Plantago holosteum Scop. Üzerinde Farmakognozik Araştırmalar

Abstract

ABSTRACT Genç, Y., Pharmacognostical Investigations on Plantago holosteum Scop., Hacettepe University, Institute of Health Sciences, Pharmacognosy Program, Doctor of Philosophy Thesis, Ankara, 2017. The genus Plantago (Plantaginaceae) is represented by 21 species in Turkey, 2 of them are endemic and widely used in Anatolia. Antitumoral, antiinflammatory, antifungal and antibacterial effects of some Plantago species were reported in literature. Wound healing, antiinflammatory, antidiabetic and anticancer effects are main usages of Plantago species in traditional medicine. Therefore; bioactivity guided studies especially focused on wound healing effect were performed on Plantago holosteum Scop., which is widely spread in Turkey and the active compounds were isolated. Wound healing consists of antiinflammatory and radical scavenging parameters; thus radical scavenging activity against DPPH, NO, SO and ABTS radicals as well as antiinflammatory activity on LPS stimulated RAW 264.7 macrophages by monitorizing level of NO, PGE2 and TNF-α mediators of aqueous extract and fractions were evaluated. Moreover, protective and restorative effects of the extract on H2O2 - induced damage of L929 murine fibroblasts were performed. In addition; cytotoxic effects of the extract and main fractions were evaluated on carcinoma cells HEp-2 and normal cells L929 and RAW 264.7. Structures of 13 compounds, isolated from active fractions obtained by bioactivity guided studies, were determined by means of advanced spectroscopical methods (1D NMR, 2D NMR and Mass spectra). Aucubin (PH-1), monomelittoside (PH-2) and melittoside (PH-3) were isolated as iridoid glucosides, while acteoside (PH-4=PH-13), isoacteoside (PH-5), leucosceptoside A (PH-6), martynoside (PH-7), echinacoside (PH-8), arenarioside (PH-9=PH-20) and 4,3''''-dimetoxyarenarioside (PH-10) were isolated as phenylethanoid glycosides. In addition; a lignan glucoside, dihydrodehydrodiconiferyl alcohol-9'-O-β-glucopyranoside (PH-12) was also isolated. Structure determination study of a phenylpropionic acid glycoside (PH-11) is still continuing. Aucubin, acteoside and isoacteoside are key metabolites on chemotaxonomic and pharmacological studies of Plantago species. Isolation of these compounds from P. holosteum and determination of positive results on wound healing and antiinflammatory activity studies supported and improved of chemotaxonomic and pharmacological studies on Plantago species. Key Words: Plantago species, wound healing effect, anti-inflammatory effect, hydrogen peroxide, oxidative damage, cytotoxic effect, isolation, phytochemistry Supporting Organizations: HUBAB (Project No: 014 D07 301 002-640) and HUBAB (Thesis Support / Project No: TDK-2017-13724)