Use of Candida albicans and its oestrogen binding protein as a bio-recognition element for detection of oestrogen

Compared with bacteria, yeast have rarely been studied for use as a biocomponent for biosensors. Yeast are easy to culture and are eukaryotes, which means their biochemistry in many respects is similar to that of higher organisms. C. albicans and some other yeast species are known to have an oestrogen binding protein (EBP), which oxidises NAD(P)H to NAD(P)+ Oestrogen, when present, binds to the NAD(P)H oxidation site which leads to an accumulation of NAD(P)H (Madani, et al. 1994). Previous research has shown that oestrogen can be quantified using S. cerevisiae whole cells as the detection element and measuring NAD(P)H with a double mediator electrochemical system. This thesis employs the mediated electrochemical systems to investigate the influence of growth phase on EBP production in C. albicans and the response of cells of different ages to different concentrations of oestrogen. A cell not known to possess EBP (Arxula adeninivorans) was also investigated for its response to 17β-oestradiol. As expected, A. adeninivorans did not show a detectable response to 17β-oestradiol but surprisingly, its catabolism was inhibited. By using C. albicans cell lysate in the oestrogen detecting assay, utility was systematically increased and the complexity of the whole cell assay was decreased. In this assay, only a hydrophilic mediator was used, removing the need for a lipophilic mediator. The assay was used successfully in a complex medium, the upper detection limit was raised to 100 nM of 17β-oestradiol, and the assay period was reduced to 20 min. The electrodes were modified to directly detect NAD(P)H in cell lysate at a lower potential to avoid interference by oxidants such as ascorbic acid. Furthermore, EBP was purified using 17β-oestradiol affinity chromatography, and the protein was used with NADH in an oestrogen bioassay. In this assay NADH was electrochemically detected directly and could differentiate ‘with’ and ‘without oestrogen’ samples. This research also showed that a mediator can interact directly with EBP, i.e. without the use of NADH and further, direct electron transfer from EBP to both glassy carbon and pyrolyzed photoresist film (PPF) electrodes were demonstrated (i.e. without the use of a mediator). This research has further simplified the assay and will facilitate the development of rapid oestrogen detecting protein biosensor

In-vivo study of quetiapine fumarate superporous hydrogels

This study aims to design and evaluate a gastroretentive drug delivery system using second generation Superporous hydrogels using Factorial design approach. Optimized formulation was assessed for pharmacokinetic parameters by In-vivo study. Pharmacokinetic analysis of Quetiapine Fumarate plasma concentration–time data provided the following pharmacokinetic parameters like Cmax values ranging (690.58 ± 1.1 ng/mL to 524.37 ± 1.6 ng/mL), Tmax values ranging (1.5 ± 0.0 to 6.0 ± 0.0 Hours), AUC values ranging (5345.67 ± 11.34 h.ng/mL to 5345.67 ± 4.59 h.ng/mL). Results obtained for the formulated product prepared with superporous hydrogel technology shows prolonged release while maintaining Q Value with reduce plasma drug fluctuations in comparison to the Pure drug

Evaluation of chickpea as alternative to soy in plant-based beverages, fresh and fermented

A novel plant-based beverage made with garbanzo chickpeas was developed. Compared to soymilk, the chickpea beverage contained lower amounts of protein (1.21 vs. 2.09 g/100 g), fat (0.34 vs. 0.74 g/100 g) and sugar (0.24 vs. 0.33 g/100 g), due to a higher starch content (2.08 vs. 0.14 g/100 g). Fermentability of the chickpea beverage was acceptable, with colony forming units (CFU) increasing from about 5 × 10⁴ to 7.4 × 10⁶ after a 16-h fermentation, whereas in soy the final value was 1.7 × 107. Nonetheless, syneresis was significantly higher than that of the soy counterpart: 19.4 vs. 3.8%. This was attributed to the weaker protein network in the fermented chickpea beverage and to the high starch level that may have led to starch retrogradation during storage, hence resulting in whey expulsion. Sensory analysis revealed that the fresh chickpea beverage was as acceptable as the soy one. On the contrary, the fermented chickpea beverage received lower ratings than the soy one for appearance. This study showed that chickpea can be a promising alternative to soy in the development of a fresh plant-based beverage, while optimisation is required to apply it in a fermented beverage

