1
|
Nishikawa M, Ohara N, Naito Y, Saito Y, Amma C, Tatematsu K, Baoyindugurong J, Miyazawa D, Hashimoto Y, Okuyama H. Rapeseed (canola) oil aggravates metabolic syndrome-like conditions in male but not in female stroke-prone spontaneously hypertensive rats (SHRSP). Toxicol Rep 2022; 9:256-268. [PMID: 35242585 PMCID: PMC8866840 DOI: 10.1016/j.toxrep.2022.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 11/30/2021] [Accepted: 01/25/2022] [Indexed: 11/18/2022] Open
Abstract
Canola oil shortens life of male SHRSP. Testis is the target of canola oil toxicity. Inhibition of negative regulation by testosterone of aldosterone production may be a trigger of canola oil toxicity. Facilitation of hypertension by aldosterone may lead to life-shortening. Increased plasma lipids by canola oil have no relevance to life-shortening.
This study was conducted to investigate whether or not there are sex differences in canola oil (CAN)-induced adverse events in the rat and to understand the involvement and the role of testosterone in those events, including life-shortening. Stroke-prone spontaneously hypertensive rats (SHRSP) of both sexes were fed a diet containing 10 wt/wt% soybean oil (SOY, control) or CAN as the sole dietary fat. The survival of the males fed the CAN diet was significantly shorter than that of those fed the SOY diet. In contrast, the survival of the females was not affected by CAN. The males fed the CAN diet showed elevated blood pressure, thrombopenia and insulin-tolerance, which are major symptoms of metabolic syndrome, whereas such changes by the CAN diet were not found in the females. Plasma testosterone was significantly lower in animals of both sexes fed the CAN diet than in those fed the SOY diet, but interestingly, the lowered testosterone was accompanied by a marked increase in plasma aldosterone only in the males. These results demonstrate significant sex differences in CAN-toxicity and suggest that those sex differences may be attributable to the increased aldosterone level, which triggers aggravation of the genetic diseases specific to SHRSP, that is, metabolic syndrome-like conditions, but only in the males. The present results also suggest that testosterone may negatively regulate aldosterone production in the physiology of the males, and the inhibition of that negative regulation caused by the CAN diet is one of the possible causes of the adverse events.
Collapse
Affiliation(s)
- Mai Nishikawa
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi 463-8521, Japan
| | - Naoki Ohara
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi 463-8521, Japan
- Corresponding author.
| | - Yukiko Naito
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Yoshiaki Saito
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | - Chihiro Amma
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi 463-8521, Japan
| | - Kenjiro Tatematsu
- Gifu Pharmaceutical University, 5-6-1 Mitabora, Gifu, Gifu 502-8585, Japan
| | - Jinhua Baoyindugurong
- Inner Mongolia Agricultural University, College of Food Science and Engineering, Zhaowuda Rd. 306, Hohhot, Inner Mongolia 010018, PR China
| | - Daisuke Miyazawa
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi 463-8521, Japan
| | - Yoko Hashimoto
- School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Harumi Okuyama
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi 463-8521, Japan
| |
Collapse
|
2
|
Fully hydrogenated canola oil extends lifespan in stroke-prone spontaneously hypertensive rats. Lipids Health Dis 2021; 20:102. [PMID: 34511125 PMCID: PMC8436556 DOI: 10.1186/s12944-021-01540-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/31/2021] [Indexed: 11/10/2022] Open
Abstract
Background Canola oil (Can) and several vegetable oils shorten the lifespan of stroke-prone spontaneously hypertensive rats (SHRSP). Although similar lifespan shortening has been reported for partially hydrogenated Can, the efficacy of fully hydrogenated oils on the lifespan remains unknown. The present study aimed to investigate the lifespan of SHRSP fed diets containing 10 % (w/w) of fully hydrogenated Can (FHCO) or other oils. Methods Survival test: Upon weaning, male SHRSP were fed a basal diet for rodents mixed with one of the test oils —i.e., FHCO, Can, lard (Lrd), and palm oil (Plm) throughout the experiment. The animals could freely access the diet and drinking water (water containing 1 % NaCl), and their body weight, food intake, and lifespan were recorded. Biochemical analysis test: Male SHRSP were fed a test diet with either FHCO, Can, or soybean oil (Soy) under the same condition, except to emphasize effects of fat, that no NaCl loading was applied. Soy was used as a fat source in the basal diet and was set the control group. Blood pressures was checked every 2 weeks, and serum fat levels and histological analyses of the brain and kidney were examined after 7 or 12 weeks of feeding. Results During the survival study period, the food consumption of FHCO-fed rats significantly increased (15–20 % w/w) compared with that of rats fed any other oil. However, the body weight gain in the FHCO group was significantly less (10–12 %) than that in the control group at 9–11 weeks old. The FHCO (> 180 days) intervention had the greatest effect on lifespan, followed by the Lrd (115 ± 6 days), Plm (101 ± 2 days), and Can (94 ± 3 days) diets. FHCO remarkably decreased the serum cholesterol level compared with Can and the systolic blood pressure from 12 to 16 weeks of age. In addition, while some rats in the Can group exhibited brain hemorrhaging and renal dysfunction at 16 weeks old, no symptoms were observed in the FHCO group. Conclusion This current study suggests that complete hydrogenation decreases the toxicity of Can and even prolongs the lifespan in SHRSP. Supplementary Information The online version contains supplementary material available at 10.1186/s12944-021-01540-7.
