Forsythiaside attenuates lipopolysaccharide-induced inflammatory responses in the bursa of Fabricius of chickens by downregulating the NF-κB signaling pathway

Forsythiaside inhibits cigarette smoke-induced lung inflammation by activation of Nrf2 and inhibition of NF-κB

Cigarette smoke has been reported to be the major cause of chronic obstructive pulmonary disease (COPD). It causes persistent inflammation by regulating the redox-sensitive pathways. Forsythiaside, an active constituent isolated from the Chinese medicinal herb Forsythia suspensa, has been reported to have anti-inflammatory and anti-oxidant effects. Thus, in this study, we investigated the protective effects of forsythiaside against cigarette smoke-induced lung inflammation in mice. COPD mice model was established by cigarette smoke. Forsythiaside was given 2h before cigarette smoke exposure for five consecutive days. Bronchoalveolar lavage fluid and lung tissues were collected to assess pathological changes, lipid peroxidation, inflammatory cytokine production, Nrf-2, and NF-κB expression. Our results showed that forsythiaside attenuated the infiltration of inflammatory cells, NO and inflammatory cytokines TNF-α, IL-6 and IL-1β production, and reversed the CS-induced decrease of glutathione/glutathione disulfide (GSH/GSSG) ratio. Western blot analysis showed that forsythiaside inhibited cigarette smoke-induced NF-κB activation. In addition, forsythiaside dose-dependently up-regulated the expression of Nrf2 and HO-1. In conclusion, forsythiaside protected against cigarette smoke-induced lung injury through activating Nrf2 and inhibiting NF-κB signaling pathway.

Lycium ruthenicum polysaccharide attenuates inflammation through inhibiting TLR4/NF-κB signaling pathway

Polysaccharide has been reported to possess diverse biological activities, however, the inflammatory activity of polysaccharide isolated from Lycium ruthenicum remains unknown so far. In the present study, we investigated the effects of L. ruthenicum polysaccharide (LRGP3) on inflammatory reaction induced by lipopolysaccharide (LPS) in mouse macrophage RAW264.7 cells and some potential underlying mechanisms. Our results showed that LRGP3 treatment significantly inhibited the LPS-induced NO production and the mRNA expression of iNOS, as well as the level of Toll-like receptor 4 (TLR4). Furthermore, LRGP3 treatment prevented the IκBα degradation and reduced phospho-NF-κB p65 protein expression in LPS-stimulated RAW264.7 cells. Meanwhile, the levels of pro-inflammatory cytokines, such as interleukin (IL)-α, IL-6, tumor necrosis factor (TNF)-α were suppressed by LRGP3 in LPS-stimulated RAW264.7 cells. Taken together, our results suggested that LRGP3 attenuated LPS-induced inflammation via inhibiting TLR4/NF-κB signaling pathway.