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Structure, metabolism and biological functions of steryl glycosides in mammals. Biochem J 2021; 477:4243-4261. [PMID: 33186452 PMCID: PMC7666875 DOI: 10.1042/bcj20200532] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/09/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022]
Abstract
Steryl glycosides (SGs) are sterols glycosylated at their 3β-hydroxy group. They are widely distributed in plants, algae, and fungi, but are relatively rare in bacteria and animals. Glycosylation of sterols, resulting in important components of the cell membrane SGs, alters their biophysical properties and confers resistance against stress by freezing or heat shock to cells. Besides, many biological functions in animals have been suggested from the observations of SG administration. Recently, cholesteryl glucosides synthesized via the transglycosidation by glucocerebrosidases (GBAs) were found in the central nervous system of animals. Identification of patients with congenital mutations in GBA genes or availability of respective animal models will enable investigation of the function of such endogenously synthesized cholesteryl glycosides by genetic approaches. In addition, mechanisms of the host immune responses against pathogenic bacterial SGs have partially been resolved. This review is focused on the biological functions of SGs in mammals taking into consideration their therapeutic applications in the future.
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Feng S, Belwal T, Li L, Limwachiranon J, Liu X, Luo Z. Phytosterols and their derivatives: Potential health‐promoting uses against lipid metabolism and associated diseases, mechanism, and safety issues. Compr Rev Food Sci Food Saf 2020; 19:1243-1267. [DOI: 10.1111/1541-4337.12560] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Simin Feng
- College of Food Science and TechnologyZhejiang University of Technology Hangzhou 310014 People's Republic of China
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro‐Products Postharvest Handling Ministry of Agriculture, Zhejiang Key Laboratory for Agri‐Food Processing, National‐Local Joint Engineering Laboratory of Intelligent Food Technology and EquipmentZhejiang University Hangzhou 310058 People's Republic of China
- Key Laboratory of Food Macromolecular Resources Processing Technology Research, China National Light IndustryZhejiang University of Technology Hangzhou 310014 People's Republic of China
| | - Tarun Belwal
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro‐Products Postharvest Handling Ministry of Agriculture, Zhejiang Key Laboratory for Agri‐Food Processing, National‐Local Joint Engineering Laboratory of Intelligent Food Technology and EquipmentZhejiang University Hangzhou 310058 People's Republic of China
| | - Li Li
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro‐Products Postharvest Handling Ministry of Agriculture, Zhejiang Key Laboratory for Agri‐Food Processing, National‐Local Joint Engineering Laboratory of Intelligent Food Technology and EquipmentZhejiang University Hangzhou 310058 People's Republic of China
| | - Jarukitt Limwachiranon
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro‐Products Postharvest Handling Ministry of Agriculture, Zhejiang Key Laboratory for Agri‐Food Processing, National‐Local Joint Engineering Laboratory of Intelligent Food Technology and EquipmentZhejiang University Hangzhou 310058 People's Republic of China
| | - Xingquan Liu
- School of Agriculture and Food SciencesZhejiang Agriculture and Forestry University Hangzhou 311300 People's Republic of China
| | - Zisheng Luo
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro‐Products Postharvest Handling Ministry of Agriculture, Zhejiang Key Laboratory for Agri‐Food Processing, National‐Local Joint Engineering Laboratory of Intelligent Food Technology and EquipmentZhejiang University Hangzhou 310058 People's Republic of China
- Ningbo Research InstituteZhejiang University Ningbo 315100 People's Republic of China
- Fuli Institute of Food ScienceZhejiang University Hangzhou 310058 People's Republic of China
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Lin X, Ma L, Moreau RA, Ostlund RE. Glycosidic bond cleavage is not required for phytosteryl glycoside-induced reduction of cholesterol absorption in mice. Lipids 2011; 46:701-8. [PMID: 21538209 DOI: 10.1007/s11745-011-3560-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 04/15/2011] [Indexed: 10/18/2022]
Abstract
Phytosteryl glycosides occur in natural foods but little is known about their metabolism and bioactivity. Purified acylated steryl glycosides (ASG) were compared with phytosteryl esters (PSE) in mice. Animals on a phytosterol-free diet received ASG or PSE by gavage in purified soybean oil along with tracers cholesterol-d(7) and sitostanol-d(4). In a three-day fecal recovery study, ASG reduced cholesterol absorption efficiency by 45 ± 6% compared with 40 ± 6% observed with PSE. Four hours after gavage, plasma and liver cholesterol-d(7) levels were reduced 86% or more when ASG was present. Liver total phytosterols were unchanged after ASG administration but were significantly increased after PSE. After ASG treatment both ASG and deacylated steryl glycosides (SG) were found in the gut mucosa and lumen. ASG was quantitatively recovered from stool samples as SG. These results demonstrate that ASG reduces cholesterol absorption in mice as efficiently as PSE while having little systemic absorption itself. Cleavage of the glycosidic linkage is not required for biological activity of ASG. Phytosteryl glycosides should be included in measurements of bioactive phytosterols.