Collapse
|
3
|
Miyazawa D, Ohara N, Yamada K, Yasui Y, Kitamori K, Saito Y, Usumi K, Nagata T, Nonogaki T, Hashimoto Y, Miyashiro Y, Homma S, Okuyama H. Dietary soybean oil, canola oil and partially-hydrogenated soybean oil affect testicular tissue and steroid hormone levels differently in the miniature pig. Food Chem Toxicol 2020; 135:110927. [DOI: 10.1016/j.fct.2019.110927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 11/28/2022]
|
4
|
Hashimoto Y, Mori M, Kobayashi S, Hanya A, Watanabe SI, Ohara N, Noguchi T, Kawai T, Okuyama H. Canola and hydrogenated soybean oils accelerate ectopic bone formation induced by implantation of bone morphogenetic protein in mice. Toxicol Rep 2014; 1:955-962. [PMID: 28962307 PMCID: PMC5598561 DOI: 10.1016/j.toxrep.2014.10.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 10/27/2014] [Accepted: 10/27/2014] [Indexed: 01/07/2023] Open
Abstract
Canola oil (Can) and hydrogenated soybean oil (H2-Soy) are commonly used edible oils. However, in contrast to soybean oil (Soy), they shorten the survival of stroke-prone spontaneously hypertensive (SHRSP) rats. It has been proposed that the adverse effects of these oils on the kidney and testis are caused at least in part by dihydro-vitamin K (VK) 1 in H2-Soy and unidentified component(s) in Can. Increased intake of dihydro-VK1 is associated with decreased tissue VK2 levels and bone mineral density in rats and humans, respectively. The aim of the present study was to determine the effects of these oils on bone morphogenetic protein (BMP)-induced ectopic bone formation, which is promoted by VK2 deficiency, in relation to the role of VK in the γ-carboxylation of osteocalcin and matrix Gla protein. A crude extract of BMPs was implanted into a gap in the fascia of the femoral muscle in 5-week-old mice maintained on a Soy, Can, or H2-Soy diet. Newly formed bone volume, assessed by three-dimensional X-ray micro-computed tomography and three-dimensional reconstruction imaging for bone, was 4-fold greater in the Can and H2-Soy groups than in the Soy group. The plasma carboxylated osteocalcin (Gla-OC) and total OC (Gla-OC plus undercarboxylated osteocalcin [Glu-OC]) levels were significantly lower in the Can group than in the Soy group (p < 0.05). However, these levels did not significantly differ between the H2-Soy and Soy groups. The plasma Gla-OC/Glu-OC ratio in the Can and H2-Soy groups was significantly lower (in Can; p = 0.044) or was almost significantly lower (in H2-Soy; p = 0.053) than that in the Soy group. In conclusion, Can and H2-Soy accelerated BMP-induced bone formation in mice to a greater extent than Soy. Further research is required to evaluate whether the difference in accelerated ectopic bone formation is associated with altered levels of VK2 and VK-dependent protein(s) among the three dietary groups.
Collapse
Key Words
- 4056): Vitamin K3 (PubChem CID: 4055)
- BMP, bone morphogenetic protein
- Bone morphogenetic protein
- Can, canola oil
- Canola oil
- Dihydro-vitamin K1 (PubChem CID: 152059)
- Ectopic calcification
- G6PDH, glucose-6-phosphate dehydrogenase
- Gla, carboxyglutamic acid
- Gla-OC, carboxylated osteocalcin
- Glu-OC, undercarboxylated osteocalcin
- H2-Soy, hydrogenated soybean oil
- Hydrogenated soybean oil
- Matrix Gla protein
- Osteocalcin
- SHRSP rat, stroke-prone spontaneously hypertensive rat
- Soy, soybean oil
- TRI/3D-BON, three-dimensional reconstruction imaging for bone
- VK, vitamin K
- Vitamin K
- Vitamin K1 (PubChem CID: 52384607)
- Vitamin K1 hydroquinone (PubChem CID: 5280585)
- Vitamin K2 (PubChem CID
- cMGP, carboxylated matrix Gla protein
- dihydro-VK1, 2′, 3′-dihydro-vitamin K1
- mCT, micro-computed tomography
- ucMGP, undercarboxylated MGP
Collapse
Affiliation(s)
- Yoko Hashimoto
- Department of Biochemistry, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Mayumi Mori
- Department of Pharmacology, Nagoya City University Graduate School of Medical Science, Kawasumi, Mizuho-ku, Nagoya 467-8601, Japan
| | - Shuichiro Kobayashi
- Department of Periodontology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Akira Hanya
- Food Research Center, Aichi Center for Industry and Science Technology, 2-1-1 Shinpukuji-cho, Nishi-ku, Nagoya 451-0083, Japan
| | - Shin-Ichi Watanabe
- Kinjo Gakuin University College of Pharmacy, Omori, Moriyama-ku, Nagoya 463-8521, Japan
| | - Naoki Ohara
- Kinjo Gakuin University College of Pharmacy, Omori, Moriyama-ku, Nagoya 463-8521, Japan
| | - Toshihide Noguchi
- Department of Periodontology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Tatsushi Kawai
- Department of Dental Material Science, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Harumi Okuyama
- Kinjo Gakuin University College of Pharmacy, Omori, Moriyama-ku, Nagoya 463-8521, Japan
| |
Collapse
|
5
|
Cai J, Jang JY, Kim J, Shin K, Kim KS, Park D, Kim TS, Lee SP, Ahn B, Choi EK, Lee J, Kim YB. Comparative effects of plant oils on the cerebral hemorrhage in stroke-prone spontaneously hypertensive rats. Nutr Neurosci 2014; 19:318-26. [PMID: 24856006 DOI: 10.1179/1476830514y.0000000132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Since oils and fats can induce metabolic syndrome, leading to cardiovascular and cerebrovascular diseases, the present study was performed to find out whether the plant oils affect the cerebral hemorrhage in stroke-prone spontaneously hypertensive (SHR-SP) rats. METHODS From 47 days of age, male SHR-SP rats were given drinking water containing 1% NaCl to induce hypertension, and simultaneously fed semi-purified diets containing 10% perilla oil, canola oil, or shortening. The onset time of convulsion following cerebral hemorrhage was recorded, and the areas of hemorrhage and infarction were analyzed in the stroke brains. RESULTS In comparison with 58-day survival of SHR-SP rats during feeding NaCl alone, perilla oil extended the survival time to 68.5 days, whereas canola oil shortened it to 45.7 days. Feeding perilla oil greatly reduced the total volume of cerebral hemorrhage from 17.27% in the control group to 4.53%, while shortening increased the lesions to 21.23%. In a microscopic analysis, perilla oil also markedly decreased the hemorrhagic and infarction lesions to 1/10 of those in control rats, in contrast to an exacerbating effect of shortening. In blood analyses, perilla oil reduced blood total cholesterol and low-density lipoproteins which were increased in SHR-SP, but canola oil further increased them and markedly lowered platelet counts. DISCUSSION Perilla oil delayed and attenuated cerebral hemorrhage by improving hyperlipidemia in hypertensive stroke animals, in contrast to the aggravating potential of canola oil and shortening. It is suggested that perilla oil should be the first choice oil for improving metabolic syndrome in hypertensive persons at risk of hemorrhagic stroke.
