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Proceedings. Biological Sciences Apr 2018With the expansion of urban centres in the mid-twentieth century and the post-1970 decrease in pesticides, populations of double-crested cormorants () and ring-billed...
With the expansion of urban centres in the mid-twentieth century and the post-1970 decrease in pesticides, populations of double-crested cormorants () and ring-billed gulls () around Lake Ontario (Canada and USA) have rapidly rebounded, possibly to unprecedented numbers. Along with the use of traditional palaeolimnological methods (e.g. stable isotopes, biological proxies), we now have the capacity to develop specific markers for directly tracking the presence of waterbirds on nesting islands. Here, we apply the use of lipophilic sterols and stanols from both plant and animal-faecal origins as a reliable technique, independent of traditional isotopic methods, for pinpointing waterbird arrival and population growth over decadal timescales. Sterol and stanol concentrations measured in the guano samples of waterbird species were highly variable within a species and between the three species of waterbirds examined. However, cholesterol was the dominant sterol in guano, and phytosterols were also high in ring-billed gull guano. This variability highlights a specialist piscivorous diet for cormorants compared to a generalist, omnivorous diet for gulls, which may now often include grain and invertebrates from agricultural fields. A ratio that includes cholesterol and sitosterol plus their aerobically reduced products (cholestanol, stigmastanol) best explained the present range of bird abundance across the islands and was significantly correlated to sedimentary δN. Overall, we demonstrate the use of sterols and stanols as a direct means for tracking the spatial and temporal presence of waterbirds on islands across Lake Ontario, and probably elsewhere.
Topics: Animals; Biomarkers; Birds; Charadriiformes; Diet; Environmental Biomarkers; Environmental Monitoring; Hydrogenation; New York; Ontario; Oxidation-Reduction; Population Dynamics; Sterols
PubMed: 29695442
DOI: 10.1098/rspb.2018.0631 -
Bioscience Reports Apr 2018: Non-alcoholic fatty liver disease (NAFLD) associates with low levels of serum plant sterols in cross-sectional studies. In addition, it has been suggested that the... (Clinical Trial)
Clinical Trial
: Non-alcoholic fatty liver disease (NAFLD) associates with low levels of serum plant sterols in cross-sectional studies. In addition, it has been suggested that the hepatic sterol transport mechanisms are altered in NAFLD. Therefore, we investigated the association between serum, liver and bile plant sterols and sitostanol with NAFLD.: Out of the 138 individuals (age: 46.3 ± 8.9, body mass index: 43.3 ± 6.9 kg/m², 28% men and 72% women), 44 could be histologically categorized to have normal liver, and 94 to have NAFLD. Within the NAFLD group, 28 had simple steatosis and 27 had non-alcoholic steatohepatitis. Plant sterols and sitostanol were measured from serum (=138), liver (=38), and bile (=41). The expression of genes regulating liver sterol metabolism and inflammation was measured (=102).: Liver and bile sitostanol ratios to cholesterol were higher in those with NAFLD compared to those with histologically normal liver (all <0.022). Furthermore, liver sitostanol to cholesterol ratio correlated positively with histological steatosis and lobular inflammation ( > 0.407, <0.01 for both). In contrast, liver sitosterol to cholesterol ratio correlated negatively with steatosis ( = -0.392, =0.015) and lobular inflammation ( = -0.395, =0.014). Transcriptomics analysis revealed suggestive correlations between serum plant sterol levels and mRNA expression.: Our study showed that liver and bile sitostanol ratios to cholesterol associated positively and liver sitosterol ratio to cholesterol associated negatively with liver steatosis and inflammation in obese individuals with NAFLD..
Topics: Adult; Bile; Female; Humans; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Obesity; Sitosterols
PubMed: 29540533
DOI: 10.1042/BSR20171274 -
The Journal of Pediatrics Sep 2017To assess the association between biomarkers of thyroid status and 5α-stanols in patients with sitosterolemia treated with ezetimibe (EZE). (Clinical Trial)
Clinical Trial
OBJECTIVES
To assess the association between biomarkers of thyroid status and 5α-stanols in patients with sitosterolemia treated with ezetimibe (EZE).
STUDY DESIGN
Eight patients with sitosterolemia (16-56 years of age) were studied during 14 weeks off EZE therapy and 14 weeks on EZE (10 mg/day). Serum thyroid biomarkers (free triiodothyronine [FT3], free thyroxine [FT4], FT3/FT4 ratio, thyroid-stimulating hormone), 5α-stanols (sitostanol and cholestanol), and cholestanol precursors (total cholesterol and its synthesis marker lathosterol, and 7α-hydroxy-4-cholesten-3-one cholestenol) were measured at baseline and during the 14 weeks off EZE and on EZE.
