European Journal of Biological Research

In vivo assessment of anti-inflammatory and antioxidant activities of Phlomis crinita polyphenols

Mon, 24 Apr 2023 22:26:05 +0200

The leaves of Phlomis crinita are traditionally used in Algerian medicine for the treatment of pain and inflammatory conditions. In order to find a potential application for this native species, the anti-inflammatory and antioxidant effects were investigated on various in vivo experimental models, and the total phenolic compounds and flavonoid contents were determined. The carrageenan-induced paw edema method was used to evaluate the anti-inflammatory activity of the extract in vivo, while the in vivo antioxidant effect was assessed by estimating oxidative stress parameters (MDA, CAT, and SOD). Phytochemical screening revealed the presence of substances with high therapeutic values. In vivo anti-inflammatory studies show that plant extract has a significant and dose-dependent impact on the inhibition of edema formation. The maximum percentage inhibition value was 87.79% after 4 h at a concentration of 500 mg/kg. Moreover, the administration of the extract significantly enhanced the activities of antioxidant enzymes in the livers of mice. It significantly (p ˂ 0.05) increased CAT and SOD activities and significantly (p ˂ 0.05) decreased the MDA level activity, compared to the control inflammatory group. Our findings support that Phlomis crinita can be considered as a promising source of therapeutic bioactive compounds.

DOI: http://dx.doi.org/10.5281/zenodo.7860334

Toxigenic fungi and contamination by AFB1 in Algerian traditional foods markets

Ammar-Rachad Medjdoub, Abdellah Moussaoui, Houcine Benmehdi — Mon, 24 Apr 2023 21:14:26 +0200

This work focused on the realization of a mycological and mycotoxicological study of certain foods manufactured in a traditional way (couscous and spice of Capsicum annuum known locally under the name of sweet hror) and marketed in the city of Bechar. The physico-chemical analyzes revealed that all the samples were poorly hydrated where the average values of relative humidity ranged between 7.23% and 13.58%. For the pH, the values varied between 5.22 and 6.95. The enumeration of the fungal flora indicated that the couscous samples (coarse and fine) represented a contamination rate of 2.92*10² and 1.71*10² CFU/g respectively. While, the sweet hror samples represented a higher contamination rate (4.68*10² CFU/g), with a clear dominance of the genera of Aspergillus (46.42%) and Penicillium (26.28%). Otherwise, the mycotoxicological analysis showed us that 78.55% of the Aspergillus isolates of the group (flavus-parasiticus) tested were producers of aflatoxins (B₁ and G₁) and that 86.66% of the isolates of A. ochraceus and 40% of Penicillium species, were ochratoxin A producers. In addition, the detection of mycotoxins at the sample level revealed that 63.63% of couscous samples were contaminated with mycotoxins. While sweet hror was the most contaminated (78.57%). Furthermore, the quantification of AFB₁ by HPLC-FLD for 4 samples of sweet hror revealed only one contaminated sample (21.75 µg/kg). Generally, it can be admitted that the rate of contamination by AFB₁ was too high, which can be considered a real risk to human health.

DOI: http://dx.doi.org/10.5281/zenodo.7860257

Potential utilization of industrial waste as feed material for the growth and reproduction of earthworms

Anjali Singh, Keshav Singh — Mon, 13 Mar 2023 20:38:18 +0100

The issue of managing organic waste such as animal waste and industrial waste has emerged as a result of the fast development in urbanization around the world. It can be hazardous to the environment and public health if these are not properly stored, collected, and disposed of. These biological wastes can be turned into nutrient-rich biofertilizers using the vermicomposting process. The bio-oxidative method includes the combined activity of earthworms and microbes. The pH, organic carbon, organic matter, and the C:N ratio of the various organic waste mixtures showed a declining tendency during this process but the content of nitrogen, available phosphorous and exchangeable potassium showed a rising trend as the vermicomposting time progressed. Maximum earthworm growth and reproduction were reported better in different feed materials prepared from industrial wastes. Therefore, the present review article is based on the knowledge of using earthworms to stabilize waste.