Cooking water functional properties

Aquafaba was shown to replace egg white in confectionery products. Nonetheless, limited information was available on its physicochemical properties. Thus, recent studies investigated legume cooking water as texturizer. Most samples were slightly acidic (pH 6.1–6.5). Foaming capacity ranged from 38% to 97% based on legume type, within range of egg white solutions of similar concentration. A direct correlation to protein content was found. Despite the boiling process, most protein was soluble (86–100%). Ultrasounds treatments enhanced foaming properties of Aquafaba up to 548%. All foams were highly stable, potentially due to saponins. Emulsifying properties were outstanding, reaching values of 47 m2/g (lentils) and 100% (chickpeas). A combination of fibre, protein and saponins potentially contributed to highly stable emulsions. Higher hydrophobicity was observed, with absorption capacity of oil exceeding that of water (2.7–3.2 vs. 0.1–2.2 g/g) due to the presence of more hydrophobic sites on macromolecules. Finally, excellent prebiotic potential was determined. Most cooking water contained high levels of fermentable oligosaccharides, protein and minerals to support bacterial growth. The only exception was soy, possibly due to the higher phytate content. In summary, pulses cooking water are good foaming and gelling agents and excellent emulsifiers. Prebiotic potential opens the door to new applications

The potential of Lactobacillus spp. for modulating oxidative stress in the gastrointestinal tract

The gastrointestinal (GI) tract is crucial for food digestion and nutrient absorption in humans. However, the GI tract is usually challenged with oxidative stress that can be induced by various factors, such as exogenous pathogenic microorganisms and dietary alterations. As a part of gut microbiota, Lactobacillus spp. play an important role in modulating oxidative stress in cells and tissues, especially in the GI tract. Oxidative stress is linked with excessive reactive oxygen species (ROS) that can be formed by a few enzymes, such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs). The redox mechanisms of Lactobacillus spp. may contribute to the downregulation of these ROS‐forming enzymes. In addition, nuclear factor erythroid 2 (NFE2)‐related factor 2 (Nrf‐2) and nuclear factor kappa B (NF‐κB) are two common transcription factors, through which Lactobacillus spp. modulate oxidative stress as well. As oxidative stress is closely associated with inflammation and certain diseases, Lactobacillus spp. could potentially be applied for early treatment and amelioration of these diseases, either individually or together with prebiotics. However, further research is required for revealing their mechanisms of action as well as their extensive application in the future

Investigating yeast cell responses to oestrogen by electrochemical detection

Candida albicans and some other yeast species are known to have an oestrogen binding protein (EBP), which oxidises NAD(P)H to NAD(P)+. 17-oestradiol, when present, binds to the NAD(P)H oxidation site which leads to an accumulation of NAD(P)H. Our previous research has shown that oestrogens can be quantified using Saccharomyces cerevisiae cells as the detection element and a double mediator electrochemical system to measure NAD(P)H. In a modification to the whole cell method, C. albicans cell lysate and a single hydrophilic mediator was used to quantify 17-oestradiol. This paper employs the mediated electrochemical systems to investigate the influence of growth phase on EBP production in C. albicans and the response of cells of different ages to different concentrations of oestrogen. A cell not known to possess EBP (Arxula adeninivorans) was also investigated for its response to 17-oestradiol. As expected, A. adeninivorans did not show a detectable response to 17-oestradiol, but surprisingly, its catabolism was inhibited

