Inhibitory effects of lupane‑type triterpenoid saponins from the leaves of Acanthopanax gracilistylus on lipopolysaccharide-induced TNF‑α, IL‑1β and high‑mobility group box 1 release in macrophages.

Acanthopanax gracilistylus (AGS) has long been used in traditional Chinese medicine for the treatment of various inflammatory diseases. 3‑O‑β‑D‑glucopyranosyl 3α, 11α‑dihydroxylup‑20(29)‑en‑28‑oic acid, acantrifoside A, acankoreoside D, acankoreoside B and acankoreoside A are major lupane‑type triterpenoid saponins derived from AGS. In the present study, these five saponins were isolated from AGS by chromatography and their anti‑inflammatory activities were investigated in lipopolysaccharide (LPS)‑treated RAW264.7 macrophages. Cell viability was evaluated by MTT assay. Tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β and NF‑κB p65 were measured by ELISA. The gene expression levels of TNF‑α and IL‑1β was detected by reverse‑transcription polymerase chain reaction. And high‑mobility group box 1 (HMGB1) were analyzed by western blotting. The results demonstrated that these five saponins significantly suppressed LPS‑induced expression of TNF‑α and IL‑1β at the mRNA and protein level in RAW264.7 cells. Further analysis revealed that acankoreoside A and acankoreoside B were able to reduce the secretion of HMGB1 and NF‑κB activity induced by LPS in RAW264.7 macrophages. Taken together, these results suggested that the anti‑inflammatory activity of AGS‑derived saponins may be associated with the downregulation of TNF‑α and IL‑1β, and the 'late‑phase' proinflammatory cytokine HMGB1, via negative regulation of the NF‑κB pathway in RAW264.7 cells.