Berberis lycium Royle fruit extract mitigates oxi-inflammatory stress by suppressing NF-κB/MAPK signalling cascade in activated macrophages and Treg proliferation in splenic lymphocytes.

Abstract

Although Berberis plant species have been advocated as immune modulators, information regarding their mechanism(s) of action is limited. Therefore, in the present study we assessed the efficacy of Berberis lycium Royle fruit extract (BLFE) in the attenuation of lipopolysaccharide (LPS)-induced oxi-inflammatory aggravation and concanavalin A (Con-A)-induced proliferation in murine peritoneal macrophages and lymphocytes, respectively. BLFE strongly suppressed production of the oxidative and inflammatory effector molecules nitric oxide (NO), reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), inflammatory cytokines (TNF-α/IL-6/IL-1β/IFN-γ) as well as chemokines (MCP-1 and RANTES), with a concomitant enhancement in heme oxygenase-1 (HO-1) and IL-10 levels. Subsequent mechanistic analysis revealed that BLFE strongly inhibited the phosphorylation of IκBα as well as MAPKs such as extracellular signal-regulated kinase (ERK), p38 MAPK, and c-Jun NH2-terminal kinase (JNK), thereby directly resulting in the suppression of nuclear factor-κB (NF-ĸB) and c-Jun activation, ultimately culminating in the observed attenuation of inflammatory molecules. Additionally, BLFE appeared to mitigate Con-A-induced proliferation of Tregs (CD3+ CD4+ CD25+) thereby suggesting its modulatory effects on adaptive immune cells. UPLC-DAD-ESI-QTOF-MS/MS of BLFE revealed the presence of major bioactive phenolics and alkaloids including chlorogenic acid, rutin, catechin and quercetin 3-D-galactoside, berberine and magnoflorine, which could have synergistically contributed to the above findings. Overall, this work provides evidence that BLFE may be effective in the mitigation of inflammatory disorders, especially those associated with NF-κB/MAPK activation.