Phospholipase A2 Concentrations Research Articles

Exploring the Anticonvulsant Properties of a Celecoxib-Phospholipid Conjugate: Synthesis, Activation, and Evaluation of Cytotoxicity.

Epilepsy poses a significant global health challenge, particularly in regions with limited financial resources hindering access to treatment. Recent research highlights neuroinflammation, particularly involving cyclooxygenase-2 (COX-2) pathways, as a promising avenue for epilepsy management. This study aimed to develop a Cyclooxygenase-2 inhibitor with potential anticonvulsant properties. A promising drug candidate was identified and chemically linked with phospholipids through docking analyses. The activation of this prodrug was assessed using phospholipase A2 (PLA2)-mediated hydrolysis studies. The conjugate's confirmation and cytotoxicity were evaluated using Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), and Sulphoramide B (SRB) assays. Docking studies revealed that the Celecoxib-Phospholipid conjugate exhibited a superior affinity for PLA2 compared to other drug-phospholipid conjugates. FT-IR spectroscopy confirmed the successful synthesis of the conjugate, while DSC analysis confirmed its purity and formation. PLA2-mediated hydrolysis experiments demonstrated selective activation of the prodrug depending on PLA2 concentration. SRB experiments indicated dose-dependent cytotoxic effects of Celecoxib, phospholipid non-toxicity, and efficient celecoxib-phospholipid conjugation. This study successfully developed a Celecoxib-phospholipid conjugate with potential anticonvulsant properties. The prodrug's specific activation and cytotoxicity profile makes it a promising therapeutic candidate. Further investigation into underlying mechanisms and in vivo studies is necessary to assess its translational potential fully.

Evolution of interfacial mechanics of lung surfactant mimics progression of acute respiratory distress syndrome.

How acute respiratory distress syndrome progresses from underlying disease or trauma is poorly understood, and there are no generally accepted treatments resulting in a 40% mortality rate. However, during the inflammation that accompanies this disease, the phospholipase A2 concentration increases in the alveolar fluids leading to the hydrolysis of bacterial, viral, and lung surfactant phospholipids into soluble lysolipids. We show that if the lysolipid concentration in the subphase reaches or exceeds its critical micelle concentration, the surface tension, γ, of dipalmitoyl phosphatidylcholine (DPPC) or Curosurf monolayers increases and the dilatational modulus, [Formula: see text], decreases to that of a pure lysolipid interface. This is consistent with DPPC being solubilized in lysolipid micelles and being replaced by lysolipid at the interface. These changes lead to [Formula: see text] which is the criterion for the Laplace instability that can lead to mechanical instabilities during lung inflation, potentially causing alveolar collapse. These findings provide a mechanism behind the alveolar collapse and uneven lung inflation during ARDS.

Snake Venom-specific Phospholipase A2: A Diagnostic Marker for the Management of Snakebite Cases.

Snakebites are a common cause of morbidity and mortality, especially in tropical countries. Snakebites in any community are managed based on the clinical features and intravenous administration of antisnake venom (ASV). The administration of ASV is either deficient or given in excess based on clinical decisions and whole blood clotting test results. The present study is designed to analyze the level of snake venom component in the blood of snakebite in association with the clinical features. Blood samples were collected from the patients admitted to Karnataka Institute of Medical (KIMS) hospital with a history of snakebite considering the inclusion criteria. Serum was collected from the blood of snakebite patients before and after ASV and used to assess the level of venom-specific phospholipase A2 (PLA2) enzyme using the enzyme-linked immunosorbent assay (ELISA) method. Quantitative ELISA results revealed that the snake venom-specific PLA2 in the victim's blood was in the range of 0.3-1.27 mg/mL before the administration of ASV. However, the concentration of PLA2 after 24 hours of ASV administration was decreased in most of the patients. Further, it was observed that envenomation complications were directly proportional to the amount of snake venom-specific PLA2 found in the blood of the snakebite patient. The study concludes that snake venom-specific PLA2 in the blood of snakebite patients could be used as a reliable venom marker, which helps in determination of appropriate ASV dosage in snakebite patients. Kaulgud RS, Hasan T, Vanti GL, Veeresh S, Uppar AP, Kurjogi MM. Snake Venom-specific Phospholipase A2: A Diagnostic Marker for the Management of Snakebite Cases. Indian J Crit Care Med 2022;26(12):1259-1266.

