Clinical and Experimental Pharmacology and Physiology (2003) 30, 470–475DIETARY MUSHROOM (PLEUROTUS OSTREATUS) AMELIORATES ATHEROGENIC LIPID IN HYPERCHOLESTEROLAEMIC RATS Shahdat Hossain,*† Michio Hashimoto,* Emran Kabir Choudhury,§ Nuhu Alam,‡ Shahjalal Hussain,¶ Moynul Hasan,∫ Shahabuddin Kabir Choudhury# and Ishtiaq Mahmud§ *Department of Physiology, Shimane Medical University, Shimane, Japan, Departments of †Biochemistry and Molecular Biology, ‡Botany and #Pharmacy, Jahangirnagar University, §Department of Biochemistry & Molecular Biology, University of Dhaka, ¶International Center for Diarrheal Diseases and Research and ∫Center for Scientific and Industrial Research, Dhaka, Bangladesh SUMMARY 1. The effects of edible oyster mushroom Pleurotus ostreatus on plasma and liver lipid profiles and on the plasma total antioxidant status were estimated in hyper- and normocholesterolaemic Long Evans rats. 2. The feeding of 5% powder of the fruiting bodies of P. ostreatus mushrooms to hypercholesterolaemic rats reduced their plasma total cholesterol by approximately 28%, lowdensity lipoprotein–cholesterol by approximately 55%, triglyceride by approximately 34%, non-esterified fatty acid by approximately 30% and total liver cholesterol levels by > 34%, with a concurrent increase in plasma high-density lipoprotein– cholesterol concentration of > 21%. However, these effects were not observed in mushroom-fed normocholesterolaemic rats. 3. Mushroom feeding significantly increased plasma fatty acid unsaturation in both normo- and hypercholesterolaemic rats. 4. Plasma total anti-oxidant status, as estimated by the oxidation of 2,2-azino-bis-[3-ethylbenz-thiazoline-6-sulphonic-acid], was significantly decreased in mushroom-fed hypercholesterolaemic rats, concomitant with a decrease in plasma total cholesterol. 5. The present study suggests that 5% P. ostreatus supplementation provides health benefits, at least partially, by acting on the atherogenic lipid profile in the hypercholesterolaemic condition. Key words: atherogenic lipid profile, hypercholesterolaemia, Pleurotus ostreatus, total anti-oxidant status, unsaturation index. INTRODUCTION An additional economic burden becomes inevitable in countries continually struggling against disease and malnutrition. Although mushrooms are increasingly being recognized as important food products for their significant role in human health, nutrition and disease, their consumption in many developing countries, particularly in Bangladesh, is extremely limited, one reason probably being that the health benefits derived from various edible mushrooms are largely unknown. Thus, one of the objectives of the present study was to generate awareness of the beneficial effects of edible mushrooms, particularly of Pleurotus ostreatus, on hypercholesterolaemia, which poses serious health problems in both developed and developing countries. Mushrooms provide a wide variety of physiologically ameliorative active components: Pleurotus sajo-caju exhibits hypotensive effects through its active ingredients, which affect the renin– angiotensin system;1 Trichloma mongolcium produces vasorelaxation because of its lectin content;2 P. ostreatus possesses antitumour activity3 and hypoglycaemic effects in experimentally induced diabetes;4 Lentinus edodes (Shitake) and Grifola frondosa (Mitake) mushrooms have antihypertensive effects in spontaneously hypertensive rats;5 and Agaricus bisporous decreases serum low-density lipoprotein–cholesterol (LDL-C) by increasing the expression of low-density lipoprotein (LDL) receptor mRNA levels and LDL receptor activity.6 Considerable experimental evidence suggests that one of the most important food components that helps reduce serum cholesterol is its polyunsaturated fatty acid (PUFA) content.7–11 The fatty acid pattern of three mushroom species, namely P. ostreatus, Ganoderma lucidium and Agaricus bisporous, have been analysed.12 Of these, P. ostreatus contains