Objective: To study the curative effect and mechanism of the water extract from Siraitiae Fructus on acute pharyngitis model rats. Method: For 5 consecutive days

the ammonia saray was used to establish the animal model of acute pharyngitis. the modeling rats were randomly divided into blank group

dexamethasone group

the water extract of Siraitiae Fructus groups (0.5

1.5

4.5 g·kg-1)

and lavage administration for 5 days.The pharyngeal pathological changed

white blood cell count (WBC) and the expression of interleukin (IL)-1β

IL-6 and tumor necrosis factor alpha(TNF )-α in serum were observed. Result: The middle and high dose of the water extract of Siraitiae Fructus could improve the pathological changes (P<0.01) and WBC (P<0.05

P<0.01). It had obvious inhibitory effect on the expression of IL-1β(P<0.05

P<0.01)

IL-6 (P<0.01) and TNF-α (P<0.01) in serum. Conclusion: The water extract of Siraitiae Fructus has good treatment effect on the acute pharyngitis

its mechanism may be related to inhibition of pharyngeal pathological changes and the expression of inflammatory cytokine.