Background : In ancient, roots of Rumex crispus, called wooi-daehwang, were used for various symptoms and diseases like cough, phlegm, bronchitis and hepatitis, caused inflammatory. As a part of ongoing research to elucidate and characterize anti-inflammatory nutraceuticals, solvent-partitioned fractions from R. crispus root were tested for their ability to suppress inflammation. In this study, NO synthesis inhibitory activity of solvent-partitioned fractions from R. crispus root on LPS-stimulated RAW264.7 mouse macrophages was evaluated.
Methods and Results : The EtOH extracts were suspended in water. The aqueous layer was further partitioned in diethylether, ethylacetate and n-butanol, sequentially. RAW264.7 cells were seeded onto 96-well plates, and cells were allowed to adhere for 6 h and then were pretreated with the R. crispus root extracts for 24 h. Cellular nitric oxide (NO) production was stimulated by adding lipopolysaccharide (LPS). Absorbance was measured at 520 ㎚ by microplate reader. NO synthesis inhibitory activity potential of these fractions was evaluated by assessing NO production by LPS-stimulated RAW264.7 cells in the presence and absence of the solvent-partitioned R. crispus root fractions. NO synthesis inhibitory activity of diethylether fraction diluted in 50 ㎍/㎖, 25 ㎍/㎖, 12.5 ㎍/㎖, 6.25 ㎍/㎖, 3.125 ㎍/㎖ was 79.2%, 70.9%, 59.5%, 16.1%, and 11.8%, respectively. And NO synthesis inhibitory activity range of another fractions, EtOAc, n-BuOH and aqueous layer, were 0 - 30.2%, 0 - 20.1% and 3.8 - 22.4%, respectively.
Conclusion : From the above results, it showed that diethylether fraction have strong NO synthesis inhibitory activity, it was suggested that R. crispus root have NO synthesis inhibitory effects. R. crispus root possesses anthraquinones, such as chrysophanol, parietin, and anthrones etc. According to previous studies, R. crispus semen extract has analgesic and hepatoprotective effect as anti-inflammatory, and extract of R. napalensis has cyclooxygenase (COX)-2, COX-1 inhibitory and free radical scavenging effect. Our present study has shown that R. crispus root extracts anti-inflammatory effects probably by suppressing iNOS expressions, and resulting in the inhibition of NO synthesis.