the highest amount of n-3 linolenic acid (LNA; C18 : 3, n-3: 11.6 ± 0.2, 1.60 ± 0.25 and 5.20 ± 0.32 g/g dry weight for P. ostreatus, G. lucidium and A. bisporous, respectively) and the least amount of arachidonic acid (AA; C20 : 4, n-6: 10.8 ± 0.5, 13.0 ± 1.6 and 64.0 ± 0.5 g/g dry weight for P. ostreatus, G. lucidium and A. bisporous, respectively) and lipid peroxidation products (LPO; 1.60 ± 0.10, 2.25 ± 0.12 and 9.2 ± 1.0 nmol/mg protein for P. ostreatus, G. lucidium and A. bisporous, respectively). The latter two parameters (AA and LPO) ‘exacerbate platelet functions’,13 whereas LNA acts as a precursor of the physiologically important PUFA, such as eicosapentaenoic acid (EPA; C20 : 5, n-3) and docosahexae- Correspondence: Michio Hashimoto, Department of Physiology, Shimane Medical University, Izumo, Shimane 693-8501, Japan. Email:
[email protected] Received 14 November 2002; revision 14 January 2003; accepted 16 February 2003. The composition of the mineral mixture added to the diet was as follows (in g/100 g vitamin mixture): calcium gluconate 28. METHODS Animals Forty young female Long Evans rats (97 ± 11 g) were used in the present study.15.25. wheat bran 19. STA.4. Plasma triglyceride (TG) was also measured using a commercially available reagent kit (TG-test. The assay relies on the ability of anti-oxidants in the plasma to inhibit oxidation of 2. under 12 h dark– light cycles (light 8.00 h). Plasma fatty acid measurements Plasma fatty acids were determined by the one-step method of Lepage and Roy. nicotinic acid 12. UK). the temperature was then raised 2ЊC/min to 240ЊC and maintained there for 30 min. ostreatus mushrooms were purchased locally from the Japancollaborated Mushroom Cultivation Center (Savar. The composition of the vitamin mixture in the diet was as follows (in g/100 g vitamin mixture): retinyl acetate 9. Hewlett Packard). The final plasma antioxidant concentration was obtained from a calibration curve constructed with 6-hydroxy-2.2 Lipid peroxide (nmol/mg protein) 1. The temperature was then increased 5ЊC/3 min to 255ЊC and maintained for 5 min. LLA. KI 9. FeSO4 0.125. pyridoxine HCl 1. Total cholesterol was analysed with a commercially available analytical kit (Total Cholesterol E-test. mineral mixture 0.00 h.0 ϫ 10−4.0. as described previously. NaF 2.2Ј-azino-bis-[3-ethylbenz-thiazoline-6-sulphonic-acid acid] (ABTS) to ABTS+ by peroxidase (metomyoglobin) and H2O2. detector temperature 250ЊC. ascorbic acid 24. PLA. The powder was mixed with the basal diet. Low-density lipoprotein–cholesterol was calculated as follows: LDL-C = (TC − ((TG/5) + HDL-C)) and VLDL-C was calculated as: VLDL-C = (TC − (HDL-C + LDL-C)) Plasma non-esterified fatty acid (NEFA) concentrations were measured with a commercially available kit (Wako Pure Chemical Industries). The major fatty acid composition. Rats were fed for 5 weeks. casein 8.5. carrier (He) flow 2. stearic acid. lipid peroxide and protein content of the powder is given in Table 1. dark 20.5 ϫ 10−2. which may relate to the plasma cholesterol pool. Wako Pure Chemical Industries.0 mL/ min. The composition of the basal diet was as follows (in g/100 g): wheat flour 50. double bonds per each fatty acid)/100. K2HPO4 17. NC + MS). Bangladesh). Antrim. Rats were fed a basal diet containing: (i) no mushrooms (normocholesterolaemic control rats. (ii) 5% powder of P.8-tetramethylchroman-2-carboxylic acid as a standard. USA). its beneficial effects on plasma and liver lipid profiles in relation to TAS were investigated in normoand hypercholesterolaemic rats. SeO2 3.60 ± 0. the anti-oxidants in the plasma suppress absorbance at 600 nm to a degree that is proportional to their concentration. total lipids were extracted with chloroform/methanol (2 : 1 v/v) according to the method of Folch et al. AA. inositol 47. ostreatus improves hypercholesterolaemia noic acid (DHA.05. ostreatus mushroom (normocholesterolaemic + mushroom rats.64 ± 0. Liver total cholesterol