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Yu WQ, Wang XL, Ji HH, Miao M, Zhang BH, Li H, Zhang ZY, Ji CF, Guo SD. CM3-SII polysaccharide obtained from Cordyceps militaris ameliorates hyperlipidemia in heterozygous LDLR-deficient hamsters by modulating gut microbiota and NPC1L1 and PPARα levels. Int J Biol Macromol 2023; 239:124293. [PMID: 37011745 DOI: 10.1016/j.ijbiomac.2023.124293] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023]
Abstract
Accumulating evidence has demonstrated that polysaccharides derived from edible fungi have lipid-lowering effects in mice. However, the lipid metabolism mechanisms in mice and humans are different. We have previously elucidated the structural characteristics of the alkali-extracted polysaccharide CM3-SII obtained from Cordyceps militaris. This study aimed to investigate whether CM3-SII could ameliorate hyperlipidemia in a heterozygous low-density lipoprotein receptor (LDLR)-deficient hamster model of hyperlipidemia. Our data demonstrated that CM3-SII significantly decreased total plasma cholesterol, non-high-density lipoprotein cholesterol, and triglyceride levels in heterozygous LDLR-deficient hamsters. Unlike ezetimibe, CM3-SII could enhance the concentration of plasma apolipoprotein A1 and the expression of liver X receptor α/ATP-binding cassette transporter G8 mRNA pathway and suppress the expression of Niemann-Pick C1-like 1, which help to reduce cholesterol levels further. Moreover, the results of molecular docking analysis demonstrated that CM3-SII could directly bind to Niemann-Pick C1-like 1 with high affinity. The triglyceride-lowering mechanisms of CM3-SII were related to its downregulation of sterol regulatory element-binding protein 1c and upregulation of peroxisome proliferator-activated receptor α. Importantly, CM3-SII increased the abundance of Actinobacteria and Faecalibaculum and the ratio of Bacteroidetes/Firmicutes. Thus, CM3-SII attenuated hyperlipidemia by modulating the expression of multiple molecules involved in lipid metabolism and the gut microbiota.
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Gao S, Chen W, Zhang Y, Zhao X, Chang K, Huang Y. Guar gum improves growth performance, intestinal microbiota homeostasis, and hepatic lipid metabolism in juvenile largemouth bass (Micropterus salmoides) fed high-fat diets. Int J Biol Macromol 2023; 235:123807. [PMID: 36828086 DOI: 10.1016/j.ijbiomac.2023.123807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/03/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023]
Abstract
The study aimed to investigate the effects of guar gum on the growth performance, gut microbiota composition, and hepatic lipid metabolism of largemouth bass (Micropterus salmoides) fed high-fat diets. Experimental fish were fed a normal-fat diet (Control), high-fat diet (HF), or HF diets supplemented with 0.3 %, 1 %, and 3 % guar gum (GG0.3, GG1, and GG3, respectively) for eight weeks. The results showed that HF significantly decreased fish growth performance, increased hepatic lipid accumulation, upregulated the expression of sterol regulatory element binding proteins 1 (SREBP1), and downregulated the expression of liver X receptor alpha (LXRα), cytochrome P450 7A1 (CYP7A1), and CYP8B1, compared to Control. However, these problems of high-fat diets were significantly alleviated by GG 0.3. The intestinal microbial communities of the GG0.3 and Control were similar but distinctly different from that of the HF group. Compared to HF, GG0.3 significantly increased the relative abundances of Firmicutes and Lactococcus and decreased the relative abundance of Tenericutes, Mesomycoplasma, and Phenylobacterium. In addition, the GG0.3 and GG1 treatments significantly enhanced the bile salt hydrolase (BSH) activity in the digesta compared to HF. In conclusion, 0.3 % guar gum supplementation can improve growth performance, intestinal health, and hepatic lipid metabolism in fish fed high-fat diets.
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Affiliation(s)
- Shiyang Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China.
| | - Weijun Chen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
| | - Yuanyuan Zhang
- Centre for Research on Environmental Ecology and Fish Nutrition of the Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Xiaoyu Zhao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
| | - Kuo Chang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
| | - Yuchao Huang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
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Cronin P, Joyce SA, O’Toole PW, O’Connor EM. Dietary Fibre Modulates the Gut Microbiota. Nutrients 2021; 13:nu13051655. [PMID: 34068353 PMCID: PMC8153313 DOI: 10.3390/nu13051655] [Citation(s) in RCA: 215] [Impact Index Per Article: 71.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/06/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Dietary fibre has long been established as a nutritionally important, health-promoting food ingredient. Modern dietary practices have seen a significant reduction in fibre consumption compared with ancestral habits. This is related to the emergence of low-fibre “Western diets” associated with industrialised nations, and is linked to an increased prevalence of gut diseases such as inflammatory bowel disease, obesity, type II diabetes mellitus and metabolic syndrome. The characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as high plasma cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Gut microbial signatures are also altered significantly in these cohorts, suggesting a causative link between diet, microbes and disease. Dietary fibre consumption has been hypothesised to reverse these changes through microbial fermentation and the subsequent production of short-chain fatty acids (SCFA), which improves glucose and lipid parameters in individuals who harbour diseases associated with dysfunctional metabolism. This review article examines how different types of dietary fibre can differentially alter glucose and lipid metabolism through changes in gut microbiota composition and function.