DOI: http://dx.doi.org/10.5281/zenodo.7730476

Mucosal membranes, their interactions to microbial infections and immune susceptibility in human hosts

Ravi Kant Upadhyay — Thu, 02 Mar 2023 23:04:33 +0100

This article presents mucosal immune defense in response to various pathogenic infections in different hosts including man. Internally, the mucosal layer (membrane) covers the respiratory, digestive, nasal, and urogenital systems and serves as a physical barrier against many groups of infections. The host pathogen's interaction with membrane receptors is highlighted in this article, as well as the commensal gut microbiota's protective function in directing both general and targeted immune defense. In order to combat numerous diseases of various types, this review emphasizes the importance of crosstalk between mucosal locations, mucosal adjuvant design, and antigen delivery mechanisms. Additionally, it denotes the function of inflammasomes, lipocalin 2, Muc2 hyaluronan, and probiotics in maintaining homeostasis, regulating the gut microbiota, and enhancing immunological protection against enteric infection and gastrointestinal inflammation. For novel potential vaccines that could activate innate and adaptive immunity in mucosal tissue, there is an urgent need to look for new protective antigens, delivery mechanisms, and mucosal adjuvants. In order to prevent the spread of infections that are drug-resistant, seek protection, and assure host immunological tolerance, this article emphasizes the necessity for new antigens in the construction of new vaccines.

DOI: http://dx.doi.org/10.5281/zenodo.7693677

Blocking IgE with L-glutamic acid analogs as an alternative approach to allergy treatment

Tue, 28 Feb 2023 21:06:22 +0100

IgE-mediated allergic diseases have increased in the last decades. The most prevalent allergens from these seeds are Ric c1 and Ric c3, isoforms of 2S albumin. These allergenic proteins cross-react with allergens from peanut, shrimp, fish, corn, gramineous, house dust, and tobacco. The usual allergy treatment employs antihistaminic, immunotherapies and, omalizumab (Xolair)-based anti-IgE therapy. However, antihistaminics relieve symptoms, and the high cost of omalizumab limits its use for continuous treatment. We propose an alternative immunotherapeutic approach, denoted “IgE-blockage” by L-glutamic acid or modified-glutamic acid. Six compounds, D-glutamic acid, L-glutamic acid, N-methyl-L-glutamic acid, N-acetyl-L-glutamic acid, N-(4-nitrobenzoyl)-L-glutamic acid, and N-carbamyl-L-glutamic, were tested as a blocker. To evaluate motor coordination and the sedative/hypnotic activity of L-glutamic acid, a rota-rod test and a thiopental sodium-induced sleeping test were used. The compounds, L-glutamic acid and L-nitrobenzoyl glutamic acid, were the most active compounds to block the interaction of castor allergens with IgE. These compounds also prevent cross-responses with allergens from food sources and inhalants that cross-react with them. In the sleeping test, the groups that received L-glutamic acid at doses of 10 and 30 mg/kg had a sleeping time similar to the vehicle control group. No changes in the animals' behavior were observed and there was no difference between the L-glutamic acid groups and the vehicle control groups in the rota-rod test. L-glutamic acid and L-nitrobenzoyl glutamic acid can used as IgE blocker to prevent allergic diseases.

DOI: http://dx.doi.org/10.5281/zenodo.7686100

Antidiabetic potential of mucilage fraction extracted from Astragalus gyzensis seeds

Tue, 07 Feb 2023 21:51:51 +0100

The objective of the current work is to extract a new mucilage fraction from Astragalus gyzensis Bunge. seeds, which are collected from the El-Oued province (septentrional Algerian Sahara) and evaluated for their antidiabetic potential. The mucilage fraction is obtained using hot water extraction followed by alcoholic precipitation of polysaccharides by cold ethanol (96%). The primary investigation was performed by describing the main structural features of the extract through colorimetric assays, Fourier-transform infrared spectroscopy and thin-layer chromatography analysis using two systems. Biological activity was also monitored by antidiabetic activity by testing the inhibition of α-amylase and α-glucosidase enzymes in vitro. The extraction yield was 20.69%. The chemical composition mainly consisted of 78.60±0.29% carbohydrates, among them 63.92±0.67% neutral sugar, 15.78±0.76% uronic acid, 8.08±0.04% proteins and 2.57±0.05% phenolic compounds. The results obtained by thin-layer chromatography analysis showed the dominance of mannose and galactose. Fourier-transform infrared spectrum showed characteristic bands expected galactomannans. The investigations highlighted the antihyperglycemic effect in a dose-dependent manner by the inhibition of the α-amylase enzyme (IC50=0.8±0.005 mg/mL). These factors make it suitable for the industrial application of dietary supplement fiber made for diabetic individuals.

