We investigated the mechanisms of anti-Candida action of isoquinoline alkaloid berberine, active constituent of medically important plants of Barberry species. The effects on membrane, morphological transition, synthesis of ergosterol and the consequent changes in membrane permeability have been studied. Polarization and lipid peroxidation level of the membrane following berberine treatment have been addressed. Minimal inhibitory concentration (MIC) of berberine against C. albicans was 17.75 μg/mL. Cytotoxic effect of berberine was concentration dependent, and in sub-MIC concentrations inhibit morphological transition of C. albicans cells to its filamentous form. Results showed that berberine affects synthesis of membrane ergosterol dose-dependently and induces increased membrane permeability causing loss of intracellular material to the outer space (DNA/protein leakage). Berberine also caused membrane depolarization and lipid peroxidation of membrane constituents indicating its direct effect on the membrane. Moreover, ROS levels were also increased following berberine treatment indicating further the possibility of membrane damage. Based on the obtained results it seems that berberine achieves its anti-Candida activity by affecting the cell membrane.
Background: Among natural compounds, present in every day diet, flavonoids have shown beneficial effect in prevention of cardiovascular diseases that can be attributed, at least partially to the described antiaggregatory activity i.e. antiplatelet effects of flavonoids. Due to the ever increasing pharmacological interest in antiplatelet agents a systematic experimental evaluation of large flavonoid series is needed. Methods: A set of thirty flavonoid aglycones has been selected for the evaluation. All measurements of aggregation were done under standardized and firmly controlled in vitro conditions. The whole blood samples, multiple platelet functional analyzer and adenosine diphosphate (ADP) as a weak agonist of aggregation were selected for this purpose. Results: The results were expressed as minimal concentration of flavonoid that can significantly lower the platelet aggregation compared to the corresponding untreated sample (minimal antiaggregatory concentration - MINaAC). All analyzed flavonoids exhibited antiaggregatory activity MINaAC ranging from 0.119 μM to 122 μM, while the most potent representatives were 3,6-dihydroxyflavone (0.119 μM) and syringetin (0.119 μM). Conclusions: Measurable antiplatelet activity established at submicromolar flavonoid concentrations suggests that even a dietary consumption of some flavonoids can make an impact on in vivo aggregation of platelets. These findings also point out a therapeutical potential of some flavonoids.
1 March 2021 in Archives of Industrial Hygiene and Toxicology
In 2018, some sartan medicinal products were reported to be contaminated with nitrosamine compounds, which are potent mutagenic carcinogens. Two nitrosamines received particular attention: N -nitrosodimethylamine (NDMA) and N -nitrosodiethylamine (NDEA). These have since been confirmed in different types of medicinal products, including ranitidine and metformin. Consequently, the European Medicines Agency (EMA) started an investigation into the cause of contamination and an assessment of the risk to patients taking contaminated medicinal products. The main source of contamination were changes in production, which involves combinations of amines and nitrogen compounds and the use of specific catalysts and reagents. Withdrawals of medicinal products that took place in Croatia did not lead to a shortage of sartan- or metformin-containing medicines. Moreover, ranitidine had been preventively withdrawn all over the EU, including Croatia, creating shortages at the time, but was subsequently replaced with therapeutic alternatives.
In the present study we investigated activity of oleuropein, a complex phenol present in large quantities in olive tree products, against opportunistic fungal pathogen Candida albicans. Oleuropein was found to have in vitro antifungal activity with a minimal inhibitory concentration (MIC) value of 12.5 mg·mL−1. Morphological changes in the nuclei after staining with fluorescent DNA-binding dyes revealed that apoptosis was a primary mode of cell death in the analyzed samples treated with subinhibitory concentrations of oleuropein. Our results suggest that this antifungal agent targets virulence factors essential for establishment of the fungal infection. We noticed that oleuropein modulates morphogenetic conversion and inhibits filamentation of C. albicans. The hydrophobicity assay showed that oleuropein in sub-MIC values has significantly decreased, in both aerobic and anaerobic conditions, the cellular surface hydrophobicity (CSH) of C. albicans, a factor associated with adhesion to epithelial cells. It was also demonstrated that the tested compound inhibits the activity of SAPs, cellular enzymes secreted by C. albicans, which are reported to be related to the pathogenicity of the fungi. Additionally, we detected that oleuropein causes a reduction in total sterol content in the membrane of C. albicans cells, which might be involved in the mechanism of its antifungal activity.
