Potential of Mycelia-Derived Ganoderma lucidum Polysaccharide Extracts (PS-G) on Bacterial Growth Inhibition and Neutrophil Priming

Abstract

Mycelia-derived Ganoderma lucidum PS-G (polysaccharide extract) was separately extracted with hot water and ethanol, and compared with extracts of Pharmanex Reishimax®, a commercial Ganoderma lucidum product from fruting bodies and spores. The extracts were tested for bacterial growth inhibition on Staphylococcus aureus and Pseudomonas aeruginosa by agar cup diffusion. All treatments exhibited inhibitory effects on S. aureus (A-0, B-2.15, C-4.63, D-4.62, E-3.83, F-4.42, G-3.75 cm, mean diameter of zones of inhibition)* and P. aeruginosa (0, 4.67, 4.35, 3.83, 4.73 and 3.93 cm of ZOI for treatments A-G, respectively). Mycelia-derived extracts showed more inhibitory activity on bacterial growth than Reishimax® extracts, and were comparable with amoxicillin on the preliminary bacterial inhibitory assay. Aqueous extracts proved to be more effective than ethanol extracts for both PS-G and Reishimax®, although no significant difference between the extraction solvents was determined (2.59 and 1.93 cm ZOI for water and ethanol on S. aureus', 2.73 and 2.15 for water and ethanol on P. aeruginosa) Also, extracts from younger mycelia (1 to 3 weeks old) showed greater activity than those from older mycelia (4 to 6 weeks old). Incubation of neutrophils in 50, 100, 150 and 200pg/mL preparations of partially purified PS-G for a 10-min period showed obvious differences on the gross morphological characteristics of treated and untreated neutrophils. The effect of partially purified PS-G on the neutrophils was concentration-dependent.