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Affiliation(s)
- Peter Cronin
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
- APC Microbiome Ireland, University College Cork, T12 K8AF Cork, Ireland; (S.A.J.); (P.W.O.)
| | - Susan A. Joyce
- APC Microbiome Ireland, University College Cork, T12 K8AF Cork, Ireland; (S.A.J.); (P.W.O.)
- School of Biochemistry and Cell Biology, University College Cork, T12 K8AF Cork, Ireland
| | - Paul W. O’Toole
- APC Microbiome Ireland, University College Cork, T12 K8AF Cork, Ireland; (S.A.J.); (P.W.O.)
- Department of Microbiology, University College Cork, T12 K8AF Cork, Ireland
| | - Eibhlís M. O’Connor
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
- APC Microbiome Ireland, University College Cork, T12 K8AF Cork, Ireland; (S.A.J.); (P.W.O.)
- Health Research Institute, University of Limerick, V94 T9PX Limerick, Ireland
- Correspondence:
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Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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Dumolt JH, Ma M, Mathew J, Patel MS, Rideout TC. Gestational hypercholesterolemia alters fetal hepatic lipid metabolism and microRNA expression in Apo-E-deficient mice. Am J Physiol Endocrinol Metab 2019; 317:E831-E838. [PMID: 31453710 PMCID: PMC6879864 DOI: 10.1152/ajpendo.00138.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Maternal hypercholesterolemia (MHC) is a pathological condition characterized by an exaggerated rise in maternal serum cholesterol during gestation, which can alter offspring hepatic lipid metabolism. However, the extent that these maladaptations occur during gestation and the molecular mechanisms involved remain unknown. MicoRNAs (miRNA) are small, noncoding RNAs that contribute to the development and progression of nonalcoholic fatty liver disease. Therefore, we sought to determine the degree to which in utero exposure to excessive cholesterol affects fetal hepatic lipid metabolism and miRNA expression. Twelve female apoE-/- mice were randomly assigned to two different chow-based diets throughout gestation: control (CON) or the CON diet with cholesterol (0.15%). MHC reduced maternal fecundity and reduced litter size and weight. On gestational day 18, fetuses from MHC dams possessed increased placental cholesterol and hepatic triglycerides (TG), which were accompanied by a downregulation in the expression of hepatic lipogenic and TG synthesis and transport genes. Furthermore, fetal livers from MHC mothers showed increased miRNA-27a and reduced miRNA-200c expression. In summary, in utero exposure to MHC alters fetal lipid metabolism and lends mechanistic insight that implicates early changes in miRNA expression that may link to later-life programming of disease risk.
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Affiliation(s)
- Jerad H Dumolt
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York
| | - Min Ma
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York
| | - Joyce Mathew
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York
| | - Mulchand S Patel
- Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York
| | - Todd C Rideout
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York
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Dumolt JH, Browne RW, Patel MS, Rideout TC. Malprogramming of Hepatic Lipid Metabolism due to Excessive Early Cholesterol Exposure in Adult Progeny. Mol Nutr Food Res 2018; 63:e1800563. [PMID: 30447138 DOI: 10.1002/mnfr.201800563] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/13/2018] [Indexed: 12/21/2022]
Abstract
SCOPE The programming of hepatic lipid dysfunction in response to early cholesterol exposure and the influencing effects of postnatal diet is evaluated in apoE-/- mice. METHODS AND RESULTS In two separate studies, female mice are assigned to a standard chow (S) or a cholesterol-enriched chow (C) diet during gestation and lactation. Male offspring from each dam are weaned on a postnatal S or a hypercaloric western (W) diet resulting in four experimental groups: S-S and C-S (Experiment 1) and S-W and C-W (Experiment 2). At weaning, litters from hypercholesterolemic mothers weighed less (p < 0.05) and pups had higher blood lipids, glucose, and hepatic cholesterol compared with pups from S-fed mothers. Adult C-S offspring demonstrate an atherogenic lipid profile and increased (p < 0.05) hepatic cholesterol and triglyceride content with altered lipid regulatory mRNA expression and protein content compared with S-S offspring. Alternatively, no difference (p > 0.05) is observed between S-W and C-W in serum and hepatic lipid profiles; however, serum AST and ALT are higher (p < 0.05) in C-W versus S-W offspring. CONCLUSION The degree of hepatic lipid deposition observed in adult offspring exposed to excessive early cholesterol is influenced by the postnatal diet.