analysis To determine the liver cholesterol content. To identify the peaks.95. vitamin K 0. Furthermore. riboflavin 2. oleic acid. soybean oil 1.17 these two fatty acids play an important role in the physiological functions of the cardiovascular system.0 ϫ 10−4. cholecalciferol 1. arachidonic acid. Avondale. LNA. The initial temperature of 180ЊC was held for 4 min after injection. table salt 0. USI.6 ± 0. Wako Pure Chemical Industries).6. are not available. using assay kits for TC and HDL-C (Total Cholesterol E-test and HDL-C test. the effects of mushrooms on the plasma fatty acid profile and total anti-oxidant status (TAS) of experimental subjects.06.18 by direct transmethylation. ␣-tocopherol acetate 0.13 using gas chromatography (model 5890. Hewlett Packard. Because of the low AA and LPO content of P. Dhaka.01 Data are the mean±SEM with triplicate determinations.5 ϫ 10−4. D-calcium pantothenate 9.19 The extract was passed through glass pasteur pipettes filled with glass wool.125. palmitic acid.8 ± 0.10 Protein (mg/g tissue) 11.3. gas chromatography–mass spectrometry (GC-MS) was performed on a JEOL JMS mass spectrometer (model D300.5 ϫ 10−3.7. whereas high-density lipoprotein (HDL)– Table 1 Fatty acid profile and lipid peroxide and protein the contents of Pleurotus ostreatus mushroom Fatty acid composition (g/g) OLA LLA LNA 363 ± 6 533 ± 35 11.5 PLA 510 ± 37 STA 184 ± 13 AA 10. KCl 12. The amount of ABTS+ produced is monitored by reading the absorbance at 600 nm. ostreatus. egg white 10. OLA. Determination of TAS Total anti-oxidant status was determined spectrophotometrically with a commercially available kit (Randox Laboratories.5 USI 1.25.0.P. The chromatograms were identified and quantified by a JEOL JMA-2000S mass data analysis system (Nippon Denshi). rice polishings 11. .55. Under these reaction conditions.20 Chemical analysis Plasma total cholesterol (TC) was measured enzymatically using the cholesterol oxidase assay. Osaka. The fruiting bodies were dried in sunlight and crushed into a powder.5 ϫ 10−3.14 There is considerable data supporting the belief that the health benefit obtained through the lowering of blood cholesterol may derive from the effects of EPA and DHA.5. Egg white was replaced with 5% dried mushroom powder for diets fed to the mushroom-fed groups (NC + MS and HC + MS). Osaka. or (iv) 1% cholesterol plus 5% mushroom powder (HC + MS rats).2. PA. 471 cholesterol (HDL-C) was measured by the same procedure after precipiting LDL and very low-density lipoprotein (VLDL) with magnesium sulphate and phosphotungstic acid. Mushroom collection Fresh P.6 ± 1.00–08. folic acid 9.16 In addition to their roles in the development and function of the central nervous system. thiamine HCl 2.2 ϫ 10−3.00–20.0. unsaturation index calculated as (mol% of each (poly)unsaturated fatty acid ϫ no.5 ϫ 10−4. hypercholesterolaemic (HC) rats). Rats were housed in an animal room at 23 ± 2ЊC. dual flame ionization detectors and an autosampler (model HP 7673. The extract was then dried extensively with a stream of N2 gas. However. Protein was measured according to the method of Lowry et al.30. CaCO3 26.5. linolenic acid. The conditions for measurement were as follows: injection temperature 200ЊC. Japan). n-3).6. NC). vitamin mixture 0. C22 : 6.0 ϫ 10−4. then divided randomly into four groups.6. Na-molybdate 3. Nippon Denshi. (iii) 1% cholesterol (high cholesterol. linoleic acid. CrSO2 1. CuSO4 0. MgSO4 12. Wako Pure Chemical Industries). data on the effects of mushroom feeding on normocholesterolaemic animals are scarce. cyanocobalamine 9.4. The ABTS+ has a relatively stable blue–green colour. Japan) equipped with a chemical ionizer. MnSO4 0. 