The influence of Rooibos (Aspalathus linearis) on adrenal steroidogenic P450 enzymes

Date
2009-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
This study: 1. Describes the preparation of unfermented and fermented rooibos methanol and aqueous extracts. 2. Investigates the influence of unfermented and fermented rooibos methanol and aqueous extracts on the binding of natural steroid substrates to ovine adrenal microsomal cytochrome P450 enzymes, demonstrating that the binding of natural steroids is inhibited in the presence of rooibos extracts. 3. Describes an assay demonstrating the inhibitory effect of rooibos extracts on the catalytic activity of cytochrome 17α-hydroxylase (CYP17) and cytochrome 21-hydroxylase (CYP21) in ovine adrenal microsomes. 4. Investigates the influence of unfermented and fermented rooibos methanol extracts on the catalytic activity of individual cytochrome P450 enzymes – CYP17 and baboon CYP21, that are expressed in COS1 cells. 5. Demonstrates that fractions of the unfermented rooibos methanol extract inhibits the binding of natural steroid substrate to microsomal cytochrome P450 enzymes as well as the catalytic activity of baboon CYP21 expressed in COS1 cells. 6. Investigates the inhibitory influence of individual rooibos flavonoids on the catalytic activity of baboon CYP21 expressed in COS1 cells.
Description
Thesis (MSc (Biochemistry))--University of Stellenbosch, 2009.
Keywords
Aspalathus linearis, Cytochrome P-450, Adrenal steroidogenesis, Flavonoids, Enzymes, Metalloenzymes, Dissertations -- Biochemistry, Theses -- Biochemistry
Citation