Collapse
Affiliation(s)
- Jingmei Cai
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Ja-Young Jang
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Jihyun Kim
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Kyungha Shin
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Kwang Sei Kim
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Dongsun Park
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | | | | | - Byeongwoo Ahn
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Ehn-Kyoung Choi
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| | - Junsoo Lee
- c Department of Food Science and Technology , Chungbuk National University , Cheongju , Korea
| | - Yun-Bae Kim
- a College of Veterinary Medicine, Chungbuk National University , Cheongju , Korea
| |
Collapse
|
6
|
Ratnayake S, Lewandowski P. Rapid bioassay-guided screening of toxic substances in vegetable oils that shorten the life of SHRSP rats. Lipids Health Dis 2010; 9:13. [PMID: 20122175 PMCID: PMC2837656 DOI: 10.1186/1476-511x-9-13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Accepted: 02/02/2010] [Indexed: 11/12/2022] Open
Abstract
It has been consistently reported that vegetable oils including canola oil have a life shortening effect in Stroke-Prone Spontaneously Hypertensive Rats (SHRSP) and this toxic effect is not due to the fatty acid composition of the oil. Although it is possible that the phytosterol content or type of phytosterol present in vegetable oils may play some role in the life shortening effect observed in SHRSP rats this is still not completely resolved. Furthermore supercritical CO2 fractionation of canola oil with subsequent testing in SHRSP rats identified safe and toxic fractions however, the compounds responsible for life shortening effect were not characterised. The conventional approach to screen toxic substances in oils using rats takes more than six months and involves large number of animals. In this article we describe how rapid bioassay-guided screening could be used to identify toxic substances derived from vegetable oils and/or processed foods fortified with vegetable oils. The technique incorporates sequential fractionation of oils/processed foods and subsequent treatment of human cell lines that can be used in place of animal studies to determine cytotoxicity of the fractions with structural elucidation of compounds of interest determined via HPLC-MS and GC-MS. The rapid bioassay-guided screening proposed would require two weeks to test multiple fractions from oils, compared with six months if animal experiments were used to screen toxic effects. Fractionation of oil before bio-assay enhances the effectiveness of the detection of active compounds as fractionation increases the relative concentration of minor components.
Collapse
Affiliation(s)
- Sunil Ratnayake
- Molecular Nutrition Unit, School of Medicine, Deakin University, Pigdons Road, Waurn Ponds VIC 3217, Australia
| | | |
Collapse
|
7
|
Ohara N, Naito Y, Kasama K, Shindo T, Yoshida H, Nagata T, Okuyama H. Similar changes in clinical and pathological parameters in Wistar Kyoto rats after a 13-week dietary intake of canola oil or a fatty acid composition-based interesterified canola oil mimic. Food Chem Toxicol 2009; 47:157-62. [DOI: 10.1016/j.fct.2008.10.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 09/27/2008] [Accepted: 10/26/2008] [Indexed: 11/26/2022]
|
8
|
Ohara N, Kasama K, Naito Y, Nagata T, Saito Y, Kuwagata M, Okuyama H. Different effects of 26-week dietary intake of rapeseed oil and soybean oil on plasma lipid levels, glucose-6-phosphate dehydrogenase activity and cyclooxygenase-2 expression in spontaneously hypertensive rats. Food Chem Toxicol 2008; 46:2573-9. [PMID: 18508177 DOI: 10.1016/j.fct.2008.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 04/02/2008] [Accepted: 04/11/2008] [Indexed: 10/22/2022]
Abstract
We intended to determine whether or not dietary canola oil (CO) elevates plasma lipids and oxidative stress, since both of these are, possibly, related to the CO-induced life shortening through exacerbation of hypertension-associated vascular lesions found in stroke-prone spontaneously hypertensive rats (SHRSP). Spontaneously hypertensive rats (SHR) were used in this study to avoid a potential bias in the results due to the irregular death by stroke seen in SHRSP. SHR were fed for 26 weeks on a chow containing either, 10 wt/wt% of CO or soybean oil (SO), i.e., the control. Elevated plasma lipids and glucose-6-phosphate dehydrogenase (G6PD) activation in the liver and erythrocyte were found in SHR fed CO compared to that fed SO, while anti-oxidative enzymes other than G6PD were not activated. The CO diet brought about significant vascular lesions in the kidney, in which abundant cyclooxygenase-2 (COX-2) positive foci were immunochemically located in the juxtaglomerular apparatus. These results suggest that dietary CO induces a hyperlipidemic condition, in which G6PD may serve as an NADPH provider, and aggravates genetic diseases in SHR (also, probably, in SHRSP). The increased COX-2 expression indicates a role of renin-angiotensin-aldosterone system activation in the increased vascular lesions, whereas the effects of oxidative stress remain unclear.
