Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

The divine substance as māsūra and muftaraqa. An attempt of reinterpretation of the Trinitarian terminology in the light of the teaching of Abū Rā’iṭa’s al-Risāla fī l-thālūth al-muqaddas

Este artículo trata de la terminología trinitaria de Abū Rā’iṭa contenida en su al-Risāla fi l-thālūth al-muqaddas. Concretamente, se centra en una expresión que simboliza la unidad de la sustancia divina y la multiplicidad de hipóstasis, es decir “māsūra y muftaraqa”. Ofrecemos un intento de reinterpretación del significado de estos términos clave de acuerdo con la comprensión de la doctrina trinitaria de Abū Rā’iṭa.

Enhancing bioactive fatty acids of the meat from lambs reared in intensive systems through nutritional modulation

Tese de Doutoramento em Ciências Veterinárias, especialidade de Produção Animal

Bioactive compounds of citrus as health promoters

Citrus are a group of fruit species, quite heterogeneous in many aspects, including chemical composition of the fruit. Since ancient times, some citrus fruits were used to prevent and cure human diseases. In the recent decades, it has been demonstrated that fruits can actually help prevent and cure some diseases and above all, they are essential in a balanced diet. Citrus fruits, as one of the groups of fruit species, with greater importance in the world, have been studied for their effects on human health. Some species of citrus were referred as potential antioxidant based therapy for heart disease, cancer and inflammation. Fruit peels and seeds have also high antioxidant activity. The health benefits of citrus fruit have mainly been attributed to the high level of bioactive compounds, such as phenols (e.g., flavanone glycosides, hydroxycinnamic acids), carotenoids and vitamin C. These compounds are present in the fruit pulp and hence in the juice. But some bioactive compounds can be found in parts of the fruit which usually are not used for human food. The content of bioactive compounds depends on the species and cultivar, but also depends on the production system followed in the orchard. Citrus fruits, their derivatives and their by-products (peel, pulp and oil) are reach in different bioactive compounds and its maturity, postharvest and agroindustry processes influence their composition and concentration. The aim of this chapter was to review the main bioactive compounds of the different components of citrus and their relationship to health.

Factors Influencing the Implementation of Substance Use Prevention Programs in Elementary Schools

Prevention scientists have called for more research on the factors affecting the implementation of substance use prevention programs. Given the lack of literature in this area, coupled with evidence that children as early as elementary school engage in substance use, the purpose of this study was to identify the factors that influence the implementation of substance use prevention programs in elementary schools. This study involved a mixed methods approach comprised of a survey and in-person interviews. Sixty-five guidance counselors and teachers completed the survey, and 9 guidance counselors who completed the survey were interviewed individually. Correlation analyses and hierarchical multiple regression were conducted. Quantitative findings revealed ease of implementation most frequently influenced program implementation, followed by beliefs about the program’s effectiveness. Qualitative findings showed curriculum modification as an important theme, as well as difficulty of program implementation. The in-person interviews also shed light on three interrelated themes influencing program implementation – The Wheel, time, and scheduling. Results indicate the majority of program providers modified the curriculum in some way. Implications for research, policy, and practice are discussed, and areas for future research are suggested.

The Influence of Gender on Perceived Treatment Need among a Community Sample of Substance Users

Purpose: Most individuals do not perceive a need for substance use treatment despite meeting diagnostic criteria for substance use disorders and they are least likely to pursue treatment voluntarily. There are also those who perceive a need for treatment and yet do not pursue it. This study aimed to understand which factors increase the likelihood of perceiving a need for treatment for individuals who meet diagnostic criteria for substance use disorders in the hopes to better assist with more targeted efforts for gender-specific treatment recruitment and retention. Using Andersen and Newman’s (1973/2005) model of individual determinants of healthcare utilization, the central hypothesis of the study was that gender moderates the relationship between substance use problem severity and perceived treatment need, so that women with increasing problems due to their use of substances are more likely than men to perceive a need for treatment. Additional predisposing and enabling factors from Andersen and Newman’s (1973/2005) model were included in the study to understand their impact on perceived need. Method: The study was a secondary data analysis of the 2010 National Survey on Drug Use and Health (NSDUH) using logistic regression. The weighted sample consisted of a total 20,077,235 American household residents (The unweighted sample was 5,484 participants). Results of the logistic regression were verified using Relogit software for rare events logistic regression due to the rare event of perceived treatment need (King & Zeng, 2001a; 2001b). Results: The moderating effect of female gender was not found. Conversely, men were significantly more likely than women to perceive a need for treatment as substance use problem severity increased. The study also found that a number of factors such as race, ethnicity, socioeconomic status, age, marital status, education, co-occurring mental health disorders, and prior treatment history differently impacted the likelihood of perceiving a need for treatment among men and women. Conclusion: Perceived treatment need among individuals who meet criteria for substance use disorders is rare, but identifying factors associated with an increased likelihood of perceiving need for treatment can help the development of gender-appropriate outreach and recruitment for social work treatment, and public health messages.

