Evaluation of in vitro antioxidant, anti-inflammatory, anticoagulant and antiplatelet potential of Rhus mysorensis

Since ancient times human beings are using plant-based medicines for the treatment of various ailments, especially in the rural areas, due to their availability and affordability. Rhus mysorensis (RM) is widely used as a traditional medicine to treat various ailments. Owing to its potential medicinal value, the present study was designed to explore the in vitro antioxidant, anti-inflammatory, anticoagulant and antiplatelet properties of purified column fraction of RM. The methanol extract of stem bark powder was sequentially fractioned by solvent partitioning. The liquid methanol fraction was further fractionated by column chromatography using gradient elution. Eluted fractions were analyzed using HPLC for percentage purity and yield. The fraction with higher percentage of purity and yield was assessed for in vitro antioxidant activity by measuring SOD and GPx activities, anti-inflammatory activity by the inhibition of nitric oxide (NO) production in LPS induced RAW264.7 cells, anticoagulation by plasma recalcification time and antiplatelet activity by agonists induced platelet aggregation respectively. The antioxidant potency of column fraction (B8) revealed that, highest enzyme activities were recorded at a concentration of 320µg/ml. The enzyme activity was found to be 2.45 U/ml for SOD and 135.75 U/L for GPx respectively. Purified column fraction (B8) of RM significantly reduces the production of NO in LPS stimulated RAW 264.7 cell lines at 320????g/ml concentration with 31.90% of inhibition. The anticoagulant activity of purified fraction was determined in terms of plasma recalcification time. Interestingly, the fraction showed the most potent anticoagulant activity both in PRP and PPP as it prolonged the clotting time. The findings indicate that the stem bark of RM possesses potent antioxidant, anti-inflammatory, anticoagulant and antiplatelet activities, supporting the use of this species for treating oxidative stress-induced inflammatory diseases. Further, bioactivity guided fractionation studies to characterize and identify specific phytochemicals responsible for these biological activities are needed.

Preparation of modified polysulfone material decorated by sulfonated citric chitosan for haemodialysis and its haemocompatibility

Polysulfone (PSF) works potentially in haemodialysis due to its great mechanical and chemical stability, but performs poorly in haemocompatibility. For promoting the unpleasant haemocompatibility, sulfonated citric chitosan (SCACS) with the structure and groups similar to heparin was primarily synthesized by acylation and sulfonation. Furthermore, the chloroacylated PSF was pretreated by electrophilic chloroacetyl chloride to achieve more active sites for further reaction; the following membranes underwent the amination and were named amination polysulfone (AMPSF) membranes. Moreover, SCACS with abundant carboxyl and sulfonic groups was covalently grafted at the surface of pretreated PSF membranes, called PSF-SCACS membranes. The PSF-SCACS membranes were successfully synthesized and characterized by 1 H NMR, ATR-FTIR and XPS. In addition, the water contact angle of PSF-SCACS membranes decreased by 47° and the morphologies of the membranes changed little compared with the unmodified PSF membranes. The haemocompatible testing results, including protein adsorption, platelet adhesion, haemolysis rate, plasma recalcification time, activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT), demonstrated that the PSF-SCACS membranes possessed excellent haemocompatible performances, and SCACS played an important role in the modification.

Preparation and Characterization of Chitosan from Perna viridis (Linnaeus, 1758) shell waste as raw material

Chitosan is extracted from Perna viridis as the staring source via the cycle of chitin deacetylation, which is conducted at 90°C for 6 hours using 40% NaOH. Physiochemical properties such as yield (18%), ash content (0.626%), moisture content (2.9%), and solubility, degree of deacetylation (55), fat binding capability (209%) and water binding ability (254 %) revealed that P.viridis is an important alternative source of chitosan. Fourier transforms infrared spectroscopy (FTIR) analysis showed the characteristic peaks of OH at 3400cm-1 and amine at 1660cm-1, the X-ray diffraction (XRD) analysis suggested two critical characteristic peaks at 18° and 34° at (2θ). Scanning electron microscope (SEM) was used to evaluate the surface morphology of isolated chitosan. Thermogravimetric analysis (TG/DTA) was also used to describe the thermal stability of P.viridis chitosan. The procoagulant capacity, plasma recalcification time assays and minimal bactericidal activity verified the hemocompatibility and antibacterial activity of the preparation of chitosan.

Synthesis, Characterization, Hydrolytic Cleavage, and Biological Activity Studies of 2-[(1e)-N-{2-[(2-{(Z)-[1-(2-Hydroxyphenyl)Ethylidene] Amino}Ethyl)Amino]Ethyl}Ethanimidoyl]Phenol

A Schiff base ligand 2-[(1E)-N-{2-[(2-{(Z)-[1-(2-hydroxyphenyl) ethylidene] amino}ethyl)amino]ethyl} ethanimidoyl]phenol L was hydrolyzed by copper cation which lead to formation of 8,8-dichloro-2H,3H,5H,6H-1,3-diaza-2-cupracyclopenta[1,3-a]1,3-diaza-2-cupracyclopentane hydrate (Complex), characterized by UV, IR, Powder XRD and by elemental analysis. In vitro antioxidant and anticoagulant, activities of L were evaluated. Antioxidant potential of L was assessed by DPPH scavenging, β-carotene bleaching test, hydroxyl radical scavenging method, ABTS radical scavenging test, and by reducing power test. In vitro anticoagulant effect of L at the 84 µg/mL; showed the maximum prolongation of plasma recalcification time which is comparable with that of the anticoagulant drug; heparin. In conclusion, results of the present investigation indicate that the ligand L can be a potential anticoagulant agent. Keywords: Schiff base; Antioxidant; Free radicals; Anticoagulant.

