Investigation of Urease and Xanthine Oxidase Inhibition and the Antioxidant Properties of Lamium orientale, along with its Essential Oil Composition

This study aimed to investigate the anti-urease and anti-xanthine oxidase (XO) activities, essential oil components, and antioxidant properties of Lamium orientale populations in the Nevşehir Province, Turkey. The methanolic extracts of L. orientale were tested for their inhibitory effects on the urease and XO enzymes. Essential oil components were analyzed using solid-phase microextraction (SPME), followed by gas chromatography-mass spectrometry (GC-MS). Antioxidant potential was assessed by measuring total phenolic content (TPC), ferric reducing antioxidant power (FRAP) assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Results showed that L. orientale exhibits significant enzyme inhibitory potential, with IC₅₀ values of 39.54 ± 0.98 µg/mL for anti-urease activity and 28.05 ± 0.88 µg/mL for anti-XO activity. Essential oil analysis identified 22 components, with acetoin (20.80%) and pentadecanolide (14.21%) as the main constituents. The total phenolic content was 4.48 ± 0.08 mg GAE/g of dry sample. The FRAP value was 59.33 ± 0.90 µmol FeSO₄/g, and the DPPH radical scavenging activity (IC₅₀) was 0.63 ± 0.01 mg/mL. This is the first study to report the inhibition potential of urease and xanthine oxidase (XO) in the genus Lamium , highlighting the potential of L. orientale as a source of new bioactive compounds.