Bioactive Compounds in Three Edible Lentinus Mushrooms

Abstract

The generation of free radicals is a major issue in the development of carcinogenesis-induced mutations and tumor promotion. Bioactive compounds which are able to scavenge free radicals and provide protections against cancers caused by them are called antioxidants. We aimed to show that bioactive compounds from mushrooms will be valuable for health promotion. Catechin is a major group of phenolic compounds found in 3 species of mushroom, Lentinus squarrosulus , Lentinus polychrous and Lentinus edodes , especially in L. squarrosulus by LC-MS. The percentage of inhibition of free radical scavenging activity by DPPH assay was higher than 70 % in ethanolic extract of L. squarrosulus and L. polychrous , while in L. edodes it was lower as 30 %. Using FRAP to investigate the micromolar trolox equivalent of L. squarrosulus also showed it to be higher than the other 2 species. The highest amount of total phenolic compound was displayed in L. squarrosulus extract , which corresponds with the DPPH and FRAP assays. An anticancer protein, polysaccharide peptide (PSP), was also detected at a level of approximately 70 kDa via western immunoblotting. The amounts of PSP from protein extracts of L. squarrosulus , L. polychrous and L. edodes were 9.87 ± 0.03, 0.41 ± 0.03 and 0.17 ± 0.04 mg/g protein, respectively, by using ELISA method. The cell viability of human colorectal adenocarcinoma, HT-29, diminished significantly in the treatment group with protein extract from L. squarrosulus. This L. squarrosulus extract may be an effective natural product for clinical trials in patients, because these edible mushrooms are nontoxic and are also a consumable food for human health. doi: 10.14456/WJST.2015.80