syringin and Edema

Syringin, a major active substance isolated from Eleutherococcus senticosus, has been found to have anti-inflammatory effect. The aim of this study was to investigate the effects and underlying mechanisms of syringin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.. We established an LPS-induced ALI model in mice. We also detected the lung wet-to-dry ratio, myeloperoxidase activity, and inflammatory cytokines tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6 to estimate the index of lung injury in mice. Furthermore, the expression of nuclear factor-erythroid 2-related factor-2 (Nrf2), heme oxygenase-1, and nuclear factor κB (NF-κB) was detected by Western blot analysis.. The results showed that the increases in lung wet-to-dry ratio, myeloperoxidase activity, malondialdehyde content, and levels of tumor necrosis factor alpha, IL-1β, and IL-6 induced by LPS were significantly inhibited by treatment of syringin. The phosphorylation of IκB-α and p65 NF-κB caused by LPS was inhibited by syringin. Furthermore, syringin was found to upregulate the expression of Nrf2 and heme oxygenase 1.. In conclusion, the results suggest that syringin protects against LPS-induced ALI by activating Nrf2 and inhibiting NF-κB signaling pathway.

Topics: Acute Lung Injury; Animals; Cytokines; Drug Evaluation, Preclinical; Edema; Eleutherococcus; Glucosides; Heme Oxygenase-1; Lipopolysaccharides; Lung; Male; Malondialdehyde; Membrane Proteins; Mice, Inbred BALB C; NF-E2-Related Factor 2; NF-kappa B; Peroxidase; Phenylpropionates; Phytotherapy; Plant Extracts

In the present study, syringin, isolated by activity-guided fractionation of the ethyl acetate (EtOAc) extracts of the stem bark of Magnolia sieboldii, and sinapyl alcohol, the hydrolysate of syringin, were evaluated for anti-inflammatory and antinociceptive activities. Sinapyl alcohol (20, 30 mg/kg/day, p. o.) inhibited increased vascular permeability by acetic acid in mice and reduced acute paw edema by carrageenan in rats more so than syringin. When analgesic activity was measured using the acetic acid-induced writhing test and the hot plate test, sinapyl alcohol was much more potent than syringin in a mouse model. In addition, sinapyl alcohol more potently inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor (TNF)-alpha production by macrophages than syringin. Consistent with these observations, the expression levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 was reduced by sinapyl alcohol in a concentration-dependent manner. These results suggest that the anti-inflammatory and antinociceptive effects of syringin after oral administration may be attributed to its in vivo transformation to sinapyl alcohol.

Topics: Acetic Acid; Administration, Oral; Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Carrageenan; Dose-Response Relationship, Drug; Edema; Glucosides; Magnolia; Male; Mice; Mice, Inbred ICR; Phenylpropionates; Phytotherapy; Plant Extracts