Sinomenine hydrochloride inhibits the progression of plasma cell mastitis by regulating IL-6/JAK2/STAT3 pathway

Plasma cell mastitis (PCM) is a special form of mastitis characterized by periductal inflammation and large-scale plasma cell infiltration. At present, the recurrence rate of PCM after excision is quite high, making PCM a major problem for mammary surgeons. However, no effective drug exists for the treatment of PCM. Numerous studies have demonstrated that Sinomenine hydrochloride (SH) has potent anti-inflammatory and immunoregulatory properties. However, the efficacy and the underlying mechanisms of SH in the treatment of PCM remain unclear. In the present study, we first investigated the therapeutic effects of SH in the PCM mouse model and clarified the possible mechanisms. We found that the levels of plasmocytes and lymphocytes infiltration were alleviated significantly in the 100 mg/kg SH group compared to the control group. In addition, few CD138+ plasma cells were found in the mammary glands of the 100 mg/kg SH group. The levels of Bcl-2 in the 100 mg/kg SH group were dramatically decreased compared with those in the saline group. Mechanistically, we demonstrated that SH inhibited the progression of PCM mainly through downregulating IL-6/JAK2/STAT3 levels. Collectively, our results suggested that SH could inhibit the progression of PCM by suppressing IL-6/JAK2/STAT3 cascades and ultimately achieve a therapeutic effect in PCM. This study provides theoretical support for the clinical application of SH in the treatment of PCM.