Collapse
Affiliation(s)
- Naoki Ohara
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, Kanagawa 257-8523, Japan.
| | | | | | | | | | | | | |
Collapse
|
9
|
Ohara N, Naito Y, Nagata T, Tachibana S, Okimoto M, Okuyama H. Dietary intake of rapeseed oil as the sole fat nutrient in wistar rats - Lack of increase in plasma lipids and renal lesions -. J Toxicol Sci 2008; 33:641-5. [DOI: 10.2131/jts.33.641] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Naoki Ohara
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center
- Open Research Center for Lipid Nutrition and Gender Specificity, Kinjo Gakuin University
| | - Yukiko Naito
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center
| | - Tomoko Nagata
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center
| | - Shigehiro Tachibana
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center
| | - Mari Okimoto
- Division of Toxicology, Hatano Research Institute, Food and Drug Safety Center
| | - Harumi Okuyama
- Laboratory of Preventive Nutraceutical Sciences, Kinjo Gakuin University College of Pharmacy
- Open Research Center for Lipid Nutrition and Gender Specificity, Kinjo Gakuin University
| |
Collapse
|
10
|
Okuyama H, Yamada K, Miyazawa D, Yasui Y, Ohara N. Dietary lipids impacts on healthy ageing. Lipids 2007; 42:821-5. [PMID: 17546469 DOI: 10.1007/s11745-007-3073-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 04/28/2007] [Indexed: 10/23/2022]
Abstract
Healthy ageing is gaining attention in the lipid nutrition field. As in vivo biomarkers of healthy ageing, we have evaluated the survival, learning/memory performance, and physical potencies in rodents fed a diet supplemented with high-linoleic acid (LNA, omega6) safflower oil or high-alpha-linolenic acid (ALA, omega3) perilla oil for long periods. The results suggested that perilla oil with a low omega6/omega3 ratio is beneficial for healthy ageing. In order to address this issue further, we determined the survival of stroke-prone SHR (SHRSP) rats fed a conventional rodent diet supplemented with 10% fat or oil. Survival was longer with omega3-rich oils compared with omega6-rich oils. However, some kinds of vegetable oils and hydrogenated oils shortened the survival of SHRSP rats to an unusual degree (ca. 40% compared with that of omega6-rich oil) that could not be accounted for by the fatty acid and phytosterol composition of the oils. The observed decrease in platelet counts was associated with pathological changes in the kidney and other organs. Dihydro-vitamin K1 is proposed as a likely candidate as a stroke-stimulating factor in hydrogenated oils. Thus, factors other than fatty acids (omega6/omega3 balance) and phytosterols must be taken into account when fats and oils are evaluated in relation to healthy ageing.
Collapse
Affiliation(s)
- Harumi Okuyama
- Laboratory of Preventive Nutraceutical Sciences, Kinjo Gakuin University College of Pharmacy, 2-1723 Omori, Moriyamaku, Nagoya, 463-8521, Japan.
| | | | | | | | | |
Collapse
|
11
|
Ohara N, Naito Y, Nagata T, Tatematsu K, Fuma SY, Tachibana S, Okuyama H. Exploration for unknown substances in rapeseed oil that shorten survival time of stroke-prone spontaneously hypertensive rats. Effects of super critical gas extraction fractions. Food Chem Toxicol 2005; 44:952-63. [PMID: 16364530 DOI: 10.1016/j.fct.2005.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 09/08/2005] [Accepted: 11/04/2005] [Indexed: 11/21/2022]
Abstract
To identify the causative substances for the shortening of survival time by rapeseed (Canola) oil in stroke-prone spontaneously hypertensive rats (SHRSP), SHRSP were fed on a standard chow supplemented with 10 w/w% soybean oil (control), rapeseed oil, one of the fractions of rapeseed oil obtained by super critical gas extraction (SCE) under a pressure of 180-bar or 350-bar, at 40 degrees C, or the residue from the extraction (with 0.5% NaCl in drinking water). In another series of experiment, SHRSP were fed for 8 weeks on the above-mentioned diets without salt loading and autopsied. Fatty acid compositions in these diets were similar, except in the soybean oil diet, and phytosterol contents were: (diet containing) 180-bar fraction>residue>rapeseed oil>350-bar fraction>soybean oil. Survival times in the rapeseed oil, 350-bar fraction and residue groups were shorter than, whereas that in the 180-bar fraction was similar to in the soybean oil group. In the 8-week feeding experiment, chronic nephropathy was found frequently in the groups other than the soybean oil group. The heart weights were higher in the rapeseed oil and residue groups. Cerebral necrosis was found in the residue group. Taken together, the followings are concluded, (1) Neither the fatty acid composition, nor the amount of phytosterols in the diets appeared to be decisive in the shortening of life. (2) SCE appeared to produce a safe (180-bar) fraction, though it failed to separate clearly the causative substances into specific fractions. (3) The factors that facilitate the genetic disease of SHRSP appear to exist in rapeseed oil. However, they might not be identical to those responsible for the life-shortening, since there were no findings common across the rapeseed oil, 350-bar and residue groups, which showed similar life-shortening.
Collapse
Affiliation(s)
- Naoki Ohara
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan.
| | | | | | | | | | | | | |
Collapse
|
12
|
WATANABE N, KIMURA F, KOJIMA F, ENDO Y, FUJIMOTO K, KIKUCHI Y. Effect of Sterols in Dietary Fats on Whole Blood Viscosity of Stroke-Prone Spontaneously Hypertensive Rats (SHRSP). J Oleo Sci 2005. [DOI: 10.5650/jos.54.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Nakamichi WATANABE
- Department of Food Science and Nutrition, Faculty of Human Ecology, Showa Women’s University
- Laboratory of Food and Bio-molecular Science, Graduate School of Agricultural Science, Tohoku University
| | - Fumiko KIMURA
- Laboratory of Food and Bio-molecular Science, Graduate School of Agricultural Science, Tohoku University
| | - Fumito KOJIMA
- Laboratory of Food and Bio-molecular Science, Graduate School of Agricultural Science, Tohoku University
| | - Yasushi ENDO
- Laboratory of Food and Bio-molecular Science, Graduate School of Agricultural Science, Tohoku University
| | - Kenshiro FUJIMOTO
- Laboratory of Food and Bio-molecular Science, Graduate School of Agricultural Science, Tohoku University
| | - Yuji KIKUCHI
- Microchannel Array Technology Team, National Food Research Institute
| |
Collapse
|
13
|
Tatematsu K, Fuma SY, Nagase T, Ichikawa Y, Fujii Y, Okuyama H. Factors other than phytosterols in some vegetable oils affect the survival of SHRSP rats. Food Chem Toxicol 2004; 42:1443-51. [PMID: 15234074 DOI: 10.1016/j.fct.2004.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2003] [Accepted: 04/12/2004] [Indexed: 11/22/2022]
Abstract
Unusual survival-shortening activities of some vegetable oils were detected in stroke-prone spontaneously hypertensive (SHRSP) rats, and phytosterol (PS) in the oils and the tissue tocopherol status have been suggested to be the factors for the activities. Here, we re-evaluated the contribution of PS to the survival-shortening, and examined the hepatic tocopherol status. A basal diet for rodents and a test oil were mixed at a 9:1 ratio, and the diet was given to male SHRSP rats upon weaning. The total and major PS contents of the diets and tissue lipids did not correlate with relative survival time. The free fatty acid fractions obtained by lipase and alkaline hydrolyses of canola oil (Can) and the original Can contained PS in comparable amounts but the free fatty acid fractions did not exhibit survival-shortening activities compared with the soybean oil (Soy) group. The activity was not detected in the ethyl acetate extracts of the aqueous phase after the hydrolysis. When a commercially available PS preparation was added to the Soy diet at an amount 2.8-fold higher than that in the Can diet, the mean survival time was shortened but was still significantly longer than that of the Can group. The hepatic tocopherol level was significantly higher in the Can group than in the hydrogenated Soy group and Soy group, but the former two groups exhibited a survival-shortening activity. These results indicate that factors other than PS, tocopherol status and fatty acid composition in some vegetable oils are critical for the survival-shortening activity observed in SHRSP rats.