Background: Pharmacists are commonly tasked with recommending the appropriate dietary supplement and advising the patients of their correct and safe use. Previous research, conducted on pharmacy students, showed that they did not always use the evidence based sources of information, with personal use identified as a significant predictor influencing the decision to recommend a supplement. Objectives: To compare use, perceptions and knowledge of dietary supplements of pharmacists with different years of work experience and to explore factors that could influence their recommendation of supplements. Methods: A questionnaire based cross-sectional study was conducted on Croatian community pharmacists in September 2017. The questionnaire explored pharmacists’ demographic characteristics, use, perceptions and knowledge of dietary supplements. Pharmacists (N=102) were divided in two groups based on their work experience: P0 (<10 years) and P1 (≥10 years). Results: All included pharmacists had high knowledge scores without differences between groups (P0=10, IQR 9-12 vs P1=11, IQR 9-12, expressed as median and interquartile range (IQR), p=0.275). Less experienced pharmacists perceived there was less research conducted on the dietary supplements compared to their more experienced counterparts (P0=1, IQR 1-2 vs P1=2, IQR 2-3, expressed as median and interquartile range, p<0.001). Groups differed in sources used when choosing the appropriate supplement with P0 using higher quality sources such as systematic reviews in comparison to P1 (32.1% vs 8.7%, p=0.004). Pharmacists’ decision to recommend a dietary supplement was influenced by their personal use (odds ratio 0.216, 95%CI 0.068:0.689, p=0.01) and work experience (odds ratio 0.154, 95%CI 0.045:0.530, p=0.003). Conclusions: Pharmacists did not use the high quality sources when recommending dietary supplements and their decision to recommend the supplement was not based on objective evaluation of evidence. Further education about the practice of evidence-based pharmacy is necessary, with special emphasis on senior pharmacists who might have missed that aspect during their formal education.
11 February 2019 in Antimicrobial Resistance & Infection Control
The aim of this study was to investigate whether marketed antibiotics package sizes are in accordance with treatment durations recommended in guidelines for prescribing antibiotics in sore throat and urinary tract infections. National drug database was searched with limitation to Antibacterials for systemic use. Formulations which did not have pre-specified dosage unit by the manufacturer were excluded (e.g. powders for oral solutions). The final list contained 94 drugs with 23 different active substances. This list was then cross-referenced with selected antimicrobial prescribing guidelines provided by Intersectoral Society for Antibiotic Resistance Control (ISKRA), National Institute for Health and Care Excellence (NICE) and The Infectious Diseases Society of America (IDSA). Seven packages matched ISKRA guidelines on sore throat while 16 were mismatched. Considering drug packages under reimbursement, 3 matched ISKRA guidelines and 8 were mismatched. Only 3 packages matched IDSA guidelines for comparable indications, and 18 were mismatched. When considering NICE guidelines there were 5 mismatched and only one package that was in accordance with the guidelines. ISKRA guidelines for urinary tract infections matched 23 packages and mismatched 58 packages. IDSA guidelines for urinary tract infections matched one package and were mismatched in 15 cases. One of the causes of leftover antibiotics is poor accordance of antibiotic package size with treatment recommendation duration. This should be identified as a potential target for reduction of excess antibiotics in the community. Measures that promote patient adherence to therapy and patient education should be considered essential to manage proper handling of leftover antibiotics.