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Affiliation(s)
- Xiaobo Lin
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, Campus Box 8127, 660 South Euclid Ave., St. Louis, MO 63110, USA
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Lin X, Ma L, Racette SB, Anderson Spearie CL, Ostlund RE. Phytosterol glycosides reduce cholesterol absorption in humans. Am J Physiol Gastrointest Liver Physiol 2009; 296:G931-5. [PMID: 19246636 PMCID: PMC2670661 DOI: 10.1152/ajpgi.00001.2009] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series of three single-meal tests given at intervals of 2 wk to each of 11 healthy subjects. In a randomized crossover design, participants received approximately 300 mg of added phytosterols in the form of phytosterol glycosides or phytosterol esters, or placebo in a test breakfast also containing 30 mg cholesterol-d7. Cholesterol absorption was estimated by mass spectrometry of plasma cholesterol-d7 enrichment 4-5 days after each test. Compared with the placebo test, phytosterol glycosides reduced cholesterol absorption by 37.6+/-4.8% (P<0.0001) and phytosterol esters 30.6+/-3.9% (P=0.0001). These results suggest that natural phytosterol glycosides purified from lecithin are bioactive in humans and should be included in methods of phytosterol analysis and tables of food phytosterol content.
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Affiliation(s)
- Xiaobo Lin
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Program in Physical Therapy, and Center for Applied Research Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Lina Ma
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Program in Physical Therapy, and Center for Applied Research Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Susan B. Racette
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Program in Physical Therapy, and Center for Applied Research Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Catherine L. Anderson Spearie
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Program in Physical Therapy, and Center for Applied Research Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Richard E. Ostlund
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Program in Physical Therapy, and Center for Applied Research Sciences, Washington University School of Medicine, St. Louis, Missouri
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Karamyan VT, Speth RC. Animal models of BMAA neurotoxicity: a critical review. Life Sci 2007; 82:233-46. [PMID: 18191417 DOI: 10.1016/j.lfs.2007.11.020] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/20/2007] [Accepted: 11/26/2007] [Indexed: 01/26/2023]
Abstract
Of all the molecules reported to have toxicological effects, BMAA (beta-methylamino alanine) stands out as having the most checkered past. In the late 1960's it was reported to be a toxic component of the cycad flour consumed by Chamorros on Guam which caused the high incidence of amyotrophic lateral sclerosis (ALS) in Guam, that was associated with a Parkinson's disease-like dementia complex (ALS-PDC). However, because ALS-PDC is a slow onset disease, manifesting itself as long as 30 years following exposure to the putative neurotoxin, and only acute toxic effects of BMAA were observed in animal studies, interest in BMAA waned. A seminal study by Spencer et al., in 1987 showing neurological impairments with long-term BMAA-fed monkeys revived the hypothesis that BMAA could cause ALS-PDC. However, the amounts of BMAA used in that study were viewed as being the equivalent of a person consuming their body weight of cycad flour every day. Again, the BMAA hypothesis was discarded. Recently a third iteration of the BMAA hypothesis has been proposed. It is based on the discovery of a novel dietary source of BMAA via biomagnification of BMAA in flying foxes, once consumed in great amounts by Chamorros. Also, reports that BMAA can be incorporated into plant and animal proteins, a heretofore unrecognized dietary source of BMAA, further solidified this new hypothesis. However, once again this hypothesis has its detractors and it remains controversial. This manuscript critically evaluates in vivo studies directed at establishing an animal model of BMAA-induced ALS-PDC and their implications for this hypothesis.