Social Capital, HIV Risk Behavior and Substance Use among Recent Latino Immigrants in South Florida

Social capital, or social cohesion or group connectedness, can influence both HIV risk behavior and substance use. Because recent immigrants undergo a change in environment, one of the consequences can be a change in social capital. There may be an association among changes in social capital, and HIV risk behavior and substance use post immigration. The dissertation focused on the interface of these three variables among recent Latino immigrants (RLIs) in South Florida. The first manuscript is a systematic review of social capital and HIV risk behavior, and served as a partial background for the second and third manuscripts. Twelve papers with a measure of social capital as an independent variable and HIV risk as the dependent variable were included in the analysis. Eleven studies measured social capital at the individual level, and one study measured social capital at the group level. HIV risk was influenced by social capital, but the type of influence was dependent on the type of social capital and on the study population. Cognitive social capital, or levels of collective action, was protective against HIV in both men and women. The role of structural social capital, or levels of civic engagement/group participation, on HIV risk was dependent on the type of structural social capital and varied by gender. Microfinance programs and functional group participation were protective for women, while dysfunctional group participation and peer-level support may have increased HIV risk among men. The second manuscript was an original study assessing changes in social capital and HIV risk behavior pre to post immigration among RLIs in South Florida (n=527). HIV risk behavior was assessed through the frequency of vaginal-penile condom use, and the number of sexual partners. It was a longitudinal study using secondary data analysis to assess changes in social capital and HIV risk behavior pre immigration to two years post immigration, and to determine if there was a relationship between the two variables. There was an 8% decrease in total social capital (p ˂ .05). Reporting of ‘Never use’ of condoms in the past 90 days increased in all subcategories (p ˂ .05). Single men had a decrease in number of sexual partners (p ˂ .05). Lower social capital measured on the dimension of ‘friend and other’ was marginally associated with fewer sexual partners. The third manuscript was another original study looking at the association between social capital and substance use among RLIs in South Florida (n=527). Substance use with measured by frequency of hazardous alcoholic drinking, and illicit drug use. It was a longitudinal study of social capital and substance-use from pre to two years post immigration. Post-immigration, social capital, hazardous drinking and illicit drug use decreased (p˂.001). After adjusting for time, compared to males, females were less likely to engage in hazardous drinking (OR=.31, p˂.001), and less likely to engage in illicit drug use (OR=.67, p=.01). Documentation status was a moderator between social capital and illicit drug use. ‘Business’ and ‘Agency’ social capital were associated with changes in illicit drug use for documented immigrants. After adjusting for gender and marital status, on average, documented immigrants with a one-unit increase in ‘business’ social capital were 1.2 times more likely to engage in illicit drug use (p˂.01), and documented immigrants with one-unit increase in ‘agency’ social capital were 38% less likely to engage in illicit drug use (p˂.01). ‘Friend and other’ social capital was associated with a decrease in illicit drug use among undocumented immigrants. After adjusting for gender and marital status, on average, undocumented immigrants with a one-unit increase in ‘friend and other’ social capital were 45% less likely to engage in hazardous drinking and 44% less likely to use illicit drugs (p˂.01, p˂.05). Studying these three domains is relevant because HIV continues to be a public health issue, particularly in Miami-Dade County, which is ranked among other U.S. regions with high rates of HIV/AIDS prevalence. Substance use is associated with HIV risk behavior; in most studies, increased substance use is associated with increased chances of HIV risk behavior. Immigration, which is the hypothesized catalyst for the change in social capital, has an impact on the dynamic of a society. Greater immigration can be burdensome on the host country’s societal resources; however immigrants are also potentially a source of additional skilled labor for the workforce. Therefore, successful adaption of immigrants can have a positive influence on receiving communities. With Florida being a major receiver of immigrants to the U.S, this dissertation attempts to address an important public health issue for South Florida and the U.S. at large.

