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Micera M, Botto A, Geddo F, Antoniotti S, Bertea CM, Levi R, Gallo MP, Querio G. Squalene: More than a Step toward Sterols. Antioxidants (Basel) 2020; 9:antiox9080688. [PMID: 32748847 PMCID: PMC7464659 DOI: 10.3390/antiox9080688] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/16/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022] Open
Abstract
Squalene (SQ) is a natural triterpene widely distributed in nature. It is a metabolic intermediate of the sterol biosynthetic pathway and represents a possible target in different metabolic and oxidative stress-related disorders. Growing interest has been focused on SQ’s antioxidant properties, derived from its chemical structure. Strong evidence provided by ex vivo models underline its scavenging activity towards free radicals, whereas only a few studies have highlighted its effect in cellular models of oxidative stress. Given the role of unbalanced free radicals in both the onset and progression of several cardiovascular diseases, an in depth evaluation of SQ’s contribution to antioxidant defense mechanisms could represent a strategic approach in dealing with these pathological conditions. At present experimental results overall show a double-edged sword role of squalene in cardiovascular diseases and its function has to be better elucidated in order to establish intervention lines focused on its features. This review aims to summarize current knowledge about endogenous and exogenous sources of SQ and to point out the controversial role of SQ in cardiovascular physiology.
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Affiliation(s)
- Marco Micera
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
- Exenia Group S.r.l., 10064 Pinerolo (TO), Italy;
| | | | - Federica Geddo
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
| | - Susanna Antoniotti
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
| | - Cinzia Margherita Bertea
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
| | - Renzo Levi
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
| | - Maria Pia Gallo
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
- Correspondence:
| | - Giulia Querio
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy; (M.M.); (F.G.); (S.A.); (C.M.B.); (R.L.); (G.Q.)
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Ibrahim N‘I, Fairus S, Zulfarina MS, Naina Mohamed I. The Efficacy of Squalene in Cardiovascular Disease Risk-A Systematic Review. Nutrients 2020; 12:E414. [PMID: 32033387 PMCID: PMC7071298 DOI: 10.3390/nu12020414] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 01/31/2020] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION Cardiovascular disease (CVD) is the leading cause of death worldwide. Squalene (SQ), an intermediate for the cholesterol biosynthesis, has been proposed to act similarly to statins via inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in the liver. PURPOSE This paper explores the effects of SQ in CVD. METHODS A systematic review of the literature was performed to identify relevant studies about SQ and CVD. A comprehensive search in Medline and Scopus for relevant studies published between the years 1946 and 2019 was performed. The main inclusion criteria were that the study was published in English; that the study reported association or effect of SQ and CVD; and that CVD should be related to lifestyle variables, aging, or experimentally induced conditions. RESULTS The literature searches identified 5562 potentially relevant articles, whereby 21 studies met the inclusion criteria. There were three human studies and 18 animal experimental studies included in this paper. Only one human study reported positive outcome of SQ in CVD. The remaining two studies reported inconsistent and/or no effect. For animal studies, 15 studies reported positive effect while the remaining reported negative and/or no effect of SQ on various related parameters. CONCLUSIONS This evidence-based review emphasizes the potential of SQ being used for cardiovascular-related diseases. The effect of SQ, especially of plant-based warrants further exploration. Controlled human observational studies should be performed to provide comprehensive evidence.