Africanized Bee Venom (Apis mellifera Linnaeus): Neuroprotective Effects in a Parkinson's Disease Mouse Model Induced by 6-hydroxydopamine.

This study evaluated the neuroprotective effects of the Africanized bee venom (BV) and its mechanisms of action after 6-hydroxydopamine-(6-OHDA)-induced lesion in a mice model. Prior to BV treatment, mice received intrastriatal microinjections of 6-OHDA (no induced dopaminergic neuronal death) or ascorbate saline (as a control). BV was administered subcutaneously at different dosages (0.01, 0.05 or 0.1 mg·Kg−1) once every two days over a period of 3 weeks. The open field test was carried out, together with the immunohistochemical and histopathological analysis. The chemical composition of BV was also assessed, identifying the highest concentrations of apamin, phospholipase A2 and melittin. In the behavioral evaluation, the BV (0.1 mg·Kg−1) counteracted the 6-OHDA-induced decrease in crossings and rearing. 6-OHDA caused loss of dopaminergic cell bodies in the substantia nigra pars compacta and fibers in striatum (STR). Mice that received 0.01 mg·Kg−1 showed significant increase in the mean survival of dopaminergic cell bodies. Increased astrocytic infiltration occurred in the STR of 6-OHDA injected mice, differently from those of the groups treated with BV. The results suggested that Africanized BV has neuroprotective activity in an animal model of Parkinson’s disease.

Role of renin-angiotensin-aldosterone system activation and other metabolic variables in relation to arterial inflammation in HIV.

Arterial inflammation remains increased among persons with HIV (PWH) compared with persons without HIV (PWOH) even when controlling for traditional risk factors. We sought to understand whether increased renin-angiotensin-aldosterone system (RAAS) activation may be related to arterial inflammation in PWH and when compared with PWOH. Twenty PWH and 9 PWOH followed a controlled, standardized low and liberal sodium diet to simulate a RAAS-activated and RAAS-suppressed state, respectively. We measured serum lipoprotein-associated phospholipase A2 (LpPLA2) concentrations following both conditions to assess the physiologic dynamics of aldosterone in relation to arterial inflammation. LpPLA2 levels were significantly higher among PWH versus PWOH during both the RAAS-activated state[5.3(4.2, 6.1) versus 4.0(3.0, 4.8)nmol/L, median(interquartile range),p = .01]) and RAAS-suppressed state[4.4(3.9, 5.3) versus 3.8(3.4, 4.1)nmol/L,p = .01]. Among PWH, but not PWOH, LpPLA2 increased significantly with RAAS activation(p = .03). LpPLA2 levels measured during the RAAS-suppressed state among PWH remained relatively higher than LpPLA2 levels under both conditions among PWOH. Log LpPLA2 was related to log aldosterone during the RAAS-activated state(r = .39,p = .04) among all participants. Log LpPLA2 was correlated with visceral fat(r = .46,p = .04) and log systolic blood pressure(r = .57,p = .009) during a RAAS-activated state when an increase in aldosterone was stimulated in HIV. LpPLA2 is increased during a RAAS-activated state among PWH, but not among PWOH. Further, LpPLA2 was increased in both RAAS-activated and suppressed states in PWH compared with PWOH. These data suggest a biological link between increased aldosterone and arterial inflammation in this population. Future studies should test RAAS blockade on arterial inflammation as a targeted treatment approach in HIV.

Plasma lipoprotein-associated phospholipase A2 is associated with acute ischemic stroke in patients with atrial fibrillation