Bioactive Phenols in Small Fruits and Berries

Bioactive compounds are extra nutritional constituents occurring naturally in plant foods in small amounts, however in quantities enough to produce bioactive effects. Among bioactive compounds the phenolic compounds are a very large set of molecules, which include several groups such as for example flavonoids, phenolic acids or tannins. Small fruits and berries include a wide diversity of fruits, like grapes, strawberries, blackberries, blueberries, raspberries, cherries, hardi kiwi, gooseberries, cranberries, currants (black, white, red), physalis, crowberries, açaí, elderberries, dates or goji berries, and these frequently have been reported as having particularly high concentrations of phenolic compounds with antioxidant activity. Hence, the objective of this chapter is to review the literature about the type and contents of different phenolic compounds present in small fruits and berries, as well as their bioactive properties, including antioxidant capacity. All the fruits and berries investigated in this chapter were particularly rich in bioactive compounds, including phenolic compounds that provide the fruits with high antioxidant properties. The most relevant health promoting effects include anti-cancer, anti-inflamatory, neuro protective, cardio protective or anti-diabetes, thus indicating that these foods are a valuable resource to prevent and treat diseases.

Chemical Composition and Bioactive Compounds in Bananas and Postharvest Alterations

Bananas arise as one of the most popular fruits consumed all around the world. Banana belongs to the genus Musa from the family Musaceae. It is original from tropical regions and presents a strong ability to protect itself from the oxidative stress caused by extreme climatic conditions such as intense sunshine and high temperature. For this protection, bananas increase the production of bioactive compounds with antioxidant activity, which protect the fruit from the oxidative damage. Scientific studies have demonstrated that bananas (both in the pulp and peel) contain different antioxidant compounds, like vitamins (A, B, C and E), β-carotene and phenolic compounds (catechin, epicatechin, lignin, tannins, anthocyanins). Furthermore, banana is also notably rich in minerals, like potassium and phosphorus. The knowledge about the chemical composition and the contents in compounds with biological activity is of high interest given the importance of bananas as a valuable food all over the world. However, because bananas are perishable due to some factors like chemical reactions, including those that result in the production of ethylene, their postharvest conservation in pivotal for the commercialization. The effects of postharvest treatments and storage conditions on the composition of bananas are, therefore, essential. In this way, the present chapter focus on the composition of bananas, including macronutrients, micronutrients and bioactive compounds, as well as the effect of postharvest treatments and storage conditions in the quality of bananas.

Bullying Involvement and Adolescent Substance Use: A Study of Multilevel Risk and Protective Factors

Thesis (Master, Psychology) -- Queen's University, 2016-08-02 13:18:40.65

Production of bioactive metabolites by intestinal bacteria

The adult intestinal microbiota comprises a microbial ecosystem of approximately 100 trillion microorganisms, with specific bacterial communities holding distinct metabolic capabilities. Bacteria produce a range of bioactive compounds to survive unfavourable stimuli and to interact with other organisms, and generate several bioactive products during degradation of dietary constituents the host is not capable of digesting. This thesis addressed the impact of feeding potential probiotic bacteria and other dietary strategies such as pure fatty acids and prebiotics, on gut microbiota composition, short chain fatty acid (SCFA) production and modulation of metabolism in animal models. In the first experimental chapter (Chapter 2) a gas chromatography method for the quantification of SCFA was optimized and applied in the analysis of caecal samples obtained in animal studies described in other chapters of this thesis. In Chapter 3, t10, c12 CLA supplementation was shown to significantly alter murine gut microbiota composition and SCFA production rather than no supplementation. These changes were suggested to be extra factors affecting host lipid metabolism. Chapter 4 described the contrasting effects of CLA-producing strains, Bifidobacterium breve DPC 6330 and B. breve NCIMB 702258, on murine fat distribution/composition and gut microbiota composition, suggesting that these changes were most likely strain-dependent. In Chapter 5, dietary GABA-producing strain Lactobacillus brevis DPC 6108 was shown to significantly increase (p<0.05) serum insulin in healthy rats, leading to a second experiment using a type 1 diabetes rat model. Lb. brevis DPC 6108 administration did not change insulin levels in diabetic rats, but attenuated high levels of glucose when compared to diabetic control. However, an auto-immune-induced diabetes model was suggested as a better model to study GABA-related effects on diabetes. In Chapter 6 bovine milk oligosaccharides, 6’sialyllactose and Beneo Orafti P95 oligofructose supplementations were associated with depletion or reduction of less favourable bacteria, demonstrating that ingestion of these oligosaccharides might be a safe and effective approach to modulate populations of the intestinal microbiota. In Chapter 7 (General discussion) the major findings of all studies were reviewed and discussed.

