Alpha-Pinene and Tannic Acid Inhibit Trichomonas vaginalis Protozoan Cells by Inducing Apoptosis.

Background: Trichomoniasis is one of the most common sexually transmitted infections worldwide. The growing concern of drug resistance of this infection has cautioned the need for new drug development. We evaluated the potential antiproliferative and apoptotic effect of α-pinene and tannic acid (TA) on Trichomonas vaginalis cells. In addition, the cytotoxicity of agents on Vero cells was investigated. Methods: Trichomonas cells were axenically cultured in TYI-S-33 medium. In vitro antiproliferative activity of α-pinene, TA, and metronidazole was investigated against Trichomonas cells. The assays were carried out in triplicate using microtiter plate and trypan blue staining method. Annexin V/PI staining with flow cytometry was used to evaluate apoptosis induction. In addition, the cytotoxic effect was measured by MTT assay. Results: α-Pinene and TA exhibited significant inhibition of the Trichomonas cells and the lowest IC50 values were 22.9 µg/ml and 140 µg/ml at 48 hours' incubation, respectively. The CC50 was found at 116 µg/ml for α-pinene and 473 µg/ml for TA, after 48 hours of treatment. The flow cytometry study demonstrated that the natural compounds induced apoptosis in Trichomonas cells. After 24 hours of treatment, the induction of apoptosis was 5.2% - 36.6% at concentrations of 3.9 - 62.5 µg/ml for α-pinene and TA induced-apoptosis was 6.1% - 53.8% at concentrations of 125-2000 µg/ml. Conclusion: Although the results show the antiproliferative and apoptotic effect of α-pinene and TA on Trichomonas cells, in vivo studies are needed to further clarify the effects of these compounds.

Polyethyleneimine Functionalized Mesoporous Magnetic Nanoparticles with Enhanced Antibacterial and Antibiofilm Activity in an Alternating Magnetic Field.

Despite a lot of research on the antibacterial effect of Fe3O4 nanoparticles, their interactions with biofilm matrix have not been well understood. The surface charge of nanoparticles mainly determines their ability to adhere on the biofilm. In this work, negatively charged Fe3O4 nanoparticles were synthesized via a trisodium citrate-assisted solvothermal method and then the surfaces were functionalized using polyethyleneimine (PEI) to obtain positively charged Fe3O4 nanoparticles. The antibacterial and antibiofilm activities of both negatively and positively charged Fe3O4 nanoparticles in an alternating magnetic field were then systematically investigated. The positively charged Fe3O4 nanoparticles showed a strong self-adsorbed attachment ability to the planktonic and sessile cells, resulting in a better antibacterial activity and enhanced biofilm eradication performance compared to the conventional Fe3O4 nanoparticles with negative charges. Fe3O4@PEI nanoparticles produced physical stress and thermal damage in response to an alternating magnetic field, inducing the accumulation of intracellular reactive oxygen species into live bacterial cells, bacterial membrane damage, and biofilm dispersion. Utilizing an alternating magnetic field along with positively charged nanoparticles leads to a synergistic antibacterial approach to improve the antibiofilm performance of magnetic nanoparticles.

Corrosion behavior of high nitrogen nickel-free austenitic stainless steel in the presence of artificial saliva and Streptococcus mutans.

High nitrogen nickel-free austenitic stainless steels (HNSs) have great potentials to be used in dentistry owing to its exceptional mechanical properties, high corrosion resistance, and biocompatibility. In this study, HNSs with nitrogen of 0.88 wt% and 1.08 wt% displayed much lower maximum pit depths than 316L stainless steel (SS) after 21 d of immersion in abiotic artificial saliva (2.2 µm and 1.7 µm vs. 4.5 µm). Microbiologically influenced corrosion (MIC) evaluations revealed that Streptococcus mutans biofilms led to much severer corrosion of 316L SS than HNSs. Corrosion current densities of HNSs were two orders of magnitude lower than that of 316L SS after incubation of 7 d (37.5 nA/cm2 and 29.9 nA/cm2 vs. 5.63 µA/cm2). The pitting potentials of HNSs were at least 550 mV higher than that of 316L SS in the presence of S. mutans, confirming the better MIC resistance of HNSs. Cytotoxicity assay confirmed that HNSs were not toxic to MC3T3-E1 cells and allowed better sessile cell growth on them than on 316L SS. It can be concluded that HNSs are more suitable dental materials than the conventional 316L SS.

Microbial corrosion of metals: The corrosion microbiome.

Microbially catalyzed corrosion of metals is a substantial economic concern. Aerobic microbes primarily enhance Fe0 oxidation through indirect mechanisms and their impact appears to be limited compared to anaerobic microbes. Several anaerobic mechanisms are known to accelerate Fe0 oxidation. Microbes can consume H2 abiotically generated from the oxidation of Fe0. Microbial H2 removal makes continued Fe0 oxidation more thermodynamically favorable. Extracellular hydrogenases further accelerate Fe0 oxidation. Organic electron shuttles such as flavins, phenazines, and possibly humic substances may replace H2 as the electron carrier between Fe0 and cells. Direct Fe0-to-microbe electron transfer is also possible. Which of these anaerobic mechanisms predominates in model pure culture isolates is typically poorly documented because of a lack of functional genetic studies. Microbial mechanisms for Fe0 oxidation may also apply to some other metals. An ultimate goal of microbial metal corrosion research is to develop molecular tools to diagnose the occurrence, mechanisms, and rates of metal corrosion to guide the implementation of the most effective mitigation strategies. A systems biology approach that includes innovative isolation and characterization methods, as well as functional genomic investigations, will be required in order to identify the diagnostic features to be gleaned from meta-omic analysis of corroding materials. A better understanding of microbial metal corrosion mechanisms is expected to lead to new corrosion mitigation strategies. The understanding of the corrosion microbiome is clearly in its infancy, but interdisciplinary electrochemical, microbiological, and molecular tools are available to make rapid progress in this field.

