Phospholipase A2 Inhibitor Research Articles

In-silico, in-vitro antioxidant and anti-inflammatory potential of cynanchum callialatum leaves

Inflammatory disorders, including various forms of rheumatic diseases, are a serious global issue. For the treatment of such disorders, the world's population is increasingly turning to herbal treatments. Many plants have been tested for anti-inflammatory and anti-arthritic properties, but only a handful have reached the therapeutic level. The purpose of this research is to determine the anti-inflammatory potential of Cynanchum callialatum leaves using in-silico and in-vitro investigations. The leaves' ethanol extract was produced and analysed for antioxidant capability using the DPPH and nitric oxide scavenging assays. Through molecular docking investigations, the phytoconstituents found in the leaves were docked against PLA2, COX-1, COX-2, and 5-LOX proteins. µAt 1000 µg/ml, the leaf extract had a maximum inhibitory percentage of 67.61 percent (nitric oxide) and 70.41 percent (DPPH), with an IC50 of 414.4 g/ml (nitric oxide) and 446.6 µg/ml (DPPH) (DPPH). The docking investigations indicated that the ligands inhibited the PLA2 protein via a mechanism and were submitted to a PLA2 inhibition experiment. The extract inhibited the enzyme by 71.92 percent at 1000 µg/ml, with an IC50 of 289.8 µg/ml. To assess the full inhibitory efficacy of PLA2, the phytoconstituents must be exposed to additional preclinical and clinical research.

A genus-wide study on venom proteome variation and phospholipase A2 inhibition in Asian lance-headed pit vipers (genus: Trimeresurus)

High molecular weight proteins are present abundantly in viper venoms. The amino acid sequence can be highly variable though, contributing to the structure and function diversity of snake venom protein. This, however, remains unresolved in many species. The study investigated the venom protein variability in a distinct clade of Asian pit vipers (Trimeresurus species) through comparative proteomics, applying gel electrophoresis (SDS-PAGE), liquid chromatography-tandem mass spectrometry (LCMS/MS), and bioinformatic approaches. The proteomes revealed a number of conserved protein families, within each are variably expressed protein paralogs that are unrelated to the snake phylogeny and geographic origin. The expression levels of two major enzymes, i.e., snake venom serine proteinase and metalloproteinase, correlate weakly with procoagulant and hemorrhagic activities, implying co-expression of other functionally versatile toxins in the venom. The phospholipase A2 (PLA2) abundance correlates strongly with its enzymatic activity, and a unique phenotype was discovered in two species expressing extremely little PLA2. The commercial mono-specific antivenom effectively neutralized the venoms' procoagulant and hemorrhagic effects but failed to inhibit the PLA2 activities. Instead, the PLA2 activities of all venoms were effectively inhibited by the small molecule inhibitor varespladib, suggesting its potential to be repurposed as a highly potent adjuvant therapeutic in snakebite envenoming.

Zahabba Patch: Innovation of Gingival Mucoadhesion Patch Combination of Ginger (Zingiber Officinale) and Black Cubit (Nigella Sativa) as Gingivitis Treatment

Background The prevalence of periodontal disease in Indonesia reaches 74.1%. Treatment of gingivitis by administering NSAIDs has a side effect of gastritis. Anti-inflammatory and analgesic derived from natural ingredients are known to cause minimal side effects on the patient's body. The active compounds gingerol in ginger (Zingiber officinale) and quercetin in black cumin (Nigella sativa) are known to function as good anti-inflammatory and analgesic agents. Objectives This study aims to analyze the effectiveness of gingerol in ginger extract and qurcetin in black cumin as an anti-inflammatory and analgesic packaged in a mucoadhesion patch as a treatment for gingivitis. Material and Methods Preparations of gingerol and quercetin were obtained by biocomputation using the PyRx program, the Pymol program, the RCSB PDB website, the Lipinski rule of five page, the PDBSum website, and also the pkCSM website. Physicochemical, pharmacokinetic, toxicity, and molecular docking tests were carried out to determine the biocompatibility of the active ingredients used. Results In the physicochemical tests, the compounds glycerol and quercetin can penetrate somatic cell membranes, have good solubility in water, can dissolve easily in the blood, are easily distributed in the body, and can maintain their position and bond strength with the target macro protein. The results of the AMES toxicity, Hepatotoxicity and skin sensitization tests showed negative values for both gingerol and quercetin. In the molecular docking test, the gingerol and quercetin compounds have a tendency to form bonds with COX-1 compared to arachidonic acid without having to increase the dose so that they become competitors to the native ligand. Conclusion The active compounds gingerol in ginger extract (Zingiber officinale) and quercetin in black cumin extract (Nigella sativa) contained in Zahabba patch are good anti-inflammatory and analgesic by inhibiting the synthesis of pro-inflammatory cytokines such as PGI2, PGE2, and TXA2 by being competitive inhibitor of the enzyme phospholipase A2 against membrane lipids and the enzyme cyclooxygenase-1 (COX-1) against arachidonic acid.

