Investigating the Anti-Inflammatory and Pain-Relieving Properties of Glaucium corniculatum (L.) Rud subsp. refractum (NAB) Cullen and Glaucium leiocarpum Boiss., Along with Their Active Compounds

The genus Glaucium (Papaveraceae), comprising approximately 30 species, is widely distributed across the Mediterranean region, Europe, North Africa, and Central and Southwest Asia. In the flora of Türkiye, the genus is represented by 11 taxa and is commonly known as “boynuzlu gelincik” and “çömlek çatlatan”. The aim of this study is to explore the analgesic and anti-inflammatory properties of Glaucium corniculatum (L.) Rud subsp. refractum (NAB) Cullen, and Glaucium leiocarpum Boiss., which are found in Türkiye and are known for their high alkaloid content. Traditionally, G. leiocarpum has been used for wound care, cuts, bruises, acne, hemorrhoids, headache, and diarrhea, while G. corniculatum subsp. refractum has been employed as an antitussive and for external applications against ocular inflammations. Ethanolic extracts and crude alkaloid fractions from the aerial parts were evaluated in vivo in anti-inflammatory and antinociceptive test models. Anti-inflammatory activity was assessed by the carrageenan-induced paw edema model, while antinociceptive activity was determined using tail-flick and hot-plate tests. G. leiocarpum ethanolic extract (200 mg/kg) showed the highest anti-inflammatory activity, effectively suppressing carrageenan-induced edema (1.58 ± 0.30–1.73 ± 0.51 mL), and displayed the strongest antinociceptive activity, with tail-flick latencies reaching 23.91 ± 2.08 s (90 min) and 22.23 ± 1.97 s (150 min) and hot-plate latencies of 22.27 ± 4.76 s (30 min) and 23.00 ± 4.61 s (90 min). Bioactivity-guided fractionation of the most active extract was carried out using various chromatographic techniques. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses were employed throughout the isolation process to monitor fractions and determine their phytochemical profiles. As a result, two compounds were obtained and subsequently evaluated for their biological activities. The chemical structures of the isolated compounds were elucidated by spectroscopic methods, including 1H-NMR, 13C-NMR, 2D-NMR, and LC-MS analyses as kaempferol-3-O-glucorhamnoside and quercetin-3-O-glucorhamnoside. Biological activity evaluation demonstrated that these compounds significantly contributed to the observed antinociceptive activity. These findings confirm that Glaucium species are traditionally used and highlight their potential to provide bioactive compounds with anti-inflammatory and pain-relieving effects.