Mechanism of antifungal activity of antimicrobial peptide APP, a cell-penetrating peptide derivative, against Candida albicans: intracellular DNA binding and cell cycle arrest.

We investigated the antifungal properties and anti-candidal mechanism of antimicrobial peptide APP. The minimum inhibitory concentration of APP was 8 µM against Candida albicans and Aspeogillus flavus, the concentration against Saccharomyces cerevisiae and Cryptococcus neoformans was 16 µM, while 32 µM inhibited Aspergilla niger and Trichopyton rubrum. APP caused slight depolarization (12.32 ± 0.87%) of the membrane potential of intact C. albicans cells when it exerted its anti-candidal activity and only caused 21.52 ± 0.48% C. albicans cell membrane damage. APP interacted with cell wall membrane, caused potassium efflux and nucleotide leakage. However, confocal fluorescence microscopy experiment and flow cytometry confirmed that FITC-labeled APP penetrated C. albicans cell membrane with 52.31 ± 1.88% cell-penetrating efficiency and accumulated in the cytoplasm. Then, APP interact with C. albicans genomic DNA and completely suppressed DNA migration above weight ratio (peptide/DNA) of 2, and significantly arrested cell cycles during the S-phase (S-phase cell population was 27.09 ± 0.73%, p < 0.05) after penetrating the cell membrane. Results indicated that APP kills C. albicans for efficient cell-penetrating efficiency, strong DNA-binding affinity and significant physiological changes inducing S-phase arrest in intracellular environment.

[Comparison of serum lipid and protein oxidation products levels in patients with different types of dyslipidemia].

OBJECTIVE: To explore serum redox status differences among different types of dyslipidemia patients. METHOD: One hundred and nineteen healthy people and two hundred and ninety four dyslipidemic participants on clinical examination were divided into six groups: control group, hypercholesterolemia (HTC), hypertriglyceridemia (HTG), combined hyperlipidemia (CH), low level of high-density lipoprotein cholesterol (LHDL) and hyperlipidemia with LHDL (HBL + LHDL) according to blood lipid profiles. Malonaldehyde (MDA), total antioxidant capacity (T-AOC), advanced oxidation protein products (AOPP) and dityrosine (DT) in serum were measured. RESULTS: In all participants, the T-AOC, AOPP and DT levels in HTG, CH and HBL + LHDL groups were significantly (P < 0.05) higher than that in controls, further, LHDL with or without hyperlipidemia had elevated (P < 0.05) MDA level compared with control, HTC and HTG groups, whereas levels of AOPP and DT in LHDL were not different with controls. Triglycerides values showed a positive correlation with MDA, T-AOC, AOPP and DT. CONCLUSION: Level of serum oxidative stress was higher in hyperlipidemia patients than in healthy people, and high triglycerides levels were more likely to cause an imbalance in redox status.

Antibacterial activity and dual mechanisms of peptide analog derived from cell-penetrating peptide against Salmonella typhimurium and Streptococcus pyogenes.

A number of research have proven that antimicrobial peptides are of greatest potential as a new class of antibiotics. Antimicrobial peptides and cell-penetrating peptides share some similar structure characteristics. In our study, a new peptide analog, APP (GLARALTRLLRQLTRQLTRA) from the cell-penetrating peptide ppTG20 (GLFRALLRLLRSLWRLLLRA), was identified simultaneously with the antibacterial mechanism of APP against Salmonella typhimurium and Streptococcus pyogenes. APP displayed potent antibacterial activity against Gram-negative and Gram-positive strains. The minimum inhibitory concentration was in the range of 2 to 4 µM. APP displayed higher cell selectivity (about 42-fold increase) as compared to the parent peptide for it decreased hemolytic activity and increased antimicrobial activity. The calcein leakage from egg yolk L-α-phosphatidylcholine (EYPC)/egg yolk L-α-phosphatidyl-DL-glycerol and EYPC/cholesterol vesicles demonstrated that APP exhibited high selectivity. The antibacterial mechanism analysis indicated that APP induced membrane permeabilization in a kinetic manner for membrane lesions allowing O-nitrophenyl-ß-D-galactoside uptake into cells and potassium release from APP-treated cells. Flow cytometry analysis demonstrated that APP induced bacterial live cell membrane damage. Circular dichroism, fluorescence spectra, and gel retardation analysis confirmed that APP interacted with DNA and intercalated into the DNA base pairs after penetrating the cell membrane. Cell cycle assay showed that APP affected DNA synthesis in the cell. Our results suggested that peptides derived from the cell-penetrating peptide have the potential for antimicrobial agent development, and APP exerts its antibacterial activity by damaging bacterial cell membranes and binding to bacterial DNA to inhibit cellular functions, ultimately leading to cell death.

