Lentinus tigrinus is a wood-decay fungus known for its nutritional, culinary,
and medicinal benefits. It contains bioactive compounds like polyphenols, terpenes, and
flavonoids that exhibit antioxidant, anti-microbial, and anti-inflammatory effects. These
natural antioxidants are increasingly recognized for their potential to prevent oxidative
damage linked to aging and chronic diseases. This study investigates the antioxidant
activity of hydroalcoholic extracts obtained from L. tigrinus sporophores cultivated on
hazelnut shells (Lt1_HS), a waste material rich in phenolic compounds, and sporophores
cultivated on sawdust (Lt1_S). Bioactivity tests, including DPPH, TBARS, MTT, and DCFHDA
assays, were performed to assess the hydroalcoholic extracts’ efficiency. The results
showed that all the extracts contained various bioactive compounds, primarily polyphenols.
Notably, the caffeoylquinic acids present in HS and Lt1_HS are linked to anti-peroxidant
effects. Biological analyses demonstrated that the Lt1_HS extract has higher anti-peroxidant
activity (IC50 0.77 ± 0.01 mg/mL) compared to Lt1_S (IC50 1.36 ± 0.01 mg/mL) and reduces
the accumulation of reactive oxygen species in HaCaT cells by 80%. However, the specific
bioactive compounds responsible for these antioxidant effects are still unclear, and further
analysis will be conducted. Additionally, this study promotes recycling hazelnut shells as a
valuable substrate for fungal cultivation, supporting sustainable waste management.