Amygdalin attenuates neuroinflammatory injury via down-regulating toll-like receptors-2/toll-like receptors-4-nuclear factor kappa-B signaling pathway in BV2

Background: Amygdalin is the essential component of the traditional Chinese medicinal drug peach kernel. The early studies of amygdalin are mainly focused on antitussive and tumor anti-tumor, but there are few studies on the treatment of neuroinflammation. Objectives: The purpose of this study was to explore the anti-inflammatory effect of amygdalin on lipopolysaccharide (LPS)-induced neuron–microglia and its protective mechanism for toll-like receptors (TLRs) signaling pathways. Materials and Methods: Griess, quantitative PCR, and flow cytometry were used to detect the influence of amygdalin on the release of inflammatory factors from BV2 mouse microglia (BV2 cells). The anti-inflammatory pathway of amygdalin was further explored by western blotting. At the same time, the effect of amygdalin on LPS-induced oxidative stress damage in BV2 cells was detected by WST-8 and fluorescence probe. Results: After LPS induction, the pro-inflammatory factors such as nitric oxide, interleukin-6, tumor necrosis factor-alpha, interleukin-1β, and recombinant NLR Family, Pyrin Domain Containing Protein3 were significantly increased. However, the levels were reversed significantly after treatment with amygdalin. In addition, amygdalin significantly inhibited the increase of TLR4, TLR2, and its downstream signal myeloid differentiation primary response gene 88 and P-NF-κB p65 in BV2 cells induced by LPS. Amygdalin can also reverse the abnormal expression of LPS-induced oxidative stress indexes such as cyclooxygenase-2, reactive oxygen species, and superoxide dismutase. Conclusion: Amygdalin may reduce the LPS-induced accumulation of pro-inflammatory substances via the down-regulating of the TLR2/TLR4-nuclear factor kappa-B signaling pathway.