Determinants of knowledge about aflatoxin and fumonisin contamination in sorghum and postharvest practices among caregivers of children aged 6-59 months in Kerio Valley, Kenya.

Stunting among children under five years old is still a problem in many developing countries including Kenya. However, there is little information linking stunting with mycotoxin contamination of complementary foods. The aim of this study was to assess knowledge about aflatoxin and fumonisin contamination in sorghum alongside postharvest handling and storage practices among caregivers of children under five years old in Kerio Valley, Kenya. A cross-sectional study was conducted to obtain data from 353 randomly selected caregivers of children aged 6-59 months. Qualitative data were obtained through Focus Group Discussions and Key Informant Interviews. Overall, majority of the caregivers of young children had poor knowledge (61.8%) about mycotoxin contamination of food, and poor postharvest handling and storage practices (74.5%). The caregiver's knowledge about mycotoxins was significantly associated with age [(AOR=4.629, (95% Cl: 2.530-8.472), p < .001], education level [(AOR=0.275, (95% Cl: 0.088-0.434), p = .001], marital status [(AOR=15.187, (95% Cl: 1.830-126.007), p = .012], and household monthly income [(AOR=2.623, (95% Cl: 1.550-4.439), p < 0,001]. Furthermore, the caregiver's age [(AOR=3.845, (95% Cl: 1.558-9.490), p = .003], education level [(AOR=0.196, (95% Cl: 0.088-0.434), p < .001], monthly income [(AOR=3.291, (95% Cl: 1.550-6.986), p = .002], and knowledge on mycotoxin contamination of sorghum [AOR, 5.428 (95% Cl: 2.855-10.319), p < .001] were significantly associated with postharvest handling and storage practices except for marital status [AOR, 3.579 (95% Cl: 0.403-31.775), p = .252]. In conclusion, caregivers of young children had poor knowledge about mycotoxin contamination of complementary foods and suboptimal postharvest handling and storage practices of sorghum. This increases the risk of mycotoxin exposure to young children and necessitates mitigation measures including sensitization campaigns and social behavior change communication.

Variation in the Factors Associated With Diet Quality of Children Aged 6 to 23 Months in Low and High Agroecological Zones of Rongai Subcounty, Kenya.

BACKGROUND: Adequate quality complementary diets and appropriate feeding practices are important for proper growth and development of young children. OBJECTIVE: To assess factors associated with diet diversity, meal frequency, and acceptable diet of children aged 6 to 23 months in two agroecological zones of Rongai subcounty, Kenya. METHODS: A cross-sectional study was conducted among 384 mothers/caregivers with children aged 6 to 23 months. A structured questionnaire was used to assess sociodemographic characteristics and child feeding practices. Diet diversity, meal frequency, and acceptable diet were derived from a 24-hour recall of child's food intake. Factors associated with diet quality were determined using binary logistic regression. RESULTS: Mean child diet diversity score was 3.54 ± 1.0 of 7 food groups, with 56.8% of the children achieving minimum dietary diversity. A majority of the children (81.8%) received minimum meal frequency (MMF), with significant (P < .05) difference between low (91.1%) and high (75.2%) agricultural potential areas. Children who received minimum acceptable diet (MAD) were only 34.1%. Mother/caregiver education level positively (P < .05) associated with minimum diet diversity in low potential area (adjusted odds ratio [AOR] = 3.79, 95% CI: 1.47-9.75) and with MAD in high potential area (AOR = 1.87, 95% CI: 1.01-3.46). Other factors associated with MDD, MMF, and MAD included household income and slow feeding in low potential area, and child gender and active feeding in high potential area. CONCLUSION: There is a variation in factors associated with diet quality and child feeding practices in different agroecological zones. Therefore, nutrition education and behavior change communication interventions aimed at improving child nutrition should be context-specific.

