Rhododendron luteum Sweet Flower Supercritical CO[sub.2] Extracts: Terpenes Composition, Pro-Inflammatory Enzymes Inhibition and Antioxidant Activity

• Published in: International journal of molecular sciences 2024-09, Vol.25 (18)
• Main Authors: Lyko, Lena, Olech, Marta, Gawlik, Urszula, Krajewska, Agnieszka, Kalemba, Danuta, Tyskiewicz, Katarzyna, Piórecki, Narcyz, Prokopiv, Andriy, Nowak, Renata
• Format: Article
• Language: English
• Subjects: Chemical properties; Health aspects; Liquid carbon dioxide; Materia medica, Vegetable; Plant extracts; Rhododendron
• ISSN: 1422-0067
• DOI: 10.3390/ijms25189952

Terpenes are plant secondary metabolites known for their anti-inflammatory and antioxidant activities. According to ethnobotanical knowledge, Rhododendron luteum Sweet was used in traditional medicine against inflammation. The present study was conducted to determine the triterpene profile and antioxidant and anti-inflammatory activity of supercritical CO[sub.2] (SC-CO[sub.2] ) extracts of Rhododendron luteum Sweet flower (RLF). An LC-APCI-MS/MS analysis showed the presence of eight pentacyclic triterpenes and one phytosterol in the extracts obtained with pure CO[sub.2] as well as CO[sub.2] with the addition of aqueous ethanol as a co-solvent. Among the compounds detected, oleanolic/ursolic acid, β-sitosterol and 3β -taraxerol were the most abundant. The extract obtained with pure SC-CO[sub.2] was additionally subjected to HS-SPME-GC-FID-MS, which revealed more than 100 volatiles, mainly eugenol, β -phenylethanol, dodecane, β -caryophyllene, estragole and (Z )- and (E )-cinnamyl alcohol, followed by δ -cadinene. The extracts demonstrated significant hyaluronidase inhibition and exhibited varying modes of lipoxygenase and xanthine oxidase inhibitory activities. The studies of RLF have shown that their SC-CO[sub.2] extracts can be a rich source of triterpenes with anti-inflammatory potential.