DOI: http://dx.doi.org/10.5281/zenodo.7618530

Analyses of Omicron genomes from India reveal BA.2 as a more transmissible variant

Ashwin Atkulwar, Aakif Rehman, Yashal Imaan, Mumtaz Baig — Sun, 05 Feb 2023 21:43:04 +0100

In the current study, the phylodynamics and phylogenomics of Omicron variants are being examined to provide insight into their evolution. We analyzed 564 genomes deposited to the GISAID database from various states of India. A Pangolin COVID-19 Lineage Assigner tool was used to assign lineages to all retrieved genomes. Maximum likelihood (MLE) tree construction and Reduced Median Joining (RM) network were performed. For phylodynamic analysis, the basic reproduction number (R0) was estimated. A Maximum likelihood tree (MLE) confirms the separation of genomes into two distinct clades, BA. 1. and BA. 2. A very high reproduction number (R0) of 2.445 was estimated for the lineage BA.2. Telangana has the highest R0 value in the country, indicating a high prevalence of the BA.2 lineage. The construction of the Reduced Median (RM) network reveals an evolution of some autochthonous haplogroups and haplotypes, which further supports the rapid evolution of Omicron as opposed to its previous variants. Phylogenomic analyses using maximum likelihood (ML) and RM also reveal the likelihood of the emergence of sub-sublineages and novel haplogroups respectively. Due to the recombinant nature and high transmissibility of the Omicron virus, we suggest continuous and more widespread genome sequencing in all states of India to track the evolution of SARS-CoV-2.

DOI: http://dx.doi.org/10.5281/zenodo.7607992

Serum creatinine and urea assays on Atellica® CH and Architect® ci4100: method comparison

Mon, 16 Jan 2023 21:23:42 +0100

Serum creatinine and urea are markers of renal function usually measured in conjunction. This study aims to evaluate the comparability of a new analyzer incorporated to our laboratory, Atellica® with the established analyzer, Architect ® ci 4100 in serum creatinine and urea assays. We ran 110 tests for creatinine and 107 for urea. In both analyzers, serum creatinine assay is based on the Jaffe reaction while urea measurement is based on the Roch-Ramel enzymatic reaction. Linear association between methods was evaluated using Pearson's correlation coefficient. Methods comparability was assessed using Passing-Bablok and Deming linear regression. Differences between analyzers were evaluated using Bland-Altman plot. For serum creatinine, regression equations are Atellica = 0.9721 x Architect - 2.7282 (Passing & Bablok) and Atellica = 0.8884 x Architect + 1.3456 (Deming). The mean difference between the two methods is -11.7 µmol/L as indicated by Bland-Altman plot. For urea, regression lines are expressed as Atellica = 1.0252 x Architect – 0.1609 (Passing-Bablok) and Atellica = 1.1424 x Architect – 0.9532 (Deming). Bland-Altman plot presented a mean difference of -0.1 mmol/L. These results could be described as a very good agreement between the two methods, the two analyzers could be used interchangeably.

DOI: http://dx.doi.org/10.5281/zenodo.7542158

Impacts of prolonged exposure to low concentration of titanium dioxide nanoparticles on cell cycle control and DNA repair

Nada El Zahed, Andreas Kakarougkas — Tue, 27 Dec 2022 20:39:06 +0100

Although the toxicological profile of titanium dioxide nanoparticles is not fully illuminated, large quantities of titanium dioxide nanoparticles (TiO₂NPs) are now produced. In our study, we evaluated the cytotoxic and genotoxic impacts of titanium dioxide nanoparticles on different cell lines (normal, cancer and DNA repair-deficient cells). MTT assay was used to evaluate the cytotoxicity, γ-H2AX and 53BP1 assay was used to evaluate the genotoxicity and G2/M assay was used to study the impacts of titanium dioxide nanoparticles on cell cycle regulation. In this study normal and DNA repair-deficient cell lines were used to study the repair mechanism of titanium dioxide nanoparticles induced DNA damage. G2/M checkpoint maintenance was also evaluated. We demonstrate that prolonged exposure to low concentrations of titanium dioxide nanoparticles does not induce significant cytotoxicity but induces significant genotoxicity, particularly DNA double-strand breaks (DNA DSBs). Furthermore, this study demonstrated that DNA DSBs at heterochromatin region are ATM-dependent and DNA DSBs at euchromatin region are ATM-independent and DNA PKcs dependent. After exposure to titanium dioxide nanoparticles, we show that the activation of G2/M checkpoint is DNA DSBs dependent threshold as does checkpoint release. All in all, we showed that prolonged exposure to low concentrations of titanium dioxide nanoparticles does not affect cell viability but causes DNA damage and cell cycle checkpoint adaptation which may lead to genetic instability.

