Antioxidant Potential of the Extract of Green Tea (Camellia sinensis) and Red Tea (Hibiscus sabdariffa) in Atherogenesis Process in Rats with Atherogenic Diet

Tea is the second most-commonly consumed liquid after water. Several epidemiological studies indicated that polyphenol consumptionof green tea as well as other herbal polyphenol may reduce the incidence rate of degenerative diseases, particularly the risk ofatherosclerosis. Therefore, the potential and the antioxidant mechanism of the extract of green tea and red tea on the prevention ofendothelial dysfunction should be studied further. The objective of this study was to disclose the preventive effect of the administrationof green tea (Camellia sinensis) and red tea extract to oxidative stress and atherogenesis in rats given with atherogenic diet. This wasa laboratory experimental study using separate sample pretest-post-test control group design. The experimental animals of Wistarstrain Rattus norvegicus were randomly divided into seven groups, 1 pretest group, 4 treatment groups, i.e., atherogenic and red tea of150 mg (A+TM150), atherogenic and red tea of 300 mg (A+TM300), atherogenic and green tea 150 mg (A+TH150), and atherogenicand green tea 300 mg (A+TH300), and 2 control groups, normal diet (ND) and atherogenic diet (AD). Each group consist of four rats.Data were analyzed multivariately using computerized statistical program. This study revealed that foam cell count in aortic tissue ofAD group was significantly higher (p < 0.05) compared to that in ND group, and so were the F2 isoprostan and ADMA levels both inaortic tissue and serum. SOD activity either in aortic tissue or serum in AD group was lower but not significant than that in ND. Inall treatment groups (A+TM150, A+TM300, A+TH150, A+TH300), the four parameters showed significant difference (p < 0.05) ascompared to AD. The highest reduction of foam cells was found in A+TH150 group. The highest reduction of ADMA in tissue and serumwas found in A+TM300 group. The highest reduction of F2 isoprostan in endothelial tissue and serum was found in A+TM300 group.The highest increase of SOD in aortic tissue and serum was found in A+TH300. Atherogenic diet that given for 8 weeks successfullyinduced an oxidative stress and atherogenesis in rats. The administration of green tea and red tea was able to improve oxidative stressand reduce the progress of atherogenesis in rats with atherogenic diet. The preventive mechanism of red and green tea extract againstatherogenesis is by relieving oxidative stress through the increase of SOD activity.