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Effects of extraction solvents on polyphenols content and biological activity of Ajuga iva extracts
Different solvent systems have been used for the extraction of polyphenols from plant material, however, the appropriate solvent system is more effective for extracting the total phenolic of any plant extract and evaluating the antibacterial activity is not determined yet. Thus, the objective of this research was to determine the most effective solvent for extraction and characterization of polyphenols as well as antibacterial activity of the aerial parts Ajuga iva extracts. The Soxhlet method was devised to extract polyphenols from aerials parts of Ajuga iva powders, for this matter, three different solvents were used In order to analyze and quantify the result an in vitro evaluation of the antibacterial activity of the various plant extracts was carried out. The preliminary evaluation of the chemical composition made it possible to highlight the presence of some chemical groups. The quantitative determination of polyphenols is twofold, first the dichloromethanic extract contains the highest levels of polyphenols (3.38 mg GAE/g), second the ethanolic extract contains the highest levels of flavonoids (6.59 mg CE/g DW) and tannins (14.58 mg CE/g DW). On other hand, a remarkable antibacterial activity of some tested extracts was detected. The results showed that solvents with different polarities significantly affected polyphenol content and antibacterial activity.
DOI: http://dx.doi.org/10.5281/zenodo.640208
Broad antibacterial spectrum of endophytic fungi isolated from halophyte Suaeda fruticosa in Algeria
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.702827
A novel coronavirus (SARS-CoV-2): current status and challenges
In December, 2019 a new public health crisis threatened the world with the emergence of new zoonotic virus, the 2019 novel coronavirus. SARS-Cov-2 or severe acute respiratory syndrome coronavirus-2 belongs to the family of coronaviruses named for the crown-like spikes on its surfaces. SARS-CoV-2 causes COVID-19 (Coronavirus Disease-2019), a contagious viral infection that attacks primarily throat and lungs causing pneumonia-like symptoms. It is speculated that SARS-CoV-2 seem to have come from a bat, but the intermediate reservoir is still unknown. This review will address SARS-CoV-2 structure, clinical features, SARS-CoV-2 genome and its different variant, diagnosis, and treatment and also gives a bird's eye view on the epidemiology and pathology based on current evidence.
DOI: http://dx.doi.org/10.5281/zenodo.656139
Synthesis of oxadiazole substituted new carbazole derivatives as antioxidant and antiurease agent
Heterocyclic compounds containing nitrogen together with an oxygen atom in their structures are an important class of medicinal chemistry compounds due to their interesting diverse biological applications. Some compounds including carbazole ring, which are aromatic organic compounds in tricyclic structure, show biological activity in a wide spectrum. Oxadiazole compounds attract the attention of many chemists thanks to their antibacterial, antitumor, anticancer, anti-viral, antimicrobial, anti-HIV, antituberculosis and antioxidant properties. In this study, new oxadiazole substituted carbazole derivatives were synthesized and their antioxidant, antiurease activities were investigated. 9H-carbazole is a good starting material for the synthesis of carbazole derivatives. The antioxidant and antiurease activities of synthesized oxadiazole substituted new carbazole derivatives were investigated. Antioxidant activity methods such as DPPH (1,1’-diphenyl-2-picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) radical scavenging activities and iron reducing power capacities were used to determine antioxidant activity of the compounds. All synthesized carbazole compounds showed antioxidant and antiurease activity. While compound 4 shows the strongest enzyme inhibition activity, the least active compound was found 5. All tested compounds showed higher enzyme inhibition activity than thiourea. The highest and the lowest antioxidant activities were observed as compounds 3 and 6, respectively.
DOI: http://dx.doi.org/10.5281/zenodo.661244
Hyoscyamus muticus L. subsp. falezlez methanolic extract: phytochemical composition and biological activities
This study aims to assess the phytochemical analysis and evaluate the antioxidant and antimicrobial activities of the methanolic extract obtained from the Algerian Hyoscyamus muticus L. subsp. falezlez leaves of Timimoun region. Methanolic extract of the plant contained the highest quantity of phenolics (148.00 ± 3.07 µg GAE/mg extract) and flavonoids (41.43 ± 0.90 µg QE/mg extract). The High-Performance Liquid Chromatography (HPLC) results showed dominance in the phenolic compounds: orientin, vitexin 2-O-rhamnoside and n-OH-cinnamic acid. Eight metabolites were identified and quantified by Gas Chromatography-Mass Spectrometry (GC-MS) which included five fatty acids, one dicarboxylic acid derivative, one bicyclic hydrocarbon and one fatty acid derivate. The GC-MS analysis revealed that palmitic acid (32.56%), linolenic acid (21.34%) and linoleic acid (11.24%) were the three major components. The methanolic extract showed an antioxidant activity for DPPH, ABTS, reducing power and phenanthroline assays. The strongest antioxidant activity was obtained with phenanthroline assay (value of A0.5 <3.125 µg/mL). The antimicrobial investigation on thirteen microbial strains revealed that the methanolic extract showed low to moderate antibacterial activity against the Gram-positive and negative tested bacteria and no antifungal activity on all the tested fungi. This work suggests the use of leaves from H. muticus L. subsp. falezlez as a source of bioactive compounds with applications in the pharmaceutical, cosmetic and food industries.
DOI: http://dx.doi.org/10.5281/zenodo.675736
Novel mutations of PCCA and PCCB genes found by whole-exome sequencing related to propionic acidemia patients
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.737427
Prevalence of rifampicin-resistant Mycobacterium tuberculosis in Kebbi state, Nigeria
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.742004
Investigation of antibacterial and antioxidant properties of three medicinal plants from Gaziantep, Turkey
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.744894
Encapsulation effects of galactomannans combined with xanthan on the survival of two lactic strains under simulated digestive hostilities
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.704863
Efficacy of essential oils as antiseptics on the productive characteristics of the mulberry silkworm Bombyx mori L.
The study aimed to test the efficacy of three essential oils (basil Ocimum basilicum L., lemon Citrus limon (L.) Osbeck, and thyme Thymus vulgaris L.) as disinfectants, including their positive and negative effects, on the biological and productive parameters of the silkworm Bombyx mori. Biological parameters: basil oil treatment at 2000 ppm the highest significant 5th instar larval weight and pupal weight were 2.226 g and 0.787 g. In addition, at the same concentration, recorded the lowest significant mortality percentage and 5th instar larval duration, were 0.787 g and 5.09% respectively. On the other hand, lemon and thyme oils at 4000 ppm come in the second place the same parameters, compared to the control and the chemical disinfectant. While it is equal to the concentration of 8000 ppm for the oils tested in all biological parameters with the control and chemical disinfectant. Economical parameters: basil oil at 2000 ppm and lemon and thyme oils at 4000 ppm had the highest significance for cocoon weights, cocoon shell weight, and silk productivity, which were 1.203 g, 0.220 g, 2.34 cg for basil oil, 1.139 g, 0.210 g, 2.367 cg for lemon oil and 1.265 g, 0.216 g, 2.397 cg for thyme oil, compared with control and disinfectant chemical groups (0.993 g, 0.157 g, 1.49 cg and 0.991 g, 0.160 g, 1.68 cg, respectively). The highest significant difference of cocoon percentages was seen with basil oil at 2000 ppm, compared to the other treatments.
DOI: http://dx.doi.org/10.5281/zenodo.590659