Resistance is increasing to several critical antimicrobials used to treat Salmonella typhimurium infection, urging people to search for new antimicrobial agents. In this work, we reported the possibility of a potent antimicrobial peptide cathelicidin-BF found in the venom of the snake Bungarus fasciatus in treating Salmonella typhimurium infection. We tested its activity in biological fluids and in vivo using a mouse model of Salmonella typhimurium infection, and examined the effect of cathelicidin-BF on Salmonella invasion to epithelial cells. In addition, the biodistribution of cathelicidin-BF was evaluated by using in vivo optical imaging. The results revealed that cathelicidin-BF was unstable in gastrointestinal tract, but retained substantially active in murine serum. Cathelicidin-BF attenuated the clinical symptoms of Salmonella infected-mice, significantly reduced the number of internalized Salmonella and attenuated Salmonella-induced decreases in TER in epithelial cells. Our results provide a first indication for the potential of cathelicidin-BF as a novel therapeutic option for salmonellosis.
We investigate the feasibility of using optical fibre Bragg gratings for the sensing of ultrasonic fields for medical applications. In preliminary experimental investigations, ultrasonic waves with a frequency of 950kHz have been detected with a noise limited pressure resolution of approximately 10.2 atmospheres in a 3kHz measurement bandwidth.
Corilagin is a member of polyphenolic tannins. Its antimicrobial activity and action mechanism against Escherichia coli, Staphylococcus aureus and Candida albicans were investigated through membrane permeability. Crystal violet staining determination, outer membrane (OM) and inner membrane (IM) permeability, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and atomic force microscopy (AFM) were used as methods for our investigation. The minimum inhibitory concentrations were 62.5, 31.25 and 62.5 µg/mL for E. coli, S. aureus and C. albicans, respectively. Crystal violet results and SDS-PAGE of supernatant proteins showed that corilagin dose-dependently affected membrane permeability of E. coli and C. albicans but not of S. aureus. OM and IM permeability assays revealed comparable results for E. coli. By using AFM, we demonstrated extensive cell surface alterations of corilagin-treated E. coli and C. albicans. SDS-PAGE of precipitated proteins revealed possible targets of corilagin, i.e. Fib, Sae R, Sar S in S. aureus and Tye 7p in C. albicans. In conclusion, corilagin inhibited the growth of E. coli and C. albicans by disrupting their membrane permeability and that of S. aureus by acting on Fib, Sae R and Sar S but not on membrane integrity.
Context: Astaxanthin (ASX), a xanthophyll carotenoid derived from microalgae Haematococcus pluvialis, mitigating skin photoaging and age-related skin diseases by its antioxidant and anti-inflammatory effects in animal studies. Objective: The aim was to systematically evaluate if ASX applications have anti-ageing effects in humans. Methods: A comprehensive search of PubMed, Scopus and Web of Science found a total of eleven studies. Nine randomised, controlled human studies assessed oral ASX effects and two open-label, prospective studies evaluated topical, oral-topical ASX effects on skin ageing. GetData Graph Digitizer was used to extract mean values and standard deviations of baseline and endpoint, and Cochrane Collaboration’s tool assessed RoB for all included studies. Review Manager 5.4 was used to conduct meta-analysis of RCTs; the results were reported as effect size ± 95% confidence interval. Results: Oral ASX supplementation significantly restored moisture content (SMD = 0.53; 95% CI = 0.05, 1.01; I2 = 52%; p = 0.03) and improved elasticity (SMD = 0.77; 95% CI = 0.19, 1.35; I2 = 75%; p = 0.009) but did not significantly decrease wrinkle depth (SMD = −0.26; 95% CI = −0.58, 0.06; I2 = 0%; p = 0.11) compared to placebo. Open-label, prospective studies suggested slightly protective effects of topical and oral-topical ASX applications on skin ageing. Conclusions: Ingestion and/or topical usages of ASX may be effective in reducing skin ageing and have promising cosmetical potential, as it improves moisture content and elasticity and reduces wrinkles.
Endophytes in plants may be co-producer of the bioactive compounds of their hosts. We conducted a study to bioprospect for saponin-producing endophytic fungi from Panax notoginseng and evaluate the antimicrobial activity of saponins. Two novel fungal endophytes, Fusarium sp. PN8 and Aspergillus sp. PN17, were isolated from traditional Chinese medicinal herb P. notoginseng. After eight days of fermentation, the total saponins produced in the culture broth of PN8 and PN17 were 1.061 and 0.583 mg mL, respectively. The saponin extracts exhibited moderate to high (inhibition zone diameter 15.7-28.4 mm, MIC 1.6-12.5 mg mL) antimicrobial activity against pathogens tested. Further analysis showed that triterpenoid saponins produced by Fusarium PN8 were Rb, Rd and 20(S)-Rg, while Aspergillus PN17 had the ability to synthesise ginsenoside Re, Rd and 20(S)-Rg. The isolated endophytes may be used as potential sources for microbial production of plant secondary metabolites and for antimicrobial agents.
The increasing numbers of elderly Alzheimer’s disease (AD) patients because of a steady increase in the average lifespan and aging society attract great scientific concerns, while there were fewer effective treatments on AD progression due to unclear exact causes and pathogenesis of AD. Moderate (200-500 mg/d) and regular caffeine consumption from coffee and tea are considered to alleviate the risk of AD and have therapeutic potential. This paper reviewed epidemiological studies about the relationship of caffeine intake from coffee or/and tea with the risk of AD and summarized the caffeine-related AD therapies based on experimental models. And further well-designed and well-conducted studies are suggested to investigate the optimal dosages, frequencies, and durations of caffeine consumption to slow down AD progression and treat AD.
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