DOI: http://dx.doi.org/10.5281/zenodo.7487421

Investigation of antibacterial and antioxidant properties of three medicinal plants from Gaziantep, Turkey

Sinem Aydin, Mustafa Sümbül — Fri, 16 Dec 2022 22:01:44 +0100

Current research aimed to reveal antibacterial and antioxidant properties of acetone and ethyl acetate extracts of Phlomis armeniaca, Echinophora tenuifolia subsp. sibthorpiana and Moringa oleifera plants obtained from herbalists in Gaziantep. Extracts of P. armeniaca, E. tenuifolia subsp. sibthorpiana and M. oleifera plants have antibacterial effect at varying degrees against test bacteria. Both ethyl acetate and acetone extracts of P. armeniaca plant exhibited higher antibacterial activity than studied other plant extracts. It was also found that the antioxidant activity increased with increasing concentrations. Since antioxidant and antibacterial activities were observed in almost all of the tested plant extracts, it was concluded that P. armeniaca, E. tenuifolia subsp. sibthorpiana and M. oleifera plants could be natural sources of antioxidant and antibacterial.

DOI: http://dx.doi.org/10.5281/zenodo.7448940

Prevalence of rifampicin-resistant Mycobacterium tuberculosis in Kebbi state, Nigeria

Fri, 09 Dec 2022 22:40:33 +0100

Tuberculosis remains a global public health burden in low and middle-income countries. The emergence and spread of drug-resistant microbial strains in high-burden countries like Nigeria pose a threat to achieving the One health approach. This study aimed at determining the prevalence of rifampicin resistance in sputum specimens of patients in Kebbi State, Nigeria using the GeneXpert Assay. It was a retrospective cross-sectional study and was carried out in Kebbi, North-Western Nigeria among patients who were confirmed positive for tuberculosis infection and visited the designated health zones, for various local government areas within the state. Sputum samples were analyzed using the GeneXpert technique. Data entry was made using Microsoft Excel and analyzed with SPSS version 20. A p-value less than 0.05 was taken as significant. The overall prevalence of rifampicin-resistant Mycobacterium tuberculosis (RR-MTB) was 5.8% (14/240). The majority of the study participants were within the age grade 31-40 years (8.77%) and male participants (7.2%) were preponderant in comparison to female participants (2.7%). There was a significant association between settlement and rifampicin resistance in the study (p=0.05). The results showed that drug-resistant tuberculosis is prevalent in Kebbi State with a higher incidence observed in the Zuru Local Government Area of the state as compared to previous findings. This shows that improving the prevention and control efforts of tuberculosis in the state with relation to adequate regulatory strategies and policy formulation is of paramount importance.

DOI: http://dx.doi.org/10.5281/zenodo.7420049

Zika and SARS-CoV-2: neuroinflammation and neurodegenerative outcomes

Mon, 28 Nov 2022 22:40:02 +0100

Through the emergence of new viral infectious diseases, epidemics and pandemics have brought great impacts on public health in recent decades. In this review, we sought to understand the association between the neurological outcomes of two relevant infectious diseases, Zika and COVID-19. Zika can trigger neurological and ophthalmic damage in children born from infected mothers, as well as, Guillain-Barré syndrome, encephalitis, and myelitis in adults. On the other hand, the SARS-CoV-2 virus has great potential to trigger an inflammatory process in the optic nerve, with optic neuritis as the most reported pathology. Although Zika and SARS-CoV-2 infections are associated with different clinical manifestations, both may trigger similar pathogenic processes, through the induction of pro-inflammatory chemokines and cytokines release, triggering neurological and ophthalmological damage in infected patients. Elements in common have been found in both infections, such as antibodies against myelin oligodendrocyte glycoprotein, and the production of CXCL10, a chemokine responsible for the activation of several cellular types (T cells, eosinophils, monocytes and NK cells) in which are responsible to the induction of a cytokine cascade in the body. Based on these last findings, we suggest that both infections have similar activation characteristics as well as common pathogenic mechanisms associated with central nervous system involvement.