ObjectiveTo investigate the association between lipoprotein-associated phospholipase A2 (Lp-PLA2) concentration and the incidence of acute ischemic stroke (AIS) in patients with atrial fibrillation (AF). MethodsA total of 257 patients admitted to the Kaifeng Central Hospital were enrolled in this study. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression analysis were used to determine the association between Lp-PLA2 and AIS in patients with AF. ResultsIn AF group, plasma Lp-PLA2 concentrations were significantly higher in patients with AIS than in those without it (277.4 vs 155.1, p < 0.001). And in the group of AIS patients, patients with AF also had a significantly higher level of Lp-PLA2 concentration than those without (277.4 vs 204.2, p < 0.001). The analysis of the ROC curve showed a significant diagnostic value of Lp-PLA2 for the incidence of AIS in patients with AF (AUC = 0.840, 95% CI: 0.737–0.871, p < 0.001), and the optimal cut-off point was 220.5 ng/ml, with a sensitivity and specificity of 82.14% and 75.5%, respectively. All AF patients were divided into two subgroups: the high Lp-PLA2 group (≥220.5 ng/ml) and the low Lp-PLA2 group (<220.5 ng/ml). And multivariate logistic regression analysis showed that after adjustment of confounders, Lp-PLA2 (OR 12.48, 95%CI 5.73–27.16, p < 0.001) was independently associated with the incidence of AIS in patients with AF. ConclusionsPlasma Lp-PLA2 concentration was independently associated with the development of AIS in patients with AF. Lp-PLA2 is a potential biomarker for stratification of risk for AIS in patients with AF.

The Effect of Curcuma longa on Inflammatory Mediators and Immunological, Oxidant, and Antioxidant Biomarkers in Asthmatic Rats.

The effects of Curcuma longa (C. longa) on total and differential WBC, inflammatory and immunologic mediators, and oxidant and antioxidant biomarkers in bronchoalveolar lavage fluid (BALF) of rats model of asthma were assessed. Animals were divided to 5 groups including control (C), asthma (sensitized to ovalbumin), and asthmatic groups treated with 0.75, 1.50, and 3.00 mg/ml C. longa (CL) and 1.25 μg/ml dexamethasone (D) (8 rats in each group). Total and differential WBC count, concentrations of phospholipase A2 (PLA2), total protein (TP), interferon-gamma (IFN-γ), interleukin-4 (IL-4), immunoglobulin E (IgE), NO2, NO3, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and thiol in BALF were assessed. Total and most differential WBC counts and BALF levels of PLA2, TP, IgE, IL-4, and oxidants in asthma group were higher but antioxidants and IFN-γ levels as well as IFN-γ/IL-4 ratio were lower than control group (p < 0.001 for all cases). Total WBC and levels of PLA2, IgE, NO2, and NO3 were significantly reduced following treatment with C. longa, compared to asthma group (p < 0.001 for all cases). In groups treated with dexamethasone and two higher concentrations of C. longa, neutrophil and eosinophil counts as well as TP, IL-4, and MDA levels were significantly decreased but IFN-γ, IFN-γ/IL-4 ratio, and antioxidants were increased (except IFN-γ/IL-4 ratio), compared to asthma group (p < 0.05 to p < 0.001). Compared to dexamethasone, C. longa exerted more pronounced effects on lung inflammation, oxidative stress, and immune system in asthmatic rats.

Color stability and lipid oxidation in pork sausage as affected by rosemary extract and phospholipase A 2 : A possible role for depletion of neutral lipid hydroperoxides

Rosemary extract (R) was added to pork sausage and compared with a novel antioxidant mixture of R and phospholipase A2 (R + P) as well as a treatment of synthetic antioxidants (Syn). Through 245 days of −20°C storage, lipid hydroperoxides (LOOH), redness, and hexanal were similar between R and R + P. However, earlier in storage, R + P decreased LOOH compared with R (p < .05); the neutral lipid hydroperoxides were decreased 3.3-fold (p < .001), whereas free fatty acid hydroperoxides and polar lipid hydroperoxides were not significantly lowered. Through the long-term storage, Syn had lower LOOH and hexanal than R + P yet redness was lower in Syn (p < .05). In unseasoned sausage, R + P demonstrated higher redness and lower hexanal values than R treatment (p < .05). These results suggest that R + P could offer an effective natural antioxidant in pork sausage and the antioxidant mechanism may be related to the suppression of neutral lipid hydroperoxides. Novelty impact statement This research demonstrates a novel antioxidant mixture consisting of low concentrations of rosemary extract and phospholipase A2 (PLA2) in pork sausage. The fractionation of total lipids into lipid classes suggested that the antioxidant action of the mixture was related to decreasing neutral lipid hydroperoxides. The antioxidant mixture stabilized color more effectively than synthetic antioxidants in seasoned sausage yet markers of lipid oxidation were lower in the synthetic treatment.