RESULTS
EZE increased FT3/FT4 (10% ± 4%; P = .02). EZE reduced plasma and red blood cells sitostanol (-38% ± 6% and -20% ± 4%; all P < .05) and cholestanol (-18% ± 6% and -13% ± 3%; all P < .05). The change in plasma cholestanol level on EZE inversely correlated with the change in FT3/FT4 (r = -0.86; P = .01). EZE lowered total cholesterol (P < .0001) and did not affect 7α-hydroxy-4-cholesten-3-one cholestanol. EZE increased (P < .0001) lathosterol initially, but the level was not sustained, resulting in similar levels at week 14 off EZE and on EZE.
CONCLUSION
In patients with STSL, 5α-stanols levels might be associated with thyroid function. EZE reduces circulating 5α-stanols while increasing FT3/FT4, implying increased conversion of T4 to T3, thus possibly improving thyroid hormone status.
TRIAL REGISTRATION
ClinicalTrials.govNCT01584206.
Topics: Adolescent; Adult; Anticholesteremic Agents; Cholestanol; Cholestenones; Cholesterol; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Sitosterols; Thyrotropin; Thyroxine; Triiodothyronine; Young Adult
PubMed: 28625503
DOI: 10.1016/j.jpeds.2017.05.049 -
PloS One 2017Steroids are used as faecal markers in environmental and in archaeological studies, because they provide insights into ancient agricultural practices and the former...
Steroids are used as faecal markers in environmental and in archaeological studies, because they provide insights into ancient agricultural practices and the former presence of animals. Up to now, steroid analyses could only identify and distinguish between herbivore, pig, and human faecal matter and their residues in soils and sediments. We hypothesized that a finer differentiation between faeces of different livestock animals could be achieved when the analyses of several steroids is combined (Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids). We therefore reviewed the existing literature on various faecal steroids from livestock and humans and analysed faeces from old livestock breed (cattle, horse, donkey, sheep, goat, goose, and pig) and humans. Additionally, we performed steroid analyses on soil material of four different archaeological periods (sites located in the Lower Rhine Basin, Western Germany, dating to the Linearbandkeramik, Urnfield Period / Bronze Age, Iron Age, Roman Age) with known or supposed faecal inputs. By means of already established and newly applied steroid ratios of the analysed faeces together with results from the literature, all considered livestock faeces, except sheep and cattle, could be distinguished on the basis of their steroid signatures. Most remarkably was the identification of horse faeces (via the ratio: epi-5β-stigmastanol: 5β-stigmastanol + epicoprostanol: coprostanol; together with the presence of chenodeoxycholic acid) and a successful differentiation between goat (with chenodeoxycholic acid) and sheep/cattle faeces (without chenodeoxycholic acid). The steroid analysis of archaeological soil material confirmed the supposed faecal inputs, even if these inputs had occurred several thousand years ago.
Topics: Animals; Archaeology; Bile Acids and Salts; Biomarkers; Breeding; Feces; Gas Chromatography-Mass Spectrometry; Humans; Livestock; Soil; Steroids; Sterols
PubMed: 28060808
DOI: 10.1371/journal.pone.0164882 -
PloS One 2014Neanderthal dietary reconstructions have, to date, been based on indirect evidence and may underestimate the significance of plants as a food source. While...
Neanderthal dietary reconstructions have, to date, been based on indirect evidence and may underestimate the significance of plants as a food source. While zooarchaeological and stable isotope data have conveyed an image of Neanderthals as largely carnivorous, studies on dental calculus and scattered palaeobotanical evidence suggest some degree of contribution of plants to their diet. However, both views remain plausible and there is no categorical indication of an omnivorous diet. Here we present direct evidence of Neanderthal diet using faecal biomarkers, a valuable analytical tool for identifying dietary provenance. Our gas chromatography-mass spectrometry results from El Salt (Spain), a Middle Palaeolithic site dating to ca. 50,000 yr. BP, represents the oldest positive identification of human faecal matter. We show that Neanderthals, like anatomically modern humans, have a high rate of conversion of cholesterol to coprostanol related to the presence of required bacteria in their guts. Analysis of five sediment samples from different occupation floors suggests that Neanderthals predominantly consumed meat, as indicated by high coprostanol proportions, but also had significant plant intake, as shown by the presence of 5β-stigmastanol. This study highlights the applicability of the biomarker approach in Pleistocene contexts as a provider of direct palaeodietary information and supports the opportunity for further research into cholesterol metabolism throughout human evolution.