Effect of proteases secreted from a marine isolated bacterium Bacillus vietnamensis on the corrosion behaviour of different alloys.

The adverse corrosion and corrosion inhibitory effects of the marine isolated bacterium Bacillus vietnamensis were determined on different alloys. The corrosion rates of the steel alloys increased in the presence of Bacillu vietnamensis; although the alloys containing Cu were found to be protected from corrosion when exposed to this bacterium. The first assay bacterial mechanism confirmed the presence of protease enzyme, which was then identified by LC-MS/MS analysis. We proposed that Cu ions coordinated with proteases and bonded with water molecules. This coordination process decreased the oxygen availability in the environment, thereby inhibiting the corrosion of the copper alloys.

Study of the relationship between APOA-II -265T>C polymorphism and HDL function in response to weight loss in overweight and obese type 2 diabetic patients.

BACKGROUND: It has been reported that people may respond differently to the same environmental changes because of genome variations. OBJECTIVE: The main purpose of the present study is to determine gene-diet interactions between -265T>C apolipoprotein A-II polymorphisms and evaluate the effect of weight loss on parameters related to HDL function. METHODS: In the present study, 56 overweight and obese type 2 diabetic patients were chosen from 697 genotype-specified subjects. After matching for gender, age and BMI, an equal number of patients were chosen for each genotype of APOA-II (TT/TC and CC group). After six-week calorie restriction programme, 44 patients completed the study. Serum paraoxonase-1 (PON1), paraoxonase-3 (PON3), pentraxin-3 (PTX3), and PTX3 gene expression in peripheral blood mononuclear cells were compared between two genotypes and also before and after the intervention separated in each genotype. RESULTS: The mean differences of PON enzymes and PTX3 between groups were not significant at the baseline. After weight loss, the mean weight, BMI and serum concentration of PON1 and PON3 decreased significantly and PTX3 increased in total population. Although, the mean differences of PON enzymes and PTX3 between two groups were not significant. However, in comparison of mean differences within the groups, decreased PON3 and increased PTX3 have been observed only in TT group. CONCLUSION: A comparison of the mean differences in PON3 and PTX3 within two genotype groups showed that T allele carriers are more sensitive to lifestyle modification, and serum PON3 and PTX3 levels significantly changed only in the TT/TC group.

The effect of weight loss on HDL subfractions and LCAT activity in two genotypes of APOA-II -265T>C polymorphism.

BACKGROUND: People may have different responses to the same environmental changes. It has been reported that genome variations may be responsible for these differences. Also, HDL subfractions may be influenced by different genetic variations. The aim of the present study was to determine gene-diet interactions and to evaluate the influence of weight loss on HDL subfractions between two genotypes of -265 T>C APOA-II polymorphism. METHODS: In the present study, 56 overweight and obese patients with type 2 diabetes mellitus were selected from 697 genotype-specified subjects. After matching for gender, age and BMI at the beginning of the study, an equal number of patients remained on each genotype of APOA-II (TT/TC and CC group). After a 6-week calorie restriction program, 44 patients completed the study. Serum HDL subfractions, including HDL2 and HDL3 and LCAT activity, were compared between the two genotypes and, before and after the intervention, were separated in each genotype. RESULTS: Serum concentration of HDL and its subfractions decreased significantly due to the weight loss. A comparison of the mean changes between the genotypes showed that HDL3 significantly decreased in the CC genotype while, in the TT/TC group, the serum concentration of HDL2 was significantly reduced. However, the increase of LCAT activity was not significant among the two genotypes. CONCLUSION: A comparison of mean changes of variables within two genotype groups showed that C homozygote carriers lead to a general shift toward larger size HDL subfractions and T allele carriers shift toward smaller size HDL subfractions after weight loss.

A comparative study of selenium concentration and glutathione peroxidase activity in normal and breast cancer patients.

OBJECTIVE: The present study was undertaken to compare plasma Se values and glutathione peroxidase (GPX) activity in normal and breast cancer patients. DESIGN: In a case-control study, forty-five breast cancer patients and the same number of healthy women were randomly selected from their population. Se was measured in plasma by atomic absorption spectrophotometry and GPX activity in erythrocytes was measured using a standard spectrophotometric method. RESULTS: Plasma Se concentration in healthy women and breast cancer patients was in the normal range, with no statistically significant difference observed between the two groups (138.40 (sd 40.36) microg/l v. 132.15 (sd 35.37) microg/l, respectively). Erythrocyte GPX activity was significantly (P<0.01) higher in breast cancer patients (24.81 (sd 11.66) U/g Hb) compared with healthy women (20.29 (sd 4.24) U/g Hb). CONCLUSION: The present study indicated that Se deficiency was not a problem in the participants, and sufficient quantity of this element could increase GPX activity to have a protective effect against oxidative damage.