Combined Assessment of Elevated Plasma Lipoprotein-Associated Phospholipase A2 and Plaque Enhancement Improved Accuracy in the Risk of Acute Ischemic Stroke in Patients with Intracranial Artery Stenosis

PurposeWe evaluated the relationship between plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) concentration and plaque characteristics in patients with intracranial artery stenosis and their clinical relevance in acute ischemic stroke. MethodsEighty-seven patients with intracranial atherosclerotic stenosis (66 males, 21 females) were retrospectively enrolled. Plasma Lp-PLA2 concentration was measured, and vessel wall magnetic resonance imaging (VW-MRI) was used to determine intracranial vascular stenosis and plaque characteristics, including plaque enhancement, surface morphology, and T1 hyperintensity. Binary logistic regression was used to evaluate the relationship between Lp-PLA2 concentration and plaque characteristics of intracranial artery after adjusting for demographic and confounding factors and to assess their diagnostic efficacy for the risk of acute ischemic stroke. ResultsAfter adjustment for demographic, medication and related lipid factors, Lp-PLA2 elevation was associated with plaque enhancement (odds ratio [OR]=12.7, 95% confidence interval [CI] 2.51–64.82, P=0.002) and surface irregularity (OR=2.9, 95% CI 1.06–7.98, P=0.038). Both Lp-PLA2 elevation (OR=8.8, 95% CI 1.64–47.72, P=0.011) and plaque enhancement (OR=34.3, 95% CI 5.88–200.4, P=0.001) were associated with acute ischemic stroke. Receiver operating characteristic curve analysis showed that the area under the curve for Lp-PLA2 concentration and plaque enhancement combined in the diagnosis of acute ischemic stroke was 0.884, significantly higher than that for Lp-PLA2 concentration (0.724) and plaque enhancement (0.794) alone. ConclusionElevated Lp-PLA2 is associated with plaque enhancement and plaque surface irregularity. Combined assessment of Lp-PLA2 concentration and plaque enhancement is of greater diagnostic value for the risk of acute ischemic stroke in patients with intracranial artery stenosis.

Association between serum secretory phospholipase A2 and risk of ischaemic stroke.

Previous literature has demonstrated an association between high serum levels of type II secretory phospholipase A2 (sPLA2) concentration and an increased risk of coronary artery disease. However, such association has not been established in terms of ischaemic stroke risk. The aim was to evaluate the association between both sPLA2 concentration and activity as continuous variables with risk of future ischaemic stroke. A nested case-control study was conducted using data from the European Prospective Investigation into Cancer-Norfolk study. Cases (n=145) in the current study were participants who developed ischaemic stroke during follow-up, with controls (n=290) matched in a 2:1 ratio based on age and sex. Statistical analyses were performed using SPSS (version 25.0) software. Logistic regression was used to determine odds ratios (OR) and corresponding 95% confidence intervals (95% CIs) for ischaemic stroke. After adjusting for a wide array of cardiovascular confounders, sPLA2 activity was found to be associated with an increased risk of ischaemic stroke using both multiple imputations with chained equations and complete case analysis: OR 1.20 (95% CI 1.01-1.43) and OR 1.23 (95% CI 1.01-1.49), respectively. However, sPLA2 concentration was not found to be associated with increased risk of ischaemic stroke. The activity of sPLA2, but not sPLA2 concentration, is associated with an increased risk of future ischaemic stroke. This finding may be significant in risk group stratification, allowing targeted prophylactic treatment, or the development of novel therapeutic agents.

Effectiveness of enzymes on structural, functional and creep-recovery behavior of freshly prepared meringue's batter using liquid egg albumen.

In this research, the impacts of varying concentration of phospholipase A2 (PLA), protease and lipase enzyme-treated liquid egg white (LEW) were prepared using meringue batters. The gelling physico-chemical, and rheological properties such as rheological creep-recovery compliance behavior, color value (L*, a*, b*, ∆E*, Chroma, Hue and WI), gelling strenght, pH value, gelling index as TPA parameter and specific density of freshly prepared meringue batter were analyzed. The specific density of meringue batter of control (0.49 ± 0.01) was significantly decreased (P < 0.05) after enzyme treatments of PLA (0.39 ± 0.01), lipase (0.33 ± 0.01), and protease (0.37 ± 0.01). Also, the enzymatic treatment significantly decreased the b* values from - 0.08 ± 0.07 to - 0.76 ± 0.04, - 0.70 ± 0.06, and - 0.73 ± 0.03, respectively. The Burgers model was used to characterize rheological behavior of enzyme treated and freshly prepared meringue samples. Creep-recovery responses of samples were satisfactory (R2 > 0.99) for evaluation of creep-recovery behavior. This research points out the efficacy of lipase pre-treated LEW in meringue preparation on improving functionality such as batter density and gelling properties.

