Objective: To compare the effect of different flavonoids on a cell anti-inflammation

immunity and chondrocyte proliferation based on the decomposed formula of Yaotongning capsule (YTNC)

in order to provide basis for screening candidate fractions treating rheumatoid bone diseases. Method: Five flavonoids:Glycyrrhiza uralensis (Fgu)

Epimedium sagittatum (Fes)

Carthamus tinctorius (Fct)

Davallia mariesii (Fdm)

Taxillus chinensis (Ftc)

at 50% and their proportional compounds were mixed into alkaloids of Strychnos nux-vomica and Ephedra sinica to obtain six formulas. Their half effective inhibitory concentration (IC50) and half effective concentrations (EC50) were adopted to evaluate the effect of the samples in promoting interleukin-6(IL-6)

IL-1β

tumor necrosis factor-α(TNF-α) inflammatory factor in macrophages Ana-1

inhibiting prostaglamd in E2(PGE2) secretion released from Ana-1 cells induced by LPS and promoting chondrocyte proliferation. The optimization method based on least squares was applied to calculate additive EC50/IC50 value of each sample. The interactions between the effective fractions were analzed by comparing the differences between the additive EC50/IC50 values with the corresponding experimental EC50/IC50 values. Result: The formula mainly consisting of Fdm had the best effect in promoting the secretion of IL-1β. The formula consisting of Fct had the best effect in stimulating IL-6 secretion

and other activities second only to the best formulas. The formula consisting of Strychnos nux-vomica

Ephedra sinica and the five flavonoids had the best effect among the inhibiting PGE2 secretion and promoting TNF-α secretion and chondrocyte proliferation

and a strong synergistic effect among the effective fractions in this formula was observed. In the model for promoting chondrocyte proliferation

there were strong antagonistic effects among effective fractions in the formula consisting of single flavonoid and alkaloid. Conclusion: There is excellent synergistic interaction among different kinds of flavonoids. Fct

Fdm and flavonoid mixtures have good synthetic pharmacological activities in anti-inflammation

immunomodulation and chondrocyte proliferation

suggesting that Fct

Fdm and flavonoid mixtures can be used to optimize candidate effective fractions of flavonoids for traditional Chinese medicines for treating rheumatism bone diseases.