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Affiliation(s)
- Jerad H Dumolt
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, 14214, USA
| | - Richard W Browne
- Department of Biotechnical and Clinical Laboratory Sciences, University at Buffalo, Buffalo, NY, 14214, USA
| | - Mulchand S Patel
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14214, USA
| | - Todd C Rideout
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, 14214, USA
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Lackeyram D, Young D, Kim CJ, Yang C, Archbold TL, Mine Y, Fan MZ. Interleukin-10 is differentially expressed in the small intestine and the colon experiencing chronic inflammation and ulcerative colitis induced by dextran sodium sulfate in young pigs. Physiol Res 2016; 66:147-162. [PMID: 27782738 DOI: 10.33549/physiolres.933259] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Intestinal inflammation induced with dextran sodium sulfate (DSS) is used to study acute or chronic ulcerative colitis in animal models. Decreased gut tissue anti-inflammatory cytokine IL-10 concentration and mRNA abundance are associated with the development of chronic bowel inflammation. Twelve piglets of 3 days old were fitted with an intragastric catheter and randomly allocated into control and DSS groups by administrating either sterile saline or 1.25 g of DSS/kg body weight (BW) in saline per day, respectively, for 10 days. Growth rate and food conversion efficiency were reduced (p<0.05) in the DSS piglets compared with the control group. Quantitative histopathological grading of inflammation in the jejunum and colon collectively showed that the DSS treatment resulted in 12 fold greater (p<0.05) inflammation severity scoring in the colon than in the jejunum, indicative of chronic ulcerative colitis in the colon. Upper gut permeability endpoint was 27.4 fold higher (p<0.05) in the DSS group compared with the control group. The DSS group had higher concentrations and mRNA abundances (p<0.05) of TNF-alpha and IL-6 in the jejunal and colonic tissues compared with the control group. Colonic concentration and mRNA abundance of IL-10 were reduced (p<0.05), however, jejunal IL-10 mRNA abundance was increased (p<0.05) in the DSS group compared with the control group. In conclusion, administration of DSS at 1.25 g/kg BW for 10 days respectively induced acute inflammation in the jejunum and chronic inflammation and ulcerative colitis in the colon with substantially decreased colonic concentration and mRNA abundance of IL-10 in the young pigs, mimicking the IL-10 expression pattern in humans Associated with chronic bowel inflammation.
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Affiliation(s)
- D Lackeyram
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada.
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Liu J, Iqbal A, Raslawsky A, Browne RW, Patel MS, Rideout TC. Influence of maternal hypercholesterolemia and phytosterol intervention during gestation and lactation on dyslipidemia and hepatic lipid metabolism in offspring of Syrian golden hamsters. Mol Nutr Food Res 2016; 60:2151-2160. [PMID: 27213832 DOI: 10.1002/mnfr.201600116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/15/2016] [Accepted: 05/11/2016] [Indexed: 01/29/2023]
Abstract
SCOPE Although there is a normal physiological rise in maternal lipids during pregnancy, excessive maternal hyperlipidemia during pregnancy increases cardiovascular disease risk for both the mother and offspring. There are limited safe lipid-lowering treatment options for use during pregnancy, therefore, we evaluated the influence of maternal phytosterol (PS) supplementation on lipid and lipoprotein metabolism in mothers and progeny. METHODS AND RESULTS Female Syrian golden hamsters were randomly assigned to three diets throughout prepregnancy, gestation, and lactation (n = 6/group): (i) Chow (Chow), (ii) chow with 0.5% cholesterol (CH), and (iii) chow with 0.5% CH and 2% PS (CH/PS). Compared with newly weaned pups from Chow dams, pups from dams fed the CH-enriched diet demonstrated increases (p < 0.05) in total-C, LDL-C, HDL-C, and total LDL and VLDL particle number. Pups from CH-fed mothers also exhibited higher hepatic CH concentration and differential mRNA expression pattern of CH regulatory genes. Pups from PS-supplemented dams demonstrated reductions (p < 0.05) in serum total-C, non-HDL-C, and LDL-C but also increased triglycerides compared with pups from CH-fed dams. Maternal PS supplementation reduced (p < 0.05) hepatic CH and increased the abundance of HMG-CoAr and LDLr protein in newly weaned pups compared with the CH group. CONCLUSION Results suggest that maternal PS supplementation is largely effective in normalizing CH in pups born to mothers with hypercholesterolemia, however, the cause and long-term influence of increased triglyceride is not known.
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Affiliation(s)
- Jie Liu
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Aadil Iqbal
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Amy Raslawsky
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Richard W Browne
- Department of Biotechnical and Clinical Laboratory Sciences, University at Buffalo, Buffalo, NY, USA
| | - Mulchand S Patel
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Todd C Rideout
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
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Mukthamba P, Srinivasan K. Hypolipidemic and antioxidant effects of dietary fenugreek (Trigonella foenum-graecum) seeds and garlic (Allium sativum) in high-fat fed rats. FOOD BIOSCI 2016. [DOI: 10.1016/j.fbio.2016.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rideout TC, Carrier B, Wen S, Raslawsky A, Browne RW, Harding SV. Complementary Cholesterol-Lowering Response of a Phytosterol/α-Lipoic Acid Combination in Obese Zucker Rats. J Diet Suppl 2015; 13:283-99. [PMID: 25664679 DOI: 10.3109/19390211.2015.1008616] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To investigate the cholesterol-lowering effectiveness of a phytosterol/α-lipoic acid (PS/αLA) therapy, thirty-two male Zucker rats were randomly assigned to 1 of 4 diets for 30 days: (i) high fat diet (HF, 40% energy from fat); (ii) HF diet supplemented with 3% phytosterols; (iii) HF diet supplemented with 0.25% αLA; or (iv) HF diet supplemented with PS (3%) and αLA (0.25%, PS/αLA). Compared with the HF diet, combination PS/αLA proved more effective in reducing non-HDL cholesterol (-55%) than either the PS (-24%) or the αLA (-25%) therapies alone. PS supplementation did not affect LDL particle number, however, αLA supplementation reduced LDL particle number when supplemented alone (-47%) or in combination with PS (-54%). Compared with the HF-fed animals, evidence of increased HDL-particle number was evident in all treatment groups to a similar extent (21-22%). PS-mediated interruption of intestinal cholesterol absorption was evident by increased fecal cholesterol loss (+52%) and compensatory increase in HMG-CoA reductase mRNA (1.6 fold of HF), however, αLA supplementation did not affect fecal cholesterol loss. Hepatic mRNA and protein expression patterns suggested that αLA modulated multiple aspects of cholesterol homeostasis including reduced synthesis (HMG-CoA reductase mRNA, 0.7 fold of HF), reduced bile acid synthesis (CYP7a1 expression, 0.17 of HF), and increased cholesterol clearance (reduced PCSK9 mRNA, 0.5 fold of HF; increased LDLr protein, 2 fold of HF). Taken together, this data suggests that PS and αLA work through unique and complementary mechanisms to provide a superior and more comprehensive cholesterol lowering response than either therapy alone.
