Comparative evaluation of antioxidant, cytoprotective, and anti-arthritic activities of pomegranate peel powder and coarse powdered date seeds: implications for functional nutrition

• Pomegranate peel powder (PPP) showed significantly stronger antioxidant activity than coarse powdered date seeds across all assays. • PPP provided superior cytoprotective effects through erythrocyte membrane stabilization and protection against oxidative DNA damage. • Anti-arthritic potential of PPP was confirmed by marked inhibition of protein denaturation and protease activity. • The biological efficacy of PPP is attributed to synergistic multi-target interactions of its polyphenolic constituents. • Agro-waste-derived PPP represents a promising functional ingredient for nutraceutical and clinical nutrition applications. Agro-industrial byproducts are recognized as sustainable sources of bioactive compounds with potential applications in functional foods. Pomegranate peel and coarse powdered date seeds are among the most abundant fruit processing residues, yet remain underutilized despite their rich in polyphenols, organic acids and other phytochemicals composition. This study aimed to comparatively evaluate the antioxidant, cytoprotective, acetylcholinesterase inhibitory, and anti-arthritic activities of pomegranate peel powder (PPP) and coarse powdered date seeds (CPDS) using a panel of in vitro assays. Antioxidant capacity was assessed by DPPH radical scavenging and reducing power methods, while cytoprotective activity was evaluated using erythrocyte membrane stabilization and protective against oxidative DNA damage methods. Anti-arthritic potential was determined using protein denaturation and proteinase inhibition methods, and acetylcholinesterase inhibitory activity was also examined. PPP exhibited significantly higher activity compared to CPDS across most assays. PPP demonstrated stronger DPPH radical scavenging activity (IC 50 = 6.73 µg/mL) compared to CPDS (IC 50 = 19.18 µg/mL), along with enhanced anti-hemolytic activity (IC 50 = 155.14 ± 1.58 µg/mL vs. 287.02 ± 2.93 µg/mL for CPDS) and stronger protein denaturation inhibition (44.73% vs. 35.78%, p < 0.05). These findings suggest that the superior biological activity of PPP may be attributed to its higher phenolic content . This supports the idea of using chemicals from pomegranate peel in functional foods and nutraceutical formulas that aim to make cells stronger and lower the health risks associated with inflammation.