Figure 5. Tetrandrine-primed MSC attenuated TNF-α secretion by macrophages (in vitro) and in a mouse ear skin inflammation model (in vivo).

(A) RAW264.7 mouse macrophages were treated with 100 ng/mL LPS for 24 h and then co-cultured with MSC primed with 5 μM or 10 μM tetrandrine for 24 h, with or without inhibitors. Mouse TNF-α in the conditioned medium was measured by ELISA. (B) 1 × 10⁶ tetrandrine-primed MSC were retro-orbitally injected into a mouse ear skin LPS-inflammation model. 18 h after injection, primed MSC significantly decreased the TNF-α level in the inflamed ear (LPS ear) compared to unprimed MSC, as detected via ELISA of homogenized ear tissue. T-MSC: tetrandrine-primed MSC; (L): LPS-stimulated; *, **, ***, ^†P < 0.05.