Topics: Animals; Biomarkers; Cholestanol; Cholesterol; Feces; Gas Chromatography-Mass Spectrometry; Humans; Meals; Neanderthals; Sitosterols
PubMed: 24963925
DOI: 10.1371/journal.pone.0101045 -
Advances in Nutrition (Bethesda, Md.) Nov 2013Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of... (Review)
Review
Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of common foods. Understanding the cholesterol-lowering impact of the food matrix and the PS characteristics would maximize their success and increase the benefit to consumers. This review systematically examines whether the PS characteristics and the fatty acid composition of foods with added PS affects serum LDL-c. A total of 33 studies published between the years 1998 and 2011 inclusive of 66 individual primary variables (strata) were evaluated. The functional food matrices included margarine, mayonnaise, yogurt, milk, cheese, meat, grain, juice, and chocolate. Consistently, ≥10% reductions in LDL-c were reported when the characteristics of the food matrix included poly- and monounsaturated fatty acids known to lower LDL-c. Also, >10% mean reductions in LDL-c were reported when β-sitostanol and campestanol as well as stanol esters were used. These characteristics allow both low-fat and high-fat foods to successfully incorporate PS and significantly lower LDL-c.
Topics: Anticholesteremic Agents; Cholesterol, LDL; Diet; Dietary Fats; Fatty Acids, Unsaturated; Functional Food; Humans; Hypercholesterolemia; Phytosterols; Phytotherapy; Plant Extracts; Sitosterols
PubMed: 24228192
DOI: 10.3945/an.113.004507 -
Proceedings of the National Academy of... Dec 2012Disentangling the effects of climate change and anthropogenic activities on the environment is a major challenge in paleoenvironmental research. Here, we used fecal...
Disentangling the effects of climate change and anthropogenic activities on the environment is a major challenge in paleoenvironmental research. Here, we used fecal sterols and other biogeochemical compounds in lake sediments from northern Norway to identify both natural and anthropogenic signals of environmental change during the late Holocene. The area was first occupied by humans and their grazing animals at ∼2,250 ± 75 calendar years before 1950 AD (calendar years before present). The arrival of humans is indicated by an abrupt increase in coprostanol (and its epimer epicoprostanol) in the sediments and an associated increase in 5β-stigmastanol (and 5β-epistigmastanol), which resulted from human and animal feces washing into the lake. Human settlement was accompanied by an abrupt increase in landscape fires (indicated by the rise in pyrolytic polycyclic aromatic hydrocarbons) and a decline in woodland (registered by a change in n-alkane chain lengths from leaf waxes), accelerating a process that began earlier in the Holocene. Human activity and associated landscape changes in the region over the last two millennia were mainly driven by summer temperatures, as indicated by independent tree-ring reconstructions, although there were periods when socioeconomic factors played an equally important role. In this study, fecal sterols in lake sediments have been used to provide a record of human occupancy through time. This approach may be useful in many archeological studies, both to confirm the presence of humans and grazing animals, and to distinguish between anthropogenic and natural factors that have influenced the environment in the past.
Topics: Agriculture; Animals; Archaeology; Climate Change; Environment; Feces; Geologic Sediments; History, Ancient; Humans; Norway; Sterols
PubMed: 23185025
DOI: 10.1073/pnas.1212730109 -
PloS One 2012In vitro and animal studies have suggested that plant sterols and stanols increase cytokine production by T-helper-1 cells. This may be beneficial for patient groups...
BACKGROUND
In vitro and animal studies have suggested that plant sterols and stanols increase cytokine production by T-helper-1 cells. This may be beneficial for patient groups characterized by a T-helper-2 dominant immune response, e.g. asthma patients. (1) to evaluate whether sitostanol induces a T-helper-1 shift in peripheral blood mononuclear cells (PBMCs) from asthma patients, and (2) to unravel the role of regulatory T-cells in this respect.
METHODOLOGY/PRINCIPAL FINDINGS
PBMCs from 10 asthma patients and 10 healthy subjects were isolated and incubated with 1.2 µM sitostanol, while stimulated with 5 µg/ml PHA. Similar amounts of cholesterol were used to determine whether effects were specific for plant stanols or for sterols in general. Changes in cytokine production were measured using antibody arrays and ELISAs. Changes in regulatory T-cell population size were measured by flow cytometry, using intracellular Foxp3 staining. Sitostanol increased production of IFNγ by 6.5% and IL-2 by 6.0% compared to cholesterol (p<0.01). No changes in IL-4 and IL-13 were found. Interestingly, this effect was only present in PBMCs from asthma patients. The number of Foxp3+ cells tended to increase and their activity, measured by IL-10 production, increased after sitostanol treatment in PBMCs from asthma patients compared to controls by 32.3% (p = 0.077) and 13.3% (p<0.05), respectively.
CONCLUSIONS/SIGNIFICANCE
Altogether, the sitostanol-induced Thelper-1 shift in PBMCs from asthma patients and the stimulating effects of sitostanol on Treg cell numbers and activity indicate a possible novel approach for plant stanol ester enriched functional foods in the amelioration of asthmatic symptoms. Functional effects, however, require further evaluation.
