Phenolic composition and in vitro antioxidant activity of hydro-methanolic extract from Punica granatum pericarps

This study evaluates the efficacy of hydro-methanolic extraction for recovering bioactive compounds from pomegranate (Punica granatum L.) pericarp and characterizes its antioxidant potential. A high extraction yield of 43.85% was obtained, surpassing many values reported in the literature and corroborating recent optimization of extraction parameters. The total phenolic content (TPC), determined by the Folin-Ciocalteu method, was 109.11 ± 0.015 mg GAE/g of dry extract. The total flavonoid content (TFC), assessed by aluminum chloride complexation, was 151.57 ± 0.007 mg CE/g. These results, consistent with current data, confirm the richness of the plant material, influenced by agronomic and methodological factors. The antioxidant activity, evaluated by the DPPH assay, revealed exceptional potency with an IC₅₀ value of 0.30 μg/mL. This activity is 433-fold superior to that of the ascorbic acid reference standard (IC₅₀ = 130.0 μg/mL) and ranks among the highest documented for a natural antioxidant. A statistically robust positive correlation (r > 0.987, p < 0.001) was established between TPC, TFC, and radical scavenging activity, confirming these compounds as the primary contributors to the antioxidant effect. This dose-dependent activity is attributed to the synergistic action of major polyphenols identified in the literature (ellagitannins such as punicalagin, ellagic acid, anthocyanins), acting through complementary mechanisms of radical scavenging, metal chelation, and modulation of redox-sensitive signaling pathways (Nrf2, NF-ĸB). The biological implications of this profile are substantial. Beyond its primary antioxidant activity, the extract demonstrates promising therapeutic potential documented in preclinical models, including anti-inflammatory (cytokine modulation), antidiabetic (á-glucosidase inhibition), and antitumor effects via apoptosis induction, cell cycle arrest, and angiogenesis inhibition. These results validate the hydro-methanolic pomegranate pericarp extract as a highly concentrated source of bioactive polyphenols with significant antioxidant power and multifaceted therapeutic relevance.