Anti-inflammatory Effects of Various Mushrooms in LPS-stimulated RAW264.7 Cells

Abstract

Mushrooms have been widely cultivated and consumed as foods and herbal medicines owing to their various biological properties. However, few studies have evaluated the anti-inflammatory effects of mushrooms. Here, we investigated the effects of mushroom extracts (MEs) on lipopolysaccharide (LPS)-induced inflammation in macrophages (RAW264.7 cells). First, we extracted MEs with either water or ethanol. Using LPS-treated RAW264.7 cells, we measured cell proliferation and NO production. Gene expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 (IL-6), and IL-1β was assessed by RT-PCR, and protein abundance of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) and phosphorylation of p65 were determined by immunoblotting. MEs prepared using both water and ethanol inhibited LPS-induced inflammation in RAW264.7 cells. Nitric oxide (NO) levels induced by LPS were reduced by treatment with MEs. Isaria japonica Yasuda water extracts and Umbilicaria esculenta (Miyoshi) Minks ethanol extracts significantly decreased the mRNA expression of inflammation-related cytokine genes including TNF-α, IL-6, and IL-1β. Similarly, the protein abundance of iNOS and COX-2 was also decreased. The phosphorylation of p65, a subunit of nuclear factor-κB was at least partly suppressed by MEs. This study suggests that mushrooms could be included in the diet to prevent and treat macrophage-related chronic immune diseases.