0 ± 0. compared with NC rats. Values in the same row with different superscripts are significantly different at P < 0.9 ± 1. normocholesterolaemic rats.32 ± 0. n-3) USI NC (n = 5) 34.3a 46.5 and 123 ± 10.b 29.0 ± 7.01a 0.5 ± 0.5%.35 ± 0.0a0 1. respectively.0 ± 0.4a00 HC (n = 10) 105 ± 5b00 33.0 ± 3.and VLDL-C levels in NC + MS rats did not change compared with NC rats.5 ± 1.13 ± 0.2 ± 3. VLDL-C. Plasma HDL-C in HC + MS rats increased significantly (P < 0.9c0 0.5 ± 1.0 ± 4.0 ± 4.0a00 1.95a 0.and 8.6 ± 2.and very low-density lipoprotein– cholesterol.0 ± 4.0b0 15. Plasma TG levels in NC + MS and HC rats did not change compared with NC rats. NC + MS.5a00 29.15a 1.30 ± 0. HC + MS.and VLDL-C decreased significantly in HC + MS rats (by 55 and 32. Plasma LDL.40 ± 0.b 0.3b0 0. Both LDL.04a 2.0a0 101 ± 11a0 1.9a0 43. n-3) Docosapentaenoic acid (C22 : 5.20 ± 0. In HC rats.03c Results are mean±SEM. the addition of 1% cholesterol to the diet increased NEFA levels quantitatively. normocholesterolaemic control rats.5 ± 1.8 ± 2.04b HC (n = 5) 31. low.b0 6.0 ± 1.02a NC + MS (n = 5) 29.8a00 34.01c 25. in HC + MS rats. Plasma HDL-C in NC + MS rats increased slightly.b 18. Berkely. mushroom-fed normocholesterolaemic rats.62 ± 0.0 ± 3.0 and 140 ± 10. Plasma HDL-C levels were not affected in HC rats compared with NC rats. RESULTS Effects of mushroom feeding on bodyweight There were no significant differences in bodyweight after 5 weeks between NC and NC + MS rats (151 ± 9.5 ± 1.0b0 15.8-fold compared with NC and NC + MS rats.8 ± 2.5a0 18.01b 0.b 26. Effects of mushroom feeding on plasma levels of TC and lipoprotein–cholesterol Plasma TC concentrations in NC and HC rats after mushroom feeding for 5 weeks are given in Table 2. double bond(s) per fatty acid))/100).0a.56 ± 0.8b0 20.02a 0.10b 30.7a.7a00 97.0 ± 3.60 ± 0.15a. n-9) Linoleic acid (C18 : 2.0 ± 0. Plasma TC concen- Table 2 Effects of dietary Pleurotus ostreatus mushroom on plasma and liver lipid profiles of normo. mushroom-fed hypercholesterolaemic rats.0b0 1. HC. Plasma NEFA in NC + MS rats was not affected.0c0 13.80a 53. NEFA.5 ± 0. TG.01a 0.03a 2.05 (one-way ANOVA then Fisher’s PLSD for post hoc comparison). triglyceride.02a 2.0 ± 0. P < 0.0 ± 1.50 ± 0. HC. total cholesterol.0 ± 0.23 ± 0. high (1%) cholesterol-fed hypercholesterolaemic rats.0c0 40.5a 0.6a 27. TC in HC + MS rats decreased by 28% compared with HC rats. however.b 0.5 ± 1.and hypercholesterolaemic rats Parameters Plasma parameters TC (mg/dL) HDL-C (mg/dL) LDL-C (mg/dL) VLDL-C (mg/dL) TG (mg/dL) NEFA (mmol/L) Liver parameters Cholesterol (g/mg protein) NC (n = 10) 53. In HC rats.05 ± 0.55 ± 0. NC. n-3) Docosahexaenoic acid (C22 : 6. USI. TC increased by 98% compared with levels in NC rats. calculated as ((⌺ (mol% of each poly(unsaturated) fatty acid ϫ no.6. VLDL-C did not change compared with NC and NC + MS rats.and hypercholesterolaemic rats Fatty acid (mg/dL) Palmitic acid (C16 : 0) Stearic acid (C18 : 0) Oleic acid (C18 : 1.5 g.03a 2.1b0 20.50 ± 0. palsma TG concentrations decreased by 34%. n-6) Linolenic acid (C18 : 3. non-esterified fatty acid.0 ± 1. n-6) Eicosapentaenoic acid (C20 : 5.b 19.02b 23.30 ± 0.23 ± 0. LDL-C.30 ± 0. Plasma LDL-C in 1%-cholesterolfed HC rats increased 7.05 was considered statistically significant. respectively.55 ± 0.5a00 7.5b0 67.5 ± 1.0 ± 2.10a. CA.0 ± 1. Table 3 Effect of dietary Pleurotus ostreatus mushroom on plasma fatty acid profile of normo. unsaturation index. respectively) compared with HC rats.5 ± 1. NC.02b 26.12a 20.9b0 0.0a00 93.1 ± 2.85 ± 0.9 ± 1. mushroom-fed normocholesterolaemic rats.09a 1.05) compared with HC rats. respectively).0 ± 0. HDL-C.0b0 24. however.0 ± 10.08a 1.9c0 13.04b HC + MS (n = 5) 24. trations in NC + MS rats were not affected by mushroom feeding.0 ± 5.5b0 HC + MS (n = 10) 76.85 ± 0. but not significantly.0a. USA). n-3) Arachidonic acid (C20 : 4.0 ± 0.4 ± 1.3b0 34.20 ± 0.21 ± 0. However. TC.5 g.1a0 39. high (1%) cholesterol-fed hypercholesterolaemic rats.0 ± 2.05a 19.1 ± 1. respectively) or between HC and HC + MS rats (155 ± 10.75 ± 0.6a.0 ± 2.0 ± 1. but not Statistical analysis Results are expressed as the mean±SEM.05 (one-way ANOVA then Fisher’s PLSD for post hoc comparison). high-. Values in the same row that