Topics: Adolescent; Adult; Animals; Anticholesteremic Agents; Asthma; Cells, Cultured; Cholesterol; Cytokines; Female; Humans; K562 Cells; Killer Cells, Natural; Leukocytes, Mononuclear; Lymphocyte Activation; Lymphocyte Count; Lysosomal-Associated Membrane Protein 1; Male; Middle Aged; Natural Killer T-Cells; Pyroglyphidae; Sitosterols; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Th17 Cells; Young Adult
PubMed: 23091602
DOI: 10.1371/journal.pone.0046895 -
The Science of the Total Environment Dec 2012Organic compounds such as sterols and hormones have been detected in surface waters at ecologically relevant concentrations with sources including effluent discharged...
Organic compounds such as sterols and hormones have been detected in surface waters at ecologically relevant concentrations with sources including effluent discharged from publicly owned treatment works (POTWs) as well as leachate and runoff from land amended with municipal sludge (biosolids). Greater than 20% of regulated effluents discharged into U.S. surface waters experience in-stream dilution of <10-fold and potential impacts are particularly likely in receiving waters dominated by POTW effluents. The increasing use of biosolids on agricultural land exerts additional stress, thereby necessitating environmental monitoring for potential ecological and human health effects. Alternatively or in addition to monitoring efforts, screening for potentially hazardous chemicals can be performed using empirical models that are scalable and can deliver results rapidly. The present study makes use of data from U.S. EPA's Targeted National Sewage Sludge Survey (TNSSS) to predict the aqueous-phase concentrations and removal efficiencies of 10 sterols (campesterol, β-sitosterol, stigmasterol, β-stigmastanol, cholesterol, desmosterol, cholestanol, coprostanol, epicoprostanol, and ergosterol) as well as the putative toxicity posed by four specific hormones based on their reported biosolids concentrations using published empirical models. Model predictions indicate that removal efficiencies for sterols are uniformly high (~99%) and closely match removal rates calculated from chemical monitoring at POTWs (paired t-test; p=0.01). Results from toxicity modeling indicate that the hormones estrone, estradiol and estriol had the highest leaching potentials amongst the compounds considered here and that 17 β-ethinylestradiol was found to pose a potentially significant threat to fathead minnows (Pimephales promelas) via run-off or leaching from biosolids-amended fields. This study exemplifies the use of in silico analysis to (i) identify potentially problematic organic compounds in biosolids, (ii) predict influent and effluent levels for hydrophobic organic compounds (HOCs) of emerging concern, and (iii) provide initial estimates of runoff concentrations, in this case for four prominent hormones known to act as endocrine disruptors.
Topics: Animals; Endocrine Disruptors; Environmental Monitoring; Ethinyl Estradiol; Fishes; Hormones; Models, Theoretical; Risk Assessment; Rivers; Soil Pollutants; Sterols; Waste Disposal, Fluid; Water Pollutants, Chemical
PubMed: 22682556
DOI: 10.1016/j.scitotenv.2012.05.042 -
Water Research Sep 2012Improving the microbiological quality of coastal and river waters relies on the development of reliable markers that are capable of determining sources of fecal...
Improving the microbiological quality of coastal and river waters relies on the development of reliable markers that are capable of determining sources of fecal pollution. Recently, a principal component analysis (PCA) method based on six stanol compounds (i.e. 5β-cholestan-3β-ol (coprostanol), 5β-cholestan-3α-ol (epicoprostanol), 24-methyl-5α-cholestan-3β-ol (campestanol), 24-ethyl-5α-cholestan-3β-ol (sitostanol), 24-ethyl-5β-cholestan-3β-ol (24-ethylcoprostanol) and 24-ethyl-5β-cholestan-3α-ol (24-ethylepicoprostanol)) was shown to be suitable for distinguishing between porcine and bovine feces. In this study, we tested if this PCA method, using the above six stanols, could be used as a tool in "Microbial Source Tracking (MST)" methods in water from areas of intensive agriculture where diffuse fecal contamination is often marked by the co-existence of human and animal sources. In particular, well-defined and stable clusters were found in PCA score plots clustering samples of "pure" human, bovine and porcine feces along with runoff and diluted waters in which the source of contamination is known. A good consistency was also observed between the source assignments made by the 6-stanol-based PCA method and the microbial markers for river waters contaminated by fecal matter of unknown origin. More generally, the tests conducted in this study argue for the addition of the PCA method based on six stanols in the MST toolbox to help identify fecal contamination sources. The data presented in this study show that this addition would improve the determination of fecal contamination sources when the contamination levels are low to moderate.
Topics: Animals; Cattle; Cholestanes; Cholestanol; Cholestanols; Feces; Fresh Water; Humans; Phytosterols; Principal Component Analysis; Rivers; Seawater; Sitosterols; Swine; Water Microbiology; Water Pollutants, Chemical
PubMed: 22673347
DOI: 10.1016/j.watres.2012.05.003