ISOLATION OF PROTEIN FROM THE SPINE VENOM OF PTEROIS VOLITANS FOUND IN THE INDONESIAN OCEAN, USING A HEATING PROCESS, FOR ANTICANCER, ANTIRETROVIRAL, ANTIBACTERIAL, AND ANTIOXIDANT ASSAYS

Objective: This research investigates the antibacterial, anticancer, antioxidant, and antiretroviral activities of the lionfish spine poison extract.&#x0D; Methods: Isolation and purification of the phospholipase A2 (PLA2) protein obtained from the spine poison were conducted through the following stages, including, extraction of the venom by sonication, heating, and purification using gradual saturation levels of ammonium sulfate. Furthermore, the purity and concentration of PLA2 were analyzed using the Lowry test and Marinetti’s method, respectively, while its protein content was ascertained through SDS-PAGE. Toxicity was then evaluated employing the brine shrimp lethality test (BSLT), and its anticancer activity was assessed in human cervical carcinoma cells (HeLa cells). Finally, its antioxidant, antibacterial, and antiretroviral activities were analyzed using the DPPH method, agar diffusion test against Salmonella sp. and E. coli, and SRV-2 and RT-qPCR tests, respectively.&#x0D; Results: The protein demonstrated 37.79% inhibition for anticancer activity, IC50 1312 ppm for antioxidant activity, 98.81%, and 89.28% inhibition of E. coli and Salmonella sp. respectively for antibacterial activity and 98.13% inhibition for antiretroviral activity.&#x0D; Conclusion: It can be concluded that lionfish (Pterois volitans) has the potential to be developed as an antioxidant, anticancer, antibacterial, and antiretroviral agent. Furthermore, the pharmacological activity of its spine venom was determined by isolating PLA2 protein from its extract, using an optimum heating temperature of 70 °C and an ammonium sulfate saturation level of 80%.

Serum concentration of phospholipase A2 and platelet aggregation during hyperbaric oxygen therapy in patients with ischemic heart disease

To study changes in serum PLA2 concentration and its relation to platelet aggregation activity during HBO in patients with stable CHD. We examined 42 patients with stable angina FC II-III, 27 received antiplatelet therapy (Cardiomagnyl 75 mg: acetylsalicylic acid + magnesium hydroxide), and 15 patients did not. All patients received a 10-day course of HBO at 1.2 atmosphere mode for 40 min. Platelet hemostasis and serum PLA2 concentration were evaluated. Platelet aggregation was tested using Biola LA-230-2 aggregation analyzer (Biola Scientific, Russia). The platelets count and mean platelet volume (MPV) were determined on a Mindray BS-3200 hematology analyzer (Mindray, China). PLA2 levels were determined by enzyme immunoassay using Model 680 microplate reader (Bio-Rad, USA). Residual platelet reactivity was evaluated by 5.0 ADP-induced aggregation. Assessment of the HBO effect on the functional state of platelets depending on their aggregation activity and the therapy taken showed a significant increase in spontaneous aggregation and ADP-induced aggregation at inducer concentration of 1.0 μM (p=0.049) in patients with baseline hyperaggregation taking Cardiomagnyl after HBO. No significant changes in PLA2 concentration were observed. At the same time, patients with baseline hyperaggregation who did not take antiplatelet agents had no changes in platelet aggregation activity and a decreased serum PLA2. In patients with baseline normal aggregation receiving an antiplatelet drug, a course of HBO had no effect on platelet aggregation activity and PLA2 level. In patients with baseline normal aggregation who did not take antiplatelet agents, a course of HBO resulted in significant decrease in PLA2 levels and no changes in platelet aggregation activity. In patients with low aggregation activity (hypoaggregation) who took antiplatelet agents, a significant increase in spontaneous aggregation and no change of serum PLA2 after an HBO course was observed. The study showed a divergent response to the hyperbaric oxygen, depending on the antiplatelet therapy and the background aggregation.