DOI: http://dx.doi.org/10.5281/zenodo.7374340

Novel mutations of PCCA and PCCB genes found by whole-exome sequencing related to propionic acidemia patients

Mon, 28 Nov 2022 22:15:24 +0100

Propionic acidemia (PROP) is an autosomal recessive inherited metabolic deficiency caused by multimeric mitochondrial enzyme propionyl‐coenzyme A (CoA) carboxylase (PCC). PCC enzyme contains a and b subunits, encoded by the PCCA and PCCB genes that mutations in both subunits are related to propionic acidemia. About 50% of disease-causing variants have been found in PCCA and most mutations related to propionic acidemia are missense mutations. The present study involves three families that are suspicious to hereditary propionic acidemia syndrome. The first family has four, the second family has one, and the third family has two passed-away children. All these families were diagnosed with the same clinical conditions such as poor feeding, vomiting, hypotonia, and lethargy. In the process of finding and confirming the mutation, pathological tests and whole-exome sequencing and sanger sequencing were done. In order to pathological tests and whole-exome sequencing, this is the first report of three novel variants related to propionic acidemia: 1. Novel pathogenic homozygous NM_000532.5: c.503_505del: p.Glu168del mutation of the PCCB exon5 gene, 2. Novel pathogenic homozygous splicing NM_000282:c.1900- 1G>A mutation of PCCA exon22 and exon21, 3. Novel compound heterozygous pathogenic NM_000532.5: c.503_505del: p.Glu168del and likely pathogenic NM_000532.5:c.539T>C: P.F180S mutation of the PCCB exon5 gene. The study shows that PCCA and PCCB have a great role in hereditary propionic acidemia and the results of the present study may be of importance in genetic counseling and finding the best treatment of this syndrome.

DOI: http://dx.doi.org/10.5281/zenodo.7374273

Phenolic profile and biological activities of Aloe barbadensis (Miller) from western Algeria

Wed, 02 Nov 2022 22:01:47 +0100

Aloe vera is widely used in conventional medicine in Algeria to treat various diseases. This study aims to evaluate the chemical composition and biological activities of Aloe vera collected from western Algeria. Two extracts of ethanolic (EEA) and aqueous (AEA) were used to determine the total phenolic and flavonoid content. HPLC was applied to determine the amount of 15 compounds they contain, while the antioxidant activity was determined by the DPPH method. The antimicrobial activity experiment was conducted against five selected bacterial strains. Finally, an in vivo study on Swiss albino mice was conducted to discover the toxicity using Lorke’s method and anti-inflammatory activity using the Carrageenan method. The EEA extract shows the highest total phenol content of 37.00±0.37mg GAE/g and total flavonoid content of 9.14±0.19 mg CE/g. The AEA contains hydroxybenzoic and benzoic acid with other ingredients (0.84 and 0.82 mg/g, respectively). The EEA contains 0.93 mg/g of benzoic acid. Aloe vera has antioxidant activity with IC₅₀ values equal to 0.821 mg/ml for EEA and 1.993 mg/ml for AEA. The AEA inhibits E. coli and S. aureus with a bacteriostatic effect; EEA is the best inhibitor of S. aureus and S. mutans with the bactericidal effect. Aloe vera is practically nontoxic (LD₅₀is 3800 mg/kg of the AEA and superior to 5000 mg/kg of EEA). The AEA gives the best inhibition of edema, 85.96% at (100 mg/kg). Aloe vera leaves are an important resource of polyphenols, which have interesting antioxidant power, and antimicrobial and anti-inflammatory activities.

DOI: http://dx.doi.org/10.5281/zenodo.7274997

Chemical composition, in vitro antioxidant and anti-inflammatory activities of Juniperus oxycedrus subsp. oxycedrus extracts from Algeria