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Affiliation(s)
- Todd C Rideout
- a 1 Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions , University at Buffalo , Buffalo , NY , USA
| | - Bradley Carrier
- a 1 Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions , University at Buffalo , Buffalo , NY , USA
| | - Shin Wen
- a 1 Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions , University at Buffalo , Buffalo , NY , USA
| | - Amy Raslawsky
- a 1 Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions , University at Buffalo , Buffalo , NY , USA
| | - Richard W Browne
- b 2 Biotechnical and Clinical Laboratory Sciences, University at Buffalo , Buffalo, NY, USA
| | - Scott V Harding
- c 3 Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London , London , United Kingdom
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Alpha-lipoic acid reduces LDL-particle number and PCSK9 concentrations in high-fat fed obese Zucker rats. PLoS One 2014; 9:e90863. [PMID: 24595397 PMCID: PMC3942488 DOI: 10.1371/journal.pone.0090863] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/05/2014] [Indexed: 01/09/2023] Open
Abstract
We characterized the hypolipidemic effects of alpha-lipoic acid (LA, R-form) and examined the associated molecular mechanisms in a high fat fed Zucker rat model. Rats (n = 8) were assigned to a high fat (HF) diet or the HF diet with 0.25% LA (HF-LA) for 30 days and pair fed to remove confounding effects associated with the anorectic properties of LA. Compared with the HF controls, the HF-LA group was protected against diet-induced obesity (102.5±3.1 vs. 121.5±3.6,% change BW) and hypercholesterolemia with a reduction in total-C (−21%), non-HDL-C (−25%), LDL-C (−16%), and total LDL particle number (−46%) and an increase in total HDL particles (∼22%). This cholesterol-lowering response was associated with a reduction in plasma PCSK9 concentration (−70%) and an increase in hepatic LDLr receptor protein abundance (2 fold of HF). Compared with the HF-fed animals, livers of LA-supplemented animals were protected against TG accumulation (−46%), likely through multiple mechanisms including: a suppressed lipogenic response (down-regulation of hepatic acetyl-CoA carboxylase and fatty acid synthase expression); enhanced hepatic fat oxidation (increased carnitine palmitoyltransferase Iα expression); and enhanced VLDL export (increased hepatic diacylglycerol acyltransferase and microsomal triglyceride transfer protein expression and elevated plasma VLDL particle number). Study results also support an enhanced fatty acid uptake (2.8 fold increase in total lipase activity) and oxidation (increased CPT1β protein abundance) in muscle tissue in LA-supplemented animals compared with the HF group. In summary, in the absence of a change in caloric intake, LA was effective in protecting against hypercholesterolemia and hepatic fat accumulation under conditions of strong genetic and dietary predisposition toward obesity and dyslipidemia.
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Rideout TC, Ramprasath V, Griffin JD, Browne RW, Harding SV, Jones PJH. Phytosterols protect against diet-induced hypertriglyceridemia in Syrian golden hamsters. Lipids Health Dis 2014; 13:5. [PMID: 24393244 PMCID: PMC3896966 DOI: 10.1186/1476-511x-13-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 12/13/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In addition to lowering LDL-C, emerging data suggests that phytosterols (PS) may reduce blood triglycerides (TG), however, the underlying mechanisms are not known. METHODS We examined the TG-lowering mechanisms of dietary PS in Syrian golden hamsters randomly assigned to a high fat (HF) diet or the HF diet supplemented with PS (2%) for 6 weeks (n = 12/group). An additional subset of animals (n = 12) was provided the HF diet supplemented with ezetimibe (EZ, 0.002%) as a positive control as it is a cholesterol-lowering agent with known TG-lowering properties. RESULTS In confirmation of diet formulation and compound delivery, both the PS and EZ treatments lowered (p < 0.05) intestinal cholesterol absorption (24 and 31%, respectively), blood non-HDL cholesterol (61 and 66%, respectively), and hepatic cholesterol (45 and 55%, respectively) compared with the HF-fed animals. Blood TG concentrations were lower (p < 0.05) in the PS (49%) and EZ (68%)-treated animals compared with the HF group. The TG-lowering response in the PS-supplemented group was associated with reduced (p < 0.05) intestinal SREBP1c mRNA (0.45 fold of HF), hepatic PPARα mRNA (0.73 fold of HF), hepatic FAS protein abundance (0.68 fold of HD), and de novo lipogenesis (44%) compared with the HF group. Similarly, lipogenesis was lower in the EZ-treated animals, albeit through a reduction in the hepatic protein abundance of ACC (0.47 fold of HF). CONCLUSIONS Study results suggest that dietary PS are protective against diet-induced hypertriglyceridemia, likely through multiple mechanisms that involve modulation of intestinal fatty acid metabolism and a reduction in hepatic lipogenesis.
