Antioxidant and antimicrobial properties of Lignosus rhinocerus / Nur Haida Mohamad

Aqueous extracts from sclerotiums of Lignosus rhinocerus was screened for total phenolic content (TPC), antioxidant activity and antimicrobial activity. Analysis of TPC was done using the Folin-Ciocalteu method. Two method for antioxidant assay was used which are 1, l-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging system and xanthine oxidase (XOD) superoxide scavenging system. Antimicrobial activity was screened using the microdilution test to measure minimum inhibitory concentration and minimum bactericidal concentration. Six type of microorganisms strain was used which are Staphylococcus aureus ATCC25923 (A methicillin susceptible S.aureus isolate), Staphylococcus aureus ATCC33591 (A multi drug resistant S.aureus (MRSA) isolate), Escherichia coli ATCC10536, Pseudomonas aeruginosa ATCC27853, Candida Albican ATCC1023 l and Microsporum canis ATCC36299. From the results obtained, the total phenolic compound (TPC) for this sample was 2226.89 ± 0.67 mg/lOOg GAE. LRAE exhibited high scavenging effect (over 50%) at concentrations of lOOµg/ml and 500µg/ml using xanthine oxidase (XOD) superoxide scavenging system. The LRAE only exhibited low scavenging effect (less than 10%) by using 1, l-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging method. Antimicrobial assay exert negative results when no inhibitory activity can be detected at concentration of 5µg/ml. The study shows that the samples having potential as a natural antioxidant source.