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Affiliation(s)
- Nurul ‘Izzah Ibrahim
- Pharmacoepidemiology and Drug Safety Unit, Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras 56000, Kuala Lumpur, Malaysia
| | - Syed Fairus
- Malaysian Palm Oil Board (MPOB), No. 6 Persiaran Institusi, Bandar Baru Bangi, Kajang 43000, Selangor, Malaysia
| | - Mohamed S. Zulfarina
- Pharmacoepidemiology and Drug Safety Unit, Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras 56000, Kuala Lumpur, Malaysia
| | - Isa Naina Mohamed
- Pharmacoepidemiology and Drug Safety Unit, Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras 56000, Kuala Lumpur, Malaysia
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Charach G, Argov O, Geiger K, Charach L, Rogowski O, Grosskopf I. Diminished bile acids excretion is a risk factor for coronary artery disease: 20-year follow up and long-term outcome. Therap Adv Gastroenterol 2017; 11:1756283X17743420. [PMID: 29383025 PMCID: PMC5784550 DOI: 10.1177/1756283x17743420] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 10/09/2017] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Patients with coronary artery disease (CAD) had significantly lower bile acid excretion (BAE) compared with non-CAD patients, leading to the hypothesis that the inability to efficiently excrete bile acids leads to coronary atherosclerosis development. We investigated the long-term role of BAE in CAD development and related mortality in 50 patients with proven CAD compared with that of 50 patients with chest pain and no CAD (controls) matched for clinical and laboratory characteristics. METHODS All subjects received a 4-day standard diet that included ~500 mg of cholesterol. Fecal bile acids from 24-h stool collections were measured by gas liquid chromatography. RESULTS CAD patients excreted lower amounts of total bile acids than controls (p < 0.001), less deoxycholic acid (p < 0.0001) and less lithocholic acid (p < 0.01). BAE was the best significant independent laboratory factor that predicted CAD (p < 0.05). Mortality and CAD development rates were significantly lower for the controls at the 20-year follow up. CONCLUSIONS These results showed that CAD patients had markedly decreased BAE levels compared with non-CAD controls. BAE <415 mg/day was associated with increased CAD long-term mortality. Impaired ability to excrete cholesterol might be considered an additional independent risk factor for CAD development.
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Affiliation(s)
- Gideon Charach
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, 6 Weizman Street, Tel Aviv 6423906, Israel
| | - Ori Argov
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, Israel
| | - Karyn Geiger
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, Israel
| | - Lior Charach
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, Israel
| | - Ori Rogowski
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, Israel
| | - Itamar Grosskopf
- Department of Internal Medicine ‘C’, Tel Aviv Sourasky Medical Center, Affiliated to Tel Aviv University, Sackler Medical School, Israel
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Boulila A, Bejaoui A. Lycium intricatum Boiss.: An unexploited and rich source of unsaturated fatty acids, 4-desmethylsterols and other valuable phytochemicals. Lipids Health Dis 2015; 14:59. [PMID: 26104186 PMCID: PMC4485344 DOI: 10.1186/s12944-015-0055-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/09/2015] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Lycium intricatum Boiss., a Solanaceous shrubbery is used in Tunisia as a windbreak and medicinal plant. However, it is considered as underexploited specie despite its high potential to serve as source with economic and nutritional value. To date only limited information about its phytochemistry, especially of its oil has been published. This work provides data on fatty acids, phytosterols and vitamin D composition of L. intricatum seed oil. It opens up new possibilities of developing L. intricatum as a new crop that contains phytochemicals with high added value little influenced by selection or commercial breeding. FINDINGS The composition of fatty acids, phytosterols and vitamin D in L. intricatum seed oil was assessed by GC-FID. The main fatty acids of L. intricatum seed oil were linoleic acid (49.47%), palmitoleic acid (27.96%) and erucic acid (13.62%). Palimtic acid was present at low percentage (0.63%). The content of unsaturated fatty acids was high as 94.04%. The sterolic fraction was composed of stigmasterol (18.56 mg/100 g), β-sitosterol (13.04 mg/100 g). L. intricatum oil is an oily matrix that contains hydrocarbons, mainly squalene (63.36 mg/100 g), and two triterpenic alcohol erythrodiol (80.36 mg/100 g) and uvaol (24.06 mg/100 g). provitamin D was present in high quantity (8.12 mg/100 g). CONCLUSIONS From these results it has been shown that L. intricatum seeds have great potential as a source of fatty acids and phytosterols for natural health products.
