Abstract: Numerous studies have demonstrated that aged black garlic (ABG) has strong anti-oxidant
activity. Little is known however regarding the anti-inflammatory activity of ABG. This study
was performed to identify and compare the anti-oxidant and anti-inflammatory effects of ABG
extract (ABGE) with those of fresh raw garlic (FRG) extract (FRGE). In addition, we investigated
which components are responsible for the observed effects. Hydrogen peroxide (H2O2) and
lipopolysaccharide (LPS) were used as a pro-oxidant and pro-inflammatory stressor, respectively.
ABGE showed high ABTS and DPPH radical scavenging activities and low ROS generation in
RAW264.7 cells compared with FRGE. However, inhibition of cyclooxygenase-2 and 5-lipooxygenase
activities by FRGE was stronger than that by ABGE. FRGE reduced PGE2, NO, IL-6, IL-1, LTD4,
and LTE4 production in LPS-activated RAW264.7 cells more than did ABGE. The combination of
FRGE and sugar (galactose, glucose, fructose, or sucrose), which is more abundant in ABGE than in
FRGE, decreased the anti-inflammatory activity compared with FRGE. FRGE-induced inhibition of
NF-B activation and pro-inflammatory gene expression was blocked by combination with sugars.
The lower anti-inflammatory activity in ABGE than FRGE could result from the presence of sugars.
Our results suggest that ABGE might be helpful for the treatment of diseases mediated predominantly
by ROS.