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Affiliation(s)
- Todd C Rideout
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA.
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Treadmill Exercise Training Modulates Hepatic Cholesterol Metabolism and Circulating PCSK9 Concentration in High-Fat-Fed Mice. J Lipids 2013; 2013:908048. [PMID: 23862065 PMCID: PMC3703876 DOI: 10.1155/2013/908048] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/04/2013] [Indexed: 12/22/2022] Open
Abstract
Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a novel biomarker of LDL clearance and a therapeutic target of cardiovascular disease. We examined the effects of aerobic exercise training in modulating PCSK9 abundance and hepatic sterol regulation in high-fat-fed C57BL/6 mice. Mice (n = 8) were assigned to a low-fat (LF), high-fat (HF), or an HF with exercise (HF + EX) group for 8 weeks. The HF + EX group was progressively trained 5 days/week on a motorized treadmill. The HF + EX group was protected against body weight (BW) gain and diet-induced dyslipidemia compared with the HF group. The HF + EX group demonstrated an increase in hepatic PCSK9 mRNA (1.9-fold of HF control, P < 0.05) and a reduction in plasma PCSK9 (14%) compared with the HF group. Compared with HF mice, HF + EX mice demonstrated reduced hepatic cholesterol (14%) and increased (P < 0.05) nuclear SREBP2 protein (1.8-fold of HF group) and LDLr mRNA (1.4-fold of HF group). Plasma PCSK9 concentrations correlated positively with plasma non-HDL-C (P = 0.01, r = 0.84). Results suggest that treadmill exercise reduces non-HDL cholesterol and differentially modulates hepatic and blood PCSK9 abundance in HF-fed C57BL/6 mice.
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Jones PJH. Dietary agents that target gastrointestinal and hepatic handling of bile acids and cholesterol. J Clin Lipidol 2012; 2:S4-S10. [PMID: 21291720 DOI: 10.1016/j.jacl.2008.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 01/14/2008] [Indexed: 11/17/2022]
Abstract
Several food components have been demonstrated to exhibit cholesterol-lowering properties by interfering with cholesterol absorption and bile-acid trafficking. Such components include stearic acid, plant sterols, soluble fiber, and soy protein. Among saturated fatty acids, stearic acid is unique in its ability to reduce circulatory low-density lipoprotein cholesterol levels. This action is accompanied by an observed suppression in cholesterol absorption, an effect seen repeatedly in animal and human studies. Proposed mechanisms include micellar exclusion of cholesterol by this high melting point fatty acid, as well as the ability of stearate to alter the biliary ratios of primary to secondary bile acids, leading to a reduction in hydrophobicity index and lower overall solubility of sterols in micelles. Another dietary ingredient that interferes with absorption of sterols is soy protein, in which studies in animals and humans have identified that compared to casein, consumption of soy protein reduces intestinal absorption of cholesterol while enhancing fecal cholesterol excretion. Considerable investigation using free amino acid mixtures mirroring the composition of soy versus animal proteins has determined that co-existing agents other than soy's amino acid pattern are likely responsible for the inhibitory action of soy protein on sterol uptake. Recently, it has been shown that hydrolysates of soy protein appear to be effective in reducing sterol absorption; these are now being targeted as the possible factor responsible for the overall effect of this dietary ingredient. Plant sterols appear to impact absorption of sterols through several mechanisms, including competition with cholesterol for incorporation into micelles, co-crystallization with cholesterol to form insoluble crystals, interaction with digestive enzymes, and inhibition of cholesterol transporter proteins. Clinical trials attest to plant sterols lowering cholesterol absorption by 20% to 40%, an extent beyond which cholesterogenesis can compensate to restore normal circulatory cholesterol levels. As such, 2 g/day of plant sterols effectively lowers low-density lipoprotein cholesterol by 8% to 12%. Dietary soluble fiber represents another means of reducing intestinal cholesterol uptake, in part through enhanced bile-acid clearance through the gut. Pectin, β-glucans, fructans, and gums have been identified as agents that can work through the production of a viscous matrix that hinders movement of cholesterol and bile acids into micelles as well as the subsequent uptake of micelles into the enterocyte. Additional work on design of novel fibers that impede sterol absorption is warranted. In summary, a number of novel dietary factors exist that contribute to heart disease risk reduction via mechanisms that involve cholesterol absorption inhibition and/or biliary pathway perturbation.
