Hepatoprotective properties of rooibos tea (Aspalathus linearis) were investigated in a rat model of liver injury induced by carbon tetrachloride (CCl4). Rooibos tea, like N-acetyl-L-cysteine which was used for the comparison, showed histological regression of steatosis and cirrhosis in the liver tissue with a significant inhibition of the increase of liver tissue concentrations of malondialdehyde, triacylglycerols and cholesterol. Simultaneously, rooibos tea significantly suppressed mainly the increase in plasma activities of aminotransferases (ALT, AST), alkaline phosphatase and billirubin concentrations, which are considered as markers of liver functional state. The antifibrotic effect in the experimental model of hepatic cirrhosis of rats suggests the use of rooibos tea as a plant hepatoprotector in the diet of patients with hepatopathies., O. Uličná, M. Greksák, O. Vančová, L. Zlatoš, Š. Galbavý, P. Božek, M. Nakano., and Obsahuje bibliografii
The aim of this study was to investigate the effects of rooibos tea as a natural source of a wide scale of antioxidants on the prevention and treatment of oxidative stress in streptozotocin-induced diabetic rats. Expected significant changes of biochemical parameters characteristic for experimental diabetic state were found in plasma and tissues eight weeks after single dose streptozotocin application. Administration of aqueous and alkaline extracts of rooibos tea (or N-acetyl-L-cysteine for comparison) to diabetic rats did not affect markers of the diabetic status (glucose, glycated hemoglobin and fructosamine). Besides the parameters characterizing hepatotoxic effect of streptozotocin, rooibos tea significantly lowered advanced glycation end-products (AGEs) and malondialdehyde (MDA) in the plasma and in different tissues of diabetic rats, particularly MDA concentration in the lens. From these results we can conclude that antioxidant compounds in rooibos tea partially prevent oxidative stress and they are effective in both hydrophobic and hydrophilic biological systems. Therefore, rooibos tea as a commonly used beverage can be recommended as an excellent adjuvant support for the prevention and therapy of diabetic vascular complications, particularly for protecting ocular membrane systems against their peroxidation by reactive oxygen species.