Antibacterial activity of ethanolic extract from Derris scandens against human pathogenic bacteria

The purpose of this study was to assess the antibacterial activity of an ethanolic extract of Derris scandens against clinically isolated human pathogenic bacteria. Materials and methods: The ethanolic extract was assessed for antibacterial activity against ten human pathogenic bacteria at different concentrations (25 - 100 μg/ml) through the agar well diffusion method. Group 1 (25μg/ml), Group 2 (50μg/ml), Group 3 (75μg/ml) Group 4 (100μg/ml), Group 5 (positive control), and Group 6 (negative control) and calculated the zone of inhibition. Results and discussion: The ethanolic extract showed antibacterial activity against 8 clinical bacterial strains of the 10 pathogens tested. The highest concentration (100μg/ml) of the ethanolic extract showed a maximum of 20 and 22mm inhibition zone against E. coli and S. typhi. The mean values were 0.130, 0.141, 0.117, 0.194, and 0.120 The sample size was calculated with a pretest G power of 80%. The sample size per group is 6, and the total sample size is 60. Conclusion: The effective bacterial inhibition rate of Derris scandens might provide a promising beneficial agent against bacterial infection and help to develop future infectious disease drugs

Antioxidant and cytotoxic activities of sulfated polysaccharides from five different edible seaweeds

In recent times, there has been a growing interest in the exploration of antioxidants and global trend toward the usage of seaweeds in the food industries. The low molecular weight up to 14 kDa sulfated polysaccharides of seaweeds (Portieria hornemannii, Spyridia hypnoides, Asparagopsis taxiformis, Centroceras clavulatum and Padina pavonica) were evaluated for in vitro antioxidant activities and cytotoxic assay using HeLa cell line and also characterized by FTIR. The high yield (7.74% alga dry wt.) of sulfated polysaccharide was observed in P. hornemannii followed by S. hypnoides (0.69%), C. clavulaum (0.55%) and A. taxiformis (0.17%). In the brown seaweed P. pavonica, the sulfated polysaccharide yield was 2.07%. High amount of sulfate was recorded in the polysaccharide of A. taxiformis followed by C. clavulaum, P. pavonica, S. hypnoides and P. hornemannii as indicative for bioactivity. The FTIR spectroscopic analysis supports the sulfated polysaccharides of S. hypnoides, C. clavulatum and A. taxiformis are similar to agar polymer whereas the spectral characteristics of P. hornemannii have similarities to carrageenan. The higher DPPH activity and reducing power were recorded in the polysaccharide of brown seaweed P. pavonica than the red seaweeds as follows: DPPH activities: S. hypnoides > A. taxiformis > C. clavulatum > P. hornimanii; Reducing power: A. taxiformis > P. hornimanii > S. hypnoides > C. clavulatum. The polysaccharide fractions contain up to 14 kDa from red seaweeds P. hornemannii and S. hypnoides followed by brown seaweed P. pavonica exhibit cytotoxic activity in HeLa cancer cell line (and are similar to structural properties of carrageenan extracted from P. hornemannii). The low molecular weight agar like polymer of S. hypnoides and alginate like brown seaweed P. pavonica showing better in vitro antioxidant activities that are capable of exhibiting cytotoxicity against HeLa cell line can be taken up further in-depth investigation for nutraceutical study.University of Algarve: DL 57/2016info:eu-repo/semantics/publishedVersio

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Antibacterial activity of ethanolic extract from Derris scandens against human pathogenic bacteria

The purpose of this study was to assess the antibacterial activity of an ethanolic extract of Derris scandens against clinically isolated human pathogenic bacteria. Materials and methods: The ethanolic extract was assessed for antibacterial activity against ten human pathogenic bacteria at different concentrations (25 - 100 μg/ml) through the agar well diffusion method. Group 1 (25μg/ml), Group 2 (50μg/ml), Group 3 (75μg/ml) Group 4 (100μg/ml), Group 5 (positive control), and Group 6 (negative control) and calculated the zone of inhibition. Results and discussion: The ethanolic extract showed antibacterial activity against 8 clinical bacterial strains of the 10 pathogens tested. The highest concentration (100μg/ml) of the ethanolic extract showed a maximum of 20 and 22mm inhibition zone against E. coli and S. typhi. The mean values were 0.130, 0.141, 0.117, 0.194, and 0.120 The sample size was calculated with a pretest G power of 80%. The sample size per group is 6, and the total sample size is 60. Conclusion: The effective bacterial inhibition rate of Derris scandens might provide a promising beneficial agent against bacterial infection and help to develop future infectious disease drugs

Isolation, characterization and molecular weight determination of collagen from marine sponge Spirastrella inconstans (Dendy)

Collagen is a major structural protein of connective tissues. It can be used as a prosthetic biomaterial applicable to artificial skin, tendon ligaments and development collagen implants. In the present study, an attempt was made to isolate and characterize collagen from the marine sponge, Spirastrella inconstans. The total protein content of sponge collagen was relatively high (32%). While determining the molecular weight of crude and purified collagen through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the crude showed three bands (80, 60 and 59 kDa molecular weight) and purified showed only a single band (58 kDa). The structural properties were analyzed by using fourier transform infra red (FT-IR) spectrum and the stability of collagen was also given the single transition peak in differential scanning calorimetry (DSC). The microstructure of sponge collagen showed highly porous and interconnected scaffolds in scanning electron microscopic (SEM) analysis.Keywords: Collagen, Spirastrella inconstans, SDS-PAGE, Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM)African Journal of Biotechnology Vol. 12(5), pp. 504-51

A robust multiplex immunofluorescence and digital pathology workflow for the characterisation of the tumour immune microenvironment

Multiplex immunofluorescence is a powerful tool for the simultaneous detection of tissue‐based biomarkers, revolutionising traditional immunohistochemistry. The Opal methodology allows up to eight biomarkers to be measured concomitantly without cross‐reactivity, permitting identification of different cell populations within the tumour microenvironment. In this study, we aimed to validate a multiplex immunofluorescence workflow in two complementary multiplex panels and evaluate the tumour immune microenvironment in colorectal cancer formalin‐fixed paraffin‐embedded tissue. We stained colorectal cancer and tonsil samples using Opal multiplex immunofluorescence on a Leica BOND RX immunostainer. We then acquired images on an Akoya Vectra Polaris and performed multispectral unmixing using inForm. Antibody panels were validated on tissue microarray sections containing cores from six normal tissue types, using QuPath for image analysis. Comparisons between chromogenic immunohistochemistry and multiplex immunofluorescence on consecutive sections from the same tissue microarray showed significant correlation (rs > 0.9, p‐value < 0.0001), validating both panels. We identified many factors that influenced the quality of the acquired fluorescent images, including biomarker co‐expression, staining order, Opal‐antibody pairing, sample thickness, multispectral unmixing, and biomarker detection order during image analysis. Overall, we report the optimisation and validation of a multiplex immunofluorescence process, from staining to image analysis, ensuring assay robustness. Our multiplex immunofluorescence protocols permit the accurate detection of multiple immune markers in various tissue types, using a workflow that enables rapid processing of samples, above and beyond previous workflows