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Affiliation(s)
- Peter J H Jones
- Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, 196 Innovation Drive, Winnipeg, MB R3T 6C5, Manitoba, Canada
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Wang CY, Wu SJ, Fang JY, Wang YP, Shyu YT. Cardiovascular and intestinal protection of cereal pastes fermented with lactic acid bacteria in hyperlipidemic hamsters. Food Res Int 2012. [DOI: 10.1016/j.foodres.2012.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Pande S, Srinivasan K. Potentiation of hypolipidemic and weight-reducing influence of dietary tender cluster bean (Cyamopsis tetragonoloba) when combined with capsaicin in high-fat-fed rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8155-8162. [PMID: 22835261 DOI: 10.1021/jf301211c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Soluble fiber-rich tender cluster bean pod (Cyamopsis tetragonoloba) (CB) and a combination of CB and capsaicin, a thermogenic spice compound, were evaluated for weight-reducing effect in high-fat-fed Wistar rats. Freeze-dried CB and capsaicin were included at 15 and 0.015%, respectively, in the high-fat (30%) diet for 8 weeks. Excretion of dietary fat, fat deposition in adipose, and activities of enzymes involved in lipolysis and lipogenesis were examined. CB and capsaicin additively decreased weight gain in high-fat-fed rats, without affecting feed intake. The antiobesity potential of CB was through impeding fat accumulation in adipose and enhancing fat excretion. Decrease in adipose triglyceride by the combination was higher than their individual effects and was accompanied by enhanced activity of hormone-sensitive lipase-facilitating mobilization of depot fat. Increased fecal excretion of triglycerides by the combination of CB and capsaicin was additive. Whereas the hypolipidemic effect of the combination was higher than their individual effects, the decrease in hepatic cholesterol and triglycerides produced by the combination was additve. Thus, dietary CB significantly checked weight gain and adverse changes in lipid profile in high-fat-fed condition amounting to a cardioprotective effect. These beneficial effects were potentiated by coadministration of capsaicin.
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Affiliation(s)
- Shubhra Pande
- Department of Biochemistry and Nutrition, Central Food Technological Research Institute, CSIR, Mysore 570 020, India
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Mido S, Fath EM, Farid AS, Nonaka N, Oku Y, Horii Y. Trichinella spiralis: Infection changes serum paraoxonase-1 levels, lipid profile, and oxidative status in rats. Exp Parasitol 2012; 131:190-4. [DOI: 10.1016/j.exppara.2012.03.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 03/14/2012] [Accepted: 03/26/2012] [Indexed: 01/19/2023]
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Ying Z, Desikan R, Xu X, Maiseyeu A, Liu C, Sun Q, Ziouzenkova O, Parthasarathy S, Rajagopalan S. Modified methylenedioxyphenol analogs lower LDL cholesterol through induction of LDL receptor expression. J Lipid Res 2012; 53:879-887. [PMID: 22355094 DOI: 10.1194/jlr.m022806] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Although statin therapy is a cornerstone of current low density lipoprotein (LDL)-lowering strategies, there is a need for additional therapies to incrementally lower plasma LDL cholesterol. In this study, we investigated the effect of several methylenedioxyphenol derivatives in regulating LDL cholesterol through induction of LDL receptor (LDLR). INV-403, a modified methylenedioxyphenol derivative, increased LDLR mRNA and protein expression in HepG2 cells in a dose- and time-dependent fashion. These effects were apparent even under conditions of HMG-CoA reductase inhibition. Electrophoresis migration shift assays demonstrated that INV-403 activates SREBP2 but not SREBP1c, with immunoblot analysis showing an increased expression of the mature form of SREBP2. Knockdown of SREBP2 reduced the effect of INV-403 on LDLR expression. The activation of SREBP2 by INV-403 is partly mediated by Akt/GSK3β pathways through inhibition of phosphorylation-dependent degradation by ubiquitin-proteosome pathway. Treatment of C57Bl/6j mice with INV-403 for two weeks increased hepatic SREBP2 levels (mature form) and upregulated LDLR with concomitant lowering of plasma LDL levels. Transient expression of a LDLR promoter-reporter construct, a SRE-mutant LDLR promoter construct, and a SRE-only construct in HepG2 cells revealed an effect predominantly through a SRE-dependent mechanism. INV-403 lowered plasma LDL cholesterol levels through LDLR upregulation. These results indicate a role for small molecule approaches other than statins for lowering LDL cholesterol.
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Affiliation(s)
- Zhekang Ying
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | | | - Xiaohua Xu
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | - Andrei Maiseyeu
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | - Cuiqing Liu
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | - Qinghua Sun
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | - Ouiliana Ziouzenkova
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and
| | | | - Sanjay Rajagopalan
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH; and.
