HS-23, a Lonicera japonica extract, reverses sepsis-induced immunosuppression by inhibiting lymphocyte apoptosis

Ethnopharmacological relevance Lonicera japonica Thunberg, a widely used traditional Chinese medicine, possesses antibacterial, antiviral, and antiendotoxin activities. This study investigated the molecular mechanisms of HS-23, the ethanol extract of the dried flower buds of L. japonica, on sepsis-induced immunosuppression. Materials and methods Male ICR mice were intravenously administered HS-23 (10, 20, and 40 mg/kg) immediately (0 h) and 22 h after cecal ligation and puncture (CLP). The spleen was isolated for biochemical assays 24 h after CLP. Results HS-23 improved sepsis-induced mortality. CLP induced a marked decrease in the number of splenocytes, B cells, and natural killer cells, which was attenuated by HS-23. HS-23 also attenuated CLP-induced apoptosis in CD4⁺ and CD8⁺ T cells and inhibited both the intrinsic and extrinsic apoptotic pathway in the spleen. HS-23 attenuated the CLP-induced decrease in interleukin (IL)-17 production. CLP significantly decreased splenic production of tumor necrosis factor-α and IL-2, and these effects were attenuated by HS-23. Conclusion Our findings suggest that HS-23 reverses immunosuppression during the late phase of sepsis by inhibiting lymphocyte apoptosis and enhancing Th1 cytokine production. HS-23 warrants further evaluation as a potential therapeutic agent for the treatment of sepsis.