Phytochemical Profile, Antioxidant Capacity, and Photoprotective Potential of Brazilian Humulus Lupulus

<b>Background and Objectives</b>: The cultivation of <i>Humulus lupulus</i> has been encouraged in Brazil, despite the country's climate generally being unfavorable for its development. This study aimed to evaluate the chemical composition, antioxidant activity, and photoprotective potential of four <i>H. lupulus</i> varieties, Cascade, Columbus, Comet, and Nugget, cultivated in the northwestern region of Paraná State, Brazil. <b>Methods</b>: The varieties were grown in experimental plots. Crude extracts (CEs) of cones and leaves were obtained through dynamic maceration with solvent renewal (96% ethanol), followed by concentration in a rotary evaporator. Assays for sun protection factor (SPF), total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2.2-diphenyl-1-picrylhydrazyl (DPPH^•) radical scavenging activity, and 2.2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•⁺) were performed to assess antioxidant activity. Chemical profiling was performed using UHPLC-MS/MS. <b>Results</b>: UHPLC-MS/MS analysis revealed the presence of phenolic and organic acids, flavonoids, phenolic aldehydes, alkaloids, and α-benzopyrone-type lactones, with high concentrations of rutin (>500 µg/g) in both cones and leaves. Total phenolic content ranged from 69.70 to 95.95 µg gallic acid equivalent/mg CE; flavonoids from 170.53 to 696.67 µg quercetin equivalent/mg CE; DPPH^• EC₅₀ values ranged from 1.34 to 3.13 mg/mL; FRAP from 1.19 to 2.52 µM ferrous sulfate/mg; ABTS^•⁺ from 5.11 to 22.60 mM Trolox/mg CE; and SPF ranged from 16.02 to 39.48 in the CE of <i>H. lupulus</i> cones and leaves. Conclusions: These findings demonstrate that the cultivated varieties possess antioxidant and photoprotective properties, encouraging further studies to explore their potential applications.