Determinants of dietary diversity among women of reproductive age in two different agro-ecological zones of Rongai Sub-County, Nakuru, Kenya.

BACKGROUND: Empirical evidence on the link between agrobiodiversity and dietary diversity appears to be inconclusive. Thus, there arises a need to determine other factors that could significantly influence dietary diversity in different agro-ecological zones, as factors may vary from region to region. OBJECTIVE: The objective of this study was to document the status of agrobiodiversity and dietary diversity and to assess the determinants of dietary diversity among women of reproductive age in two different agro-ecological zones of Rongai Sub-County in Kenya. DESIGN: A cross-sectional study of 384 women aged 18-49 years was conducted. Agrobiodiversity was measured using the Shannon-Wiener index, species richness (count) and production diversity score. A 24-hour dietary recall was used to determine minimum dietary diversity for women (MDD-W) of reproductive age. RESULTS: Although the level of agrobiodiversity was different between the low and high agro-ecological zones (using Shannon-Wiener index); the women's dietary diversity was not different (p > 0.05) between low (3.78 ± 0.99) and high potential areas (3.84 ± 1.05). In multivariate logistic regression, there was no association (p > 0.05) between agrobiodiversity indicators and dietary diversity across the two agricultural zones. Factors influencing MDD-W in two agricultural zones were different. In low potential areas, woman's education level positively determined dietary diversity, while in high potential areas household gender, woman's education level, woman's age and family size influenced MDD-W. CONCLUSION: The proportion of women who met minimum dietary diversity was low. Although agrobiodiversity was different in the two agro-ecological zones, women's dietary diversity scores were similar. In low agricultural potential areas, only education level influenced women's dietary diversity while household gender, education level, age and family size were the important determinants in high agricultural potential areas. Therefore, it is recommended that nutrition interventions focusing on lessening malnutrition and improving dietary quality should pay special attention to differences in agro-ecological zones to develop region-specific interventions instead of generalizing interventions.

Association of hyperuricemia with metabolic syndrome among university workers: sex and occupational differences.

BACKGROUND: The relationship between metabolic syndrome (MetS) and hyperuricemia is not fully understood. OBJECTIVE: To examine the association of hyperuricemia with MetS and the component of MetS that is mostly influenced by hyperuricemia among university workers. METHODS: Anthropometric measurements, blood pressure, glucose, lipid profiles, renal function tests were measured in 1198 male and 1075 female (22-60 years old) workers on annual medical examination. RESULTS: Hyperuricemia was 3-fold higher in males (odds ratio, OR, 2.938, 95% confidence interval, CI, 1.909-4.522, P<0.01) than females after adjustment for age, body mass index (BMI) and renal function. Overall, individuals with hyperuricemia were 3.9-fold likely to have MetS OR, 3.903; CI (2.439-6.245), P<0.01, and dyslipidemia, 2.5 times (OR, 2.501; 95% CI, 1.776-3.521, P<0.01) after adjustment for age, BMI, sex and renal function. However, no associations were found in individuals with hypertension (OR, 1.427; 95% CI, 0.996-2.205, P=0.052) and hyperglycemia (OR, 1.476; 95% CI, 0.989-2.202, P=0.057). Administrative work positively associated (OR, 1.895; 95% CI, 1.202-2.925, P<0.05) with hyperuricemia in males and not females. CONCLUSION: Male workers with hyperuricemia, especially those working in administration were at risk of metabolic syndrome. It is important to screen, prevent and treat metabolic syndrome in individuals diagnosed with hyperuricemia at the workplace.

Cardioprotective effects of lipoic acid, quercetin and resveratrol on oxidative stress related to thyroid hormone alterations in long-term obesity.

