Anti-inflammatory effects of saponins derived from the roots of Platycodon grandiflorus in lipopolysaccharide-stimulated BV2 microglial cells

• Published in: International journal of molecular medicine 2013-06, Vol.31 (6), p.1357-1366
• Main Authors: JANG, KYUNG-JUN, KIM, HONG KI, HAN, MIN HO, OH, YOU NA, YOON, HYUN-MIN, CHUNG, YOON HO, KIM, GI YOUNG, HWANG, HYE JIN, KIM, BYUNG WOO, CHOI, YUNG HYUN
• Format: Article
• Language: English
• Subjects: AKT; Alzheimer's disease; anti-inflammation; Cytokines; Experiments; Gene expression; Inflammation; Kinases; mitogen-activated protein kinases; Neurotoxicity; nuclear factor-κB; Phosphorylation; Platycodon grandiflorus; saponins; Tuberculosis; Tumor necrosis factor-TNF
• ISSN: 1107-3756; 1791-244X
• DOI: 10.3892/ijmm.2013.1330

Radix platycodi is the root of Platycodon grandiflorus A. DC, which has been widely used as a food material and for the treatment of a number of chronic inflammatory diseases in traditional oriental medicine. In this study, the anti-inflammatory effects of the saponins isolated from radix platycodi (PGS) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated BV2 murine microglial cells were examined. We also investigated the effects of PGS on LPS-induced nuclear factor-κB (NF-κB) activation and phosphoinositide 3-kinase (PI3K)/ AKT and mitogen-activated protein kinase (MAPK) signaling pathways. Following stimulation with LPS, elevated nitric oxide (NO), prostaglandin E2 (PGE2) and pro-inflammatory cytokine production was detected in the BV2 microglial cells. However, PGS significantly inhibited the excessive production of NO, PGE2 and pro-inflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in a concentration-dependent manner without causing any cytotoxic effects. In addition, PGS suppressed NF-κB translocation and inhibited the LPS-induced phosphorylation of AKT and MAPKs. Our results indicate that the inhibitory effect of PGS on LPS-stimulated inflammatory response in BV2 microglial cells is associated with the suppression of NF-κB activation and the PI3K/AKT and MAPK signaling pathways. Therefore, these findings suggest that PGS may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory responses in activated microglial cells.