Rooibos Tea - Health Benefits & Antioxidant

ROOIBOS Tea - Health Benefits & Antioxidant

Rooibos tea originates from the leaves and stems of the indigenous South African plant Aspalathus linearis. Rooibos tea is also known as Red-Bush and grows on high mountain ranges. Rooibos has gained much attention for clinical purposes in the case of nervous tension, allergies (dermatitis), and various digestive problems. Recently, antioxidant activity has also been attributed to the tea on the basis of its flavonoid content.

Constituents of Rooibos
The main flavonoids in rooibos are dihydrochalcone aspalthin, rutin, and orientin.

What does the research say about Rooibos?
Rooibos tea is a powerful antioxidant, has anti-HIV activity, may protect brain cells from damage by toxins, and additionally has anti-tumor potential. Rooibos tea administration prevents age-related accumulation of lipid peroxides in several regions of rat brain.

Dr. Sahelian says: I have rooibos tea on my kitchen counter, along with a dozen or so different teas, and I drink a cup once in a while. I like the pleasant taste.

Subscribe to our free Supplement Research Update newsletter at Physician Formulas. Once or twice a month we email a brief abstract of several studies on various supplements and natural medicine topics, and their practical interpretation by Ray Sahelian, M.D. We will discuss rooibos studies when they become available.

Rooibos Tea Research Update
Modulation of hepatic drug metabolizing enzymes and oxidative status by rooibos (Aspalathus linearis) and Honeybush (Cyclopia intermedia), green and black (Camellia sinensis) teas in rats.
J Agric Food Chem. 2003 Dec 31;51(27):8113-9.
Rooibos and honeybush teas significantly enhanced the activity of cytosolic glutathione S-transferase alpha. A significant to marginal increase in the activity of the microsomal UDP-glucuronosyl transferase was obtained with unprocessed rooibos and honeybush teas, respectively. Oxidized glutathione (GSSG) levels were significantly reduced in the liver of all tea treated rats while reduced glutathione (GSH) was markedly increased in the liver of the herbal tea treated rats. These changes resulted in a significant increase in the GSH/GSSG ratio by the unprocessed, processed rooibos and unprocessed honeybush teas. Green and black teas markedly to significantly decreased the oxygen radical absorbance capacity in liver homogenates, respectively. Modulation of phase II drug metabolizing enzymes and oxidative status in the liver may be important events in the protection against adverse effects related to mutagenesis and oxidative damage.

Unfermented rooibos tea: quantitative characterization of flavonoids by HPLC-UV and determination of the total antioxidant activity.
J Agric Food Chem. 2003 Dec 3;51(25):7472-4.
Unfermented rooibos originates from the leaves and the stems of the indigenous South African plant, Aspalathus linearis, and it has been reported to have a higher content of flavonoids compared to that of fermented rooibos. Main compounds determined were aspalathin, isoorientin, orientin, and rutin, followed in order by isovitexin, vitexin, isoquercitrin and hyperoside, quercetin, luteolin and chrysoeryol.

Hepatoprotective effect of rooibos tea (Aspalathus linearis) on CCl4-induced liver damage in rats.
Physiol Res. 2003;52(4):461-6.
Hepatoprotective properties of rooibos tea (Aspalathus linearis) were investigated in a rat model of liver injury induced by carbon tetrachloride (CCl(4)). 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.

Effects of rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo.
Biosci Biotechnol Biochem. 2001 Oct;65(10):2137-45.
Rooibos tea contains a large amount of flavonoids and acts as a potent antioxidant. In this study, we examined the effects of Rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo. Our findings suggested that Rooibos tea extract may facilitate the antigen-specific antibody production through selective augmentation of IL-2 generation both in vitro and in vivo. Collectively, Rooibos tea intake may be of value in prophylaxis of the diseases involving a severe defect in Th1 immune response such as cancer, allergy, AIDS, and other infections.

Anti-human immunodeficiency virus activity of oligosaccharides from rooibos tea (Aspalathus linearis) extracts in vitro.
Leukemia. 1997 Apr;11 Suppl 3:128-30.
The active substances, acid polysaccharides, were extracted with 1% sodium hydroxide from the leaves of rooibos tea (Aspalathus linearis), Du Zhong Cha (Eucommia ulmoides Oliv.) and Japanese tea leaves (Camellia sinensis). The alkaline extracts of Rooibos tea and Du-Zhong tea leaves, but not Japanese tea leaves suppressed the HIV-induced cytopathicity using HIV (HTLV-III) infected MT-4 cells. From these results, it is probable that acid polysaccharides from rooibos tea were extremely safe, and that HIV infection may be suppressed by daily intake of the alkaline extracts of rooibos tea and Du-Zhong tea.

The suppression of age-related accumulation of lipid peroxides in rat brain by administration of Rooibos tea (Aspalathus linearis).
Neurosci Lett. 1995 Aug 18;196(1-2):85-8.
The protective effects of Rooibos tea, Aspalathus linearis, against damage to the central nervous system (CNS) accompanying aging were examined by both the thiobarbituric acid reaction (TBA) and magnetic resonance imaging (MRI) methods in brains of chronically Rooibos tea-treated rats. Ad libitum administration of Rooibos tea was begun with 3-month-old Wistar female rats and continued for 21 months. The contents of TBA reactive substances (TBARS) in the frontal cortex, occipital cortex, hippocampus and cerebellum in 24-month-old rats after administration with water were significantly higher than those in young rats (5 weeks old). However, no significant increase of TBARS was observed in Rooibos tea-administered aged rats. When MR images of the brains of 24-month-old rats with and without Rooibos tea as well as 5-week-old rats were taken, a decrease of the signal intensity was observed in the cerebral cortex, hippocampus and cerebellum in MR images of aged rats without Rooibos tea, whereas little change of the signal intensity was observed in MR images of the same regions of 24-month-old rats treated with Rooibos tea, whose images were similar to those of young rats. These observations suggested that (1) the age-related accumulation of lipid peroxides in the brain was closely related to the morphological changes observed by MRI, and (2) chronic Rooibos tea-administration prevented age-related accumulation of lipid peroxides in several regions of rat brain.