Effect of Canavalia gladiata Extract Fermented with Aspergillus oryzae on the Development of Atopic Dermatitis in NC/Nga Mice

Canavalia gladiata has been used as a Chinese traditional folk medicine for its anti-inflammatory properties. However, the use of C. gladiata is limited because it contains antinutritional and allergy-causing proteins. We fermented C. gladiata with Aspergillus oryzae and investigated the effects of fermented C. gladiata (FCG) on the development of atopic dermatitis (AD) in mice. The mice were divided into five groups: untreated Balb/c mice; AD control (NC/Nga mice); FCGH (NC/Nga mice fed a dietary supplement of 300 mg/kg fermented C. gladiata water extract); FCG30 (NC/Nga mice fed a dietary supplement of 300 mg/kg of fermented C. gladiata 30% ethanol extract), and FCG80 (NC/Nga mice fed a dietary supplement of 300 mg/kg of fermented C. gladiata 80% ethanol extract). We found increases in the nonessential amino acids and essential amino acid in the FCG compared with the non-FCG. FCG attenuated macroscopic and histopathological changes in dorsal skin of mice when compared with the AD control group. The FCG30 and FCG80 groups, in particular, showed significant decreases in scratching episodes when compared with the AD control group. FCG improved immune responses, including increases in IgE and histamine for AD, through attenuation of Th1/Th2 cytokine imbalance and the production of proinflammatory cytokines and chemokines. We suggest that FCG may have benefits for improvement of AD function by improving the balance of Th1/Th2 cytokines and by producing anti-inflammatory effects.