Anti-inflammatory, antibacterial and antioxidant activities of the medicinal species <em>Atractylis cancellata</em>

This research is focused on the estimation of total bioactive contents and the evaluation of in vitro pharmacological activities of crude extracts (petroleum ether, ethyl acetate and n-butanol) obtained from the species Atractylis cancellata. The antioxidant activity was assessed by three different techniques. The antibacterial activity was determined using the agar disk diffusion assay against five bacterial strains. Furthermore, the anti-inflammatory activity was evaluated by the ovalbumin method. According to the results, A. cancellata extracts are rich in several classes of secondary metabolites, especially steroids, triterpenoids, flavonoids, and alkaloids. In addition, the tested extracts showed very interesting antioxidant activities in DPPH and FRAP assays and important correlation coefficients between the results of antioxidant activities and total phenolic and flavonoid contents were found. Moreover, all the tested extracts displayed an antibacterial effect at least against three bacterial strains. The petroleum ether extract inhibited the growth of all the tested bacteria in a dose-dependent manner except Escherichia coli ATCC 25922 and it revealed a strong anti-inflammatory activity (81.77±0.05%). We conclude that A. cancellata could be an important source of natural pharmacological candidates against oxidative stress, inflammatory and microbial diseases

Assessment of in vitro anti-inflammatory, hemostatic, antimicrobial, photoprotective and antioxidant activities of the Algerian species Suaeda monodiana

425-433The efficient cutaneous wound healing process constitutes a critical challenge for clinical and fundamental research. Indeed, agents that prevent bacterial infections, the excessive production of free radicals, and inflammation may enhance wound healing. In this context, the biological activities of the methanolic extract prepared from the species Suaeda monodiana Maire were assessed. The antioxidant activity was tested by five different methods, and the sun protection factor was measured. The hemostatic activity was evaluated by determining plasma re-calcification time, and the anti-inflammatory effect was carried out by heat-inducing hemolysis and albumin denaturation tests. The antimicrobial activity was evaluated by the agar disk diffusion assay against seven strains. As a result, the tested extract has a rich chemical composition and possesses interesting photoprotective (SPF at 46.49±0.05) and antioxidant activities. This extract showed the ability to inhibit protein denaturation (IC50 at 1.22±0.8 mg/mL) and to protect the erythrocytes membrane (IC50 at 2.39±0.3 mg/mL). Moreover, the Methanol extract significantly shortens the clotting time and inhibits the growth of all the tested strains with minimum inhibitory concentrations ranging between 31.25 to 250 μg/mL. Furthermore, due to its pharmacological properties, S. monodiana species could be used in pharmaceutical formulations for the treatment of skin diseases

Proteomic analysis of Plasmodium sporozoites limited samples using the timsTOF Pro

International audienc

In‐depth proteomic analysis of Plasmodium berghei sporozoites using trapped ion mobility spectrometry with parallel accumulation‐serial fragmentation

International audienceSporozoites of the malaria parasite Plasmodium are transmitted by mosquitoes and infect the liver for an initial and obligatory round of replication, before exponential multiplication in the blood and onset of the disease. Sporozoites and liver stages provide attractive targets for malaria vaccines and prophylactic drugs. In this context, defining the parasite proteome is important to explore the parasite biology and to identify potential targets for antimalarial strategies. Previous studies have determined the total proteome of sporozoites from the two main human malaria parasites, P. falciparum and P. vivax, as well as P. yoelii, which infects rodents. Another murine malaria parasite, P. berghei, is widely used to investigate the parasite biology. However, a deep view of the proteome of P. berghei sporozoites is still missing. To fill this gap, we took advantage of the highly sensitive timsTOF PRO mass spectrometer, combined with three alternative methods for sporozoite purification, to identify the proteome of P. berghei sporozoites using low numbers of parasites. This study provides a reference proteome for P. berghei sporozoites, identifying a core set of proteins expressed across species, and illustrates how the unprecedented sensitivity of the timsTOF PRO system enables deep proteomic analysis from limited sample amounts

Combined experimental, computational studies (synthesis, crystal structural, DFT calculations, spectral analysis) and biological evaluation of the new homonuclear complexDi-µ-benzoato-bis [benzoatodipyridinecobalt (II)]

International audienceA binuclear cobalt(II) benzoate complex with pyridine as auxiliary ligands has been synthesized and identified by UV–Vis, IR spectroscopy, and TG-DTA analysis. The molecular structure of the complex was determined by single-crystal X-ray diffraction (SCXRD). Thermogravimetric analysis shows two steps decomposition of the present complex. The Co (II) ions are in a distorted octahedral environment [CoN2O4]. The crystal structure was stabilized by different intramolecular/ intermolecular interactions, including Van der Waals, hydrogen bonding, donor-acceptor, and π-π interactions between the pyridine rings. Furthermore, all density functional theory (DFT) calculations have been performed in the gas phase using the GGA-BLYP functional and the TZP basis set, and for the Time-Dependent Density Functional Theory (TD-DFT) calculations, several functionals have been used, namely the GGA BLYP and PBE, the hybrids B3LYP and PBE0, the SAOP potential model, and finally the range-separated CAMY-B3LYP functional with the TZP basis set. Good consistency was observed between the calculated and the experimental results. The bond dissociation energies (BDE) were calculated using the fragment analysis. The intermolecular interactions were investigated through the Molecular Electrostatic Potential (MEP) and supported by Hirshfeld charges analysis. To characterize the non-covalent interactions in the complex, (NCI plot) index has been computed and supported by AIM analysis. Also, the global and local reactivity descriptors have been calculated to highlight the reactive sites in the molecular structure. Moreover, the antimicrobial activity was evaluated by agar disk diffusion assay against seven pathogenic strains, and the antioxidant activity was estimated using four different techniques. In addition, the in vitro anti-inflammatory activity was assessed by the albumin denaturation method