Collapse
Affiliation(s)
- Kenjiro Tatematsu
- Department of Preventive Nutraceutical Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, Nagoya 467-8603, Japan
| | | | | | | | | | | |
Collapse
|
14
|
Tatematsu K, Hirose N, Ichikawa Y, Fujii Y, Takami A, Okuyama H. Nutritional Evaluation of an Inter-Esterified Perilla Oil and Lard in Comparison with Butter and Margarine Based on the Survival of Stroke-Prone Spontaneously Hypertensive (SHRSP) Rats. ACTA ACUST UNITED AC 2004. [DOI: 10.1248/jhs.50.108] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenjiro Tatematsu
- Department of Preventive Nutraceutical Sciences, Faculty of Pharmaceutical Sciences, Nagoya City University
| | - Natsuko Hirose
- Department of Preventive Nutraceutical Sciences, Faculty of Pharmaceutical Sciences, Nagoya City University
| | - Yuko Ichikawa
- Department of Preventive Nutraceutical Sciences, Faculty of Pharmaceutical Sciences, Nagoya City University
| | - Yoichi Fujii
- Department of Preventive Nutraceutical Sciences, Faculty of Pharmaceutical Sciences, Nagoya City University
| | | | - Harumi Okuyama
- Department of Preventive Nutraceutical Sciences, Faculty of Pharmaceutical Sciences, Nagoya City University
| |
Collapse
|
15
|
Ogawa H, Yamamoto K, Kamisako T, Meguro T. Phytosterol additives increase blood pressure and promote stroke onset in salt-loaded stroke-prone spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 2003; 30:919-24. [PMID: 14678230 DOI: 10.1111/j.1440-1681.2003.03939.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. To assess the effect of dietary phytosterol on stroke and the lifespan of salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP), we investigated the effects of the addition of phytosterol to soybean oil (phytosterol content: 0.3%) on stroke onset, lifespan following onset of stroke and overall lifespan compared with canola oil (phytosterol content: 0.9%). 2. Six-week-old male SHRSP were fed a test diet prepared by the addition of canola oil (CA diet), soybean oil (SO diet), soybean oil plus 0.6% phytosterol (SO + 0.06P diet) or soybean oil plus 4.5% phytosterol (SO + 0.45P diet) as a 10% fat source. 3. Systolic blood pressure (SBP) increased in the SO + 0.06P and SO + 0.45P groups compared with the SO group and the increase was dependent on the amount of phytosterol added, indicating that the addition of phytosterol to soybean oil may promote an increase in SBP in salt-loaded SHRSP. 4. The onset of stroke was shortest in the SO + 0.45P group and survival after the onset of stroke was shortest in the CA group. Consequently, the SO + 0.45P and CA groups showed marked lifespan shortening, indicating that a fivefold greater amount of phytosterol was required to produce an effect equivalent to that of canola oil. 5. Investigation of the mRNA expression of ATP-binding cassette (ABC) transporters involved in intestinal phytosterol absorption indicated significant decreases in the intestinal mRNA expression of Abcg5 and Abcg8 in SHRSP and Wistar-Kyoto rats compared with Wistar rats. 6. In conclusion, the addition of phytosterol to soybean oil elevated SBP and promoted the onset of stroke, which may cause a reduction in survival time. However, a fivefold greater amount of phytosterol was required to produce an effect that was equivalent to the survival time-shortening effect of canola oil. The significant decrease in the intestinal mRNA expression of Abcg5 and Abcg8 in SHRSP may be responsible, at least in part, for the unfavourable effects observed following the addition of phytosterol.
Collapse
MESH Headings
- ATP-Binding Cassette Transporters/drug effects
- ATP-Binding Cassette Transporters/genetics
- Animals
- Dose-Response Relationship, Drug
- Eating/physiology
- Fat Substitutes/administration & dosage
- Fat Substitutes/adverse effects
- Fat Substitutes/analysis
- Fatty Acids, Monounsaturated/administration & dosage
- Fatty Acids, Monounsaturated/adverse effects
- Fatty Acids, Monounsaturated/pharmacokinetics
- Gene Expression/drug effects
- Gene Expression/genetics
- Hypertension/chemically induced
- Hypertension/complications
- Intestines/anatomy & histology
- Intestines/chemistry
- Intestines/drug effects
- Male
- Phytosterols/administration & dosage
- Phytosterols/adverse effects
- Phytosterols/analysis
- RNA, Messenger/chemistry
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- Rapeseed Oil
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Rats, Wistar
- Sodium Chloride, Dietary/pharmacology
- Soybean Oil/administration & dosage
- Soybean Oil/chemistry
- Soybean Oil/pharmacokinetics
- Stroke/chemically induced
- Stroke/complications
- Stroke/mortality
Collapse
Affiliation(s)
- Hiroshi Ogawa
- Department of Hygiene and Division of Basic Medical Science, Kinki University School of Medicine, Osaka-Sayama City, Osaka, Japan.
