Antioxidant properties of methanolic extracts from Ganoderma tsugae

Abstract

Ganoderma tsugae Murrill was available in the form of mature and baby Ling chih, mycelia and fermentation filtrate. From these four forms, methanolic extracts were prepared and their antioxidant properties were studied. Methanolic extracts from mature and baby Ling chih showed high antioxidant activities (96.8% and 93.6%) at 20 mg ml −1, and had EC 50 values of 0.53 and 1.11 mg ml −1, respectively. EC 50 values in reducing power were 5.00, 2.28, 0.93 and 2.15 mg ml −1 for Ling chih, baby Ling chih, mycelia and filtrate, respectively. Methanolic extracts from mature and baby Ling chih scavenged 1,1-diphenyl-2-picrylhydrazyl radicals by 88.4% and 93.8% at 5 mg ml −1, whereas those from mycelia and filtrate scavenged by 85.7% and 79.3% at 10 mg ml −1, respectively. EC 50 values in chelating ability on ferrous ions were 4.82, 3.05, 1.10 and 3.41 mg ml −1 for Ling chih, baby Ling chih, mycelia and filtrate, respectively. Total phenols were the major naturally occurring antioxidant components found in all methanolic extracts and in the range of 24.0–35.6 mg g −1. Based on EC 50 values, G. tsugae was good in antioxidant properties except for the scavenging ability on hydroxyl radicals.