Relationship between Plasma Lipoprotein-Associated Phospholipase A2 Concentrations and Apolipoprotein in Stable Coronary Artery Disease Patients

Background Increasing evidence states that the plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) levels and apolipoprotein particles are regarded as the risk maker for cardiovascular heart disease. Nevertheless, the issue about whether Lp-PLA2 is associated with apolipoprotein particles in individuals who have been diagnosed as stable coronary artery disease (CAD) remains largely unexplored. Method All 569 participants engaged in this research, who never took lipid-lowering drugs, had been divided into groups by the coronary angiography (CAG), namely, stable CAD: n = 291; non-CAD: n = 278. The results concerning Lp-PLA2 levels were calculated by Elisa Kit, while apolipoprotein particles were measured by the department of laboratory. Results The plasma concentration of Lp-PLA2 was remarkably higher in stable CAD group than the non-CAD group (136.0 ± 60.5 ng/mL vs. 113.2 ± 65.6 ng/mL, P < 0.001). Pearson correlation analyses explained the plasma Lp-PLA2 concentration was correlated with apoB (r = 0.390, P < 0.001) and apoB/apoA1 (r = 0.450, P < 0.001), not associated with apoA1 (r = −0.099, P = 0.101). Conversely, the association remains unobserved among non-CAD patients except apoA1. Moreover, multiple linear regression revealed the relations between Lp-PLA2 concentrations and apoB (β = 0.390, P < 0.001), as well as apoB/apoA1 (β = 0.450, P < 0.001), but not apoA1 (β = −0.099, P = 0.121). After adjustment for several risk factors regarding CAD, like hypertension, gender, smoking, age, and diabetes mellitus, there had still been positive associations between the Lp-PLA2 concentration and apoB (β = 0.364, P < 0.001), as well as apoB/apoA1 (β = 0.390, P < 0.001). Conclusion The plasma levels of Lp-PLA2 provide positively a key link with apoB, apoB/apoA-1 among stable CAD, denoting the communication between Lp-PLA2 and apolipoprotein particles in the state of CAD.

Optical fiber bio-sensor for phospholipase using liquid crystal

A cost-effective and label-free optical fiber sensor was proposed to detect phospholipase A2 (PLA2) in nM concentration. The sensor is made of an alkoxysilane-modified side-polished fiber (SPF) coated with 4′-pentyl-4-cyanobiphenyl (5CB) and self-assembled phospholipid (L-DLPC). It is found that the relative transmission optical power (RTOP) of the fiber sensor decreases due to the 5CB realignment and redistribution induced by the PLA2 hydrolysis of L-DLPC. The response-time at 5 dB RTOP variation exhibits an exponential dependence on PLA2 concentration, allowing us to detect the PLA2 by the 5 dB-response time. This detection method can reduce the detection time. Compare with the traditional copper-grid sensor, the proposed novel fiber sensor has a lower detection limit (<1 nM). Furthermore, the sensor has good repeat-ability and specificity.The sensor's RTOP variation for PLA2 detection at 1 nM is ~21 times higher than that for five other enzymes (trypsin, amylase, thrombin, glucose oxidase, pepsin) at 1000 nM and lipase at 50 nM. This confirms the sensor's excellent PLA2 specificity. The fiber sensor provides a potential way to be incorporated into micro-flow chips to quantitatively detect biological molecules in a real-time and online manner.

Evaluation of physicochemical properties on meringue prepared from phospholipase A2 enzyme-hydrolyzed liquid egg albumen

