Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Sağlık Bilimleri Enstitüsü, Farmakognozi Anabilim Dalı, Turkey
Approval Date: 2019
Thesis Language: Turkish
Student: FATMA TUĞÇE GÜRAĞAÇ DERELİ
Supervisor: Esra Akkol
Abstract:
In ethnobotanical studies conducted in Turkey, it was determined that there are numerous plants used
for the treatment of central nervous system disorders among the people. The present study aimed to
investigate the antidepressant efficacy of several plants which are used for central nervous system
disorders among the people such as Centaurea kurdica Reichardt, Corydalis erdelii Zucc., Lotus
corniculatus L. subsp. corniculatus, Melilotus officinalis (L.) Pall., Primula vulgaris Huds. and
Xanthium orientale L. subsp. italicum (Moretti) Greuter. In this context, taking into account the use
of plants among the population, firstly the aqueous extracts and then n-hexane, ethyl acetate (EtOAc)
and methanol (MeOH) extracts were prepared from the branches, leaves and flowers of C. kurdica,
leaves of C. erdelii, M. officinalis and X. orientale subsp. italicum, aerial parts of L. corniculatus
subsp. corniculatus and rhizomes of P.vulgaris, successively. The efficacy of the prepared extracts
were evaluated using several in vivo models of depression. As the n-hexane extract prepared from
the branches and leaves and the methanolic extract prepared from the flowers of C. kurdica showed
high antidepressant activity in depression models, it was decided to conduct bioactivity guided
fractionation technique on C. kurdica. In this respect, the n-hexane extract was fractionated by silica
gel column chromatography to yield 5 main fractions [Fr. (1-42); Fr. (43-78); Fr. (79-105); Fr. (106-
139); Fr. (140-183)]. Fr. (43-78) and Fr. (140-183) showed significant activity in the used depression
models. According to isolation studies on these fractions, β-amyrin and the mixture of β-sitosterol
and stigmasterol were isolated from Fr. (43-78) and costunolide was isolated from Fr. (140-183). The
MeOH extract was applied to the vacuum liquid chromatography by using RP-18 silica gel column
fractionation was performed to obtain four main fractions [Fr. (1-4); Fr. (5-8); Fr. (9-23); Fr. (24-
28)]. Fr. (9-23) showed significant antidepressant activity in the used models. During the isolation
studies on this fraction quercitrin, isoquercetin and naringenin-7-O- glucopyranoside were obtained.
Consequently, the efficacy of C. kurdica against depression could be due to its sterol, flavonoid and
terpene derivative compounds.
Key Words : E t hnobotany, Asteraceae, Centaurea kurdica, Depression, Flavonoid, Sterol,
Sesquiterpene lactone