Soaking water functional properties

The soaking water of legumes containd soluble and insoluble carbohydrates, protein, minerals, phenolic and saponins. These compounds are known to improve food texture and act as prebiotics. Therefore, this chapter presents new findings on legume soaking water as texturizer (freeze-dried) and prebiotic (liquid). The low fractions of soluble carbohydrates and proteins resulted in modest foaming ability (4.0–19%), modest oil absorption capacity (2.1–2.7 g/g) and insignificant effects on water absorption. In contrast, excellent emulsifying ability was observed for split yellow peas (50 m2/g), with relevant values for green lentils and yellow soybeans. Different mechanisms have been proposed: presence of both soluble and insoluble proteins (peas), saponins (lentils) and amphiphilic proteins (soy). Remarkably, prebiotic properties were observed in liquid samples. The growth of probiotic Lactobacillioccurred to levels drastically higher than a standard nutrient broth. Oligosaccharides were abundant in haricot beans, while higher biological value of soy proteins might explain soy performance. Results of lentils and peas were lower than other legume. Antimicrobial peptides known as defensin Psd1, Psd2 (peas) and Lc-def (lentils) might have inhibited microbial growth. In summary, lentil soaking water can be freeze-dried into excellent emulsifiers, especially peas. Beans and soy soaking water are also promising prebiotics

Development of potent antiviral drugs inspired by viral hexameric DNA-packaging motors with revolving mechanism

The intracellular parasitic nature of viruses and the emergence of antiviral drug resistance necessitate the development of new potent antiviral drugs. Recently, a method for developing potent inhibitory drugs by targeting biological machines with high stoichiometry and a sequential-action mechanism was described. Inspired by this finding, we reviewed the development of anti-viral drugs targeting viral DNA-packaging motors. Inhibiting multisubunit targets with sequential actions resembles breaking one bulb in a series of Christmas lights, which turns off the entire string. Indeed, studies on viral DNA packaging might lead to the development of new antiviral drugs. Recent elucidation of the mechanism of the viral double-stranded DNA (dsDNA)-packaging motor with sequential one-way revolving motion will promote the development of potent antiviral drugs with high specificity and efficiency. Traditionally, biomotors have been classified into two categories: linear and rotation motors. Recently dis- covered was a third type of biomotor, including the viral DNA-packaging motor, beside the bacterial DNA translocases, that uses a revolving mechanism without rotation. By analogy, rotation resembles the Earth’s rotation on its own axis, while revolving resembles the Earth’s revolving around the Sun (see animations at http://rnanano.osu.edu/movie.html). Herein, we review the structures of viral dsDNA-packaging motors, the stoichiometries of motor components, and the motion mechanisms of the motors. All viral dsDNA-packaging motors, including those of dsDNA/dsRNA bacteriophages, adenoviruses, poxviruses, herpesviruses, mimiviruses, megaviruses, pandoraviruses, and pithoviruses, contain a high-stoichiometry machine composed of multiple components that work cooperatively and sequentially. Thus, it is an ideal target for potent drug development based on the power function of the stoichiometries of target complexes that work sequentially

Epigenetic modifications impact metabolite production and lifespan in yeast

Epigenetics have been shown to play a crucial role in regulating gene expression during the aging and immune response processes, with changes in epigenetic marks being linked to age-related diseases and inflammatory responses. Recently it has been revealed that S-adenosyl-l-homocysteine can extend the lifespan of the budding yeast Saccharomyces cerevisiae by mimicking caloric restriction. In this present study, we aimed to activate the production of S-adenosyl-l-homocysteine by S. cerevisiae through introducing epigenetic changes as a result of exposure to benzoic acid, a known epigenetic modifier. The impact of this on metabolite production was evaluated using LC-MS/MS. The study successfully activated and measured an overproduction of S-adenosyl-l-homocysteine (SAH) in yeast previously exposed to benzoic acid and led to lifespan extension. The link between the aging process and immune responses in yeast was further explored in the study. The production of SAH was downregulated while several inflammatory response metabolites were upregulated in aging cells. The upregulation of inflammatory response metabolites with their inherent anti-viral and antimicrobial activities could potentially be valuable for use in human health applications. By contrast, in cells with higher lifespans these inflammatory metabolites were downregulated. This finding supports the concept that aging leads to higher levels of histone methylation and acetylation, which in turn cause the production of immune response metabolites and inflammation. By contrast, it appears that lower levels of histone methylation and acetylation as seen in healthy cells, can increase production of metabolites responsible for lifespan extension, such as SAH. In summary, this study provides insights into the molecular mechanisms involved in lifespan extension and the role of metabolites in regulating aging in yeast. The research sheds light on the interplay between metabolism, epigenetics, immunity and aging and contributes to the growing field of metabolomics