Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye
Tezin Onay Tarihi: 2012
Tezin Dili: İngilizce
Öğrenci: Melike Sever
Asıl Danışman (Eş Danışmanlı Tezler İçin): Orhan Adali
Eş Danışman: Alaattin Şen
Özet:
Epilobium hirsutum L. (Onagraceae) is a flowering, tall and perennial
plant and native to Eurasia. It shows analgesic, anti-microbial and
anti-proliferative activity, and it is used in our country as an
alternative medicine. The pharmacological effect of Epilobium hirsutum
L. could be explained by the presence of polyphenolics including
steroids, tannins and flavonoids in the aerial parts. Viscum album L.
(Loranthaceae) is a shrub that grows as an epiphyte on the branches of
deciduous trees. It involves in the enhancement of macrophage phagocytic
and cytotoxic mediated abilities as well as the strengthening the
immune system. CYP24A1 and CYP27B1 are members of cytochrome P450
superfamily and the most important enzymes involved in the metabolism of
vitamin D3. CYP27B1 and CYP24A1 are mitochondrial enzymes and also
known as 25-hydroxyvitamin D3 1alpha-hydroxylase and 24-hydroxylase,
respectively. CYP24A1 involves in 24-hydroxylation of 25-OH-D3 and
1,25-(OH)2D3 which is required for the catabolism of vitamin D3
compounds while CYP27B1 involves in 1?-hydroxylation of 25-OH-D3 into
1,25-(OH)2D3. In this study, in vivo effects of Epilobium hirsutum and
Viscum album (subspecies growing on pine-trees-subsp. austriacum
(Wiesb.) Vollmann) on rat liver CYP24A1 and CYP27B1 mRNA and protein
expressions were investigated. To achieve this goal, 37.5 mg water
extract of Epilobium hirsutum L./kg body weight/day was
intraperitoneally injected to male rats for 9 days. To study the effect
of Viscum album L., 10 mg water extract of Viscum album L./kg body
weight/day was injected with the same conditions. After decapitation,
livers were removed and S1.5 fractions were prepared. Effects of
Epilobium hirsutum L. and Viscum album L. on rat liver mRNA and protein
expressions were analyzed by qRT-PCR and western blotting, respectively.
Epilobium hirsutum L. extract caused 31% and 18% decrease in rat liver
CYP24A1 (p<0.0001) and CYP27B1 (p<0.05) protein expressions,
respectively. The effect of Epilobium hirsutum L. on mRNA expression of
CYP24A1 could not be observed, because CYP24A1 mRNA was almost
undetectable in liver. Injection of Epilobium hirsutum L. to rats caused
2.7 fold increase in mRNA expression of CYP27B1 with respect to
controls and normalized with GAPDH (Glyceraldehyde 3-phosphate
dehydrogenase) expression as an internal reference (p<0.005). Viscum
album L. caused 17% decrease in CYP24A1 protein expression (p<0.05).
When rats injected with plant extract of Viscum album L., 18% decrease
in CYP27B1 protein expression was observed (p<0.05). The effect of
Viscum album L. on mRNA expression of CYP24A1 could not be observed
since CYP24A1 mRNA was almost undetectable in liver. Injection of Viscum
album L. to rats caused 3.8 fold increase in mRNA expression of CYP27B1
with respect to controls and normalized with GAPDH (Glyceraldehyde
3-phosphate dehydrogenase) expression as an internal reference
(p<0.005). In conclusion, vitamin D3 metabolism may be affected by
medicinal plants Epilobium hirsutum L. and Viscum album L. due to the
changes in mRNA and protein expressions of CYP24A1 and CYP27B1 enzymes.