (DN), has become a new focus of concern. Accordingly, the present study designed to explore the effect of rupatadine (RUP), a dual antagonist of histamine (H1) and PAF, on the progression of experimentally induced DN in rats. Rats were divided into five groups: control, RUP alone, streptozotocin (STZ)-diabetic model, STZ/RUP (3mg/kg/day), and STZ/RUP (6mg/kg/day). Treatment has continued for 4weeks after diabetes confirmation. At the end of the study, serum was collected for measurement of glucose, insulin, urea, creatinine, histamine, and PAF. Renal tissue homogenates were prepared for measuring oxidative stress indices, tumor necrosis factor (TNF-α), cystatin C, and p21. Moreover, immunohistochemical expression of transforming growth factor-β1 (TGF-β1) and p53 along with histological pictures was also conducted. Antagonizing H1 and PAF receptors by RUP ameliorated the experimentally induced DN as evident by decreasing all serum parameters augmented by STZ together with improvement of the histopathological picture. RUP administration also improved oxidative-antioxidative agents with reduction in the anti-inflammatory marker, TNF-α. Additionally, the immunohistochemical expression of the fibrosis marker; TGF-β1, was also decreased. STZ-induced DN showed a p21/p53-dependent induction of premature senescence and RUP administration decreased the expression of p21 and p53 levels in injured renal tissue. RUP represents a novel promising drug to prevent DN complicated diabetes probably via its inhibitory effect on H1 and PAF receptors. The renal protection was also related to the anti-inflammatory and antioxidant roles and PAF-facilitated senescence effect via p21/p53 signaling.

Why vasculitis probably can be ameliorated with magnesium and antagonists of ceramides and platelet-activating factor

Vasculitis is characterized as an inflammatory disease of the body’s small blood vessels, particularly in the lungs and kidneys [1-4]. Many other organ regions are usually affected which often induces morbidity and mortality [1-4].