Oyster Mushroom

Pleurotus ostreatus
(from Medicinal Mushrooms – A Clinical Guide by Martin Powell)

English name – Oyster Mushroom
Chinese name – Ping Gu
Japanese name – Hiratake

One of the principal culinary mushrooms, P. ostreatus fruiting bodies contain lovastatin in concentrations ranging from 0.7-2.8% dried weight depending on the strain.

It has also been commercialized as a source of beta glucans and related polysaccharides for immune support and health maintenance and shows promise as an anti-ageing dietary supplement.

Cholesterol Control – Dried P. ostreatus fed to hamsters at 2% of a high fat diet for 6 months is reported to have lowered VLDL by 65-80% and total serum lipid levels by 40% and to totally negate increases in triglyceride and liver cholesterol levels associated with chronic alcohol intake1-3. Multiple animal studies show P. ostreatus fed at 5% of diet to produce improvements in blood lipid levels4-10. Intake of more than 5% was seen to suppress appetite11.

Bobek et al report reductions in cholesterol in humans from intake of 15-20g/day5 and in a small ‘proof of concept’ study, 20 HIV patients taking protease inhibitors who had elevated non-HDL cholesterol (>160mg/dl) were given 15g/day freeze-dried P. ostreatus for 8 weeks resulting in an increase of HDL from an average of 37 to 40.2mg/dl and a decrease in triglycerides from 320.5 to 271.3 but no significant reduction in non-HDL cholesterol12 (abnormalities in lipid metabolism are a common side effect of anti-retroviral treatment). Khatun et al also reported P. ostreatus to reduce cholesterol levels in diabetic patients13.

Anti-aging – As well as having immunomodulatory, anti-cancer and hepatoprotective properties in common with those from other mushrooms, polysaccharides from P. ostreatus have also been shown to increase activity of catalase, superoxide dismutase and glutathione peroxidase, as well as counter age related reductions in levels of glutathione and vitamins C and E 14-19.

CLINICAL SUMMARY
Therapeutic Application – General health maintenance, especially in the elderly. Can be prescribed for cholesterol control, although Monascus purpureus products (Hong Qu Mi – Red Yeast Rice) usually give a more controlled dosage of lovastatin
Key Components – Lovastatin, polysaccharides
Dose – For general health maintenance 2-3g/day polysaccharide extract. For cholesterol control 10-15g/day dried fruit body.

1. Effect of mushroom Pleurotus ostreatus and isolated fungal polysaccharide on serum and liver lipids in Syrian hamsters with hyperlipoproteinemia. Bobek P, Ginter E, Kuniak L, Babala J, Jurcovicova M, Ozdín L, Cerven J. Nutrition. 1991;7(2):105-8.
2. Cholesterol-lowering effect of the mushroom Pleurotus ostreatus in hereditary hypercholesterolemic rats. Bobek P, Ginter E, Jurcovicová M, Kuniak L. Ann Nutr Metab. 1991;35(4):191-5.
3. Effect of oyster fungus (Pleurotus ostreatus) on serum and liver lipids of Syrian hamsters with a chronic alcohol intake. Bobek P, Ginter E, Jurcovicová M, Ozdín L, Mekinová D. Physiol Res. 1991;40(3):327-32.
4. Dose-dependent hypocholesterolaemic effect of oyster mushroom (Pleurotus ostreatus) in rats. Bobek P, Ozdín L, Kajaba I. Physiol Res. 1997;46(4):327-9.
5. Dose- and time-dependent hypocholesterolemic effect of oyster mushroom (Pleurotus ostreatus) in rats. Bobek P, Ozdín L, Galbavý S. Nutrition. 1998;14(3):282-6.
6. Hypocholesterolemic activity of the genus Pleurotus (Jacq.: Fr.) P. Kumm. (Agaricales s. I., Basidiomycetes) Nina Gunde-Cimerman et al, Int J Med Mushr 2001;3(4)
7. Evidence for the anti-hyperlipidaemic activity of the edible fungus Pleurotus ostreatus. Opletal L, Jahodár L, Chobot V, Zdanský P, Lukes J, Brátová M, Solichová D, Blunden G, Dacke C.G, Patel A.V. Br J Biomed Sci. 1997;54(4):240-3.
8. Dietary mushroom (Pleurotus ostreatus) ameliorates atherogenic lipid in hypercholesterolaemic rats. Hossain S, Hashimoto M, Choudhury E.K, Alam N, Hussain S, Hasan M, Choudhury S.K, Mahmud I. Clin Exp Pharmacol Physiol. 2003;30(7):470-5.
9. Role of oyster mushroom (Pleurotus florida) as hypocholesterolemic/antiatherogenic agent. Bajaj M, Vadhera S, Brar A.P, Soni G.L. Indian J Exp Biol. 1997;35(10):1070-5.
10. Cholesterol-lowering effect of Pleurotus species (Agaricomycetideae) (Abstracts of papers published in 1991-1999) Bobek P. Int J Med Mushr. 1999;1(4):371-380
11. A lectin from the edible and medicinal mushroom Pleurotus ostreatus (Jacq.: Fr.) Kumm. as a food intake suppressing substance. Yokoyama S, Nakamura H, Tokuyama S. Int J Med Mush. 2001;3(2-3)
12. Antihyperlipidemic effect of Pleurotus ostreatus in HIV: results of a pilot proof-of-principle clinical trial. Abrams D.I, Couey P, Shade S.B, Kelly M.E, Kamanu-Elias N, Stamets P.E. Int J Med Mushr. 2007;9(3):204
13. Oyster mushroom reduced blood glucose and cholesterol in diabetic subjects. Khatun K, et al Mymensingh Med J. 2007;16(1):94-9
14. Effect of oyster mushroom (Pleurotus ostreatus) on pathological changes in dimethylhydrazine-induced rat colon cancer. Bobek P, Galbavy S, Ozdin L. Oncol Rep. 1998;5(3):727-30.
15. Cytotoxic effect of oyster mushroom Pleurotus ostreatus on human Androgen-independent prostate cancer PC-3 cell. Gu Y.H, Sivam G. J Med Food. 2006;9(2):196-204
16. Effects of Lentinus edodes, Grifola frondosa and Pleurotus ostreatus administration on cancer outbreak and activities of macrophages and lymphocytes in mice treated with a carcinogen N-butyl-N-butnolnitrosamine. Kurashige S, Aleusawa Y, Endo F. Immunopharm. Immunodetox. 1997;19:175-183.
17. Antioxidant activity of the oyster mushroom, Pleurotus ostreatus, on CCl(4)-induced liver injury in rats. Jayakumar T, Ramesh E, Geraldine P. Food Chem Toxicol. 2006;44(12):1989-96.
18. Protective effect of an extract of the oyster mushroom, Pleurotus ostreatus, on antioxidants of major organs of aged rats. Jayakumar T et al. Exp Gerontol. 2007;42(3):183-91.
19. An extract of the oyster mushroom, Pleurotus ostreatus, increases catalase gene expression and reduces protein oxidation during aging in rats. Thanasekaran J, Aloysius P.T, Mathivanan I, Pitchairaj G.J. Chin Int Med. 2010;8(8):774-780

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