Synthesis, Characterisation, Hirshfeld surface analysis, Magnetic susceptibility, DFT calculations, pkCSM profile, and Biological activities of Novel mono‐, di‐, and multinuclear Cobalt (II) complexes

International audienceThis study explores the synthesis and diverse properties of newly synthesised water‐soluble cobalt (II) complexes (1‐3). Analysis of the complexes through various methods, including Hirshfeld surface analysis, reveals distinctive intermolecular interactions, particularly robust H‐bonding contributions to crystal packing. 2D fingerprint plots provide quantitative insights into supramolecular interactions, while TGA‐DSC analysis elucidates multi‐step decomposition processes, mainly involving organic moieties. FT‐IR and SCXRD confirm the structures of the complexes. Magnetic susceptibility measurements show paramagnetic behaviour in all complexes. FMO calculations expose HOMO‐LUMO gaps and charge transfer processes, with NBO analysis emphasizing the significance of chloride, nitrogen, and oxygen atoms in coordination. In addition, pkCSM profile was carried out. The biological properties of the complexes reveal potent antibacterial activity for 2 and 3 against Gram‐positive and Gram‐negative bacteria. Despite lower antibacterial efficacy compared to standard antibiotics, their water solubility suggests potential human pharmacological applications. In terms of anti‐inflammatory activity, all three complexes exhibit concentration‐dependent prevention of ovalbumin denaturation, with 2 being the most effective. Compound 3, despite having seven carboxyl groups, exhibits the weakest anti‐inflammatory effect, potentially attributed to complex formation obscuring these groups. Furthermore, all complexes display antioxidant activities; 1 and 2 are greater than BHT in the ferric thiocyanate assay

The claudin-like apicomplexan microneme protein is required for gliding motility and infectivity of Plasmodium sporozoites.

Invasion of host cells by apicomplexan parasites such as Toxoplasma and Plasmodium spp requires the sequential secretion of the parasite apical organelles, the micronemes and the rhoptries. The claudin-like apicomplexan microneme protein (CLAMP) is a conserved protein that plays an essential role during invasion by Toxoplasma gondii tachyzoites and in Plasmodium falciparum asexual blood stages. CLAMP is also expressed in Plasmodium sporozoites, the mosquito-transmitted forms of the malaria parasite, but its role in this stage is still unknown. CLAMP is essential for Plasmodium blood stage growth and is refractory to conventional gene deletion. To circumvent this obstacle and study the function of CLAMP in sporozoites, we used a conditional genome editing strategy based on the dimerisable Cre recombinase in the rodent malaria model parasite P. berghei. We successfully deleted clamp gene in P. berghei transmission stages and analyzed the functional consequences on sporozoite infectivity. In mosquitoes, sporozoite development and egress from oocysts was not affected in conditional mutants. However, invasion of the mosquito salivary glands was dramatically reduced upon deletion of clamp gene. In addition, CLAMP-deficient sporozoites were impaired in cell traversal and productive invasion of mammalian hepatocytes. This severe phenotype was associated with major defects in gliding motility and with reduced shedding of the sporozoite adhesin TRAP. Expansion microscopy revealed partial colocalization of CLAMP and TRAP in a subset of micronemes, and a distinct accumulation of CLAMP at the apical tip of sporozoites. Collectively, these results demonstrate that CLAMP is essential across invasive stages of the malaria parasite, and support a role of the protein upstream of host cell invasion, possibly by regulating the secretion or function of adhesins in Plasmodium sporozoites

The AMA1-RON complex drives Plasmodium sporozoite invasion in the mosquito and mammalian hosts

International audiencePlasmodium sporozoites that are transmitted by blood-feeding female Anopheles mosquitoes invade hepatocytes for an initial round of intracellular replication, leading to the release of merozoites that invade and multiply within red blood cells. Sporozoites and merozoites share a number of proteins that are expressed by both stages, including the Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck Proteins (RONs). Although AMA1 and RONs are essential for merozoite invasion of erythrocytes during asexual blood stage replication of the parasite, their function in sporozoites was still unclear. Here we show that AMA1 interacts with RONs in mature sporozoites. By using DiCre-mediated conditional gene deletion in P . berghei , we demonstrate that loss of AMA1, RON2 or RON4 in sporozoites impairs colonization of the mosquito salivary glands and invasion of mammalian hepatocytes, without affecting transcellular parasite migration. Three-dimensional electron microscopy data showed that sporozoites enter salivary gland cells through a ring-like structure and by forming a transient vacuole. The absence of a functional AMA1-RON complex led to an altered morphology of the entry junction, associated with epithelial cell damage. Our data establish that AMA1 and RONs facilitate host cell invasion across Plasmodium invasive stages, and suggest that sporozoites use the AMA1-RON complex to efficiently and safely enter the mosquito salivary glands to ensure successful parasite transmission. These results open up the possibility of targeting the AMA1-RON complex for transmission-blocking antimalarial strategies