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Affiliation(s)
- Abdennacer Boulila
- Laboratory of Natural Substances, National Institute of Research and Physico-chemical Analysis, Biotechpole of Sidi Thabet, Ariana, 2020, Tunisia.
| | - Afef Bejaoui
- Laboratory of Plant Biotechnology, National Institute of Applied Sciences and Technology, BP 676, Centre Urbain Nord, Tunis Cedex, 1080, Tunis, Tunisia.
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Gabás-Rivera C, Barranquero C, Martínez-Beamonte R, Navarro MA, Surra JC, Osada J. Dietary squalene increases high density lipoprotein-cholesterol and paraoxonase 1 and decreases oxidative stress in mice. PLoS One 2014; 9:e104224. [PMID: 25117703 PMCID: PMC4130590 DOI: 10.1371/journal.pone.0104224] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/25/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Squalene, the main hydrocarbon in the unsaponifiable fraction of virgin olive oil, is involved in cholesterol synthesis and it has been reported to own antiatherosclerotic and antiesteatosic effects. However, the squalene's role on lipid plasma parameters and the influence of genotype on this effect need to be addressed. EXPERIMENTAL APPROACHES Three male mouse models (wild-type, Apoa1- and Apoe- deficient) were fed chow semisynthetic diets enriched in squalene to provide a dose of 1 g/kg during 11 weeks. After this period, their plasma parameters and lipoprotein profiles were analyzed. KEY RESULTS Squalene administration at a dose of 1 g/kg showed decreased reactive oxygen species in lipoprotein fractions independently of the animal background and caused an specific increase in high density lipoprotein (HDL)-cholesterol levels, accompanied by an increase in phosphatidylcholine and paraoxonase 1 and no changes in apolipoproteins A1 and A4 in wild-type mice. In these mice, the cholesterol increase was due to its esterified form and associated with an increased hepatic expression of Lcat. These effects were not observed in absence of apolipoprotein A1. The increases in HDL- paraoxonase 1 were translated into decreased plasma malondialdehyde levels depending on the presence of Apolipoprotein A1. CONCLUSIONS AND IMPLICATIONS Dietary squalene promotes changes in HDL- cholesterol and paraoxonase 1 and decreases reactive oxygen species in lipoproteins and plasma malondialdehyde levels, providing new benefits of its intake that might contribute to explain the properties of virgin olive oil, although the phenotype related to apolipoproteins A1 and E may be particularly relevant.
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Affiliation(s)
- Clara Gabás-Rivera
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Barranquero
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Roberto Martínez-Beamonte
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - María A. Navarro
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Joaquín C. Surra
- Departamento de Producción Animal, Escuela Politécnica Superior de Huesca, Huesca, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Osada
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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Matthan NR, Zhu L, Pencina M, D'Agostino RB, Schaefer EJ, Lichtenstein AH. Sex-specific differences in the predictive value of cholesterol homeostasis markers and 10-year cardiovascular disease event rate in Framingham Offspring Study participants. J Am Heart Assoc 2013; 2:e005066. [PMID: 23525441 PMCID: PMC3603247 DOI: 10.1161/jaha.112.005066] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 12/24/2012] [Indexed: 01/05/2023]
Abstract
BACKGROUND Available data are inconsistent regarding factors influencing plasma cholesterol homeostasis marker concentrations and their value in predicting subsequent cardiovascular disease (CVD) events. METHODS AND RESULTS To address this issue, the relationship between markers of cholesterol absorption (campesterol, sitosterol, cholestanol) and synthesis (squalene, desmosterol, lathosterol) and 10-year CVD incidence was assessed in Framingham Offspring Study participants (cycle 6) who were without CVD at baseline and not taking lipid-lowering medications (N=2616). The primary end point was "hard" coronary heart disease (HCHD; coronary death and myocardial infarction), and the secondary end point was full CVD (HCHD plus stroke, coronary