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Affiliation(s)
- Vardan T Karamyan
- Department of Pharmacology, School of Pharmacy, University of Mississippi, MS 38677, USA
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Moreau RA, Hicks KB. The in vitro hydrolysis of phytosterol conjugates in food matrices by mammalian digestive enzymes. Lipids 2005; 39:769-76. [PMID: 15638245 DOI: 10.1007/s11745-004-1294-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
All fruits, vegetables, and grains contain phytosterols. Numerous clinical studies have documented that phytosterols lower LDL-cholesterol levels and thereby reduce the risk of cardiovascular disease. Most experts believe that the cholesterol-lowering mechanism of phytosterols requires that they be in their "free" form. In addition to their occurrence in the free form, phytosterols also occur as four common phytosterol conjugates: (i) fatty acyl esters, (ii) hydroxycinnamate esters, (iii) steryl glycosides, and (iv) fatty acylated steryl glycosides. This study was undertaken to investigate the extent of hydrolysis of four common phytosterol conjugates by mammalian digestive enzymes (cholesterol esterase and pancreatin, a mixture of pancreatic enzymes) and for comparison purposes, by KOH. Two types of purified hydroxycinnamate esters (sitostanyl ferulate and oryzanol, a mixture of hydroxycinnamate esters purified from rice bran oil) were hydrolyzed by cholesterol esterase and by pancreatin. Both cholesterol esterase and pancreatin hydrolyzed the phytosteryl esters in two functional food matrices, and they hydrolyzed the hydroxycinnamate esters in corn fiber oil. This is the first report to demonstrate that phytostanyl ferulate esters (which are present at levels of 3-6% in corn fiber oil) are hydrolyzed by pancreatic cholesterol esterase. It is also the first report that pancreatin contains enzymes that hydrolyze the fatty acyl moiety of fatty acylated steryl glycoside, converting it to steryl glycoside. Pancreatin had no effect on steryl glycosides. The ability of pancreatin to hydrolyze three other types of lipid conjugates was also evaluated. Phospholipids were completely hydrolyzed. About half of the galactolipids were hydrolyzed, and less than 10% of the polyamine conjugates were hydrolyzed. The extents of hydrolysis of phytosteryl esters by base (saponification) were also studied, and conditions commonly used for the saponification of acyl lipids (1.5 N methanolic KOH, 30 min at 70 degrees C), were found to result in a nearly 100% hydrolysis of TAG but only about 35-45% hydrolysis of the phytosteryl fatty acyl esters or phytosteryl hydroxycinnamate esters.
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Affiliation(s)
- Robert A Moreau
- Crop Conversion Science and Engineering Research Unit, ERRC, ARS, USDA, Wyndmoor, Pennsylvania 19038, USA.
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AIDA K, KINOSHITA M, TANJI M, SUGAWARA T, TAMURA M, ONO J, UENO N, OHNISHI M. Prevention of Aberrant Crypt Foci Formation by Dietary Maize and Yeast Cerebrosides in 1,2-Dimethyihydrazine-treated Mice. J Oleo Sci 2005. [DOI: 10.5650/jos.54.45] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Sugawara T, Miyazawa T. Digestion of plant monogalactosyldiacylglycerol and digalactosyldiacylglycerol in rat alimentary canal. J Nutr Biochem 2000; 11:147-52. [PMID: 10742659 DOI: 10.1016/s0955-2863(99)00086-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigated digestion of orally fed galactoglycerolipids such as monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) from wheat flour in the rat alimentary canal, especially focusing on the digestive fates of deacylated galactosylglycerol structures. After a single oral administration of MGDG (20 mg/rat), monogalactosylmonoacylglycerol and monogalactosylglycerol (MGG) were found to be major digestion products in the intestinal tract. Similarly, digalactosylmonoacylglycerol and digalactosylglycerol (DGG) were confirmed to be present in the intestinal tract after DGDG ingestion (20 mg/rat). In rats fed wheat flour glycolipids (42 mg MGDG and 81 mg DGDG per rat), completely deacylated galactosylglycerols (MGG and DGG) were not detected in portal plasma. Although the deacylated galactosylglycerols were not significantly decomposed by intestinal mucosa in vitro, they were hydrolyzed by cecal contents. The results demonstrated that orally ingested plant galactoglycerolipids in the rat alimentary canal are rapidly hydrolyzed into constituent fatty acids and that hydrophilic galactosylglycerols and the hydrophilic backbone galactosylglycerols are not absorbed from intestine or degraded into galactose and glycerol in the intestinal tract. Therefore, the presence of deacylated galactosylglycerols may affect the fermentative activity of enterobacteria in the cecum and colon.
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Affiliation(s)
- T Sugawara
- Biodynamic Chemistry Lab, Graduate School of Life Science and Agriculture, Tohoku University, Sendai, Japan
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