In vitro antioxidant and anti-neuroinflammatory effects of Elsholtzia blanda (Benth.) Benth

Abstract

Elsholtzia blanda (Benth.) Benth. (EBB) is a traditional plant in Nepal with bioactive properties, including antioxidant, cytotoxic, and antitumor activities. In this study, a methanol EBB extract was tested to evaluate the anti-inflammatory effect against lipopolysaccharide (LPS)-induced microglial (BV2) cells. EBB effectively suppressed LPS-induced nitric oxide production and inhibited the secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. In LPS-stimulated BV2 cells, EBB significantly inhibited inducible nitric oxide synthase (iNOS), TNF-α, IL-6, IL-1β, IL-8, IL-18, and IL-10 mRNA expression in a concentration-dependent manner. In particular, EBB significantly reduced the protein expression of iNOS and cyclooxygenase-2, which were upregulated by LPS. Further, EBB could alleviate the inflammatory response in microglia by suppressing the phosphorylation of mitogen-activated protein kinases. EBB also attenuated LPS-induced reactive oxygen species (ROS) in BV2 cells. In addition, EBB enhanced heme oxygenase-1 (HO-1) protein and mRNA expression. The present results show that an EBB extract could effectively suppress the neuroinflammatory response induced by LPS in BV2 cells. Accordingly, an EBB extract is a promising preventive agent against diseases involving neuroinflammatory responses.