In-silico, in-vitro antioxidant and anti-inflammatory potential of cynanchum callialatum leaves

Inflammatory disorders, including various forms of rheumatic diseases, are a serious global issue. For the treatment of such disorders, the world's population is increasingly turning to herbal treatments. Many plants have been tested for anti-inflammatory and anti-arthritic properties, but only a handful have reached the therapeutic level. The purpose of this research is to determine the anti-inflammatory potential of Cynanchum callialatum leaves using in-silico and in-vitro investigations. The leaves' ethanol extract was produced and analysed for antioxidant capability using the DPPH and nitric oxide scavenging assays. Through molecular docking investigations, the phytoconstituents found in the leaves were docked against PLA2, COX-1, COX-2, and 5-LOX proteins. µAt 1000 µg/ml, the leaf extract had a maximum inhibitory percentage of 67.61 percent (nitric oxide) and 70.41 percent (DPPH), with an IC50 of 414.4 g/ml (nitric oxide) and 446.6 µg/ml (DPPH) (DPPH). The docking investigations indicated that the ligands inhibited the PLA2 protein via a mechanism and were submitted to a PLA2 inhibition experiment. The extract inhibited the enzyme by 71.92 percent at 1000 µg/ml, with an IC50 of 289.8 µg/ml. To assess the full inhibitory efficacy of PLA2, the phytoconstituents must be exposed to additional preclinical and clinical research.

Copper(I)-Catalyzed Enantioselective α-Alkylation of 2-Acylimidazoles.

Catalytic asymmetric α-alkylation of simple carboxylic acid derivatives is a challenging issue due to the difficulties in achieving high catalytic efficiency and controlling the enantioselectivity. Herein, by using a copper(I)-(R)-DTBM-SEGPHOS complex as a catalyst and 2-acylimidazoles as pronucleophiles, a general method for the catalytic asymmetric α-alkylation of simple carboxylic acid derivatives is accomplished. Various alkyl electrophiles, including allyl bromides, benzyl bromides, propargyl bromide, and unactivated alkyl sulfonates, serve as efficient alkylation reagents. The reaction enjoys the advantages of an easy reaction protocol, good functional group tolerance, and high enantioselectivity. 2,4,6-Trimethylphenol is found as an effective additive to increase yields. Preliminary 1H NMR experiments indicate the precoordination of 2-acylimidazoles to a copper(I) catalyst, which might acidify the α-hydrogens of 2-acylimidazoles and allow facile generation of stabilized copper(I) enolates. Finally, the synthetic utility of the present method is demonstrated by the asymmetric formal synthesis of AZD2716, a potent secreted phospholipase A2 inhibitor.

Inducing phospholipase A2 and cyclooxygenase-2 expression and prostaglandins' production of human dental pulp cells by activation of NOD receptor and its downstream signaling.