insufficiency, angina pectoris, peripheral artery disease, and congestive heart failure). In cross-sectional analysis, significant differences by sex, age, body mass index, blood pressure, and smoking status were observed. In both women and men, lower cholesterol absorption was associated with higher triglyceride and lower high-density lipoprotein (HDL) cholesterol concentrations, whereas lower cholesterol synthesis was associated with higher low-density lipoprotein (LDL) cholesterol concentrations (P for trend <0.05). In women only, lower cholesterol synthesis and absorption were associated with higher non-HDL cholesterol concentrations. Using Cox proportional hazards model adjusting for standard CVD risk factors, squalene concentrations were associated with lower HCHD in women (hazard ratio=0.70 [0.5 to 0.9]). In contrast, squalene (hazard ratio=1.40 [1.1 to 1.8]) concentrations were associated with higher HCHD in men (P<0.0001 for interaction). The cholesterol absorption markers were not predictive of HCHD or full CVD in either women or men. CONCLUSIONS These data suggest significant sex differences in the 10-year prognostic value of cholesterol synthesis markers and HCHD, specifically coronary death and incidence of myocardial infarction. CLINICAL TRIAL REGISTRATION URL:http://ClinicalTrials.gov. Unique identifier: NCT00074464.
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Affiliation(s)
- Nirupa R Matthan
- Cardiovascular Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
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Lou-Bonafonte JM, Arnal C, Navarro MA, Osada J. Efficacy of bioactive compounds from extra virgin olive oil to modulate atherosclerosis development. Mol Nutr Food Res 2012; 56:1043-57. [DOI: 10.1002/mnfr.201100668] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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The role of bile Acid excretion in atherosclerotic coronary artery disease. Int J Vasc Med 2011; 2012:949672. [PMID: 21918722 PMCID: PMC3171758 DOI: 10.1155/2012/949672] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 07/14/2011] [Indexed: 02/05/2023] Open
Abstract
The impact of cholesterol and different classes of lipoproteins on the development of coronary artery disease (CAD) has been investigated in extensively during the past 50 years. The cholesterol metabolism is dependent on numerous factors, including dietary fat, fractional absorption of dietary cholesterol, tissue stores of cholesterol, endogenous cholesterol synthesis, and fecal bile excretion. Several studies showed significantly lower amounts of bile acid secretion in adult patients with CAD compared to non-CAD patients. Could it be that the inability to efficiently excrete bile acids may lead to CAD development?
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Gill S, Stevenson J, Kristiana I, Brown AJ. Cholesterol-dependent degradation of squalene monooxygenase, a control point in cholesterol synthesis beyond HMG-CoA reductase. Cell Metab 2011; 13:260-73. [PMID: 21356516 DOI: 10.1016/j.cmet.2011.01.015] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 10/22/2010] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
Abstract
Exquisite control of cholesterol synthesis is crucial for maintaining homeostasis of this vital yet potentially toxic lipid. Squalene monooxygenase (SM) catalyzes the first oxygenation step in cholesterol synthesis, acting on squalene before cyclization into the basic steroid structure. Using model cell systems, we found that cholesterol caused the accumulation of the substrate squalene, suggesting that SM may serve as a flux-controlling enzyme beyond 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR, considered as rate limiting). Cholesterol accelerated the proteasomal degradation of SM which required the N-terminal domain, partially conserved in vertebrates but not in lower organisms. Unlike HMGR, SM degradation is not mediated by Insig, 24,25-dihydrolanosterol, or side-chain oxysterols, but rather by cholesterol itself. Importantly, SM's N-terminal domain conferred cholesterol-regulated turnover on heterologous fusion proteins. Furthermore, proteasomal inhibition almost totally eliminated squalene accumulation, highlighting the importance of this degradation mechanism for the control of SM and suggesting this as a possible control point in cholesterol synthesis.