This study investigated possible mechanisms for cardioprotective effects of lipoic acid (LA), quercetin (Q) and resveratrol (R) on oxidative stress related to thyroid hormone alterations in long-term obesity. Female C57BL/6 mice were fed on high-fat diet (HFD), HFD+LA, HFD+R, HFD+Q and normal diet for 26weeks. Body weight, blood pressure, thyroid hormones, oxidative stress markers, angiotensin converting enzyme (ACE), nitric oxide synthase (NOS) and ion pump activities were measured, and expression of cardiac genes was analyzed by real-time polymerase chain reaction. HFD induced marked increase (P<.05) in body weight, blood pressure and oxidative stress, while plasma triidothyronine levels reduced. ACE activity increased (P<.05) in HFD mice (0.69±0.225U/mg protein) compared with controls (0.28±0.114U/mg protein), HFD+LA (0.231±0.02U/mg protein) and HFD+Q (0.182±0.096U/mg protein) at 26weeks. Moreover, Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities increased in HFD mice whereas NOS reduced. A 1.5-fold increase in TRα1 and reduction in expression of the deiodinase iodothyronine DIO1, threonine protein kinase and NOS3 as well as up-regulation of AT1α, ACE, ATP1B1, GSK3ß and Cja1 genes also occurred in HFD mice. Conversely, LA, Q and R inhibited weight gain; reduced TRα1 expression as well as increased DIO1; reduced ACE activity and AT1α, ATP1B1 and Cja1 gene expression as well as inhibited GSK3ß; increased total antioxidant capacity, GSH and catalase activity; and reduced blood pressure. In conclusion, LA, resveratrol and quercetin supplementation reduces obesity thereby restoring plasma thyroid hormone levels and attenuating oxidative stress in the heart and thus may have therapeutic potential in heart diseases.

A cell-penetrating peptide analogue, P7, exerts antimicrobial activity against Escherichia coli ATCC25922 via penetrating cell membrane and targeting intracellular DNA.

The antibacterial activities and mechanism of a new P7 were investigated in this study. P7 showed antimicrobial activities against five harmful microorganisms which contaminate and spoil food (MIC=4-32 µM). Flow cytometry and scanning electron microscopy analyses demonstrated that P7 induced pore-formation on the cell surface and led to morphological changes but did not lyse cell. Confocal fluorescence microscopic observations and flow cytometry analysis expressed that P7 could penetrate the Escherichia coli cell membrane and accumulate in the cytoplasm. Moreover, P7 possessed a strong DNA binding affinity. Further cell cycle analysis and change in gene expression analysis suggested that P7 induced a decreased expression in the genes involved in DNA replication. Up-regulated expression genes encoding DNA damage repair. This study suggests that P7 could be applied as a candidate for the development of new food preservatives as it exerts its antibacterial activities by penetrating cell membranes and targets intracellular DNA.

Association Between Thyroid Hormones, Lipids and Oxidative Stress Markers in Subclinical Hypothyroidism.

BACKGROUND: Oxidative stress plays a role in the pathogenesis of many chronic diseases. It is recognized in overt hypothyroidism while its existence in subclinical hypothyroidism (SCH) is not well established. The aim of this study was to determine whether there was increased oxidation of lipids and proteins in SCH, and examine their association with lipids and thyroid hormones. METHODS: Male adults (35-59 years) with SCH (n=467) and euthyroid controls (n=190) were studied. Anthropometric measurements, plasma lipids, thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total antioxidant capacity (T-AOC), lipid peroxidation products, malondialdehyde (MDA), advanced oxidation protein products (AOPP) and dityrosine concentrations were measured. RESULTS: Plasma concentrations of MDA were significantly higher (p<0.05) in SCH (8.11±1.39 nmol/mL) compared with euthyroid controls (7.34±1.31 nmol/mL) while AOPP, dityrosine and T-AOC levels were not different. MDA was not associated with TSH (ß=-0.019, P=0.759), FT4 (ß=-0.062, P=0.323) and FT3 (ß=-0.018, P=0.780) in SCH while levels increased with elevated total cholesterol (ß=0.229, P=0.001), LDL (ß=0.203, P=0.009) and triglycerides (ß=0.159, P=0.036) after adjustment for age and body mass index. T-AOC reduced (ß=-0.327, P=0.030) with increased MDA in euthyroid controls and not in SCH (ß=-0.068, P=0.349), while levels increased with elevated triglycerides in both groups. CONCLUSIONS: Oxidative stress was increased in subclinical hypothyroidism as evidenced by the elevated lipid peroxidation product, malondialdehyde, while protein oxidation was absent. Thus, reduction of oxidative stress may be beneficial in patients with subclinical hypothyroidism.