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Farid AS, Mido S, Linh BK, Hayashi T, Horii Y. An atherogenic lipid profile with low serum paraoxonase-1 activity during nematode infection in rats. Eur J Clin Invest 2010; 40:984-93. [PMID: 20695884 DOI: 10.1111/j.1365-2362.2010.02352.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Inflammation and oxidative stress are associated with cardiovascular diseases and underlying atherosclerosis. The high density lipoprotein (HDL)-associated paraoxonase-1 (PON1) enzyme is known to be involved in the protection of serum lipids from such oxidation. Nonetheless, the disturbances of lipid profile during nematode-infected model have not yet been studied. Therefore, we aimed to explore the effects of Nippostrongylus brasiliensis infection in male Wistar rats, a model of human gastrointestinal nematode infections, on hepatic PON1 synthesis and the levels of lipid parameters. MATERIALS AND METHODS Nippostrongylus brasiliensis-infected rats fed standard and high-fat diets. Serum paraoxonase and arylesterase activities were measured on day 0, 2, 4, 7, and 14 post-infection (PI). Hepatic PONs and pro-inflammatory cytokines mRNA expression levels were evaluated in a standard diet-fed groups, and the disturbances in lipid profile as well as the levels of thiobarbituric acid reactive species (TBARS) and oxidized-LDL (Ox-LDL) were measured in high-fat diet-fed groups. RESULTS We found that N. brasiliensis-infected rats fed the standard diet show a significant reduction in serum PON1 activity and down-regulation of hepatic PON1 mRNA expression as well as up-regulation of hepatic IL-1β, IL-β receptor (R), TNF-α, and TNFR1 mRNA expressions in association with hepatic recruitments of Kupffer cells and neutrohils. In the presence of the high-fat diet, N. brasiliensis infection increases serum triglycerides, total cholesterol, LDL/VLDL, TBARS and Ox-LDL as well as decreases serum HDL coinciding with a maximum serum PON1 reduction. CONCLUSIONS Nippostrongylus brasiliensis infection can induce atherogenic lipid profile and reduce serum PON1 activity.
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Affiliation(s)
- Ayman Samir Farid
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, Qalioubeya, Egypt
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Rideout TC, Harding SV, Jones PJH. Consumption of plant sterols reduces plasma and hepatic triglycerides and modulates the expression of lipid regulatory genes and de novo lipogenesis in C57BL/6J mice. Mol Nutr Food Res 2010; 54 Suppl 1:S7-13. [PMID: 20333723 DOI: 10.1002/mnfr.201000027] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To investigate emerging clinical data suggesting a triglyceride (TAG)-lowering response to plant sterol (PS) therapy, we characterized changes in TAG metabolism in 16 C57BL/6J mice fed a basal control diet (CON) or the CON diet supplemented with 2% PS for 6 wk. PS consumption reduced (p<0.05) plasma (-28%) and hepatic (-30%) TAG concentrations compared with CON mice. PS consumption increased (p<0.05) hepatic lipogenic gene expression (sterol-regulatory-element-binding protein 1c, 2.4-fold of CON; fatty acid synthase, 6.5-fold of CON) and de novo lipogenesis (4.51+/-0.72 versus 2.82+/-0.61%/day) compared with CON. PS consumption increased (p<0.05) fecal palmitate and stearate excretion and reduced body weight gain compared with CON mice. Although no change in the transcription of intestinal fatty acid absorptive genes was observed, peroxisome proliferator-activated receptor alpha mRNA was reduced (p<0.05, 2.0-fold of CON) in the PS-fed mice. In conclusion, PS-fed C57BL/6J mice showed pronounced reductions in plasma and hepatic TAG concentrations despite increases in hepatic lipogenic gene expression and de novo lipogenesis. Interference with intestinal fatty acid/TAG metabolism as suggested by increased fecal fatty acid loss and reduced weight gain may be associated with the TAG-lowering response to PS consumption.
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Affiliation(s)
- Todd C Rideout
- Richardson Centre for Functional Foods and Nutraceuticals, Winnipeg, MB, Canada.
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Harding SV, Rideout TC, Jones PJH. Hepatic nuclear sterol regulatory binding element protein 2 abundance is decreased and that of ABCG5 increased in male hamsters fed plant sterols. J Nutr 2010; 140:1249-54. [PMID: 20505021 DOI: 10.3945/jn.109.120311] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effect of dietary plant sterols on cholesterol homeostasis has been well characterized in the intestine, but how plant sterols affect lipid metabolism in other lipid-rich tissues is not known. Changes in hepatic cholesterol homeostasis in response to high dietary intakes of plant sterols were determined in male golden Syrian hamsters fed hypercholesterolemia-inducing diets with and without 2% plant sterols (wt:wt; Reducol, Forbes Meditech) for 28 d. Plasma and hepatic cholesterol concentrations, cholesterol biosynthesis and absorption, and changes in the expression of sterol response element binding protein 2 (SREBP2) and liver X receptor-beta (LXRbeta) and their target genes were measured. Plant sterol feeding reduced plasma total cholesterol, non-HDL cholesterol, and HDL cholesterol concentrations 43% (P < 0.0001), 60% (P < 0.0001), and 21% (P = 0.001), respectively, compared with controls. Furthermore, there was a 93% reduction (P < 0.0001) in hepatic total cholesterol and >6-fold (P = 0.029) and >2-fold (P < 0.0001) increases in hepatic beta-sitosterol and campesterol concentrations, respectively, in plant sterol-fed hamsters compared with controls. Plant sterol feeding also increased fractional cholesterol synthesis >2-fold (P < 0.03) and decreased cholesterol absorption 83% (P < 0.0001) compared with controls. Plant sterol feeding increased hepatic protein expression of cytosolic (inactive) SREBP2, decreased nuclear (active) SREBP2, and tended to increase LXRbeta (P = 0.06) and ATP binding cassette transporter G5, indicating a differential modulation of the expression of proteins central to cholesterol metabolism. In conclusion, high-dose plant sterol feeding of hamsters changes hepatic protein abundance in favor of cholesterol excretion despite lower hepatic cholesterol concentrations and higher cholesterol fractional synthesis.