| | | | | | | |
Collapse
|
16
|
Naito Y, Nagata T, Takano Y, Nagatsu T, Ohara N. Rapeseed oil ingestion and exacerbation of hypertension-related conditions in stroke prone spontaneously hypertensive rats. Toxicology 2003; 187:205-16. [PMID: 12699909 DOI: 10.1016/s0300-483x(03)00052-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Two groups of 20 stroke prone spontaneously hypertensive rats (SHRSP) at 5 weeks old were fed a diet containing 10 w/w% rapeseed (canola) oil or soybean oil as the only dietary fat, and given drinking water containing 1% NaCl. Life span of the canola oil group (62+/-2 days) was shorter than that of the soybean oil group (68+/-3 days). Stroke-related symptoms were observed in every animal, but the onset of those in the canola oil group, at 47+/-1 days after starting the administration was earlier than that in the soybean oil group, 52+/-2 days. Incidence of cerebral hemorrhage was similar in these groups, and no differences were found between lesions of organs in the groups. In another experiment, two groups of ten SHRSP at 5 weeks of age were fed the defatted diet and given canola oil or soybean oil by gavage at 10 w/w% of consumed food for 4 weeks without NaCl loading. After the 4-week administration, mean systolic blood pressure in the canola oil group and the soybean oil group were 233+/-2 and 223+/-0.3 mmHg, respectively. Phytosterol levels in both plasma and erythrocyte membranes reflected those contained in the oils ingested. Na(+), K(+)-ATPase activities in the brain, heart and kidney were enhanced in the canola oil group. These results indicate that promotion of hypertension-related deterioration in organs is likely to have relevance to the short life span in the canola oil group. Enhanced Na(+), K(+)-ATPase activity by phytosterols in the oil ingested may play a role in these changes.
Collapse
Affiliation(s)
- Yukiko Naito
- Laboratory of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, Kanagawa 257-8523, Japan
| | | | | | | | | |
Collapse
|
17
|
WATANABE N, ENDO Y, FUJIMOTO K. Effects of Fat Mixtures Similar to Japanese Diet on the Life Span of Stroke-Prone Spontaneously Hypertensive Rats(SHRSP). J Oleo Sci 2002. [DOI: 10.5650/jos.51.183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
18
|
Du C, Sato A, Watanabe S, Ikemoto A, Fujii Y, Okuyama H. Effect of dietary oils enriched with n-3 fatty acids on survival of mice. J Nutr Biochem 2001; 12:474-480. [PMID: 11834206 DOI: 10.1016/s0955-2863(01)00163-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Female mice were fed a conventional diet, shifted at 119 days of age to a diet supplemented with 10 wt % lard (Lar), high-linoleic (n-6) safflower oil (Saf), rapeseed oil (low-erucic, Rap), high-alpha-linolenic (n-3) perilla oil (Per) or a mixture (1:9) of ethyl docosahexaenoate (n-3) and soybean oil (DHA/Soy). Weight gain was less in the Per group than in the other groups at 497 days of age. In the Rap group, proteinuria was more severe than in the Saf, Per and DHA/Soy group, and hepatic triacylglycerol accumulation was greater than in the other groups. The mean survival time of the DHA/Soy group (753 days) was significantly longer than in the Lar group (672 days) and Saf group (689 days); the differences among other groups (e.g., 701 days in the Per group and 712 days in the Rap group) were not statistically significant. Although DHA is more susceptible to auto-oxidation than other major fatty acids in the air, an oil containing DHA was found to increase the survival of mice. Rapeseed oil that decreases the survival time of SHRSP rats was found to be safe in the mouse strain used in this study when survival was an end point.
Collapse
Affiliation(s)
- C Du
- Faculty of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, 467-8603, Nagoya, Japan
| | | | | | | | | | | |
Collapse
|
19
|
Miyazaki M, Kim YC, Gray-Keller MP, Attie AD, Ntambi JM. The biosynthesis of hepatic cholesterol esters and triglycerides is impaired in mice with a disruption of the gene for stearoyl-CoA desaturase 1. J Biol Chem 2000; 275:30132-8. [PMID: 10899171 DOI: 10.1074/jbc.m005488200] [Citation(s) in RCA: 360] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Stearoyl-CoA desaturase (SCD) is a microsomal enzyme required for the biosynthesis of oleate and palmitoleate, which are the major monounsaturated fatty acids of membrane phospholipids, triglycerides, and cholesterol esters. Two well characterized isoforms of SCD, SCD1 and SCD2, exist in the mouse. Most mouse tissues express SCD1 and 2 with the exception of the liver, which expresses mainly the SCD1 isoform. We found that asebia mice homozygous for a natural mutation of the gene for SCD1 (SCD-/-) are deficient in hepatic cholesterol esters and triglycerides despite the presence of normal activities of acyl-CoA:cholesterol acyltransferase and glycerol phosphate acyltransferase, the enzymes responsible for cholesterol ester and triglyceride synthesis, respectively, in the liver of these mice. Feeding diets supplemented with triolein or tripalmitolein to the SCD-/- mice resulted in an increase in the levels of 16:1 and 18:1 in the liver but failed to restore the 18:1 and 16:1 levels of the cholesterol ester and triglycerides to the levels found in normal mice. The SCD-/- mouse had very low levels of triglycerides in the VLDL and LDL lipoprotein fractions compared with the normal animal. Transient transfection of an SCD1 expression vector into Chinese hamster ovary cells resulted in increased SCD activity and esterification of cholesterol to cholesterol esters. Taken together, our observations demonstrate that the oleoyl-CoA and palmitoleyl-CoA produced by SCD1 are necessary to synthesize enough cholesterol esters and triglycerides in the liver and suggest that regulation of SCD1 activity plays an important role in mechanisms of cellular cholesterol homeostasis.
