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In vitro studies of iron absorption and activity of glutathione peroxidase in intestinal mucosa of the chicken
Get PDFWe examined the absorption of iron, the activity of selenoprotein glutathione peroxidase (GSH·Px) and cellular compartmentalization of metal in the chicken duodenum and ileum. The method of accumulating mucosa preparation (AMP) was used. It was shown that the intestinal iron accumulation is dose-dependent process, which has two components: transcellular and paracellular. The realization of these pathways is region-specific and depends on exposed iron levels. Slightly elevated iron status of intestinal mucosa does not influence activity of GSH·Px. At the same time the results indicate that the activity of glutathione peroxidase can be altered by iron overload. Immunohistochemistry revealed that stainable iron could be co-localized to the endolysosomal compartment. How the activity of enzyme can be affected by oxidative stress and competitive interactions of iron with selenium are discussed.
DOI: http://dx.doi.org/10.5281/zenodo.141278
Plant Growth Promoting Rhizobacteria (PGPR) and their various mechanisms for plant growth enhancement in stressful conditions: a review
Get PDFThe population has been rising in a rapid state and so is the demand of basic necessities like food requirements. Today agriculture demands increase in yield with a substantial decrease in chemical fertilizer and pesticides that are responsible for huge environmental degradation. Today a huge part of yield has been lost due to various stresses plant are subjected too. It could be broadly divided into biotic and abiotic stress. Meanwhile, plant growth promoting rhizobacteria has promised us a substantial agriculture development platform. These are generally a group of microorganism that is found either in the plane of the rhizosphere or above root impacting some positive benefits to plants. These stresses include but in no sense limited to ion toxicity, pathogen susceptibility, physiological disorder, salinity, temperature, flooding, pH etc. In response to the above-mentioned stresses plant with PGPR exhibits various sorts of response to handle these unfavorable conditions. They could be further divided into direct and indirect mechanics. PGPR has shown both synergistic as well as antagonist interaction with microorganism inhabiting in near surrounding to boost plant favorably. This review has tried to undertake all possible mechanism of PGPR along with reported studies for various possibilities through which sustainable agriculture development could take place. This review has tried to understand the mechanism to take PGPR at a commercial level under bio-fertilizer.
DOI: http://dx.doi.org/10.5281/zenodo.145599
Comparative stem anatomy of four taxa of Calycanthaceae Lindl.
Get PDFThe anatomical character is potential value in Calycanthaceae for their taxonomic study. Four species of Calycanthaceae were collected for this experiment. The experiment was done using the resin methods for preparation of the permanent slide for anatomical studies. The anatomical character like two traces of the unilocular vascular bundle, in the primary vascular cylinder, contains four cortical vascular bundles in the stem, the unilocular structure of primary cylinder, the presence of numerous intercellular space in phloem, the presence of oil cell in the form of scatter in Calycanthus whereas small size in Chimonathus. Calycanthus possess boarder pit with circular aperture while Chimonanthus possess elliptical. The tracheid is a characteristic feature of the spiral band wider in Chimonanthus than that of Calycanthus and Sinocalycanthus. The noted sclerenchymatous cells are grouped of the colony which is a characteristic feature of Sinocalycanthus and Calycanthus but in case of Chimonanthus is the long chain with the layer of the cell. Collenchymatous cell was circular with an intercellular in Calycanthus; ovoid shape with the intercellular in Chimonanthus but in Sinocalycanthus is elongation with the minor regular shape. The different character of pith cells found in hexagonal and circular shape which is also distinguished feature in Calycanthaceae. The valu-able stem anatomical characters are the importance of their function, ontogeny, and phylogeny.
DOI: http://dx.doi.org/10.5281/zenodo.119957
Biologically active phenolic acids produced by Aspergillus sp., an endophyte of Moringa oleifera
Get PDFThis study investigates the secondary metabolites of an endophytic Aspergillus sp. isolated from leaves of M. oleifera growing in Anambra State, South-Eastern Nigeria. Antimicrobial and antioxidant screening of the fungal extract and isolated compounds, as well as cytotoxicity assay of the extract against cisplatin-sensitive A2780 (sens) and cisplatin-resistant A2780 (cisR) ovarian cancer cell lines were carried out using standard methods. Chemical investigations of the fungal extract involving a combination of different chromato-graphic methods and spectroscopic techniques were carried out to isolate and characterize the constituents of the extract. At a concentration range of 1-4 mg/ml, the crude extract of Aspergillus sp. showed mild antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Candida albicans. The fungal extract showed good antioxidant activity at 500 µg/ml, with an inhibition of 72.1%. Also, at 100 µg/ml, the extract showed excellent cytotoxic activity against A2780 (sens) and A2780 (cisR), with growth inhibitions of 105.1% and 105.5% respectively. Two known pharmacologically active phenolic compounds (p-hydroxyphenyl acetic acid and ferulic acid) were isolated from the fermentation extract of the endophytic fungus. At 250 µg/ml, ferulic acid exhibited an excellent antioxidant activity with an inhibition of 90.4%, while an inhibition of 35.4% was recorded for p-hydroxyphenyl acetic acid. Ferulic acid also showed a mild antifungal activity at 500 µg/ml against A. niger with an IZD of 2 mm. p-Hydroxyphenyl acetic acid showed no antimicrobial activity. These results further confirm the potentials of endophytic fungi associated with Nigerian plants as source of bioactive compounds with pharmaceutical or industrial applications.
