Examination of the nitric oxide production-suppressing component in Tinospora tuberculata

The component of aqueous Tinospora tuberculata extract that inhibits nitric oxide (NO) production was examined using macrophages activated by the addi tion of lipopolysaccharide. The aqueous extract was partitioned with ethyl acetate. The aqueous layer was fractionated with a Diaion column. The resid ue of the aqueous extract was extracted with methanol, and partitioned with ethyl acetate. The ethyl acetate layer was found to be associated with a d istinct decrease in the NO level and inducible NO synthase. On further frac tionation, the subfraction of E-3 showed high anti-NO activity. N-trans-Fer uloyltyramine isolated from E-3 was identified as exhibiting strong anti-NO activity. This compound is the most active component of Tinospora tubercul ata with respect to the suppression of NO production.