Improving antioxidant status in aged mice by 50% ethanol extract from red bean fermented by Bacillus subtilis.

Background: The purpose of this study was to investigate the effects of 50% ethanol extracts from red bean non-fermented (RBE) and fermented by Bacillus subtilis (RBNE) on the antioxidant status of aged ICR mouse.

Results: Compared to 2-month-old ICR mouse, the plasma total antioxidant status (TAS) in 12-month-old ICR mouse decreased about 57%, while malondialdehyde (MDA) levels in the liver and brain of 12-month-old ICR mouse increased 56% and 30%, respectively. Orally administration of RBE or RBNE could completely recover the changes of MDA and plasma TAS levels due to the aging process. Vitamin E contents declined 88% in the liver and 74% in the brain of aged ICR mouse. At a level of 0.3 or 0.6 g kg(-1) body weight, RBNE raised vitamin E content in the liver and brain; however, RBE showed no significant influence. All antioxidant enzymes activities in the liver and brain of aged ICR mouse decreased compared to those activities in 2-month-old ICR mouse. RBNE could significantly enhance the superoxide dismutase activity in the brain of aged ICR mouse.

Conclusion: Oral administration of RBE or RBNE could improve antioxidant status in aged ICR mouse. Fermentation by Bacillus subtilis could enhance the antioxidant properties of red bean.