Panamanian Geisha Coffee Exhibits Antioxidant and Vasorelaxant Activities with a Favorable Safety Profile

Geisha coffee (Coffea arabica L. cv. Geisha) is internationally recognized for its exceptional sensory quality; however, its functional properties and bioactive composition remain insufficiently explored. This study evaluated the phytochemical profile, antioxidant capacity, vascular bioactivity, and toxicological safety of an aqueous extract of roasted Geisha coffee (AErGC) from the Chiriquí highlands, Panama. The chemical composition was determined using HPLC-PDA. Antioxidant activity was assessed using DPPH, ABTS, and lipid peroxidation assays. Vascular effects were studied in rat aortic rings, and safety was evaluated through Artemia salina and a single-dose acute oral toxicity model in rats (OECD 423). Chemical characterization was performed by HPLC-PDA, revealing notably elevated levels of caffeine (69.5 ± 6.4 mg/g) and 5-O-caffeoylquinic acid (74.5 ± 6.9 mg/g). The extract exhibited strong free radical scavenging capacity, with an IC₅₀ value of 14.7 ± 4.9 µg/mL in the DPPH assay, and inhibited lipid peroxidation by 72.71 ± 1.63% at 15.6 µg/mL. In endothelium-intact rings, AErGC induced a concentration-dependent vasorelaxant effect, reaching a maximum relaxation of 70.84 ± 2.9%. Toxicological results showed an LC₅₀ > 1000 µg/mL in A. salina and an oral LD₅₀ > 2000 mg/kg, classifying the extract as Category 5 (low toxicity). These findings highlight Panamanian Geisha coffee as a promising functional beverage with antioxidant and vascular protective properties, supporting its potential as a nutraceutical.