In vivo effect of Epilobium hirsutum L. and Viscum album L. on protein and mRNA expressions of rat liver vitamin D3 metabolizing CYP24A1 and CYP27B1 enzymes


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.