Sun, 02 Oct 2022 22:52:59 +0200

This study was conducted to examine chemical compositions, the anti-oxidant and anti-inflammatory properties of methanolic and aqueous extracts from aerial parts of Juniperus oxycedrus subsp oxycedrus growing in Mascara, Algeria. The quantitative assessment indicated that methanol extract was the most concentrated in phenolic, flavonoid and tannin contents (167.77±5.12 mg GAE/g DW, 90.56±2.23 mg QE/g DE and 110.21±2.38 mg CE/g DE respectively). The chromatographic analysis by HPLC showed quantitative differences in phenolic constutents, noting that Chlorogenic acid was the major compound of both extracts. Moreover, methanolic extract exhibited the highest antioxidant activity than the aqueous extract when tested by the 1,1-diphenyl-2-picrylhydrazyl (IC₅₀ 4.45±0.001 μg/mL) and phosphomolybdenum (328.52±0.071 mg of GAE/g DW) assays. Furthermore, the in vitro anti-inflammatory activity showed a strong inhibition of albumin denaturation by the methanolic extract at different concentrations when compared to standard drug diclofenac sodium. These findings confirm the richness of Algerian Juniperus oxycedrus extracts in bioactive compounds with antioxidant and anti-inflammatory capacities. These results are compatible with the use of the plant in traditional medicine.

DOI: http://dx.doi.org/10.5281/zenodo.7135281

Encapsulation effects of galactomannans combined with xanthan on the survival of two lactic strains under simulated digestive hostilities

Abdallah Rahali, Mounira Ariech, Badreddine Moussaoui, Ali Riazi — Sun, 04 Sep 2022 21:01:12 +0200

Galactomannans are the main component of locust bean gum from the fruit of the carob tree, Ceratonia siliqua L. They are a reserve of polysaccharides, found in the translucent endosperm of the seeds. They are designated as the best gels with thickening capacity and are, therefore, widely used as a natural food additive (E410) in many food, pharmaceutical and cosmetic preparations. In this study, we aim to exploit this gelling property of carob galactomannans in the microencapsulation of lactic bacteria in order to protect them from the negative effects of simulated digestive conditions. Two beneficial bacteria are used: Lactobacillus rhamnosus LBRE-LSAS and Bifidobacterium animalis subsp. lactis Bb12. Their survival in the free state or encapsulated in pure carob galactomannan gel combined with xanthan, was determined after residence in simulated in vitro digestive conditions (gastric: pH 2, pepsin 3 g/l and intestinal: bile 0.3%: W/V, pH 6.5. The results obtained show that gel encapsulation of carob galactomannans combined with xanthan improves the survival of these two beneficial strains to simulated digestive hostilities. the loss under gastric conditions 36.79% (3.55 log CFU/mL) for the non-encapsulated cells and only 12% (1.2 log CFU/mL) for the encapsulated ones. However, galactomannans alone do not appear to be effective in keeping a minimum of 10⁶ bacterial cells viable when confronted with the hostile conditions of the digestive tract where they will be called upon to exert their positive effect on health.

DOI: http://dx.doi.org/10.5281/zenodo.7048634

In silico exploration of Lycoris alkaloids as potential inhibitors of SARS-CoV-2 main protease (Mpro)

Thu, 01 Sep 2022 21:26:15 +0200

Coronavirus disease 2019 (COVID-19) is a pandemic whose adverse effects have been felt all over the world. As of August 2022, reports indicated that over 500 million people in the world had been infected and the number of rising deaths from the disease were slightly above 6.4 million. New variants of the causative agent, SARS-CoV-2 are emanating now and then and some are more efficacious and harder to manage. SARS-CoV-2 main protease (Mpro) has essential functions in viral gene expression and replication through proteolytic cleavage of polyproteins. Search for SARS-CoV-2 Mpro inhibitors is a vital step in the treatment and management of COVID-19. In this study, we investigated whether alkaloids with antiviral and myriad other bioactivities from the genus Lycoris can act as SARS-CoV-2 Mpro inhibitors. We conducted a computer-aided drug design study through screening optimal ligands for SARS-CoV-2 Mpro from a list of over 150 Lycoris alkaloids created from online databases such as ChEMBL, PubChem, ChemSpider, and published journal papers. The In silico study involved molecular docking of Lycoris alkaloids to SARS-CoV-2 Mpro active site, absorption, distribution, metabolism, elimination and toxicity (ADMET) screening and finally molecular dynamic (MD) simulations of the most promising ligand-SARS-CoV-2 Mpro complexes. The study identified 3,11-dimethoxy-lycoramine, narwedine, O-demethyllycoramine and epilycoramine as drug-like and lead-like Lycoris alkaloids with favorable ADMET properties and are very likely to have an inhibition activity on SARS-CoV-2 Mpro and may become potential drug candidates.

