Rhamnella gilgitica Attenuates Inflammatory Responses in LPS-Induced Murine Macrophages and Complete Freund's Adjuvant-Induced Arthritis Rats

Rhamnella gilgitica Mansf. et Melch, which belongs to the rhamnus family (Rhamnaceae), is traditionally used to treat rheumatism, swelling and pain in China. However, little is known about the pharmacological activities of this plant. The anti-inflammatory activities of the 70% ethanol extract of R. gilgitica (RG) in RAW264.7 macrophages and complete Freund's adjuvant (CFA)-induced arthritic rats are investigated in this study for the first time. The effects of RG on cell viability were determined by a MTT assay, and the effects of RG on pro-inflammatory mediators were analyzed by ELISA and Western blot. The effects of RG on paw thickness, thymus and spleen index were also examined in CFA-induced arthritic rats. RG suppressed the induction of proinflammatory mediators, including iNOS (inducible nitric oxide synthase), NO (nitric oxide), COX-2 (cyclooxygenase-2) and PG (prostaglandin) E2 in LPS stimulated RAW264.7 macrophages. RG also inhibited the phosphorylation and degradation of I.B-alpha, as well as the nuclear translocation of nuclear factor kappa B (NF-kappa B) p65. In addition, RG treatment significantly reduced the paw thickness in CFA-induced arthritic rats. Oral administration of RG led to a significant decrease of both the thymus and spleen index at a concentration of 100 mg/mL. Taken together, these findings suggest that RG might be an agent for further development in the treatment of a variety of inflammatory diseases.