Objective: To investigate the curative effect of Pogostemonis Herba oil in guinea pigs in the acute otitis media model. Method: Doubling dilution was used to determine the MICs (minimum inhibitory concentration) of Pogostemonis Herba oil against common pathogens in otitis media(Staphylococcus aureus

Moraxella catarrhalis and Pseudomonas aeruginosa). The acute otitis media model was established by puncturing tympanic membrane and injecting methicilln-resistant S. aureus(MRSA) at 1.0 McF· mL-1 into the middle ear. After the successful modeling

the guinea pigs were divided into six groups:Pogostemonis Herba high

middle and low dose groups (100

50

25 g· L-1)

positive groups (Vancomycin 100 g· L-1 and Ofoxacin 5 g· L-1) and the model group. All of them were dropped with corresponding drugs through ears. The model group was given isopyknic normal saline

0.04 mL a time

2 times a day

for consecutively days. Their middle ear cavities were cleaned with sterilized saline water before the first

second

fourth

sixth

eighth administration. The cleaning liquors were diluted and used for counting bacterial colonies. At the seventh day after the administration

the guinea pigs were beheaded to collect middle ear cavities for HE staining and observe the inflammatory cell infiltration and distribution on middle ear mucosa. Result: Pogostemonis Herba showed a MIC value of 0.21 g· L-1 against S. aureus and 0.026 g· L-1 against M. catarrhalis

but with no effect against P. aeruginosa. Compared with the model group

Pogostemonis Herba oil can significantly reduce the bacteria number in middle ears of guinea pigs in the acute otitis media model (P<0.05) and the inflammatory cell infiltration at the middle ear mucosa. Conclusion: Pogostemonis Herba oil has a good efficacy in treating guinea pigs in the acute otitis media model.