Collapse
Affiliation(s)
- M Miyazaki
- Departments of Biochemistry and Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | | | |
Collapse
|
20
|
Naito Y, Kasama K, Yoshida H, Ohara N. Thirteen-week dietary intake of rapeseed oil or soybean oil as the only dietary fat in Wistar Kyoto rats-change in blood pressure. Food Chem Toxicol 2000; 38:811-6. [PMID: 10930702 DOI: 10.1016/s0278-6915(00)00076-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Wistar Kyoto (WKY) rats were fed a diet containing 10% rapeseed (canola) oil or soybean oil as the only dietary fat for 13 weeks. From week 5 of feeding, systolic blood pressure of the canola oil group became higher than that of the soybean oil group. The 13-week canola oil intake increased plasma levels of Na(+) and lipids, and decreased the level of K(+) compared to those in the soybean oil group. The canola oil group also showed a high density of neutrophils and a low density of platelets compared to the soybean oil group. Moreover, the activities of catalase and superoxide dismutase in the hepatic cytosol were depressed in the canola oil group. The mechanisms for the higher blood pressure are unclear. However, an increase in body fluid via activation of Na(+) pump or Na(+), K(+)-ATPase and/or a blunt endothelium-dependent vasodilation by increased superoxide might have relevance to the elevated blood pressure. The increased plasma lipids and the changes in the densities of platelets and neutrophils appear not to be critical in WKY rats. However, these would tend to promote peripheral vascular lesions in the strains, such as spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats, which are prone to present atheroscrelotic vascular injury.
Collapse
Affiliation(s)
- Y Naito
- Department of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Hadano, Kanagawa, Japan
| | | | | | | |
Collapse
|
21
|
Naito Y, Konishi C, Ohara N. Blood coagulation and osmolar tolerance of erythrocytes in stroke-prone spontaneously hypertensive rats given rapeseed oil or soybean oil as the only dietary fat. Toxicol Lett 2000; 116:209-15. [PMID: 10996482 DOI: 10.1016/s0378-4274(00)00224-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The life-span of stroke-prone spontaneously hypertensive rats (SHRSP) has been reported to become shorter by ingestion of some vegetable oils, including rapeseed oil, when given as the sole dietary fat. The present study was undertaken to examine if the ingestion of rapeseed (canola) oil affects blood coagulating time and erythrocyte membranes. Namely, SHRSP were orally given canola oil or soybean oil as the only dietary fat (10% of diet) for 4 weeks. After the 4-week feeding, activated partial thromboplastin time (APTT) in the canola oil group (19.9+/-0.5 s, N=8) was significantly shorter than that in the soybean oil group (21.6+/-0.6 s, N=8, P<0. 05), though there were no between-group differences in plasma Ca(2+), platelet density and platelet aggregation. Erythrocytes from the canola oil group were less tolerant to low osmotic pressure than those from soybean oil group; the EC(50) values for NaCl concentration to cause hemolysis were 0.42+/-0.004 and 0.40+/-0.005% in the canola oil and the soybean oil groups, respectively (N=10, P<0.01). The canola oil-induced shortening of blood coagulation time and increased fragility in erythrocyte membranes may have relevance to the promotion of strokes in SHRSP.
Collapse
Affiliation(s)
- Y Naito
- Department of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, 257-8523, Kanagawa, Japan
| | | | | |
Collapse
|
22
|
Naito Y, Yoshida H, Nagata T, Tanaka A, Ono H, Ohara N. Dietary intake of rapeseed oil or soybean oil as the only fat nutrient in spontaneously hypertensive rats and Wistar Kyoto rats - blood pressure and pathophysiology. Toxicology 2000; 146:197-208. [PMID: 10814852 DOI: 10.1016/s0300-483x(00)00175-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats were fed a diet containing 10% rapeseed (canola) oil or soybean oil as dietary fat, and given drinking water containing 1% NaCl for 26 weeks. From the 10th week and later, systolic blood pressure in the canola oil group became higher than that in the soybean oil group in each strain. The 26-week feeding of canola oil increased plasma lipids and the neutrophil counts, and decreased the platelet counts. In the canola oil group the heart and kidney tended to become heavier with sporadically found histologic lesions. Acetylcholine- and nitroprusside-induced dilating responses of isolated aortic rings and norepinephrine- and veratridine-induced increases in vascular tone of isolated perfused mesenteric arteries were not different between the two groups in each strain. These results demonstrate that canola oil intake as the only dietary fat elevates blood pressure of the rat provided with drinking water containing 1% NaCl through mechanisms other than blunt dilating response of the blood vessel due to dysfunction of the endothelium or vascular smooth muscle, the augmented response to norepinephrine in the arteries and the increased amount of norepinephrine in the sympathetic nerve endings. The lesions in the heart and kidney in SHR may be related to a strain-specific peripheral vascular deterioration which was disclosed by the extremely high blood pressure in the canola oil group.
Collapse
Affiliation(s)
- Y Naito
- Department of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, Kanagawa, Japan
| | | | | | | | | | | |
Collapse
|
23
|
Ratnayake WM, L'Abbé MR, Mueller R, Hayward S, Plouffe L, Hollywood R, Trick K. Vegetable oils high in phytosterols make erythrocytes less deformable and shorten the life span of stroke-prone spontaneously hypertensive rats. J Nutr 2000; 130:1166-78. [PMID: 10801914 DOI: 10.1093/jn/130.5.1166] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous studies have shown that canola oil (CA), compared with soybean oil (SO), shortens the life span of stroke-prone spontaneously hypertensive (SHRSP) rats, a widely used model for hemorrhagic stroke. SHRSP rats are highly sensitive to dietary cholesterol manipulations because a deficiency of membrane cholesterol makes their cell membranes weak and fragile. Phytosterols, abundant in CA but not in SO, can inhibit the absorption of cholesterol and also replace a part of cholesterol in cell membranes. This study was performed to determine whether the high concentration of phytosterols in CA might account for its life-shortening effect on SHRSP rats. Male, 35-d-old SHRSP rats (n = 28/group) were fed semipurified diets containing CA, SO, CA fortified with phytosterols (canola oil + phytosterols, CA + P), SO fortified with phytosterols (soybean oil + phytosterols, SO + P), corn oil (CO), olive oil (OO) or a fat blend that mimicked the fat composition of a representative Canadian diet (Canadian fat mimic, CFM; 10 g/100 g diet). These fats provided 97, 36, 207, 201, 114, 27 and 27 mg phytosterols/100 g diet, respectively. Ten rats from each group were killed after 30-32 d for blood and tissue analyses. The remaining rats (18/group) were used for determination of life span. The life span of SHRSP rats fed the high phytosterol oils (CA, CA + P, SO + P and CO) was significantly (P<0.05) shorter than that of CFM- and SO-fed rats. At 30-32 d, the groups fed the high phytosterol oils had greater levels of phytosterols and significantly (P<0.05) higher ratios of phytosterols/cholesterol in plasma, RBC, liver and kidney, and a significantly (P<0.05) lower RBC membrane deformabilty index than the groups fed oils low in phytosterols (SO, OO and CFM). The mean survival times were correlated with RBC deformability index (r(2) = 0.91, P = 0.0033) and cholesterol concentration (r(2) = 0.94, P = 0.0016), and inversely correlated with RBC phytosterol concentration (r(2) = 0.58, P = 0.0798) and phytosterols/cholesterol (r(2) = 0.65, P = 0.0579), except in the OO group. This study suggests that the high concentration of phytosterols in CA and the addition of phytosterols to other fats make the cell membrane more rigid, which might be a factor contributing to the shortened life span of SHRSP rats.
