Effects of green tea, yerba mate and rooibos tea on C6 Astroglial cells

Abstract

Ethnopharmacological relevance: C amellia sinensis , A spalathus linearis and I lex paraguariensis are distributed throughout several continents, such as China, Africa and South America, where they are widely consumed as teas and are known for their antioxidant potential. Several studies discuss green tea properties and its high antioxidant capability, however, it becomes necessary to investigate the effect of infusions of other traditionally used species that are widely consumed as teas. Aim of study: To analyze the phenolic content and cytotoxicity of yerba mate (I . paraguariensis ), green tea (C . sinensis ) and rooibos (A . linearis ) infusions which possibly will advance the understanding and treatment of a number of neurodegenerative diseases Materials and methods: The effects of aqueous infusions of C . sinensis (CS) , A. linearis (AL) and I. paraguariensis (IP) had their polyphenolic content evaluated by Folin–Ciocalteu test and expressed as gallic acid equivalents (GAE%). Cellular viability of the C6 glial cells exposed to infusions at different concentrations (10500 µg/mL) for 1 h or 24 h, were evaluated by measuring MTT reduction. Results: The total polyphenolic content observed in CS is higher than in the IP and AL (19. 5; 17.1 and 16.9 GAE%, respectively), AL having a lower polyphenolic content. There was no significant differences observed regarding cell viability in the 1 h treatment. In the 24 h treatment, it was verified that AL and CS significantly decreased C6 viability only at a higher concentration, starting from 450 and 500 µg/mL, respectively. CS also showed a significant increase in C6 viability when compared to control, at 250 ᵰg/mL. On the other hand, IP significantly decreased cell viability at low concentrations (starting from 200 µg/mL). Conclusion: This study has shown that various compounds present in the aqueous extracts of CS and AL, with emphasis on the polyphenols, might have beneficial effects and should be further evaluated for the development of a healthpromoting functional beverage for the prevention or treatment of neurodegenerative diseases.