Amelioration of inflammatory responses by Socheongryong-Tang, a traditional herbal medicine, in RAW 264.7 cells and rats

Socheongryong-Tang (SCRT) is a natural medicine prescription that has been mainly used in East Asia for the treatment of inflammatory disorders, including asthma and allergic rhinitis. The present study evaluated the anti-inflammatory effects of SCRT on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and in a rat model of carrageenan (CA)-induced paw edema. Levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and prostaglandin E(2) (PGE(2)) in the culture supernatant were quantified and nitric oxide (NO) production was monitored. In addition, the effect of SCRT on the protein expression of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was assessed by western blot analysis. Furthermore, the effects of SCRT on acute inflammation in vivo and changes in the histomorphometry and histopathology of paw skin were observed using CA-treated rats. SCRT (1 mg/ml) inhibited the LPS-induced changes in the protein expression of NF-κB, JNK, ERK1/2, iNOS and COX-2, as well as the production of NO, PGE(2) and cytokines. In the rat paw edema assay, administration of 1 g/kg of lyophilized powder obtained from the aqueous extracts of SCRT for 3 consecutive days inhibited the CA-induced increases in skin thickness, mast cell degranulation, and infiltration of inflammatory cells in the ventral and dorsal pedis skin within 4 h. These results demonstrated that SCRT exerts its anti-inflammatory activities in LPS-stimulated RAW 264.7 cells through decreasing the production of inflammatory mediators, including PGE(2), NO and cytokines, via suppression of the NF-κB and JNK and ERK1/2 signaling pathways. In addition, the data of the CA-induced paw edema indicated an anti-edema effect of SCRT. SCRT (1 g/kg) reduced acute edematous inflammation through inhibition of mast cell degranulation and infiltration of inflammatory cells. Therefore, the present study provided scientific evidence for the anti-inflammatory activities of SCRT as well as the underlying mechanisms.