Lycopus maackianus Makino belongs to the Labiatae family and is used in traditional medicine to manage postpartum edema and boils. However, few studies on its antioxidant and anti-inflammatory effects have been conducted. Here, the compounds in L. maackianus methanol (MeOH) extract were profiled using ultra-high-performance liquid chromatography-time-of-flight high-resolution mass spectrometry analysis. The antioxidant activity of L. maackianus MeOH extract was shown to increase in a concentration-dependent manner by investigating the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity. Next, in lipopolysaccharide-treated BV2 cells, L. maackianus extract inactivated the nuclear factor-kappa B pathway, inhibiting nitric oxide, prostaglandin E2, interleukin-6, and tumor necrosis factor-α production and inducible nitric oxide synthase and cyclooxygenase-2 protein expression. Furthermore, L. maackianus extract protected against oxidative stress-induced cellular damage in glutamate-stimulated HT22 cells. L. maackianus MeOH extract induced heme oxygenase-1 expression and increased the translocation of nuclear factor E2-related factor 2 in the nucleus, thus exhibiting antioxidant and anti-inflammatory effects. Moreover, the in vivo antioxidant and anti-inflammatory effects of the extract were demonstrated in a zebrafish (Danio rerio) model treated with hydrogen peroxide and lipopolysaccharide. MeOH L. maackianus extract showed antioxidant and anti-neuroinflammatory effects by increasing the expression of heme oxygenase-1, establishing its therapeutic potential for neuroinflammatory diseases.
Keywords: BV2 microglia; HT22 hippocampus; Lycopus maackianus; anti-neuroinflammatory effects; antioxidant activity; zebrafish.