Aqueous extract and proteolytic hydrolysates from oyster mushroom (Pleurotus pulmonarius) and its bioactivities

Pleurotus species are edible fungi that are extensively cultivated and consumed worldwide. Their fruiting bodies contain polysaccharides and proteins. Protein hydrolysates from oyster mushrooms, Pleurotus pulmonarius, were prepared using Alcalase® in this study. The isolated protein hydrolysates were filtered to produce fractions of molecular weights of less than 3 kDa and greater than 3 kDa. Following separation by ultrafiltration spin columns, the two fractions were utilized to assess antioxidant and anti-α-glucosidase activities, as well as cell viability in a human colorectal adenocarcinoma cell line (SW480 cells). The effective concentration that scavenged 50% (IC50) of 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazl (DPPH) radicals exhibited a distinct pattern between the crude extract and protein fractions. The protein hydrolysate with a molecular weight exceeding 3 kDa showed the strongest DPPH radical scavenging activity, whereas the crude extract protein fraction exhibited the highest ABTS radical scavenging activity. The crude extract protein demonstrated the highest inhibitory effect on α-glucosidase (62.48 ± 1.52%). Additionally, this study assessed cell viabilities in a human colorectal adenocarcinoma cell line (SW480 cells). The results indicated that the crude extract protein markedly reduced the viability of the SW480 cell lines, as determined by the MTT assay. These findings indicate that crude extract and protein hydrolysates derived from the fruiting bodies of P. pulmonarius have numerous advantageous properties and may serve as a functional food ingredient.