Anti-oxidant activity with inhibition of osteoclastogenesis by Atractylodes Rhizoma extract

Astractylodes Rhizoma is commonly used in Korean folk medicine for digestion, diuresis, sedation, antibacterial agent. The present study was performed to explore the antioxidant capacities of methanolic extract of Astractylodes Rhizoma. In addition, its effect on the expression of inducible nitric oxide synthase (iNOS) in response to lipopolysaccharides (LPS) and osteoclastogenesis in macrophage cells was also tested.

The anti-oxidative activities were tested by measuring free radical scavenging activity (DPPH, NO) and reducing power. The potential mechanism of anti-oxidative action of Astractylodes Rhizoma extract was determined by performing Western blot analysis for iNOS expression in LPS-stimulated RAW 264.7 cells. The RAW cells were induced to osteoclastic cells by RANKL and LPS and the Astractylodes Rhizoma extract was tested to determine whether it inhibits osteoclastogenesis of the cells.

The extract exerted significant NO and DPPH radical scavenging activity and it had dramatic reducing power. Induction of iNOS and NO by LPS was significantly inhibited by the extract, suggesting that the Astractylodes Rhizoma extract inhibits nitric oxide (NO) production by suppressing iNOS expression. Strikingly, the Astractylodes Rhizoma extract significantly inhibited the osteclastic differentiation of RAW cells. The Astractylodes Rhizoma extract contains significant amount of anti-oxidant components including phenolics, flavonoids and anthocyanins.

These results suggest that methanolic extract of Astractylodes Rhizoma exerts remarkable anti-oxidant activity potentially via inhibiting free radicals and iNOS induction, those could lead to the inhibition of osteoclastogenesis.