Study on the 3-hydroxy-3-methyl-glutaryl CoA reductase inhibitory properties of Agaricus bisporus and extraction of bioactive fractions using pressurised solvent technologies

• Published in: Journal of the science of food and agriculture Vol. 93; no. 11; pp. 2789 - 2796
• Main Authors: Gil-Ramírez, Alicia, Clavijo, Cristina, Palanisamy, Marimuthu, Ruiz-Rodríguez, Alejandro, Navarro-Rubio, María, Pérez, Margarita, Marín, Francisco R, Reglero, Guillermo, Soler-Rivas, Cristina
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 30-08-2013; John Wiley and Sons, Limited
• Subjects: Agaricus - chemistry; Agaricus bisporus; Bioassays; Byproducts; Chemical Fractionation - methods; Cholesterol; cultivation; Dietary fiber; Enzymes; Ethyl alcohol; Food science; HMGCoA reductase cholesterol; Hydroxymethylglutaryl CoA Reductases - metabolism; Hydroxymethylglutaryl-CoA Reductase Inhibitors - chemistry; Hydroxymethylglutaryl-CoA Reductase Inhibitors - pharmacology; Inhibitors; Mushrooms; pressurised solvent extraction (PSE); Reductases; Rodents; Selenium - chemistry; Solvent extraction; Solvents; supercritical fluid extraction (SFE); white button mushroom; HMGCoA reductase cholesterol; pressurised solvent extraction (PSE); white button mushroom; cultivation; supercritical fluid extraction (SFE)
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.6102

BACKGROUND
Agaricus bisporus mushrooms were able to lower cholesterol levels in hypercholesterolaemic rats and it was suggested that dietary fibre might inhibit cholesterol absorption. However, A. bisporus extracts were also able to inhibit the 3‐hydroxy‐3‐methyl‐glutaryl CoA reductase (HMGCR, the key enzyme in the cholesterol biosynthetic pathway) and this might also contribute to the observed lowering of cholesterol levels in serum.
RESULTS
The methanol–water extracts obtained from A. bisporus were able to inhibit up to 60% the HMGCR activity using an in vitro assay. The HMGCR inhibitory capacities depended on cultivation conditions, strains, etc. The potential inhibitors were not statins, they might be β‐glucans able to scavenge the substrate and impair the enzymatic reaction. They were present during all mushroom developmental stages and similarly distributed through all the tissues including the parts discarded as a by‐product. Accelerated solvent extractions using 1:1 ethanol–water as pressurised solvent (10.7 MPa, 25°C, five cycles of 5 min) were more effective in the extraction of the HMGCiR inhibitor(s) than supercritical fluid extractions (9 MPa, 40°C) using CO2 with 10% ethanol.
CONCLUSION
A mushroom cultivation and two extraction procedures were optimised to obtain fractions from A. bisporus with high HMGCR inhibitory activities to design novel ingredients for hypocholesterolaemic functional foodstuffs. © 2013 Society of Chemical Industry