scholarly journals Cholesterol-lowering Potential and Exopolysaccharide Biosynthesis of Lactobacillus spp. isolated from Human Milk

Author(s):  
Pham Thi Thu Uyen ◽  
Nguyen Hoai An ◽  
Pham The Hai ◽  
Bui Thi Viet Ha

Recent research generated information that human milk is not only a valuable source of nutrition, but it also provides a complex microbial community, containing especially Lactobacillus species - the major components of a great number of commercial probiotics. New findings on potential applications of Lactobacillus species revealed that these bacteria have abilities to produce anti-microbial exopolysaccharides (EPS) and to reduce cholesterol in culture broth. In this study, we successfully isolated and screened for Lactobacillus bacteria from human milk samples, and finally obtained four strains, including L. plantarum BM7.13, L. plantarum BM29.7, L. acidophilus BM10.8 and L. rhamnosus BM30.4. Researching the probiotic activities of these strains showed that all strains were tolerant to the low pH (3.0) and 0.3% bile salts. Characterization of the probiotic properties indicated that all selected Lactobacillus isolates had ESP (125-326 mg/L) and exhibited strong antimicrobial activities against pathogenic microbes, such as Escherichia coli, Staphylococcus aureus, Shigella flexneri and Salmonella typhimurium. Our results also indicated that all strains displayed cholesterol assimilation capabilities in culture broth with the maximum figure recorded for L. plantarum BM7.13.

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2804-2837
Author(s):  
Chhangte Vanlalveni ◽  
Samuel Lallianrawna ◽  
Ayushi Biswas ◽  
Manickam Selvaraj ◽  
Bishwajit Changmai ◽  
...  

Herein, we have reviewed new findings in the research domain of the green synthesis of silver nanoparticles using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Junpeng Li ◽  
Shuping Hu ◽  
Wei Jian ◽  
Chengjian Xie ◽  
Xingyong Yang

AbstractAntimicrobial peptides (AMPs) are a class of short, usually positively charged polypeptides that exist in humans, animals, and plants. Considering the increasing number of drug-resistant pathogens, the antimicrobial activity of AMPs has attracted much attention. AMPs with broad-spectrum antimicrobial activity against many gram-positive bacteria, gram-negative bacteria, and fungi are an important defensive barrier against pathogens for many organisms. With continuing research, many other physiological functions of plant AMPs have been found in addition to their antimicrobial roles, such as regulating plant growth and development and treating many diseases with high efficacy. The potential applicability of plant AMPs in agricultural production, as food additives and disease treatments, has garnered much interest. This review focuses on the types of plant AMPs, their mechanisms of action, the parameters affecting the antimicrobial activities of AMPs, and their potential applications in agricultural production, the food industry, breeding industry, and medical field.


Author(s):  
Phoomjai Sornsenee ◽  
Kamonnut Singkhamanan ◽  
Surasak Sangkhathat ◽  
Phanvasri Saengsuwan ◽  
Chonticha Romyasamit

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Mohamed H. A. Suleiman ◽  
Ali A. Ateeg

Zilla spinosa is commonly used in traditional medicine to treat gastrointestinal disorders and diabetes. In this study, aqueous ethanol (AE) and aqueous methanol (AM) extracts from aerial parts and roots of Z. spinosa were investigated. The total phenolic (TPC) and flavonoid (TFC) contents and antioxidant capacities in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, hydrogen peroxide (H2O2), and ferric reducing antioxidant power (FRAP) assays were determined, and the correlations among the results were assessed using Pearson’s correlation. The antimicrobial activity was assessed through agar disc diffusion and broth microdilution assays. Phytochemical screening showed that Z. spinosa extracts had alkaloids, glycosides, saponins, triterpenoids, phenols, and flavonoids in different abundances. The aerial part-AE extract contained low TPC (30.17 ± 4.24 mg GAE/g) and TFC (7.40 ± 1.02 mg QE/g) and displayed significant antioxidant capacity in the DPPH (IC50 = 52.17 ± 7.30 μg/mL), H2O2 (91.22 ± 2.60 μg/mL), and FRAP (EC50 = 98.70 ± 2.21 μg/mL) assays. By contrast, the root-AM extract contained high amounts of TPC (87.72 ± 7.75 mg GAE/g) and TFC (25.60 ± 1.57 mg QE/g). It showed significantly high antioxidant activity with IC50 values of 12.33 ± 1.88 μg/mL in the DPPH and 39.37 ± 2.59 μg/mL in the H2O2 assays, as well as reducing power capacity with an EC50 value of 20.82 ± 1.14 μg/mL in the FRAP assay. Both TPC and TFC were exhibited negative correlations ( p < 0.01 ) with the IC50 and EC50 values obtained in the applied antioxidant assays. The aerial part-AM extract showed the highest inhibitory activity against Staphylococcus aureus (26.5 ± 0.20 mm), followed by Shigella flexneri (19.4 ± 0.40 mm) and Proteus mirabilis (17.7 ± 0.49 mm). S. aureus was the most affected microorganism with a minimum inhibitory concentration of 128 μg/mL against the aerial part-AM extract. Interestingly, all evaluated extracts showed potent antifungal activity against Candida albicans. However, aerial part-AM was the most effective, with an inhibition zone of 12.6 ± 0.17 mm. The results concluded that Z. spinosa possesses different phytochemicals displaying significant antioxidant and antimicrobial activities, thus lending credence to its use in traditional medicine.