Microbially derived bioactive peptides to improve human health

This thesis describes a study of various methods to produce bioactive peptides. Initially, the generation of anti-Cronobacter spp. peptides by fermentation of milk protein is described. Lactobacillus johnsonii DPC6026 was used to generate two previously described antimicrobial peptides. Phenotypic analysis indicated unsatisfactory casein hydrolysis. The genome of the strain was sequenced and annotated. Results showed a number of unique features present, most notably a large symmetrical inversion of approximately 750kb in comparison with the human isolate L. johnsonii NCC 533. The data suggest significant genetic diversity and intra-species genomic rearrangements within the L. johnsonii spp.. Cronobacter spp. have emerged as pathogens of concern to the powdered infant formula industry. Chapters 3 and 4 of this thesis describe novel methods to generate two antimicrobial peptides, Caseicin A and B. In Chapter 3 a bank of Bacillus strains was generated and investigated for caseicin production. Following casein hydrolysis by specific B. cereus and B. thuringiensis strains the peptides of interest were generated. Chapter 4 describes a sterile enzymatic method to generate peptides from casein. Bioinformatic tools were used to predict enzymes capable of liberating caseicin peptides from casein. Hydrolysates were generated using suitable enzymes, examined and some were found to produce peptides with activity against Cronobacter spp.. This study establishes a potential industrial-grade method to generate antimicrobial peptides. Administration of GLP-1 leads to improved glycaemic control in diabetes patients. Generation of a recombinant lactic acid bacteria capable of producing a GLP-1 analogue is described in Chapter 5. In-vivo analysis confirmed insulinotropic activity. The results illustrate a method using bacteriocin producing cellular machinery to generate bioactive peptides. This thesis describes the generation of bioactive peptides by bacterial fermentation, tailored enzymatic hydrolysis and recombinant bacterial methods. The techniques described contribute to bioactive peptide research with regards novel methods of production and industrial scale-up.

Streptococcus thermophilus APC151 strain is suitable for the manufacture of naturally GABA-enriched bioactive yogurt

Consumer interest in health-promoting food products is a major driving force for the increasing global demand of functional (probiotic) dairy foods. Yogurt is considered the ideal medium for delivery of beneficial functional ingredients. Gamma-amino-butyric acid has potential as a bioactive ingredient in functional foods due to its health-promoting properties as an anti-stress, anti-hypertensive, and anti-diabetic agent. Here, we report the use of a novel Streptococcus thermophilus strain, isolated from the digestive tract of fish, for production of yogurt naturally enriched with 2 mg/ml of gamma-amino-butyric acid (200 mg in a standard yogurt volume of 100 ml), a dose in the same range as that provided by some commercially available gamma-amino-butyric acid supplements. The biotechnological suitability of this strain for industrial production of yogurt was demonstrated by comparison with the reference yogurt inoculated with the commercial CH1 starter (Chr. Hansen) widely used in the dairy industry. Both yogurts showed comparable pH curves [ΔpH/Δt = 0.31-0.33 h-1], viscosity [0.49 Pa-s], water holding capacity [72–73%], and chemical composition [moisture (87–88%), protein (5.05–5.65%), fat (0.12–0.15%), sugar (4.8–5.8%), and ash (0.74–1.2%)]. Gamma-amino-butyric acid was not detected in the control yogurt. In conclusion, the S. thermophilus APC151 strain reported here provides a natural means for fortification of yogurt with gamma-amino-butyric acid.