DOI: http://dx.doi.org/10.5281/zenodo.140498
Probiotics in colon cancer prevention
Get PDFProbiotics are live, selected microbial strains that have a beneficial effect on the human body and when introduced into the body, they colonize in the digestive tract, especially in the large intestine, exerting a beneficial effect on the health of the host. The microbial strains, so that they can be included in the probiotics, must be thoroughly tested and meet several conditions. These microorganisms multiply in the gastrointestinal tract and are competitive for pathogenic microorganisms that cause infection. Probiotic bacteria are found in natural yogurts, sour milk, sauerkraut, pickled cucumbers. Many studies show a positive correlation between the consumption of probiotics and the risk of developing certain cancers. Probiotics are most likely to reduce the risk of developing colorectal cancer.
DOI: http://dx.doi.org/10.5281/zenodo.129766
Cucurbitaceae - the family that nourishes and heals
Get PDFA review of the activities of members of the Cucurbitaceae was carried out. Many of them are confirmed nutritious and therapeutical. Their global spread, diverse genera and phytochemical profile further confirm them as an attraction for the growth and survival of humanity. The need for alternative control measures to address resistance has heightened the passion for Cucurbitaceae in bioprospecting.
DOI: http://dx.doi.org/10.5281/zenodo.143679
The relevance of sebum composition in the etiopathogeny of acne
Get PDFAcne vulgaris is an inflammatory disease that develops around the hair follicle. Many are the interconnected etiopathogenic factors involved, among which we can mention the increase in levels of androgen hormones, sebum hypersecretion, follicular hyperkeratosis with microcomedo formation, the proliferation of the bacteria Propionibacterium acnes (P. acnes) and the resulting inflammatory response. The way this bacterial growth occurs and how it is connected with the development of the inflammatory process have been themes of many clinical and experimental trials. Modifications in the sebum composition lead to a greater proliferation and differentiation of keratinocytes that obstruct the follicular ostium and favor the formation of comedones. On the other hand, these modifications alter the follicular hydration and facilitate the proliferation of the P. acnes, which not only produces chemotactic factors but also releases lipase that oxidizes the squalene. The oxidized squalene induces the formation of pro-inflammatory cytokines and boosts the innate immunity of keratinocytes and sebocytes, thus generating the inflammatory process. The aim of this study was to review the literature regarding the new concepts on the pathogenesis of acne.
DOI: http://dx.doi.org/10.5281/zenodo.118413
Pesticides and food safety in Africa
Get PDFAfrican countries have experienced nonconformance in the levels of pesticides for local consumption and export. Sometimes this leads to rejects and other forms of embarrassment from the importing countries. Economic challenge and lack of awareness heighten the overall cost of interventions in pesticide-related food safety management. For example, not a few of the infractions were a result of incorrect ways of pesticide application. The hazard accompanying chemical pesticide application has left open a window of biological alternatives which this review article seems to explore. The bio-alternatives, including green pesticides cancel out the adverse effect of residual chemicals on crops in farm and store and so make it more attractive.
DOI: http://dx.doi.org/10.5281/zenodo.123754
Incidence of community acquired ESBL-producing bacteria among asymptomatic University students in Anambra State, Nigeria
Get PDFThis study was conducted to investigate the incidence of community acquired extended-spectrum β-lactamase (ESBL)-producing bacteria among asymptomatic students of Nnamdi Azikiwe University, Awka, Anambra State, South-East Nigeria. A total of 102 non-duplicate strains of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated from fecal samples (n=273) collected from the participating students. The isolates were subjected to antimicrobial susceptibility tests to determine their antimicrobial resistance profile. Their multiple antibiotic resistance (MAR) indices were also evaluated. Screening of the isolates for possible ESBL production was carried out by disk diffusion test using cefotaxime and ceftazidime disks. ESBL-production by the resistant strains was confirmed using the double-disk synergy test. Most of the isolates were found to be multi-drug resistant, as all K. pneumoniae and P. aeruginosa strains (100%), and 98.4% of the E. coli strains, had MAR indices ≥0.2. A total of 22 ESBL-producing bacterial species were confirmed, and the frequency of E. coli, K. pneumoniae and P. aeruginosa isolates among the ESBL-producing bacteria were n=20 (90.9%), n=2 (9.1%), and n=0 (0.0%) respectively. The total number of ESBL-producing bacterial strains isolated accounted for 8.1 % of the entire sample population. Although this prevalence rate may not indicate an alarming situation, it is important that the proliferation of ESBL-producing bacteria in the community be contained, since a high incidence of ESBL-producing organisms will create significant therapeutic problems in the near future. There is therefore need to develop strategies to reduce their spread in the community especially through monitoring, surveillance and proper detection protocol.
DOI: http://dx.doi.org/10.5281/zenodo.131471
Resistance to ceftaroline - 2018 review
Get PDFCeftaroline is a new fifth generation cephalosporin, active mostly against Gram-positive cocci, e.g. Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus). It is used in treating acute bacterial skin and skin structure infections, community acquired respiratory tract infections and methicillin-resistant S. aureus bacteremia. The main resistance mechanisms of bacteria to β-lactam antibiotics, including ceftaroline, are mutations in PBP2a, PBP3 and PBP4. Clinically significant resistance has been noted among both archived and newly-isolated strains in a laboratory test using serial passages. Ceftaroline-resistant strains have also been found in patients suffering from cystic fibrosis, ventilator-associated pneumonia and infectious endocarditis. Irresponsible antibiotic treatment using ceftaroline or other antibiotics (due to a possibility of a cross-resistance) can lead to the spread of ceftaroline resistance and, consequently, its loss of value.
DOI: http://dx.doi.org/10.5281/zenodo.130443