Total Phenolic and Flavonoid Contents, Antioxidant and Antiinflammatory Activities of Phellinus rimosus Extracts

Background: Phellinus rimosus is a medicinal mushroom with potential bioactive properties, although scientific evidence supporting its pharmacological activities remains limited. Objective: To investigate the phenolic and flavonoid contents, antioxidant capacity, and anti-inflammatory activity of ethanolic and aqueous extracts of P. rimosus. Materials and Methods: Total phenolic content (TPC) and total flavonoid content (TFC) were determined using colorimetric assays. Antioxidant activity was evaluated by DPPH, ABTS, and FRAP methods. Anti-inflammatory activity was assessed by measuring nitric oxide (NO) inhibition in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Statistical analysis was performed at P < 0.05. Results: The ethanolic extract contained significantly higher TPC (361.04 ± 5.69 mg GAE/g extract) and TFC (646.55 ± 6.29 mg RE/g extract) than the aqueous extract. It exhibited strong antioxidant activity with IC_₅₀ values of 9.56 ± 0.47 μg/mL (DPPH) and 5.40 ± 0.06 μg/mL (ABTS), and a FRAP value of 52.39 ± 0.25 mM Fe^²⁺/100 mg extract. The ethanolic extract also significantly inhibited NO production (IC_₅₀ = 54.40 ± 2.35 μg/mL) without cytotoxicity, whereas the aqueous extract showed no inhibitory effect. Conclusion: The ethanolic extract of P. rimosus demonstrates notable antioxidant and anti-inflammatory activities and may serve as a promising natural source of bioactive compounds.