Comparative proteomic analysis of Lactobacillus plantarum for the identification of key proteins in bile tolerance

<p>Abstract</p> <p>Background</p> <p>Lactic acid bacteria are commonly marketed as probiotics based on their putative or proven health-promoting effects. These effects are known to be strain specific but the underlying molecular mechanisms remain poorly understood. Therefore, unravelling the determinants behind probiotic features is of particular interest since it would help select strains that stand the best chance of success in clinical trials. Bile tolerance is one of the most crucial properties as it determines the ability of bacteria to survive in the small intestine, and consequently their capacity to play their functional role as probiotics. In this context, the objective of this study was to investigate the natural protein diversity within the <it>Lactobacillus plantarum </it>species with relation to bile tolerance, using comparative proteomics.</p> <p>Results</p> <p>Bile tolerance properties of nine <it>L. plantarum </it>strains were studied <it>in vitro</it>. Three of them presenting different bile tolerance levels were selected for comparative proteomic analysis: <it>L. plantarum </it>299 V (resistant), <it>L. plantarum </it>LC 804 (intermediate) and <it>L. plantarum </it>LC 56 (sensitive). Qualitative and quantitative differences in proteomes were analyzed using two-dimensional electrophoresis (2-DE), tryptic digestion, liquid chromatography-mass spectrometry analysis and database search for protein identification. Among the proteins correlated with differences in the 2-DE patterns of the bacterial strains, 15 have previously been reported to be involved in bile tolerance processes. The effect of a bile exposure on these patterns was investigated, which led to the identification of six proteins that may be key in the bile salt response and adaptation in <it>L. plantarum</it>: two glutathione reductases involved in protection against oxidative injury caused by bile salts, a cyclopropane-fatty-acyl-phospholipid synthase implicated in maintenance of cell envelope integrity, a bile salt hydrolase, an ABC transporter and a F0F1-ATP synthase which participate in the active removal of bile-related stress factors.</p> <p>Conclusions</p> <p>These results showed that comparative proteomic analysis can help understand the differential bacterial properties of lactobacilli. In the field of probiotic studies, characteristic proteomic profiles can be identified for individual properties that may serve as bacterial biomarkers for the preliminary selection of strains with the best probiotic potential.</p

Icacina senegalensis (Icacinaceae), traditionally used for the treatment of malaria, inhibits in vitro Plasmodium falciparum growth without host cell toxicity

<p>Abstract</p> <p>Background</p> <p>With the aim of discovering new natural active extracts against malaria parasites, <it>Icacina senegalensis </it>was selected after an ethnopharmacological survey conducted on plants used in traditional malaria treatment in Senegal.</p> <p>Methods</p> <p>Different concentrations of the plant extract and fractions were tested on synchronized <it>Plasmodium falciparum </it>cultures at the ring stage using the parasite lactate dehydrogenase assay. Their haemolytic activity and <it>in vitro </it>cytoxicity were evaluated. The chromatographic profiles of active fractions were also established.</p> <p>Results</p> <p>The plant extract and fractions revealed anti-plasmodial activity (IC₅₀< 5 μg/mL) with no toxicity (Selectivity indexes >10). The dichloromethane fraction showed stronger anti-plasmodial activity than the total extract.</p> <p>Conclusion</p> <p>Anti-plasmodial activity and toxicity of <it>I. senegalensis </it>are reported for the first time and showed promising results in malaria field research.</p

Proline-based deep eutectic solvents as greener alternative for obtaining polyphenol rich extracts of Satureja kitaibelii

INTRODUCTION: Aerial parts of Satureja kitaibelii Wierzb. ex Heuff. (Lamiaceae), in Serbia known as Rtanj’s tea, are traditionally used to treat various respiratory, urinary and other health disorders. Extracts of this herb exhibit a significant bioactivity as well37. Using deep eutectic solvents (DESs) for extraction of certain phenolic compounds is in line with the principles of green chemistry38. However, the toxicity of DESs must be considered39. OBJECTIVES: The main objectives of this work are to assess the polyphenol-extracting ability of proline (Pro) and sugar/sugar alcohol based natural DESs from commercially available Rtanj’s tea, as well as to evaluate cytotoxicity of these solvents against AsPC- 1 cells. METHOD / DESIGN: Accurately weighed Pro and sugar/sugar alcohol, were dissolved in water, frozen, and freeze-dried. The obtained seven DESs (i.e. Pro with: glucose 1:1 and 5:3, fructose 1:1 and 5:3, sorbitol 1:2, and sucrose 2:1 and 3:2) were mixed with water (30%, m/m). Polyphenol extraction was examined using commercial sample of Rtanj’s tea (manufacturer Bojan Radosavljević, Boljevac). Powdered herb (particle diameter 100-200 μm) was extracted by sonication during 30 min at room temperature with the obtained aqueous DESs (herb-to-solvent ratio 1:20), as well as with water, absolute ethanol, or 50% (v/v) ethanol under the same conditions. The qualitative analysis of extracts was conducted by both HPLC and LC-MS. The content of the identified marker compounds in the extracts, i.e. rosmarinic acid (RA) and clinopodic acid O (CAO), was determined by external calibration using RA as the standard compound. Cytotoxicity of the aqueous DESs against human pancreatic adenocarcinoma cells AsPC-1 was tested at four concentration levels (5-25%), after 48 h of incubation and propidium iodide staining. The analysis on Guava® easyCyte 12HT Benchtop flow microcapillary cytometer, was performed afterwards, using InCyte® software package. RESULTS: Upon freeze-drying, mixtures had glassy appearance and transformed into liquids after mild heating. All obtained DESs were highly viscous, and therefore mixed with water. Qualitative LC-MS analysis of 50% ethanol extract revealed the presence of phenolic acids, flavonoids, and jasmonic acid derivatives. Among phenolic acids, the dominant compounds were caffeic acid oligomers RA and CAO. Among conventional solvents, 50% ethanol was better extracting agent than absolute ethanol or water for both RA (88.2 μg/mL) and CAO (116.8 μg/mL). Water extract was also abundant with CAO (106.7 μg/mL), but contained moderate amount of RA (21.7 μg/mL). It is noteworthy to mention that the extraction with ethanol resulted in very low yield of both phenolics, with CAO concentration, being even below detection limit in the absolute ethanol extract. Concentration of RA in the tested DES extracts was higher than corresponding one in the water extract, but lower than in the 50% ethanol extract, and varied in the range from 61.6 μg/mL (in Pro-fructose 1:1 extract) to 85.6 μg/mL (Pro-glucose 1:1 extract). The extraction of CAO, with six out of seven aqueous DESs, was more efficient than with 50% ethanol, resulting in CAO concentration range from 119.6 μg/mL, in Pro-sucrose 3:2 extract, to 172.4 μg/mL, in Pro-glucose 1:1 extract. Pro-fructose 1:1 extract had the lowest content of CAO (86.7 μg/mL) among the tested DESs. At the lowest tested concentration (5%), aqueous DESs did not significantly affect survival of AsPC-1 cells in comparison to the untreated cells (83.1-90.0% and 86.6% of cells remained viable, respectively). Both proline-glucose DESs demonstrated the lowest toxicity. However, at the highest concentration (25%) all aqueous DESs caused death of more than 70% of AsPC-1 cells. CONCLUSIONS: The obtained results indicate that proline and sugar/sugar alcohol based deep eutectic solvents are good extracting agents for phenolic compounds, especially for higher caffeic acid oligomers such as clinopodic acid O. Additionally, low cytotoxicity of tested DESs is a good starting predictor of their safety and potential usage.The International Bioscience Conference and the 8th International PSU – UNS Bioscience Conference - IBSC2021, Novi Sad, 25th to 26th November 202

