Objective: To investigate the effects of Rubiae Radix et Rhizoma extract (RRE) on liver

spleen injury and the expression of forkhead box P3(Foxp3) in adjuvant-induced arthritis (AIA) rats. Method: Totally 72 Wistar rats were randomly divided into normal control (Con) group

model (AIA) group

dexamethasone (Dex) (0.125 mg · kg-1) group and RRE low

medium and high dose groups (2.5

5

10 g · kg-1)

12 rats in each group. After 7 days of adaptive feeding

0.1 mL Freund's complete adjuvant (CFA) solution was injected subcutaneously into the hind paw of each rat to establish AIA models

while the rats in normal control group were injected with an equal volume of distilled water. Drugs were given by intragastric administration for 21 consecutive days. During the administration

the volume of the inflammatory side of the paw was measured by the drainage method

and the behavior and weight gain of the rats were observed. After 21 days of administration

the swelling degree of paw and viscera index were calculated; the levels of superoxide dismutase (SOD)

malondialdehyde (MDA)

myeloperoxidase (MPO) and nitric oxide (NO) in liver tissues were detected; histopathological changes in liver and spleen tissues were observed by hematoxylin-eosin (HE) staining; and the expression of Foxp3 protein in spleen tissues was detected by immunohistochemistry. Result: As compared with the normal group

the paw swelling was significantly increased; viscera indexes of spleen and liver were significantly decreased; levels of MDA and MPO were significantly increased

and Foxp3 protein expression in spleen tissues was significantly decreased in model group (P<0.05

P<0.01). As compared with the model group

the paw swelling was significantly reduced in RRE middle and high dose groups and Dex group (P<0.05

P<0.01)

but RRE low dose group showed no significant difference; viscera indexes of spleen and liver were significantly increased in RRE low

medium and high dose groups (P<0.01)

with improvement in inflammation changes of in liver and spleen tissues. The levels of MDA and MPO were significantly decreased in RRE low

medium and high dose groups and Dex group (P<0.05

P<0.01)

while the levels of SOD and NO were significantly decreased only in RRE high dose group and Dex group; Foxp3 protein expression was significantly up-regulated in RRE middle

high dose groups and Dex group (P<0.05

P<0.01). Conclusion: RRE has obvious anti-inflammatory activity

indicating that RRE can improve liver and spleen injury

increase the levels of MDA and MPO in liver tissues

and increase the expression of Foxp3 in the spleen tissues in AIA rats to enhance the body's immune tolerance ability.