In vitro evaluation of pleiotropic properties of wild mushroom Laetiporus sulphureus

Abstract

In this study we extracted bioactive ingredients from fruiting bodies of Laetiporus sulphureus with different solvents and tested the antimicrobial and antitumor activities. The predominant lipid composition of the fruiting bodies was studied with GC–MS and revealed a high amount of oleic acid, octadecenoic acid and ergosterol derivatives. Extracts of L. sulphureus were shown to have antimicrobial activity against all fungal strains tested including Candida albicans, Geotrichum candidum, Aspergillus fumigatus, Aspergillus niger, Curvularia clavata, and Fusarium oxysporum, as well as strains of gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Shigella enterica). Antimicrobial activity of ethanol and water extracts exceeded that of other extracts based on greater inhibitory activity at a lower minimum inhibitory concentration (MIC) range (MIC of ethanol = 15.6–62.5 μg/ml and of water = 15.6–125 μg/ml). The ethanol extract also exhibited superior anti-proliferative activity against three carcinoma cell lines and did not differ from a water extract against HeLa cells with half maximal inhibitory concentrations (IC50) of 3.1 ± 1.5 and 5.1 ± 1.2 μg/ml against HCT 116 and MCF-7 cells, respectively and IC50 of 11.5 ± 2.1 and 12.1 ± 1.7 μg/ml against Hep G2 and HeLa cells, respectively. The extract inhibited growth of isolated normal mouse hepatocytes by <12%. Scanning electron microscopy was applied to characterize the structures of the microbes treated with the ethanol semi-purified fraction. These findings suggest potential use L. sulphureus extract as a natural resource with anti-proliferative activity against tumor cells and microbial infections. Keywords: Laetiporus sulphureus, Antimicrobial activity, Anti-tumor activity, Natural product, Scanning electron microscopy, Cytotoxicity