This research aimed to investigate the effects of various concentrations (0.1; 0.2 and 0.3 v/v %) of phospholipase A2 (PLA) enzyme-modified liquid egg albumen (LEA) on color, water activity, specific volume, textural profile analysis, and sensorial characteristics of cooked meringues for 90 days storage period at room temperature. Also, the rheological creep-recovery changes, specific density, color, and physico-functional properties of meringue batters were evaluated. The meringue batter density in the control group (0.47 ± 0.01) decreased significantly (p < 0.05) after PLA hydrolysis, while better specific gravity values were obtained in 0.3% enzyme concentration (0.36 ± 0.01). The use of the enzyme-hydrolyzed LEA also significantly (p < 0.05) decreased water activity with control, 0.1, 0.2 and 0.3% of PLA (0.447 ± 0.01; 0.429 ± 0.01; 0.429 ± 0.01, and 0.420 ± 0.01), respectively. The batter densities of meringues prepared by PLA enzyme decreased with increasing the enzyme concentration, while as enzyme concentration increased, the meringues lost its elasticity. The increase in enzyme concentration leads to a significant increase in meringue’s specific volume values. Sensory analysis of meringues showed that the lowest scores obtained by the control group, and the enzyme hydrolyzed with 0.2% were acceptable. The PLA modification provided the storage stability of meringues in hardness values. This study highlights the use of the PLA enzyme-modified LEA in meringue production results in the development of functional properties and storage stability.

PLA2 Inhibitor Varespladib as an Alternative to the Antivenom Treatment for Bites from Nikolsky's Viper Vipera berus nikolskii.

Although envenoming by a small East European species of viper is rarely severe, and only exceptionally fatal, lack of specific antivenom stocks in a few areas within this region and possible severe side effects of antivenom application leave most bites to be treated only with antihistamines and supportive therapy. Varespladib is an effective inhibitor of snake phospholipase, and, as such, it could be considered as first-line therapy. The Nikolsky’s viper venom contains an extremely high concentration of phospholipase A2 (PLA2), responsible for the toxic effects of the venom, as well as minor amounts of other toxins. If Varespladib can successfully inhibit PLA2 activity, the Nikolsky’s viper could be one of the first venomous snakes having an antitoxin-specific treatment regimen. To assess that, Varespladib was administered alone subcutaneously to adult male CD-1 mice (8 mg/kg) and compared to mice exposed to Vipera berus nikolskii crude venom (8 mg/kg = 10 LD50) or a combination of Varespladib and the same amount of the venom. Experimental animals were monitored for the presence of envenoming symptoms and mortality for 48 h after injection. Eighty percent of mice receiving both Varespladib and venom survived, while 100% of the control group receiving venom alone died within 4 h. Experimental results are consistent with Varespladib acting as an effective antitoxin in the mouse model against Nikolsky’s viper venom. Further studies are needed under experimental conditions that more closely resemble natural envenoming (i.e., delayed administration).

Protein isolation of Pterois volitans venomous with a heating process for antibacterial activity assay

Pterois volitans is an invasive native predatory fish species in the Indo-Pacific ocean that disrupt the food chain and damage coral reefs which cause ecosystem imbalances. These fish have venomous spines that made them inedible and avoided by a predator. Due to its rapid growth, utilization of this venom can be useful along with controlling the population. Recent studies show the benefits of phospholipase A2, which is a protein compound that contained in the venom has antibacterial activity and expected to be an antibacterial agent. In this study, we used heating and gradual purification to obtain the optimum concentration of Phospholipase A2. The protein isolates were analyzed using the Marinetti method, determination of concentration by Lowry test, identification of protein with SDS-Page, and the antibacterial activity test using agar diffusion. The results of phospholipase A2 obtained from the extract of P. volitans venom by purification method ammonium sulfate at 80% saturation with a heating time of 35 minutes had a specific enzyme activity of 0.0206 units / µg and can inhibit E. coli bacteria 98.81% and Salmonella sp. inhibit 89.28% with a concentration of 3.77 µg / ml.

Lipid Oxidation and Color Stability of Spiced and Unspiced Pork Sausage with a Novel Antioxidant Mixture of Rosemary Extract and Phospholipase A2

