The concept of bio-economy has emerged to overcome some sustainability challenges, and this involves conversion of agricultural residues and waste streams into high value-added products that can be utilized as ingredients for several bio-based industrial processes, delivering both economic growth, scientific interest and a better environment. The present work was carried out to re-utilize discarded Agaricus blazei Murill. Its nutritional composition was evaluated and ethanolic extracts were prepared by Soxhlet extraction to be further evaluated for their anti-inflammatory, anti-tyrosinase and cytotoxic properties against different tumor cell lines (SRB assay). MTT and LDH assays were also used to determine cell viability and cell death respectively in Caco-2 and HT29 cells lines. Essential nutrients such as carbohydrates, proteins and fat, were found; twenty fatty acids were detected, sugars (mannitol and trehalose), α-tocopherol and oxalic acid were also present. The extracts, up to 100 μg/mL, were able to maintain viability of Caco-2 and HT29 cells. The extracts also presented anti-tyrosinase activity (EC50 1.33±0.02 mg/mL) and with no toxicity in tumor cells. The results obtained suggested that the extracts obtained from Agaricus blazei Murill residues can be utilized as an inexpensive and sustainable source of nutraceutical and functional food ingredients.