Anti-Inflammatory Effects of Liriope platyphylla in LPS-Stimulated Macrophages and Endotoxemic Mice

In the present study, the anti-inflammatory and antisepticemic activities of a water extract of Liriope platyphylla (LP) were investigated. We first estimated the scavenging activity of DPPH and the hydroxyl radical and total phenolic contents of LP. Results indicated that LP, a rich source of phenolic compounds, showed a remarkable radical scavenging capacity. A MTT assay showed that LP treatment did not affect the toxicity against the RAW 264.7 macrophage cells, up to the concentration of 500 mu g/mL. Treatment of LP significantly attenuated the production of inflammatory mediators, such as nitric oxide (NO), interleukin-6 (IL-6), tumor-necrosis factor (TNF)-alpha and prostaglandin (PG)E-2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages cells. Moreover, LP contributed to the down-regulation of inducible NO synthase (iNOS) and TNF-alpha mRNA expression, as well as cyclooxygenase-2 (COX-2) protein expression. A western blotting assay further showed that LP inhibited activation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-kappa B. In an animal experiment using an LPS-induced septicemia model in C57BL/6 mice, oral administration of LP (40 mg/kg body weight) markedly reduced the level of TNF-alpha and IL-6 in serum and protected against LPS-induced lethal shock in mice. Taken together, the results of treatments of LP on inhibited LPS-induced inflammatory responses in both in vitro and in vivo models and indicate it may be a promising neutraceutical or medicinal agent to prevent or cure inflammation-related disease.