Evaluation of the relationship between subclinical hypothyroidism and metabolic syndrome components among workers.

OBJECTIVES: Both hyperthyroidism and overt hypothyroidism are associated with increased prevalence of metabolic syndrome and its components, while data on subclinical hypothyroidism is currently limited especially in working populations. The aim of this study was to examine the association between subclinical hypothyroidism and metabolic syndrome components in workers; and to evaluate whether there are differences by sex and occupation. MATERIAL AND METHODS: A total of 1150 university employees (male - 792, female - 358) aged 30-60 years who came for an annual medical check-up were studied. Anthropometric measurements were taken, and blood pressure, fasting plasma glucose (FPG), lipid profiles, thyroid stimulating hormone (TSH), free thyroxin (FT4) and free triiodothyronine (FT3) levels were measured. RESULTS: After adjustment for age and body mass index (BMI), TSH was positively associated with increased triglyceride (TG) levels (ß = 0.108, p = 0.020) and FPG (ß = 0.130, p = 0.006) in subclinical hypothyroid male workers. However, TSH was not associated (p > 0.05) with any component of metabolic syndrome (MS) in the euthyroid group. In females, TSH was not correlated with MS components in both euthyroid and subclinical hypothyroid groups. Furthermore, comparison by occupation showed higher TSH in subclinical hypothyroid male workers employed in administration (5.23 ± 0.52 mU/l) than those working as academics (5.12 ± 0.52 mU/l), which resulted in elevated systolic and diastolic blood pressure, FPG, total cholesterol, TG and high density lipoprotein cholesterol. In females, BMI, systolic and diastolic blood pressure, TG and FPG were significantly (p < 0.05) higher in subclinical hypothyroid administrators than those in academics. CONCLUSIONS: Subclinical hypothyroidism was associated with metabolic syndrome components in male workers and not in females. Administration workers showed increased metabolic risks compared to academics. The findings suggest that the assessment of thyroid function in individuals with metabolic syndrome in the workplace may be favorable especially among men.

Disparities in the Prevalence of Metabolic Syndrome (MS) and its Components Among University Employees by Age, Gender and Occupation.

BACKGROUND: Metabolic Syndrome (MS), a known risk factor for Cardiovascular Disease (CVD) and type II diabetes is an emerging epidemic in China. Studies carried out on the general population indicate a varied clustering of cardiovascular risks in many parts of the country. However, there is limited data on its prevalence in the working population. Workplace can serve as an important place for prevention, control and management of CVD risks. The aim of this study was to investigate the prevalence of MS and its components among University workers, and determine how the prevalence varied according to sex and occupation. METHODS: This was a cross-sectional study of 2,428 University employees (22-60 years) who received an annual clinical examination at the University hospital. Anthropometric measurements, blood pressure, Fasting Plasma Glucose (FPG), and lipid profiles were measured. MS was defined according to the National Cholesterol Education Program Adult Treatment panel III modified criteria. RESULTS: Overall prevalence of MS was 6.1%, higher in males (5.1%) than females (1.1%), and increased with age. The most prevalent MS components in all workers were hypertension (37.9%) and hypertryglyceridemia (20.8%), corresponding rates in males were 28.3% and 16.1% while females had a prevalence of 9.6% and 4.7%. After adjustment for age, administrative work was associated (p<0.05) with increased hypertension (odds ratio (OR) =1.474; 95% confidence interval (CI), 1.146-1.896) and hyperglycemia (OR=1.469; 95% CI, 1.082-1.993) in male workers, and with hypertension (OR=1.492; 95% CI, 1.071-2.080) in females. However, prevalence of hypertryglyceridemia was lower (OR=0.390; 95% CI, 0.204-0.746) in female administrators compared to those in academics. Obesity, MS and reduced High Density Lipoprotein (HDL) cholesterol prevalence was not different (p>0.05) between the two occupations in both sexes. CONCLUSIONS: Prevalence of MS and its components was higher in male workers than in females, increased with age, and were more common in administrative workers. The findings support the need for gender and occupation specific health interventions to prevent CVDs and type II diabetes in the workplace.