do not share a common superscript are significantly different at P < 0.10a 1.4a. The effects of mushroom feeding on plasma NEFA in normoand hypercholesterolaemia are given in Table 2. NC + MS. HC + MS.9a00 NC + MS (n = 10) 58.70 ± 0. Data were subjected to ANOVA then to Fisher’s PLSD test for post hoc comparison and correlation was analysed by simple regression analysis using the computer program StatViewTM II (Abacus Concepts.6b0 0.472 S Hossain et al.2a 16. . mushroom-fed hypercholesterolaemic rats.7a0 Results are the mean±SEM.5a0 17. In contrast.30 who fed rats a high cholesterol (0. NC + MS (᭹).P. because cholesterol feeding itself increases bile secretion by approximately three. rats..55%) and showed a 1. The mechanism by which mushrooms reduce plasma TC levels in hypercholesterolaemic rats is not clearly understood.and hypercholesterolaemic rats.0 + 41. the addition of 1% cholesterol to the basal diet without bile acids and/or antithyroid drugs produced hypercholesterolaemia in rats. y = 34. in order to induce hypercholesterolaemia/atherosclerosis in rats. Correlation of plasma TC and TAS Hypercholesterolaemia is known to induce increased oxidative stress in a wide variety of tissues. The plasma unsaturation indices in both groups of mushroom-fed rats increased compared with their respective controls (Table 3). which increase the intestinal absorption of cholesterol. Effects of mushroom feeding on plasma TAS The effects of mushroom feeding on plasma TAS are shown in Fig. in HC + MS rats. but the level of AA increased.27. palmitic acid and the (poly)unsaturated fatty acids (linoleic acid. normocholesterolaemic control rats (NC).83 ± 0.29 The twofold increase in plasma cholesterol in the hypercholesterolaemic rats in the present study was comparable with that reported by Bobek et al. Columns with different symbol notations indicate significant differences at P < 0. P < 0. . mushroom feeding may affect plasma cholesterol in the normocholesterolaemic condition.) significantly. Plasma NEFA decreased significantly (P < 0. this speculation does not exclude the possibility that if mushroom intake is increased and/or the dietary regimen is lengthened with mushroom feeding at the same dose. oleic acid. HC (ᮀ) and HC + MS () rats. mushroom-fed hypercholesterolaemic rats (HC + MS). cholesterol feeding is associated with other dietary additives.05 (one-way ANOVA with post hoc Fisher’s PLSD test). in the present study. 1b). ostreatus mushroom to rats significantly ameliorates the plasma atherogenic lipid profiles only in experimentally induced hypercholesterolaemic. ( ). 1a.28 However. Liver cholesterol content decreased significantly in HC + MS rats compared with HC rats. LNA and EPA) decreased significantly. 5% mushroom feeding significantly repressed the increment of plasma cholesterol.24–26 Therefore. The cholesterol content of the liver of HC rats increased markedly compared with NC rats. ( ). ostreatus improves hypercholesterolaemia 473 Fig. in NC + MS rats. (Simple regression analysis using plasma total anti-oxidant status as an independent variable and plasma cholesterol as a dependent. including bile acids and propylthiouracil (an antithyroid drug).to fourfold in rats. DISCUSSION The present study provides evidence that the feeding of 5% P. but not significantly. r = 0. Mushroom feeding significantly decreased the TAS level by approximately 30% compared with HC rats.01. However. cholesterol feeding significantly increased the TAS level by 69% compared with NC rats.3%) diet with added bile acids (0. The basal level of plasma TAS in NC rats was 0. (ᮀ). suggesting that mushroom feeding does not affect cholesterol metabolism at the basal levels requisite for normal homeostatic functions of the body. 1 (a) Effects of oyster mushroom (Pleurotus ostreatus) feeding on plasma total anti-oxidant status of normo.7-fold higher cholesterolaemia in their cholesterolfed rats compared with normal rats. lovastatin). high (1%) cholesterol-fed hypercholesterolaemic rats (HC).05) in HC + MS rats. Rats are particularly resistant to the development of hypercholesterolaemia and atherosclerosis21–23 and have a strong capability to maintain their plasma cholesterol.04 mmol/L.1x. The level decreased slightly. Interestingly. mushroom-fed normocholesterolaemic rats (NC + MS). whereas levels of AA increased in NC + MS rats compared with control (NC) rats. (). In our experimental paradigm. but not normocholesterolaemic. linoleic acid and LNA decreased significantly. Our regression analysis showed a highly significant positive correlation between plasma TC and anti-oxidant levels (Fig. (b) Scatter plot showing the relationship between plasma total cholesterol and plasma total antioxidant status of NC (᭺). Pleurotus ostreatus contains the hypocholesterolaemic agent mevinolin (monacolin K. compared with NC rats.57.31 which may be involved in decreasing Effects of mushroom feeding on plasma fatty acid profiles Plasma levels of saturated fatty acid. the levels of palmitic acid. but was not significantly different from that seen in NC rats. 3-D-glucan and pectin. 5. ACKNOWLEDGEMENT This study was supported. Tabeta R. Vitaminol. Ohashi T. In addition. P. Isolation and structure of a beta-gulcan. Fukushima M.35 It is presumed that mushroom feeding to HC rats increases the fractional turnover rate of VLDL. The fruiting bodies of maitake (G. 42: 175–9. 1985. by a Grant-in-Aid from the Center for Scientific and Industrial Research.4 Accordingly. particularly reduced glutathione. whereas LDL is not secreted as such the liver. mushrooms may provide an important health benefit by increasing plasma HDL-C and decreasing plasma LDL-C. Rev. Pleurotus ostreatus feeding to streptozotocin-induced diabetic rats significantly lowered both basal and post-prandial glycaemia. mushroom feeding significantly decreased plasma NEFA levels of hypercholesterolaemic rats. High levels of plasma NEFA lead to lipid overload in the liver and produce atherogenic hyperlipidaemia. 1987. plasma VLDL-C levels and TG content in the HC + MS group may be decreased due to increased lipoprotein lipase activity of peripheral vascular endothelial cells and/or decreased hepatic release via an increase in faecal excretion of cholesterol. 6. ostreatus ingestion has significant health benefits through the modulation of physiological functions that include various atherogenic lipid profiles and antioxidants in hypercholesterolaemia. Bobek P. ostreatus feeding helps in reducing the atherogenic lipid profile seen in association with diabetes-related complications. Lipoprotein lipase in striated muscle is enhanced in animals on a fat-rich diet. ostreatus may be a good source of nutrition that may also act as a prophylactic against hypercholesterolaemia and may provide good health benefits in hyperlipidaemia and related complications. including rats.32 Therefore. Mushroom feeding also significantly decreased hepatic cholesterol in hypercholesterolaemic rats. Nutr. it increased significantly after the feeding of 1% cholesterol. Yamaguchi M. which bind to bile acids. Wang HX. Toxicol. Cang ST. This may relate to the mushroom-induced enhanced activity of 7␣-hydroxylase (a key enzyme of cholesterol catabolism) and bile acid secretion and the subsequent increased excretion of cholesterol through the faeces. Hepatic LDL receptor mRNA in rats is increased by dietary . Fukuoka F.) Quel.and HDL-C ester into free cholesterol. which is secreted as such and/or after its conversion into bile acids into the bile duct. including -1. as indicated by the decreased levels of total anti-oxidants following mushroom feeding. 2. whereas mushroom feeding significantly decreased TAS. when rats became hypercholesterolaemic. it seems to be formed from VLDL after partial removal of TG by lipoprotein lipase. In the present series of experiments. 3. 54 (Suppl. 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