Dental caries with invasion and infection by microorganisms may induce pulpitis and intolerable pain. L-Ala-γ-D-Glu-mDAP (TriDAP) is a DAP-comprising muramyl tripeptide and a peptidoglycan degradation product found in gram-negative pulpal pathogens. TriDAP activates nucleotide-binding oligomerization domain1/2 (NOD1/NOD2) and induces tissue inflammatory responses. This study aimed to test whether TriDAP stimulates cytosolic phospholipase A2 (cPLA2), cyclooxygenase-2 (COX-2), and prostanoid production in human dental pulp cells (HDPCs) and their inhibition by signal transduction inhibitors, melatonin, and eugenol. We found that TriDAP stimulated cPLA2 and COX-2 expression as well as prostaglandin E2 (PGE2) and PGF2α secretion in HDPCs. TriDAP activated TAK1, MEK/ERK, and p38 signaling. COX-2 expression, PGE2, and PGF2α production induced by TriDAP were prevented by 5Z-7oxozeaenol, SB203580, and U0126. Moreover ASB14780 (a cPLA2 inhibitor) and the clinical drugs melatonin and eugenol suppressed TriDAP- and Poly(I:C)-stimulated PGE2 and PGF2α production. These results indicate that NOD activation in HDPCs may stimulate COX-2 expression and prostaglandin production, which are crucial in pulpal inflammatory and repair responses. The effects of TriDAP and Poly(I:C) were associated with TAK1, p38, MEK/ERK, and cPLA2 in pulpal inflammation. PLA2 inhibitors, melatonin, and eugenol can be used to control pulpal inflammation associated with NOD1/2 and TLR3 activation.

Development of Calcium-Dependent Phospholipase A2 Inhibitors to Target Cellular Senescence and Oxidative Stress in Neurodegenerative Diseases.

Significance: Cellular senescence is a critical process underlying aging and is associated with age-related diseases such as Alzheimer's disease. Lipids are implicated in cellular senescence. Fatty acids, particularly eicosanoids, have been associated with various forms of senescence and inflammation, and the associated reactive oxygen species production has been proposed as a therapeutic target for mitigating senescence. When overactivated, calcium-dependent phospholipase A2 (cPLA2) catalyzes the conversion of arachidonic acid into eicosanoids such as leukotrienes and prostaglandins. Recent Advances: With a growing understanding of the importance of lipids as mediators and modulators of senescence, cPLA2 has emerged as a compelling drug target. cPLA2 overactivation plays a significant role in several pathways associated with senescence, including neuroinflammation and oxidative stress. Critical Issues: Previous cPLA2 inhibitors have shown potential in ameliorating inflammation and oxidative stress, but the dominant hurdles in the central nervous system-targeting drug discovery are specificity and blood-brain barrier penetrance. Future Directions: With the need for more effective drugs against neurological diseases, we emphasize the significance of discovering new brain-penetrant, potent, and specific cPLA2 inhibitors. We discuss how the recently developed Virtual Synthon Hierarchical Enumeration Screening, an iterative synthon-based approach for fast structure-based virtual screening of billions of compounds, provides an efficient exploration of large chemical spaces for the discovery of brain-penetrant cPLA2 small-molecule inhibitors. Antioxid. Redox Signal. 41, 1100-1116.

Exploring the Antisnake Venom Potential of Zingiber officinale and its Bioactive Compounds Against Naja nigricollis Venom Through Computational Approaches and Experimental Validation.

Snakebite envenomation remains a significant medical challenge, particularly in tropical and subtropical regions. The present study investigates the inhibitory potential of Zingiber officinale (ginger) and its bioactive compounds against Naja nigricollis venom using in silico approaches and animal models. No protection was observed in the in vivo studies but the extract of the plant was able to prolong the time of death with mean survival time ranging from 2.01-2.83 hours. In terms of the in vitro studies, the extract was able to significantly (p<0.05) detoxify the N. nigricollis venom by 80 % at the graded doses; standard antisnake venom (ASV) offered 100 % protection to mice. Molecular docking analysis revealed strong binding affinities between the bioactive compounds and the PLA2 enzyme, indicating potential inhibitory effects. The stability and dynamics of the protein-ligand complexes were further validated through molecular dynamics (MD) simulations, which confirmed the persistence of these interactions over time. In conclusion, the findings suggest that the bioactive compounds from Z. officinale could serve as promising inhibitors of PLA2, providing a foundation for the development of novel snakebite envenomation therapies.