ObjectivesThe objective of this study was to measure the loss of redness and onset of lipid oxidation in pre-rigor pork sausage containing synthetic antioxidants (Syn) compared to rosemary extract (R), and a combination of R with different concentrations of phospholipase A2 (R+P) over both light display and frozen storage.Materials and MethodsOur work examined pre-rigor spiced and unspiced pork sausage. Tissue from sows for both spiced and unspiced sausage was coarse ground and cooled to 1–3°C with dry ice within 1-h post-exsanguination. Water, treatments and seasonings were added, and the sausage stuffed within 2 h post-exsanguination for spiced sausages. Water and treatments were added 24 h post-exsanguination for the unspiced sausage. Sausages were stored in the dark at –20°C (to 110 and 245 d for unspiced and spiced, respectively) prior to light display. Sausages were sampled for color and lipid oxidation on approximately 40-d intervals of –20°C dark storage and 7–9 d of light display (5°C). In spiced sausage, R (type HT-P) was added at 200 ppm, PLA2 was added at 0.4 ppm. Butylated hydroxyanisole (BHA), propyl gallate (PG) and citric acid (CA) were each added at 0.01% of the estimated fat and collectively formed the Syn treatment. Spices consisted of sucrose, ginger, coriander, nutmeg, white pepper, and MSG. In unspiced sausage R was added at 200 ppm, PLA2 added at 0.4 ppm and 10 ppm, and BHA, CA and PG added at the same levels as in spiced sausage. Color stability was measured based on redness (a*). Peroxide values (PVs) were measured spectrophotometrically, headspace hexanal was measured via gas chromatography (GC) and α tocopherol depletion was measured with HPLC fluorescence detection as markers of lipid oxidation. Total lipids were fractionated to gravimetrically quantify neutral lipids, free fatty acids and polar lipids and to measure PVs in the aforesaid fractions. Unspiced sausages were only stored for 110 d because of rampant lipid oxidation and loss of color.ResultsIn spiced sausage, R and R+P displayed better color stability than both the control (no antioxidant, C) and Syn. Syn displayed the lowest hexanal values. R had the highest PVs and both Syn and R+P were significantly lower. Free fatty acids were the most heavily oxidized fraction on an oil basis, while neutral lipids were the most oxidized lipid on a wet weight basis. Alpha tocopherol did not deplete through 245 d in spiced sausage but was not detected in the unspiced sausage.In unspiced sausage, R+P was examined at two different levels (0.4 ppm and 10 ppm PLA2). R+P (10 ppm) exhibited lower headspace hexanal than R alone and R+P at both levels performed as well as Syn. In addition, R+P at both levels displayed significantly better color stability than R alone and was as good as Syn.ConclusionIn conclusion, R+P decreased lipid oxidation (compared to R) and enhanced color stability (compared to R) and offer an alternative to synthetic antioxidants in pre-rigor pork sausage. Furthermore, spiced pork sausage displayed mean redness values above 9 through 245 d, compared to only 75 d in unspiced sausage.

Interleukin-6 and lipoprotein-associated phospholipase A2 are associated with functional trajectories.

Background/ObjectivesInflammatory biomarkers have been associated with stroke and mortality, but inflammation may also have detrimental effects beyond acute events. We hypothesized that serum concentrations of interleukin-6 (IL6) and lipoprotein-associated phospholipase A2 (LpPLA2) were inversely associated with long-term functional decline independently of vascular risk factors, stroke and myocardial infarction (MI) occurring during follow-up.DesignProspective population based cohort studySettingThe Northern Manhattan StudyParticipants (including the sample size)Race/ethnically diverse stroke-free individuals in northern Manhattan aged ≥40 years (n = 3298).InterventionNoneMeasurementsAnnual functional assessments with the Barthel index (BI), for a median of 13 years. BI was analyzed as a continuous variable (range 0–100). Baseline demographics, risk factors, and laboratory studies were collected, including IL6 (n = 1679), LpPLA2 mass (n = 1912) and activity (n = 1937). Separate mixed models estimated standardized associations between each biomarker and baseline functional status and change over time, adjusting for demographics, vascular risk factors, social variables, cognition, and depression measured at baseline, and stroke and MI occurring during follow-up.ResultsMean age was 69 (SD 10) years, 35% were male, 53% Hispanic, 74% hypertensive, and 16–24% diabetic. LogIL6 was associated with decline in BI over time (-0.13 points per year, 95% CI -0.24, -0.02) and marginally with baseline BI (-0.20, 95% CI -0.40, 0.01). LpPLA2 activity levels were associated with baseline BI (-0.36, 95% CI -0.68, -0.04) but not change over time, and LpPLA2 mass levels were not associated with either.ConclusionIn this large population-based study, higher serum inflammatory biomarker levels were associated with disability, even when adjusting for baseline covariates and stroke and MI occurring during follow-up.