Antioxidant response of brain regions in adult mice after daily consumption of herbal tea from Sideritis clandestina
Oxidative stress is related to aging and the pathobiology of neurodegenerative diseases, although it is not yet known whether it is a cause, a consequence or an epiphenomenon. The species of genus Sideritis (mountain tea) (Lamiaceae) are rich in polyphenolic compounds and a mountain tea of its dried aerial parts is widely consumed in Greece. This study evaluated the total antioxidant status of the brain regions of mice drinking herbal tea from Sideritis clandestina subsp. peloponnesiaca. The above plant was chosen after the evaluation, in vitro, of the polyphenolic content (using Folin-Ciocalteu method) and the antioxidant properties (using FRAP and DPPH assays) of infusions from several populations of the species Sideritis clandestina, grown in different regions of Peloponnesus. In the present study, male adult mice were given separately, water (control) and two different doses of the herbal tea, 4% and 2% (w/v), for a period of 6 weeks, at the end of which the antioxidant capacity of the cerebral cortex, cerebellum and midbrain, was determined using FRAP assay. Results showed that consumption of both 4% and 2% herbal tea elevated the antioxidant capacity of midbrain by 72% and 126% (p<0.05), respectively, whereas the antioxidant power of cerebral cortex and cerebellum was not affected significantly. A hierarchy was also observed between the control brain regions according to their antioxidant properties (cerebral cortex > cerebellum > midbrain). Our results show neuroprotective effect of consumption of herbal tea of S. clandestina subsp. peloponnesiaca in a brain region specific way, which deserves further investigation.