Characterization and Hemostatic Potential of Two Kaolins from Southern China

The physicochemical properties and potential hemostatic application of Wenchang kaolin and Maoming kaolin were inspected and evaluated. Chemical composition analysis, Fourier transform infrared (FTIR) spectroscopy, surface area determination, X-ray diffraction, particle size, scanning electron microscopy (SEM) observations, and zeta potential analysis were performed to quantify the physical and chemical properties of the two kaolins. The results showed that both kaolins have typical FTIR bands of kaolinite with a weight fraction for kaolinite over 90 wt%. Larger conglobate aggregates of Maoming kaolin demonstrated wider particle size distributions with two peaks at 3.17 and 35.57 μm, while the book-like Wenchang kaolin had narrow particle size distribution, with a frequent size of 5.64 μm. Furthermore, thrombelastography, the whole blood clotting tests (WBCT), plasma recalcification time (PRT) measurement, and MTT assay were performed to measure the clotting activities and biocompatibility of the two kaolins. The results showed that both kaolins could promote blood coagulation with good cytocompatibility, while Wenchang kaolin had a better procoagulant activity than Maoming kaolin. These findings demonstrated Wenchang kaolin to be a more suitable local source material for application as a hemostatic agent.

Heparinized Polyurethane Surface Via a One-Step Photografting Method

Traditional methods using coupling chemistry for surface grafting of heparin onto polyurethane (PU) are disadvantageous due to their generally low efficiency. In order to overcome this problem, a quick one-step photografting method is proposed here. Three heparin derivatives incorporating 0.21, 0.58, and 0.88 wt% pendant aryl azide groups were immobilized onto PU surfaces, leading to similar grafting densities of 1.07, 1.17, and 1.13 μg/cm2, respectively, yet with increasing densities of anchoring points. The most negatively charged surface and the maximum binding ability towards antithrombin III were found for the heparinized PU with the lowest amount of aryl azide/anchor sites. Furthermore, decreasing the density of anchoring points was found to inhibit platelet adhesion to a larger extent and to prolong plasma recalcification time, prothrombin time, thrombin time, and activated partial thromboplastin time to a larger extent. This was also found to enhance the bioactivity of immobilized heparin from 22.9% for raw heparin to 36.9%. This could be explained by the enhanced molecular mobility of immobilized heparin when it is more loosely anchored to the PU surface, as well as a higher surface charge.

Investigation of the Effects of Molecular Parameters on the Hemostatic Properties of Chitosan

Hemorrhea is one of the major problems in war, trauma care, and surgical operation that threaten the life of the injured and patients. As a novel polymeric hemostatic agent, biodegradable chitosan can stop bleeding through a variety of approaches. In this paper, chitosan with various molecular parameters was prepared from chitin as raw material through deacetylation, oxidative degradation, hydrophilic modification, and salt formation reactions. The influence of different polymer parameters on the hemostatic effects of chitosan was investigated by in vitro coagulation time and dynamic coagulation assay. The results showed that when the molecular weights were high (105–106) and approximate, the coagulation effect of chitosan improved with a decrease of the deacetylation degree and achieved a prominent level in a moderate degree of deacetylation (68.36%). With the same degree of deacetylation, the higher the molecular weight of chitosan, the better the procoagulant effect. The substituent derivatives and acid salts of chitosan showed significant procoagulant effects, especially the acid salts of chitosan. In addition, the hemostasis mechanism of chitosan with various parameters was preliminarily explored by analyzing the plasma recalcification time (PRT). The efforts in this paper laid a basis for further study of the structure–activity relationship and the mechanism of chitosan hemostasis.

Evaluation of hemostatic effect of polyelectrolyte complex-based dressings

The aim of this work was to develop a polyelectrolyte complex-based hemostatic dressing made from chitosan and polygalacturonic acid. Porous dressings were fabricated by ultrasonication of chitosan and alginate solutions followed by freeze-drying. Since chitosan has inherent hemostatic properties, and polygalacturonic acid is anti-inflammatory in nature, it was desired to combine these two polymers to develop an effective hemostatic dressing, which may also promote wound healing. Porous structure of the bandages was observed using field-emission scanning electron microscope. Blood clotting behavior was studied using whole blood clotting assay. Plasma recalcification time, prothrombin time, and activated partial thromboplastin time were also determined to study the mechanism of clotting. The dressings were found to accelerate clotting rates and showed increased thrombin activity with an increase in chitosan concentration.