Anti-Inflammatory and Neuroprotective Effects of Constituents Isolated fromRhodiola rosea

To determine the biological activity of Rhodiola rosea , the protein expression of iNOS and proinflammatory cytokines was measured after the activation of murine microglial BV2 cells by LPS under the exposure of constituents of Rhodiola rosea : crude extract, rosin, rosarin, and salidroside (each 1–50  μ g/mL). The LPS-induced expression of iNOS and cytokines in BV2 cells was suppressed by the constituents of Rhodiola rosea in a concentration-dependent manner. Also the expression of the proinflammatory factors iNOS, IL-1 β , and TNF- α in the kidney and prefrontal cortex of brain in mice was suppressed by the oral administration of Rhodiola rosea crude extract (500 mg/kg). To determine the neuroprotective effect of constituents of Rhodiola rosea , neuronal cells were activated by L-glutamate, and neurotoxicity was analyzed. The L-glutamate-induced neurotoxicity was suppressed by the treatment with rosin but not by rosarin. The level of phosphorylated MAPK, pJNK, and pp38 was increased by L-glutamate treatment but decreased by the treatment with rosin and salidroside. These results indicate that Rhodiola rosea may have therapeutic potential for the treatment of inflammation and neurodegenerative disease.