Neochlorogenic Acid Inhibits Lipopolysaccharide-Induced Activation and Pro-inflammatory Responses in BV2 Microglial Cells

Microglia is the resident innate immune cells that sense pathogens and tissue injury in the central nervous system. Microglia becomes activated in response to injury, infection, and other stimuli that threaten neuronal survival. Microglia activation plays an important role in neurodegenerative diseases. Neochlorogenic acid (NCA) is a natural polyphenolic compound found in dried fruits and other plants. Although previous studies have shown that phenolic acids including NCA have outstanding antioxidant, antibacterial, antiviral, and antipyretic activities, there has not yet been investigated for anti-inflammatory effects. Therefore, for the first time we have examined the potential of NCA to inhibit microglial activation and pro-inflammatory responses in the brain. We found that lipopolysaccharide-induced inducible nitric oxide synthase, and cyclooxygenase-2 expression, and nitric oxide formation was suppressed by NCA in a dose-dependent manner in BV2 microglia. NCA also inhibited the production of pro-inflammatory mediators, tumor necrosis factor-α and interleukin-1 beta. Furthermore, phosphorylated nuclear factor-kappa B p65 and p38 mitogen-activated protein kinase activation were blocked by NCA. Taken together, these results suggest that NCA exerts neuroprotective effects through the inhibition of pro-inflammatory pathways in activated microglia.