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Affiliation(s)
- Saloni Gill
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney NSW 2052, Australia
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Charach G, Grosskopf I, Rabinovich A, Shochat M, Weintraub M, Rabinovich P. The association of bile acid excretion and atherosclerotic coronary artery disease. Therap Adv Gastroenterol 2011; 4:95-101. [PMID: 21694811 PMCID: PMC3105622 DOI: 10.1177/1756283x10388682] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Excess cholesterol is usually eliminated from the body by conversion to bile acids excreted in feces as bile salts. The excretion of large amounts of bile protects against atherosclerosis, while diminished excretion may lead to coronary artery disease (CAD). OBJECTIVE To investigate a relationship between CAD and bile acid excretion. METHODS Bile acid excretion was compared between 36 patients with proven CAD and 37 CAD-free individuals (controls). The groups were comparable for demographics and selected risk factors. All subjects received a 4-day standard diet that included ∼500 mg of cholesterol. Fecal bile acids from 24-hour stool collections were measured by gas liquid chromatography. RESULTS CAD patients excreted lower amounts of total bile acids (358 ± 156 mg) than controls (617 ± 293 mg; p < 0.01) and less deoxycholic acid (188.29 ± 98.12 mg versus 325.96 ± 198.57 mg; p < 0.0001) and less lithocholic acid (115.43 ± 71.89 mg versus 197.27 ± 126.87 mg; p < 0.01). Advanced age, male gender, left ventricular ejection fraction and total bile acid levels were significant independent factors that predicted CAD (p < 0.05). Mortality, CAD and cerebrovascular accident development rates were significantly lower for the controls at the 13-year follow up. CONCLUSION CAD patients have significantly decreased bile acid excretion levels than non-CAD patients. An impaired ability to excrete cholesterol may be an additional risk factor for CAD development.
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Gylling H, Hallikainen M, Rajaratnam RA, Simonen P, Pihlajamäki J, Laakso M, Miettinen TA. The metabolism of plant sterols is disturbed in postmenopausal women with coronary artery disease. Metabolism 2009; 58:401-7. [PMID: 19217458 DOI: 10.1016/j.metabol.2008.10.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Accepted: 10/28/2008] [Indexed: 11/25/2022]
Abstract
In postmenopausal coronary artery disease (CAD) women, serum plant sterols are elevated. Thus, we investigated further whether serum plant sterols reflect absolute cholesterol metabolism in CAD as in other populations and whether the ABCG5 and ABCG8 genes, associated with plant sterol metabolism, were related to the risk of CAD. In free-living postmenopausal women with (n = 47) and without (n = 62) CAD, serum noncholesterol sterols including plant sterols were analyzed with gas-liquid chromatography, cholesterol absorption with peroral isotopes, absolute cholesterol synthesis with sterol balance technique, and bile acid synthesis with quantitating fecal bile acids. In CAD women, serum plant sterol ratios to cholesterol were 21% to 26% (P < .05) higher than in controls despite similar cholesterol absorption efficiency. Absolute cholesterol and bile acid synthesis were reduced. Only in controls were serum plant sterols related to cholesterol absorption (eg, sitosterol; in controls: r = 0.533, P < .001; in CAD: r = 0.296, P = not significant). However, even in CAD women, serum lathosterol (relative synthesis marker) and lathosterol-cholestanol (relative synthesis-absorption marker) were related to absolute synthesis and absorption percentage (P range from .05 to <.001) similarly to controls. Frequencies of the common polymorphisms of ABCG5 and ABCG8 genes did not differ between coronary and control women. In conclusion, plant sterol metabolism is disturbed in CAD women; so serum plant sterols only tended to reflect absolute cholesterol absorption. Other relative markers of cholesterol metabolism were related to the absolute ones in both groups. ABCG5 and ABCG8 genes were not associated with the risk of CAD.