In vitro anticoagulant effects of Bungarus venoms on human plasma which are effectively neutralized by the PLA2-inhibitor varespladib

Bungarus (krait) envenomings are well-known for their life-threatening neurotoxic effects. However, their impact on coagulation remains largely unexplored experimentally or clinically. This study, examined the effect of begins to examine venoms from four Bungarus species—B. caeruleus, B. candidus, B. fasciatus, and B. flaviceps on human platelet poor plasma coagulation parameters using thromboelastography and coagulation inhibition assays. B. flaviceps completely inhibited clotting, while B. caeruleus only delayed clot formation. In contrast, B. candidus and B. fasciatus did not affect clotting. Subsequent examinations into the anticoagulant biochemical mechanisms demonstrated divergent pathophysiological pathways. B. caeruleus venom anticoagulant effects were prevented by the addition of an excess of phospholipids, with anticoagulation thereby the result of phospholipid depletion. In contrast B. flaviceps anticoagulation was not affected by the addition of an excess of phospholipids. Further investigations demonstrated that B. flaviceps mediates its anticoagulant toxicity through the inactivation of coagulation enzymes. The anticoagulant effects of both B. flaviceps and B. caeruleus were nullified by varespladib, a phospholipase A2 (PLA2) inhibitor, revealing the toxin class involved. These results uncover previously unrecognized and unexplored anticoagulant effects of Bungarus venoms.

Myotoxicity of Crotoxin on C2C12 Myoblasts and its Inhibition by Crotalus Neutralizing Factor versus Enhanced Resistance in Myotubes: Exploring Toxicity and Membrane Potential.

Crotalus Neutralizing Factor (CNF) is a γ-type Phospholipase A2 (PLA2) inhibitor present in the blood of Crotalus durissus terrificus snake. Particularly, CNF inhibits the toxic action of Crotoxin (CTX), which is a major neurotoxin found in C. d. terrificus venom. CTX induces also myotoxic action and demonstrates high selectivity for skeletal muscle fibers. Consequently, CTX can diffuse beyond the site of infection, which can potentially evoke rhabdomyolysis. The present study has evaluated the effects of CTX on myoblasts and myotubes of muscle cells C2C12 in vitro and the effect of CNF on CTX-induced damage. Cytotoxicity assays were performed by measuring the mitochondrial enzyme dehydrogenase levels. Furthermore, creatine kinase and lactate dehydrogenase levels were used as indicators of muscle damage. Crotoxin has been found to have cytotoxic effects on C2C12 myoblast cells, while CNF has not shown toxic effects on these cells. Furthermore, the findings have shown CNF (50 μg/mL) to abolish CTX toxicity in myoblasts. The myotubes, differentiated cells, showed no change in mitochondrial respiration when exposed to CNF or CTX, showing greater resistance to the toxic actions of crotoxin. The data have confirmed the potential of CNF as an anti-myotoxic agent to prevent CTX-damaged myoblasts and increase resistance to the toxic effects of crotoxin on differentiated cells.

Breaking muscle: neurotoxic and myotoxic effects of Central American snake venoms and the relative efficacies of antivenom and varespladib

BackgroundThe snake genera Atropoides, Cerrophidion, and Metlapilcoatlus form a clade of neotropical pit vipers distributed across Mexico and Central America. This study evaluated the myotoxic and neurotoxic effects of nine species of Atropoides, Cerrophidion, and Metlapilcoatlus, and the neutralising efficacy of the ICP antivenom from Costa Rica against these effects, in the chick biventer cervicis nerve-muscle preparation. Given the prominence of PLA2s within the venom proteomes of these species, we also aimed to determine the neutralising potency of the PLA2 inhibitor, varespladib.ResultsAll venoms showed myotoxic and potential neurotoxic effects, with differential intra-genera and inter-genera potency. This variation was also seen in the antivenom ability to neutralise the muscle damaging pathophysiological effects observed. Variation was also seen in the relative response to the PLA2 inhibitor varespladib. While the myotoxic effects of M. mexicanus and M. nummifer venoms were effectively neutralised by varespladib, indicating myotoxicity is PLA2 mediated, those of C. godmani and M. olmec venoms were not, revealing that the myotoxicity is driven by non-PLA2 toxin types.ConclusionsThis study characterises the myotoxic and neurotoxic venom activity, as well as neutralisation of venom effects from the Atropoides, Cerrophidion, and Metlapilcoatlus clade of American crotalids. Our findings contribute significant clinical and evolutionary knowledge to a clade of poorly researched snakes. In addition, these results provide a platform for future research into the reciprocal interaction between ecological niche specialisation and venom evolution, as well as highlighting the need to test purified toxins to accurately evaluate the potential effects observed in these venoms.

