Screening of statin production by fungal strains

Statins were first isolated from Aspergillus terreus (lovastatin) and from Penicillium citrinum (mevastatin). Statins inhibit the hydroxyl methylglutaryl coenzyme A reductase (HMGR) involved in the synthesis of cholesterol and they have become very important for control of cholesterol levels in patients.

Many clinical studies demonstrated that HMGR inhibitors (statins) have antioxidant power. This work aimed at screening of statin production by fungi via the total antioxidant activity of the fermentation broth extracts, following the reaction with the stable DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. The cultivated fungi were Polyporus mori (Pollini) Fr., Collybia marasmioides (Britz.) Bresinsky & Stangl, Trametes ochracea (Pers.) Gilb. & Ryv., Perenniporia fraxinea (Fr.) Ryv., Schizopora paradoxa (Fr.) Donk, Phanerochaete chrysosporium Burdsall, Lactarius subdulcis (Fr.) S.F.Gray, Ganoderma pfeifferi Bres, Collybia acervata (Fr.) Karst., Stropharia semiglobata (Fr.) Quèl., Crucibulum laeve (Bull.) Kambly, Cyathus stercoreus (Schw.) deToni, Hebeloma truncatum (Schaeff.) Kumm., Ustilago maydis (D.C.) Corda, Calvatia utriformis (Bull.) Jaap, Bovista plumbea Pers., Antrodia sinuosa (Fr.) Karst., Phlebia radiata Fr., Hymenochaete rubiginosa (Dicks) Lév., Entoloma lividum (Bull.) Quél., Gloeophyllum odoratum (Wulf.) Imaz., Gloeophyllum sepiarium (Wulf.) Karst.

The color reaction of the fungal extracts with 0.1 mM DPPH was measured spectrophotometrically (517 nm) monitoring the loss of DPPH radical as a function of its reduction. The results, as IC₅₀ (mg/mL) values of antioxidant activity, are from 0.66 [P.mori] to 12.8 [C.marasmoides] mg/mL. Other species have intermediate values. U.maydis, C.utriformis, B.plumbea, A.sinuosa, P.radiata, H.rubiginosus, E.lividum, G.odoratum and G.sepiarium do not show a significant antioxidant activity. The statin contents (HPLC analysis) correlate well with the results in radical scavenging activity.