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Affiliation(s)
- Helena Gylling
- Department of Clinical Nutrition, University of Kuopio, FIN-70211 Kuopio, Finland.
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12
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Smith KR, Thiboutot DM. Thematic review series: skin lipids. Sebaceous gland lipids: friend or foe? J Lipid Res 2007; 49:271-81. [PMID: 17975220 DOI: 10.1194/jlr.r700015-jlr200] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sebaceous glands are intriguing glands that are found throughout the human body except on the palms of the hands and soles of the feet. The true function of these glands has yet to be determined, but there are several theories, including antioxidant effects, antibacterial effects, and transport of pheromones. Sebaceous glands produce lipids that are involved in the pathogenesis of one of the most prevalent diseases of adolescence, acne. Although the majority of lipids produced by the sebaceous gland are also produced in other areas of the body, there are two that are characteristic of the sebaceous gland, wax esters and squalene. This review seeks to present an update on the physiology of the sebaceous glands, with particular emphasis on the production of sebaceous lipids.
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Affiliation(s)
- K R Smith
- Jake Gittlen Cancer Research Foundation, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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Zhang Z, Yeung WK, Huang Y, Chen ZY. Effect of squalene and shark liver oil on serum cholesterol level in hamsters. Int J Food Sci Nutr 2002; 53:411-8. [PMID: 12396466 DOI: 10.1080/0963748021000044750] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Squalene (SQ) and shark liver oil (SLO) are popularly sold as health supplements. The present study was designed to test the hypercholesterolemic activities of pure SQ and SLO in hamsters. SQ was supplemented in diets at the levels of 0.05, 0.1 and 0.5% while SLO was added in the diet at 0.05% by weight. When compared with the control group, serum total cholesterol (TC) was elevated by 32% in the 0.05%SQ group, by 23% in the 0.10%SQ group, by 35% in the 0.5%SQ group and by 19% in the 0.05%SLO group, respectively. The similar trend was observed for serum triglycerides (TG). SQ or SLO feeding also elevated hepatic cholesterol by 97-133% in the four tested groups compared with the control hamsters. In addition, supplementations of SQ and SLO in diets caused significant accumulation of SQ in the liver and adipose tissue. The present results suggest that SQ and SLO are hypercholesterolemic at least in hamsters. Caution has to be taken when SQ or SLO are routinely consumed as health supplements.
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Affiliation(s)
- Zesheng Zhang
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, The People's Republic of China
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Rajaratnam RA, Gylling H, Miettinen TA. Cholesterol absorption, synthesis, and fecal output in postmenopausal women with and without coronary artery disease. Arterioscler Thromb Vasc Biol 2001; 21:1650-5. [PMID: 11597940 DOI: 10.1161/hq1001.097019] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypercholesterolemia is a prominent risk factor for coronary artery disease (CAD), yet cholesterol metabolism has not been evaluated in women with CAD. The objective of this study was to determine the interrelations of CAD, serum squalene and sterols, and cholesterol metabolism with each other in postmenopausal women. For this purpose, we measured serum squalene and sterols and fecal steroids (cholesterol and bile acids) and squalene by gas-liquid chromatography and evaluated cholesterol absorption and synthesis in postmenopausal women with CAD (n=29) and age-matched controls (n=20). On similar dietary lipid intake, the cholesterol absorption efficiency and mean serum cholesterol level were comparable, but the squalene-to-cholesterol ratio was higher in cases than in controls. The presence of CAD was inversely associated with fecal total steroids (logistic regression coefficient beta/SE=-2.11, P=0.04) and cholesterol synthesis (beta/SE=-2.14, P=0.04) and turnover (beta/SE=-2.19, P=0.03) after adjustment for dietary cholesterol, family history of CAD, smoking, low and high density lipoprotein cholesterol, and serum triglyceride levels. A high serum squalene ratio was not related to cholesterol synthesis but was inversely related to fecal squalene excretion, which was lower in cases than in controls. In conclusion, the presence of CAD in postmenopausal women is independently associated with altered cholesterol metabolism, as reflected by low synthesis and inefficient elimination of cholesterol.
