The inhibitory effects of Ganoderma Lucidum on NFκB related inflammatory cytokines in activated BV‐2 microglial cells

Abstract

Neurodegenerative diseases have increased significantly over the last five years, and the increase in the elderly with Alzheimer’s and dementia requires increased attention and research design to combat this critical problem. Ganoderma Lucidum extract (GLE) is a potent ancient Asian remedy for extending the life and treatment of a variety of disease states. In the current study, we investigate the neuroprotective potential effects of Ganoderma Lucidum on LPS‐activated BV‐2 microglial cells. The LPS activated BV‐2 cells have been largely used as a model to illustrate the pro‐inflammatory process involved in the activation of signaling transduction pathways associated with neuronal injury. The methodology used in this work included cell viability, nitric oxide assay, screening of pro‐inflammatory cytokines using mouse cytokine arrays, individual ELISAs to validate data from the arrays, and RT‐PCR to investigate a possible signaling pathway for GLE neuroprotective effect in activated BV‐2 microglial cells. Cell viability results showed that increasing concentrations of GLE, ranging from 0.5 to 1.3 mg/ml, induced BV‐2 cytotoxicity in a dose‐response manner (IC50: 0.79 mg/ml). Also, the results obtained indicate that lower concentrations of GLE (< 0.5mg/ml) showed to be potent in reducing the release of nitric oxide in activated BV‐2 cells. The results from the cytokine arrays showed that GLE decreased the expression of several pro‐inflammatory cytokines including Granulocyte Colony Stimulating Factor (G‐CSF), Interleukin 1‐alpha (IL1‐α), Monocyte chemotactic protein‐5 (MCP‐5), Macrophage Inflammatory Protein 3 Alpha (MIP3‐α), and Regulated on Activation Normal T Expressed and Secreted (RANTES). The data obtained were further validated using individual ELISA, and the results showed that GLE was able to decrease the expression of each one of the downregulated proteins in the cytokine arrays. RT‐PCR was performed using different genes that are involved in the NFκB signaling activation. The results also showed that GLE decreases the mRNA expression of CHUK, NFκB 1/p150, and IKBKE, which are genes that participate in the NFκB translocation to the nucleus, and subsequent release of pro‐inflammatory cytokines. The findings suggest that GLE may be a new potential therapeutic option for decreasing inflammatory responses seen in Alzheimer’s and dementia patients.Support or Funding InformationSupported by a NIMHD Grant U54 007582