Evaluation of Albumin Denaturation, and Phospholipase A2 (Pla2) Inhibition, and Phytochemical Composition of Methanol Leaf Extract of Psychotria Vogeliana, Benth (Rubiaceae)

Inflammation is a protective response elicited by physical, chemical, biochemical, and/or microbial assault on the body, which serves to prevent progression/escalation of injury. If the response is sufficient the body continues to operate normally, if the reaction is excessive a disease condition (inflammation) occurs which predisposes to various health disorders. Current treatment of inflammation includes immunosuppressant, steroidal, and nonsteroidal agents. Most of these are known to have sometimes serious side/adverse effects. Natural compounds from plants known to have pharmacological activities, including anti-inflammatory and are being used as alternatives. This study aimed to investigate the phytochemical composition and anti-inflammatory properties of the methanol leaf extract of Psychotria vogeliana. Acute toxicity study was conducted following the OECD guidelines 423 Annex 2C. Anti-inflammatory activity was evaluated using albumin denaturation, and phospholipase A2 (PLA2) inhibition assay. Phytochemical analysis was conducted using spectrophotometric methods, and GC-FID. The LD50 of the extract is more than 5000 mg/kg. The extract contained bioactive compounds such as catechin, epicateechin, resvesterol, rutin, narigenin, kaempferol, flavonones, tannins, steroids and anthocynins. Anti-inflammatory evaluation showed activity comparable to that of diclofenac. Possible mechanism of action was identified as Phospholipase A2 (PLA2) inhibition. The use of Psychotria vogeliana in traditional medicine for the management and treatment of inflammatory disorders is therefore justified.

Oral varespladib for the treatment of snakebite envenoming in India and the USA (BRAVO): a phase II randomised clinical trial

IntroductionSnakebite envenoming (SBE) results in over 500 000 deaths or disabling injuries annually. Varespladib methyl, an oral inhibitor of secretory phospholipase A2, is a nearly ubiquitous component of snake venoms....

Isolation and Pharmacological Characterisation of Pre-Synaptic Neurotoxins from Thai and Javanese Russell's Viper (Daboia siamensis) Venoms.

The widespread geographical distribution of Russell's vipers (Daboia spp.) is associated with marked variations in the clinical outcomes of envenoming by species from different countries. This is likely to be due to differences in the quantity and potency of key toxins and, potentially, the presence or absence of some toxins in venoms across the geographical spectrum. In this study, we aimed to isolate and pharmacologically characterise the major neurotoxic components of D. siamensis venoms from Thailand and Java (Indonesia) and explore the efficacy of antivenom and a PLA2 inhibitor, Varespladib, against the neuromuscular activity. These data will provide insights into the link between venom components and likely clinical outcomes, as well as potential treatment strategies. Venoms were fractionated using RP-HPLC and the in vitro activity of isolated toxins assessed using the chick biventer cervicis nerve-muscle preparation. Two major PLA2 fractions (i.e., fractions 8 and 10) were isolated from each venom. Fraction 8 from both venoms produced pre-synaptic neurotoxicity and myotoxicity, whereas fraction 10 from both venoms was weakly neurotoxic. The removal of the two fractions from each venom abolished the in vitro neurotoxicity, and partially abolished myotoxicity, of the whole venom. A combination of the two fractions from each venom produced neurotoxic activity that was equivalent to the respective whole venom (10 µg/mL), but the myotoxic effects were not additive. The in vitro neurotoxicity of fraction 8 (100 nM) from each venom was prevented by the pre-administration of Thai Russell's viper monovalent antivenom (2× recommended concentration) or preincubation with Varespladib (100 nM). Additionally, the neurotoxicity produced by a combination of the two fractions was partially reversed by the addition of Varespladib (100-300 nM) 60 min after the fractions. The present study demonstrates that the in vitro skeletal muscle effects of Thai and Javanese D. siamensis venoms are primarily due to key PLA2 toxins in each venom.