DOI: http://dx.doi.org/10.5281/zenodo.7041808

Antimicrobial activity of endophytic fungi associated with halophytic species Salsola vermiculata

Amina Zerroug, Nouari Sadrati — Tue, 30 Aug 2022 20:39:33 +0200

Endophytic fungi are known for their production of bioactive compounds with antibacterial and antifungal activity. In this study, an evaluation of the antibacterial and antifungal activity of endophytic fungi isolated from Salsola vermiculata, a halophyte species collected from Chott el Hodna, M'sila (Algeria) was carried out. The eleven isolated endophytic fungi were identified as belonging to the genera Alternaria sp., Aureobasidium sp., Phoma sp., Chrysosporium sp., Fusarium sp., Aspergillus sp., Papulaspora sp., Ulocladium sp., Humicola sp. and Pencillium sp. The antimicrobial activity of endophyte isolates was tested against phytopathogenic fungi and pathogenic bacteria using the dual culture and the agar plug diffusion methods respectively. The higher percentage inhibition of 79% was obtained by the isolate Penicillium sp. 1 against Fusarium oxysporum f.sp. ciccri. All isolated endophytic fungi showed antibacterial activity against at least one pathogenic bacterium, the greatest effect was obtained by Fusarium sp. against Pseudomonas aeruginosa ATCC 27853 and Bacillus cereus ATCC 10876 with inhibition zones of 26.33 and 25.33 mm respectively. After the comparison of the means of the zones of inhibition, the isolate Chrysosporium sp. was the most active against all pathogenic bacteria with average inhibition zones of 20.55 mm.

DOI: http://dx.doi.org/10.5281/zenodo.7036033

Broad antibacterial spectrum of endophytic fungi isolated from halophyte Suaeda fruticosa in Algeria

Sadrati Nouari, Amina Zerroug — Sat, 27 Aug 2022 22:30:19 +0200

The purpose of this work was to isolate and evaluate the antimicrobial potential of endophytic fungi isolated from Suaeda fruticosa. Endophytic isolates were identified at the genus level. The genera Fusarium (33.33%), Phoma (26.67%), Penicillium (13.33%), and Aspergillus (13.33%) were more prevalent, while Trichoderma genus (6.67%) was less common. The isolated fungal endophytes were screened for their potential antifungal and antibacterial activities. Most isolates showed different levels of inhibitory activity against at least one of the pathogens. The best inhibition percentages were those obtained by Penicillium sp. 1; 74, 71, 65, and 47% against Fusarium oxysporum f.sp. albedinis, Fusarium oxysporum f.p. ciccri, Fusarium solani var. coeruleum and Phytophthora infestans respectively. Regarding antibacterial activity, the zones of inhibition ranged from 0 to 25.5 mm. Fusarium isolates and Phoma sp. 4 showed the greatest antibacterial activity, the highest activity was observed with Fusarium sp.5 and Fusarium sp. 1, which gave zones of inhibition of 25.5 and 22.5 mm respectively against B. cereus ATCC 10876. Gram-positive bacteria were more sensitive to endophyte isolates than Gram-negative bacteria. From the results of the present work, it is possible to conclude that endophytic fungi isolated from Suaeda fruticosa could be a promising source of bioactive compounds and deserve further study.

DOI: http://dx.doi.org/10.5281/zenodo.7028278

Synthesis of nicotine derivatives and evaluation of their anti-bacterial activity

Djaafar Zemali, Mohammed Ridha Ouahrani, Salah Neghmouche Nacer — Sun, 14 Aug 2022 16:07:04 +0200

Using a convergent synthetic method, a series of nicotine derivatives were synthesized from the basic materials nicotine-N-oxide in good yields. The structures of the synthesized compounds were confirmed by spectral methods of analysis (FT-IR, 1H-NMR, and 13C-NMR). Most of the target compounds were tested for antibacterial activity against five kinds of bacteria; the tested compounds exhibited varying levels of activity against both gram-negative and gram-positive bacteria. The results of bioactivities showed that some of the target compounds exhibited good antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and Klebsiella pneumoniae. In addition, the broad spectrum anti-microbial action of nicotine derivatives developed in the present study may find immense applications in formulating new disinfection or decontamination strategies against widely spreading pathogens of clinical significance.

DOI: http://dx.doi.org/10.5281/zenodo.6990730