Collapse
Affiliation(s)
- W M Ratnayake
- Nutrition Research Division, Food Directorate, Health Protection Branch, Health Canada, Banting Research Centre, Ottawa, ON, Canada K1A 0L2
| | | | | | | | | | | | | |
Collapse
|
24
|
Ratnayake WM, Plouffe L, Hollywood R, L'Abbé MR, Hidiroglou N, Sarwar G, Mueller R. Influence of sources of dietary oils on the life span of stroke-prone spontaneously hypertensive rats. Lipids 2000; 35:409-20. [PMID: 10858026 DOI: 10.1007/s11745-000-539-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n = 23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4+/-4.0 d) was not significantly different (P > 0.05) from those fed low-sulfur canola oil (89.7+/-8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6-13 d, P < 0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times,indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.
Collapse
Affiliation(s)
- W M Ratnayake
- Nutrition Research Division, Food Directorate, Health Protection Branch, Health Canada, Ottawa, Ontario.
| | | | | | | | | | | | | |
Collapse
|
25
|
Miyazaki M, Takemura N, Watanabe S, Hata N, Misawa Y, Okuyama H. Dietary docosahexaenoic acid ameliorates, but rapeseed oil and safflower oil accelerate renal injury in stroke-prone spontaneously hypertensive rats as compared with soybean oil, which is associated with expression for renal transforming growth factor-beta, fibronectin and renin. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1483:101-10. [PMID: 10601699 DOI: 10.1016/s1388-1981(99)00180-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have noted that n-3 fatty acid-rich oils, such as fish oil, perilla oil and flaxseed oil as well as ethyl docosahexaenoate (DHA) prolonged the survival time of stroke-prone spontaneously hypertensive rats (SHRSP) rats by approximately 10% as compared with linoleate (n-6)-rich safflower oil. Rapeseed oil with a relatively low n-6/n-3 ratio unusually shortened the survival time by approximately 40%, suggesting the presence of minor components unfavorable to SHRSP rats. This study examined the effects of dietary oils and DHA on renal injury and gene expression related to renal injury in SHRSP rats. Rats fed rapeseed oil- and safflower oil-supplemented diets developed more severe proteinuria than those fed soybean oil-supplemented diet used as a control, but there were no significant differences in blood pressure. In contrast, the DHA-supplemented diet inhibited the development of proteinuria and suppressed hypertension. The mRNA levels for renal TGF-beta, fibronectin and renin were higher in the rapeseed oil and safflower oil groups after 9 weeks of feeding of the experimental diet than in the soybean oil and DHA groups. The fatty acid composition of kidney phospholipids was markedly affected by these diets. These results indicate that the renal injury observed in the groups fed safflower oil with a high n-6/n-3 ratio and rapeseed oil with presumed minor components is accompanied by increased expression of the TGF-beta, renin and fibronectin genes, and that dietary DHA suppresses renal injury and gene expression as compared with soybean oil.
Collapse
Affiliation(s)
- M Miyazaki
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, Nagoya, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Innis SM, Dyer RA. Dietary canola oil alters hematological indices and blood lipids in neonatal piglets fed formula. J Nutr 1999; 129:1261-8. [PMID: 10395585 DOI: 10.1093/jn/129.7.1261] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study was undertaken to determine the effects of canola oil on platelet characteristics, blood lipids and growth in exclusively formula-fed piglets. Piglets were fed from birth to 10 or 18 d with formula containing 51% energy from fat, with 100% fat as canola or soybean oil; 26% soybean, 59% high oleic acid sunflower and 12% flax oil (canola mimic); or 26% canola (canola blend) or soybean (soybean blend) with high oleic acid sunflower, palm and coconut oil. The canola mimic provided similar carbon chain 16 and 18 fatty acids without the sterol or 20:1 and erucic acid (22:1) of canola oil. The oil blends provided formula resembling infant formulas but with higher 16:0 and lower unsaturated fatty acid levels than in canola or soybean oil. Body weight, weight gain and heart and liver weight were not different after 10 or 18 d feeding canola when compared to soybean oil alone or blended oil formulas. Piglets fed formulas with 100% canola oil had lower platelet counts than piglets fed formula soybean oil or the canola oil mimic. Platelet counts were lower, and platelet distribution width and volume were higher, when formulas with 100% canola or soybean rather than the blended oil formulas were fed. The results show that formula fat composition influences the developing hematological system and that canola oil suppresses the normal developmental increase in platelet count in piglets by a mechanism apparently unrelated to the formula 16:0, 18:1, 18:2(n-6) or 18:3(n-3), or plasma phospholipid 20:4(n-6) or 20:5(n-3).
Collapse
Affiliation(s)
- S M Innis
- Department of Paediatrics, University of British Columbia, Vancouver, Canada V5Z 4H4
| | | |
Collapse
|