Objective: To observe the effect and mechanism of Astragalic Radix extract on chronic nonbacterial prostatitis in rats. Method: Sixty SD rats were randomly divided into 6 groups:the normal group (distilled water)

the model group (distilled water)

the cernilton group (100 mg·kg-1)

the low-

medium-and high-dose Astragalic Radix extract groups (100

200 and 400 mg·kg-1) of 10 rats each. The chronic nonbacterial prostatitis model was prepared in rats except those in the normal group by injecting carrageenan. The corresponding medicines were intragastrically administered to rats once daily for 3 weeks. The effects on levels of prostatic index (PI)

prostate-specific antigen (PSA)

tumor necrosis factor-α (TNF-α)

interleukin-1β(IL-1β)

cyclooxygenase-2 (COX-2)

prostaglandin E2 (PEG2)

transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) were determined. The pathological changes of prostate tissue in rats were observed. Result: Compared with the normal group

the levels of PI

PSA

TNF-α

IL-1β

COX-2

PEG2

TGF-β1 and CTGF increased in the model group (P<0.01). Moreover

the pathological results showed obvious inflammatory cell infiltration and fibrosis in the model group. Compared with model group

the levels of PI

PSA

TNF-α

IL-1β

COX-2

PEG2

TGF-β1 and CTGF decreased in the Astragalic Radix extract groups (P<0.01). Meanwhile

the pathological morphology had good improvement. Conclusion: This study confirmed Astragalic Radix extract had therapeutically effective effect on chronic nonbacterial prostatitis in rats.