To investigate the effect of total flavonoids of Sangbaipi (Mori Cortex), a traditional Chinese medicine monomer, on the regulation of inflammatory response in the rats with otitis media through the transforming growth factor-β1 (TGF-β1)/signal transducer and activator of transcription3 (STAT3)/nuclear factor-κB (NF-κB) signaling pathway.

Forty SPF grade SD rats were randomly divided into a normal group, a model group, a low-dose group of total flavonoids of Sangbaipi (Mori Cortex) and a high-dose group of total flavonoids of Sangbaipi (Mori Cortex), each with 10 rats. Normal group and model group were given the equal doses of 0.9% sodium chloride solution by gavage. The low and high-dose groups of total flavonoids of Sangbaipi (Mori Cortex) were given the corresponding doses (10, 30 mg/kg) once a day. The rats in each group were orally administered continuously for 14 days. The histopathological changes of hematoxylin-eosin (HE) stained tissues in each group were observed. The pathological scores of the tympanic membrane, auditory function, thickness of the middle ear mucosa and the protein expression levels of inflammatory factors and TGF-β1, STAT3 and NF-κB among different groups were compared.

In the model group, low-dose group and high-dose group, the pathological scores of the tympanic membrane, Auditory Brainstem Response (ABR) response threshold, middle ear mucosal thickness, serum levels of interleukin (IL)-1β, IL-6 and TGF-β1, as well as the grayscale values of STAT3 and NF-κB proteins were higher than those in the normal group (P<0.05). The pathological scores of the tympanic membrane, ABR response threshold, middle ear mucosal thickness, serum levels of IL-1β, IL-6 and TGF-β1, as well as the grayscale values of STAT3 and NF-κB proteins in the low-dose and high-dose groups were lower than those of the model group (P<0.05). The pathological score of the tympanic membrane, Auditory Brainstem Response (ABR) response threshold, thickness of the middle ear mucosa, serum levels of IL-1β, IL-6, and TGF-β1, as well as the gray values of STAT3 and NF-κB proteins in the high-dose group lower than those in the low-dose group (P<0.05).

The total flavonoids of Sangbaipi (Mori Cortex), a traditional Chinese medicine monomer, can alleviate the inflammatory response in the rats with otitis media, and its mechanism may be related to the regulation of TGF-β1/STAT3/NF-κB signaling pathway expression.