Hyperglycosylation impairs the inhibitory activity of rCdtPLI2, the first recombinant beta-phospholipase A2 inhibitor

Crotoxin, a phospholipase A2 (PLA2) complex and the major Crotalus venom component, is responsible for the main symptoms described in crotalic snakebite envenomings and a key target for PLA2 inhibitors (PLIs). PLIs comprise the alpha, beta and gamma families, and, due to a lack of reports on beta-PLIs, this study aimed to heterologously express CdtPLI2 from Crotalus durissus terrificus venom gland to improve the knowledge of the neglected beta-PLI family. Thereby, recombinant CdtPLI2 (rCdtPLI2) was produced in the eukaryotic Pichia pastoris system to keep some native post-translational modifications. rCdtPLI2 (~41 kDa) presents both N- and O-linked glycans. Alpha-mannosidase digested-rCdtPLI2 (1 mol) strongly inhibited (73%) CB-Cdc catalytic activity (5 moles), demonstrating that glycosylations performed by P. pastoris affect rCdtPLI2 action. Digested-rCdtPLI2 also inhibited PLA2s from diverse Brazilian snake venoms. Furthermore, rCdtPLI2 (1 mol) abolished the catalytic activity of Lmr-PLA2 (5 moles) and reduced the CTx-Cdc (5 moles) enzyme activity by 65%, suppressing basic and acidic snake venom PLA2s. Additionally, crotalic antivenom did not recognize rCdtPLI2, suggesting a lack of neutralization by antivenom antibodies. These findings demonstrate that studying snake venom components may reveal interesting novel molecules to be studied in the snakebite treatment and help to understand these underexplored inhibitors.

Broad-acting inhibitors of phospholipase A2

Broad-acting inhibitors of phospholipase A2

Development and Optimization of a Bromothymol Blue-Based PLA2 Assay Involving POPC-Based Self-Assemblies.

Phospholipase A2 (PLA2) is a superfamily of phospholipase enzymes that dock at the water/oil interface of phospholipid assemblies, hydrolyzing the ester bond at the sn-2 position. The enzymatic activity of these enzymes differs based on the nature of the substrate, its supramolecular assemblies (micelle, liposomes), and their composition, reflecting the interfacial nature of the PLA2s and requiring assays able to directly quantify this interaction of the enzyme(s) with these supramolecular assemblies. We developed and optimized a simple, universal assay method employing the pH-sensitive indicator dye bromothymol blue (BTB), in which different POPC (3-palmitoyl-2-oleoyl-sn-glycero-1-phosphocholine) self-assemblies (liposomes or mixed micelles with Triton X-100 at different molar ratios) were used to assess the enzymatic activity. We used this assay to perform a comparative analysis of PLA2 kinetics on these supramolecular assemblies and to determine the kinetic parameters of PLA2 isozymes IB and IIA for each supramolecular POPC assembly. This assay is suitable for assessing the inhibition of PLA2s with great accuracy using UV-VIS spectrophotometry, being thus amenable for screening of PLA2 enzymes and their substrates and inhibitors in conditions very similar to physiologic ones.