Unraveling the potential of breath and sweat VOC capture devices for human disease detection: a systematic-like review of canine olfaction and GC-MS analysis

The development of disease screening methods using biomedical detection dogs relies on the collection and analysis of body odors, particularly volatile organic compounds (VOCs) present in body fluids. To capture and analyze odors produced by the human body, numerous protocols and materials are used in forensics or medical studies. This paper provides an overview of sampling devices used to collect VOCs from sweat and exhaled air, for medical diagnostic purposes using canine olfaction and/or Gas Chromatography-Mass spectrometry (GC-MS). Canine olfaction and GC-MS are regarded as complementary tools, holding immense promise for detecting cancers and infectious diseases. However, existing literature lacks guidelines for selecting materials suitable for both canine olfaction and GC-MS. Hence, this review aims to address this gap and pave the way for efficient body odor sampling materials. The first section of the paper describes the materials utilized in training sniffing dogs, while the second section delves into the details of sampling devices and extraction techniques employed for exhaled air and sweat analysis using GC-MS. Finally, the paper proposes the development of an ideal sampling device tailored for detection purposes in the field of odorology. By bridging the knowledge gap, this study seeks to advance disease detection methodologies, harnessing the unique abilities of both dogs and GC-MS analysis in biomedical research

Simultaneous Determination of Various Isothiocyanates by RP-LC Following Precolumn Derivatization with Mercaptoethanol

Numerous isothiocyanates (ITCs) are poorly soluble in water which causes their precipitation in aqueous mobile phases used in reversed phase liquid chromatography (RP-LC), thus impacting the accuracy of the quantification. By comparing the amounts of ITCs injected and released from the column, losses could be estimated at 5–32% depending on polarities and concentrations. Results could be dramatically improved in terms of separation and quantification using RP-LC with a mercaptoethanol precolumn derivatization aimed at avoiding ITCs precipitation. The cancer chemoprotective allyl-ITC and sulforaphane were found in cabbage extracts at 1.2 and 2.7 μg g−1 fresh weight, respectively

Children’s and adolescents’ rising animal-source food intakes in 1990–2018 were impacted by age, region, parental education and urbanicity

Animal-source foods (ASF) provide nutrition for children and adolescents’ physical and cognitive development. Here, we use data from the Global Dietary Database and Bayesian hierarchical models to quantify global, regional and national ASF intakes between 1990 and 2018 by age group across 185 countries, representing 93% of the world’s child population. Mean ASF intake was 1.9 servings per day, representing 16% of children consuming at least three daily servings. Intake was similar between boys and girls, but higher among urban children with educated parents. Consumption varied by age from 0.6 at <1 year to 2.5 servings per day at 15–19 years. Between 1990 and 2018, mean ASF intake increased by 0.5 servings per week, with increases in all regions except sub-Saharan Africa. In 2018, total ASF consumption was highest in Russia, Brazil, Mexico and Turkey, and lowest in Uganda, India, Kenya and Bangladesh. These findings can inform policy to address malnutrition through targeted ASF consumption programmes.publishedVersio

Incident type 2 diabetes attributable to suboptimal diet in 184 countries

The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.8–14.4 million) incident T2D cases, representing 70.3% (68.8–71.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.0–27.1%)), excess refined rice and wheat intake (24.6% (22.3–27.2%)) and excess processed meat intake (20.3% (18.3–23.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.4–87.7%)) and Latin America and the Caribbean (81.8% (80.1–83.4%)); and lowest proportional burdens were in South Asia (55.4% (52.1–60.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally.publishedVersio