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Affiliation(s)
- R A Rajaratnam
- Division of Internal Medicine, Department of Medicine, University of Helsinki, Helsinki, Finland
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15
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Relas H, Gylling H, Miettinen TA. Dietary squalene increases cholesterol synthesis measured with serum non-cholesterol sterols after a single oral dose in humans. Atherosclerosis 2000; 152:377-83. [PMID: 10998465 DOI: 10.1016/s0021-9150(99)00478-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Studies considering long-term squalene consumption have revealed no consistent effects on serum cholesterol levels but the immediate effect of dietary squalene on cholesterol synthesis has not been studied. Thus, the effect of a single dose of dietary squalene on postprandial lipid metabolism was studied in 16 male volunteeers aged 22-79 years. Two oral fat meals a week apart were administered to every subject, one without (control) and the other with 500 mg of squalene. Lipids, retinyl palmitate, squalene and non-cholesterol sterols were measured at baseline and after 3, 4, 6, 9, 12 and 24 h postprandially in plasma, chylomicron, VLDL and VLDL bottom and, in six randomly chosen subjects, also in IDL, LDL and HDL. In the fasting samples, squalene was mainly transported in LDL and HDL, whereas in squalene-supplemented postprandium most of squalene was carried in the triglyceride-rich lipoproteins. Postprandial squalene and retinyl palmitate curves closely resembled each other. After the squalene-enriched dietary fat load, squalene was significantly increased compared to control fat loads in plasma, chylomicrons, VLDL and IDL. Squalene addition increased significantly lathosterol/campesterol ratio in chylomicrons and VLDL at 12 h and in VLDL bottom at 9-12 h, and increased significantly VLDL lanosterol/campesterol ratio at 12 h, indicating enhanced cholesterol synthesis caused by squalene. Plasma plant sterol levels remained unchanged. In conclusion, a single oral dose of squalene representing a potential daily dietary amount increases cholesterol synthesis within 9-12 h detected in chylomicrons, VLDL and VLDL bottom.
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Affiliation(s)
- H Relas
- Department of Medicine, Division of Internal Medicine, University of Helsinki, PO Box 340, 00029 HYKS, Helsinki, Finland
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16
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Lindbohm N, Gylling H, Rajaratnam RA, Miettinen TA. Sialic acid content of low-density lipoprotein in women with coronary artery disease. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2000; 136:110-5. [PMID: 10945239 DOI: 10.1067/mlc.2000.108148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A low sialic acid content in low-density lipoprotein (LDL) has been associated with coronary artery disease (CAD) in studies that have included mostly male subjects. We compared the sialic acid-to-apolipoprotein B ratios of total LDL and its subfractions in middle-aged women with CAD (CAD+, n = 22) with those ratios in healthy female control subjects (CAD-, n = 11). CAD+ subjects had a lower sialic acid ratio in total LDL and in its subfractions as compared with results in CAD- subjects. In total, light, and dense LDL, the sialic acid ratio was negatively correlated with the respective cholesterol and phospholipid concentrations, and in very dense LDL, it was negatively correlated with triglyceride concentration. In multivariate analysis, CAD and LDL cholesterol contributed to the explanation of the variability of LDL sialic acid ratios. In summary, a low sialic acid-to-apolipoprotein B ratio in LDL was associated with the presence of CAD in middle-aged women with mild to moderate hypercholesterolemia.
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Affiliation(s)
- N Lindbohm
- Department of Medicine, Helsinki University Central Hospital, Finland
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17
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Squalene in oils determined as squalane by gas-liquid chromatography after hydrogenation of methyl esters. J AM OIL CHEM SOC 2000. [DOI: 10.1007/s11746-000-0133-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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