Phellinus baumii ethyl acetate extract alleviated collagen type II induced arthritis in DBA/1 mice.

Mushrooms have a long history of dietary benefits in Asia due to their health-promoting effects. Phellinus baumii, a wild mushroom, has been reported to have anti-platelet, anti-inflammatory, anti-obesity and free radical scavenging activities. However, its anti-rheumatoid arthritis (RA) property remains poorly understood. Hence, we investigated the protective effect of Phellinus baumii ethyl acetate extract (PBEAE) against bovine collagen type II induced arthritis (CIA) in DBA/1 mice. PBEAE (50 and 150 mg/kg) reduced the CIA score and leukocyte count in draining lymph nodes (DLNs) and inflamed joints. PBEAE also attenuated the expressions of CD3⁺ (T cells), CD19⁺ (B cells), CD4⁺ (T-helper), CD8⁺ (T-cytotoxic), MHC class II/CD11c⁺ (antigen-presenting cells), double positives (B220⁺/CD23⁺ and CD3⁺/CD69⁺: early lymphocyte activation markers) and CD4⁺/CD25⁺ (activated T-helper) leukocyte subpopulations in DLNs. Likewise, CD3⁺ and Gr-1⁺CD11b⁺ (neutrophil) counts in inflamed joints were also decreased. Furthermore, PBEAE reduced the serum levels of anti-collagen type immunoglobulin G, tumor necrosis factor-α and interleukin (IL)-1ß and IL-6. Taken together, PBEAE impaired cellular recruitment to the inflamed joint and alleviated CIA, and thus could be considered as a potential agent against rheumatoid arthritis.

Phellinus baumii ethyl acetate extract inhibits lipopolysaccharide-induced iNOS, COX-2, and proinflammatory cytokine expression in RAW264.7 cells.

Mushrooms are valuable sources of biologically active compounds possessing anticancer, antiplatelet, and anti-inflammatory properties. Phellinus baumii is a mushroom used in folk medicine for a variety of human diseases. However, its potential anti-inflammatory effect has remained unclear. Therefore, we studied the effect of P. baumii ethyl acetate extract (PBEAE) on inflammatory mediator and proinflammatory cytokine protein and/or mRNA expression levels using the nitric oxide (NO) assay, enzyme immunoassay (EIA), western blot, and reverse transcription polymerase chain reaction (RT-PCR) in lipopolysaccharide (LPS)-stimulated macrophage like RAW264.7 cells. PBEAE markedly inhibited NO generation and prostaglandin E(2) (PGE(2)) synthesis in a concentration-dependent pattern without any cytotoxic effect at the concentration range used. PBEAE also suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. In addition, LPS-induced iNOS and COX-2 mRNA expression levels were dose-dependently inhibited by PBEAE pretreatment. Furthermore, PBEAE attenuated the mRNA expression levels of proinflammatory cytokines, specifically interleukin (IL)-1ß, IL-6, and granulocyte macrophage colony-stimulating factor (GM-CSF), in a concentration-dependent fashion. Our study suggests that P. baumii might exhibit anti-inflammatory properties by downregulating proinflammatory mediators. Thus, further study on compounds isolated from PBEAE is warranted to investigate the associated molecular mechanisms and identify the potential therapeutic targets.