Short-term and sub-chronic dietary exposure to aspalathin-enriched green rooibos (Aspalathus linearis) extract affects rat liver function and antioxidant status
Date
2015-12-18
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
An aspalathin-enriched green rooibos (Aspalathus linearis) extract (GRE) was fed to male
Fischer rats in two independent studies for 28 and 90 days. The average dietary total polyphenol
(TP) intake was 75.6 and 62.7 mg Gallic acid equivalents (GAE)/kg body weight (bw)/day over
28 and 90 days, respectively, equaling human equivalent doses (HEDs) of 12.3 and 10.2 GAE mg/kg
bw/day. Aspalathin intake of 29.5 mg/kg bw/day represents a HED of 4.8 mg/kg bw/day (90 day
study). Consumption of GRE increased feed intake significantly (p < 0.05) compared to the control
after 90 days, but no effect on body and organ weight parameters was observed. GRE significantly
(p < 0.05) reduced serum total cholesterol and iron levels, whilst significantly (p < 0.05) increasing
alkaline phosphatase enzyme activity after 90 days. Endogenous antioxidant enzyme activity in
the liver, i.e., catalase and superoxide dismutase activity, was not adversely affected. Glutathione
reductase activity significantly (p < 0.05) increased after 28 days, while glutathione (GSH) content
was decreased after 90 days, suggesting an altered glutathione redox cycle. Quantitative Real
Time polymerase chain reaction (PCR) analysis showed altered expression of certain antioxidant
defense and oxidative stress related genes, indicative, among others, of an underlying oxidative
stress related to changes in the GSH redox pathway and possible biliary dysfunction.
Description
CITATION: Van der Merwe, J. D., De Beer, D., Joubert, E. & Gelderblom, W. C. A. 2015. Short-term and sub-chronic dietary exposure to aspalathin-enriched green rooibos (Aspalathus linearis) extract affects rat liver function and antioxidant status. Molecules, 20(12):22674-22690, doi:10.3390/molecules201219868.
The original publication is available at http://www.mdpi.com/journal/molecules
The original publication is available at http://www.mdpi.com/journal/molecules
Keywords
Herbal tea, Aspalathus linearis
Citation
Van der Merwe, J. D., De Beer, D., Joubert, E. & Gelderblom, W. C. A. 2015. Short-term and sub-chronic dietary exposure to aspalathin-enriched green rooibos (Aspalathus linearis) extract affects rat liver function and antioxidant status. Molecules, 20(12):22674-22690, doi:10.3390/molecules201219868.