Cytoprotective effect on oxidative stress and inhibitory effect on cellular aging of Uncaria sinensis Havil

Abstract

The ethanol extract from the hooks and stems of Uncaria sinensis Havil (Rubiaceae) exhibited significant inhibitory activity on oxidative stress and the age-dependent shortening of the telomeric DNA length. In the peroxidation model using t-BuOOH, the Uncaria sinensis extract showed a notable cytoprotective effect on the HEK-N/F cells with 65.0 ± 3.0% of cell viability when compared with control cells at a concentration of 50 μg/ml. In addition, the Uncaria sinensis extract exhibited a significant cytoprotective effect against UVB-induced oxidative damage. The life-span of the HEK-N/F cells was elongated by 201% as a result of the continuous administration of 3 μg/ml of the Uncaria sinensis extract compared to that of the control. These observations were attributed to the inhibitory effect of the Uncaria sinensis extract on the age-dependent shortening of the telomere length as shown by the Southern blots of the terminal restriction fragments (TRFs) of DNA extracted from subculture passages.