LWT ◽  
2019 ◽  
Vol 106 ◽  
pp. 201-208 ◽  
Author(s):  
Aarti A. Boricha ◽  
Satyamitra L. Shekh ◽  
Sheetal P. Pithva ◽  
Padma S. Ambalam ◽  
Bharatkumar Rajiv Manuel Vyas

2017 ◽  
Vol 8 (4) ◽  
pp. 579-588 ◽  
Author(s):  
L.B. Acurcio ◽  
S.H.C. Sandes ◽  
R.W. Bastos ◽  
F.M. Sant’anna ◽  
S.H.S.P. Pedroso ◽  
...  

Ingestion of milks fermented by Lactobacillus strains showing probiotic properties is an important tool to maintain gastrointestinal health. In this study, Lactobacillus rhamnosus D1 and Lactobacillus plantarum B7, isolated from Brazilian artisanal cheese, were used as starters for the functional fermented milks to assess their probiotic properties in a gnotobiotic animal model. Male germ-free Swiss mice received a single oral dose of milk fermented by each sample, and were challenged with Salmonella Typhimurium five days afterwards. Milk fermented by both Lactobacillus strains maintained counts above 108 cfu/ml during cold storage. Lactobacillus strains colonised the gut of the germ-free-mice, maintaining their antagonistic effect. This colonisation led to a protective effect against Salmonella challenge, as demonstrated by reduced pathogen translocation and histological lesions, when compared to control group, especially for Lactobacillus rhamnosus D1. Additionally, mRNA expression of inflammatory (interferon gamma, interleukin (IL)-6, tumour necrosis factor alpha) and anti-inflammatory (transforming growth factor β1) cytokines was augmented in animals previously colonised and then challenged, when compared to other experimental groups. Lactobacillus plantarum B7 colonisation also promoted higher expression of IL-17, showing a proper maturation of colonised germ-free-mice immune system. IL-5 was stimulated by both strains’ colonisation and not by S. Typhimurium challenge.


Author(s):  
Tevan R ◽  
Saravanan Jayakumar ◽  
Nor Haledah Ahmad Sahimi ◽  
Nur Farah Ain Iqbal ◽  
Iffah Zapri ◽  
...  

Biosynthesis of metal nanoparticles has received a remarkable attention due to their eco-friendly and potential applications in pharmaceutical and medical fields. The searches for natural alternatives to replace biosynthetic nanoparticles have resulted in extensive studies of microalgal derived metal nanoparticles. Since there are very limited reports on Isochrysis sp. in synthesising metal nanoparticles, a novel initiative was taken to induce an environmentally friendly and low cost technique to biosynthesise the silver nanoparticles (AgNPs) using marine microalgae, Isochrysis sp. Further, the synthesised silver nanoparticles were screened against human pathogen for antimicrobial effects. The characterisation of nanoparticles were confirmed by UV visible spectroscopy, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD). The results obtained from characterisations indicate that the AgNPs have an almost spherical shape with a various size of 98.1 to 193 nm. The synthesised nanoparticles exhibited outstanding antioxidant and antimicrobial activities.


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