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Affiliation(s)
- Scott V Harding
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Canada R3T 6C5
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Rideout TC, Harding SV, Mackay D, Abumweis SS, Jones PJ. High basal fractional cholesterol synthesis is associated with nonresponse of plasma LDL cholesterol to plant sterol therapy. Am J Clin Nutr 2010; 92:41-6. [PMID: 20444957 DOI: 10.3945/ajcn.2009.29073] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The cholesterol-lowering effectiveness of plant sterol (PS) therapy is hindered by wide-ranging variability in LDL-cholesterol responsiveness across individuals. To capitalize on the LDL-cholesterol-lowering potential of PS in the clinical setting, it is paramount to characterize the metabolic factors that underlie this heterogeneity of responsiveness. OBJECTIVE The objective was to investigate the relation between cholesterol synthesis and plasma LDL-cholesterol reductions in response to PS consumption. DESIGN We evaluated previously conducted clinical PS interventions incorporating stable-isotope measures of cholesterol synthesis and conducted feeding studies in animal models of response (Syrian Golden hamsters) and nonresponse (C57BL/6J mice) to PS consumption. RESULTS From our clinical study population (n = 113), we identified 47 nonresponders (3.73 +/- 1.10% change in LDL cholesterol) and 66 responders (-15.16 +/- 1.04% change in LDL cholesterol) to PS therapy. The basal cholesterol fractional synthesis rate (FSR) as measured by direct deuterium incorporation was 23% higher (P = 0.003) in the nonresponder subgroup than in responders to PS therapy. The basal cholesterol FSR correlated (r = 0.22, P = 0.02) with the percentage change in LDL cholesterol after PS intervention. In support of our clinical observations, nonresponding mice showed a 77% higher (P = 0.001) basal cholesterol FSR than that of responding hamsters. Compared with control mice, PS-fed mice showed an increase in hepatic nuclear sterol regulatory element binding protein 2 abundance (1.3-fold of control, P = 0.04) and beta-hydroxy-beta-methylglutaryl coenzyme A reductase-mRNA expression (2.4-fold of control, P = 0.00). CONCLUSION The results suggest that subjects with high basal cholesterol synthesis are less responsive to PS treatment than are subjects with low basal cholesterol synthesis.
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Affiliation(s)
- Todd C Rideout
- Richardson Centre for Functional Foods and Nutraceuticals, Winnipeg, Canada.
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Combination drug-diet therapies for dyslipidemia. Transl Res 2010; 155:220-7. [PMID: 20403577 DOI: 10.1016/j.trsl.2009.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/22/2009] [Accepted: 12/23/2009] [Indexed: 01/07/2023]
Abstract
Expense, high drug dose, and low compliance to strict dietary therapies are current issues surrounding modern drug- and diet-based lipid-lowering approaches. Furthermore, variable patient outcomes and suboptimal response to both drug and diet therapies are increasingly evident. Therefore, the question arises as to whether more emphasis should be placed on combination diet/drug therapies to reduce cholesterol levels in patients who respond suboptimally to diet and drug monotherapies. Although considerable research has explored multidrug combination therapies, combination drug/diet therapies receive less attention. However, combined drug/diet approaches may reduce the number of drug prescriptions, the progressive increase in "optimal" drug dosage, and costs associated with pharmaceutical disease management. Future research priorities in drug/diet therapeutic approaches should not only emphasize the discovery of novel combinations but also should address potential safety issues prior to wide-scale acceptance in clinical practice. Accordingly, this review will assess current limitations associated with both drug and diet lipid-lowering therapies and explore the potential of combination drug/diet therapies in the treatment of dyslipidemia.
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Rideout TC, Harding SV, Jones PJ, Fan MZ. Guar gum and similar soluble fibers in the regulation of cholesterol metabolism: current understandings and future research priorities. Vasc Health Risk Manag 2009; 4:1023-33. [PMID: 19183750 PMCID: PMC2605338 DOI: 10.2147/vhrm.s3512] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The hypocholesterolemic effects associated with soluble fiber consumption are clear from animal model and human clinical investigations. Moreover, the modulation of whole-body cholesterol metabolism in response to dietary fiber consumption, including intestinal cholesterol absorption and fecal sterol and bile acid loss, has been the subject of many published reports. However, our understanding of how dietary fibers regulate molecular events at the gene/protein level and alter cellular cholesterol metabolism is limited. The modern emphasis on molecular nutrition and rapid progress in 'high-dimensional' biological techniques will permit further explorations of the role of genetic polymorphisms in determining the variable interindividual responses to soluble fibers. Furthermore, with traditional molecular biology tools and the application of 'omic' technology, specific insight into how fibers modulate the expression of genes and proteins that regulate intestinal cholesterol absorption and alter hepatic sterol balance will be gained. Detailed knowledge of the molecular mechanisms by which soluble fibers reduce plasma cholesterol concentrations is paramount to developing novel fiber-based "cocktails" that target specific metabolic pathways to gain maximal cholesterol reductions.
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Affiliation(s)
- Todd C Rideout
- Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba, Canada.
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Yang X, Yang C, Farberman A, Rideout TC, de Lange CFM, France J, Fan MZ. The mammalian target of rapamycin-signaling pathway in regulating metabolism and growth1,2. J Anim Sci 2008; 86:E36-50. [DOI: 10.2527/jas.2007-0567] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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