Annexin A1 binds PDZ and LIM domain 7 to inhibit adipogenesis and prevent obesity

Obesity is a global issue that warrants the identification of more effective therapeutic targets and a better understanding of the pivotal molecular pathogenesis. Annexin A1 (ANXA1) is known to inhibit phospholipase A2, exhibiting anti-inflammatory activity. However, the specific effects of ANXA1 in obesity and the underlying mechanisms of action remain unclear. Our study reveals that ANXA1 levels are elevated in the adipose tissue of individuals with obesity. Whole-body or adipocyte-specific ANXA1 deletion aggravates obesity and metabolic disorders. ANXA1 levels are higher in stromal vascular fractions (SVFs) than in mature adipocytes. Further investigation into the role of ANXA1 in SVFs reveals that ANXA1 overexpression induces lower numbers of mature adipocytes, while ANXA1-knockout SVFs exhibit the opposite effect. This suggests that ANXA1 plays an important role in adipogenesis. Mechanistically, ANXA1 competes with MYC binding protein 2 (MYCBP2) for interaction with PDZ and LIM domain 7 (PDLIM7). This exposes the MYCBP2-binding site, allowing it to bind more readily to the SMAD family member 4 (SMAD4) and promoting its ubiquitination and degradation. SMAD4 degradation downregulates peroxisome proliferator-activated receptor gamma (PPARγ) transcription and reduces adipogenesis. Treatment with Ac2-26, an active peptide derived from ANXA1, inhibits both adipogenesis and obesity through the mechanism. In conclusion, the molecular mechanism of ANXA1 inhibiting adipogenesis was first uncovered in our study, which is a potential target for obesity prevention and treatment.

SNAKE VENOM ENZYMES NEUTRALIZATION POTENTIAL OF PHYTOCHEMICALS EXTRACTED FROM DATURA ALBA SEEDS

Datura is a flowering perennial herb, belonging to the family Solanaceae, is widely distributed in many countries including Pakistan, and other tropical and sub-tropical parts of the world. The present study explored the bioactivities of phytochemicals obtained from Datura alba n-hexane and n-butanol seed extracts. The seed extracts showed the presence of flavonoids, terpenoids and alkaloids while saponins were absent. The n-hexane extract showed 100% human salivary amylase and 19% snake venom PLA2 (svPLA2) inhibition activity at examined lowest and highest concentrations respectively. It also exhibited mild (24% RSA) antioxidant activity at highest concentration (600 µg/µl) analyzed. On the other hand, salivary amylase inhibition and potent (80% RSA) antioxidant activity at 100 µg/µl concentration was observed in n-butanol extract. Interestingly, n-hexane extract showed snake venom protease while n-butanol extract showed svPLA2 enhancing activity and no venom anti-protease activity. The study demonstrated that both n-hexane and n-butanol extracts are natural sources of antioxidant and antidiabetic compounds. The n-hexane extract showed venom PLA2 neutralization which is reported for the first time. Keywords: Traditional medicine; Datura alba; Anti-phospholipase A2; Anti-amylase; Antioxidant

ProcCluster® and procaine hydrochloride inhibit the replication of influenza A virus in vitro.

Treatment of influenza A virus infections is currently limited to few direct acting antiviral substances. Repurposing other established pharmaceuticals as antivirals could aid in improving treatment options. This study investigates the antiviral properties of ProcCluster® and procaine hydrochloride, two derivatives of the local anesthetic procaine, in influenza A virus infection of A549, Calu-3 and MDCK cells. Both substances inhibit replication in all three of these cell lines in multi-cycle experiments. However, cell line-dependent differences in the effects of the substances on viral RNA replication and subsequent protein synthesis, as well as release of progeny viruses in single-cycle experiments can be observed. Both ProcCluster® and procaine hydrochloride delay endosome fusion of the virus early in the replication cycle, possibly due to the alkaline nature of the active component procaine. In A549 and Calu-3 cells an additional effect of the substances can be observed at late stages in the first replication cycle. Interestingly, this effect is absent in MDCK cells. We demonstrate that ProcCluster® and procaine hydrochloride inhibit phospholipase A2 (PLA2) enzymes from A549 but not MDCK cells and confirm that specific inhibition of calcium independent PLA2 but not cytosolic PLA2 has antiviral effects. We show that ProcCluster® and procaine hydrochloride inhibit influenza A virus infection at several stages of the replication cycle and have potential as antiviral substances.