Hepatic, renal and endogenous antioxidant status modulatory effects of chronic co-supplementation of rooibos (Aspalathus linearis) and red palm oil (Elaeis guineensis) in male Wistar rats

Abstract

Background: This study investigated the hepatic, renal and endogenous antioxidant status modulatory effects of chronic co-supplementation of rooibos and red palm oil (RPO) in male Wistar rats.Materials and Methods: Rats were randomized into four groups (n=10/group) and fed daily either standard rat chow (SRC) and water(Group I), SRC and the aqueous rooibos extract (2% w/v; Group II), SRC and RPO (200 µL/day) with water (Group III), or SRC andRPO (200 µL/day) with rooibos (2% w/v; Group IV) for 22 weeks.Results: Chronic feeding of rooibos, RPO or their combination did not induce any adverse hepatic or renal effects, as shown by serumlevels of alkaline phosphatase, alanine- and aspartate aminotransferase, lactate dehydrogenase, albumin, creatinine, blood urea nitrogenand uric acid. Histopathology analyses showed that liver from the three supplementation groups displayed normal hepatichistoarchitecture. Chronic feeding of RPO did not influence the redox status in the blood and liver significantly. Supplementation ofrooibos alone for 22 weeks significantly (P<0.05) increased the reduced glutathione (GSH) level, GSH/GSSG ratio and catalase (CAT)activity in the liver. Co-supplementation of rooibos and RPO significantly (P<0.05) increased plasma total polyphenol content, troloxequivalent antioxidant capacity (TEAC), as well as blood GSH and GSH/GSSG ratio. Plasma conjugated dienes (CD) and hepaticmalondialdehyde (MDA) levels were reduced significantly by the combination treatment, which also increased significantly the activityof CAT, glutathione reductase (GR), as well as the GSH/GSSG ratio in the liver.Conclusion: Our results suggest that chronic feeding of an aqueous fermented rooibos extract alone or in combination with RPOmodulate the endogenous antioxidant system in rats. This modulation could be indicative of a threshold effect and/or an additive effectindicating a positive interaction between the bioactive components in the rooibos and RPO; however future studies are needed toelucidate the nature and specific mechanisms involved. Also, the health status of the individual/experimental animal should be consideredbefore antioxidant supplementation, as it is suggested to affect the outcome.

Hepatic, renal and endogenous antioxidant status modulatory effects of chronic co-supplementation of rooibos (Aspalathus linearis) and red palm oil (Elaeis guineensis) in male Wistar rats (PDF Download Available).