Antioxidant activity and cytotoxicity of the edible mushroom, Pleurotus cystidiosus against Hep-2 carcinoma cells

This study was undertaken to evaluate the antioxidant activity and cytotoxicity of Pleurotus cystidiosus, an edible mushroom, against Hep-2 cancer cells. Fresh P. cystidiosus mushroom was extracted with acetone (fraction A). Fraction A was extracted into hexane, dichloromethane and ethyl acetate successively and the remaining fraction was labeled as “A4”. Fraction A4 was further separated into three fractions, A4-1, A4-2 and A4-3 using a reverse phase column. 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity and nitric oxide (NO) radical scavenging activity assays were used to investigate the reducing power of the extracts. The DPPH- EC50 of A4-2 and A4-3 were 0.81 and 0.82 mg/mL, respectively; NO - EC50 of A4-2 and A4-3 were 0.87 and 0.61 mg/mL, respectively. The results on cytotoxic effects based on MTT and LDH assays have shown that the same two extracts to have the highest activity. These results were reinforced by the cell morphological changes observed using an inverted fluorescence microscope of the treated cells. Cells incubated with the highest dose (5 mg/mL) of A4-2 and A4-3 showed cell morphological changes such as cellular swelling, irregular cell shapes, condensed cytoplasm and vacuolar areas. Hence it can be concluded that the extract of P. cystidiosus has antioxidative activity as well as cytotoxicity against Hep-2 cancer cells. It can also be speculated that the use of whole mushroom as a medicinal food may bring about health benefits.

Keywords: Abalone, DPPH radical scavenging activity, LDH activity, MTT, mushroom.

DOI: http://dx.doi.org/10.4038/jnsfsr.v40i2.4438

J.Natn.Sci.Foundation Sri Lanka 2012 40(2):107-114