Effects Of The Active Ingredients Of Dendrobium Nobile On Inflammatory Factors From LPS-activated Astrocytes

Objective To investigate the impact of total alkaloids, dendrobine and polysaccharides extracted from Dendrobium nobile on inflammatory factors, which are produced and released by lipopolysaecharide (LPS)-activated rat cerebral astrocytes (Ac), and to explore the protective mechanisms of Dendrobium total alkaloids against LPS-induced astrocytes damage. Methods:The cerebral cortex of newborn rat was dissected and astrocytes were isolated and cultured. The 3rd generation of cultural astrocytes were randomly divided into control, model (LPS 10 ng/ml), total alkaloids (0.025,0.25 and 2.5 mg/L), dendrobine (0.025,2.5 mg/L), polysaccharide (0.025,0.25 and 2.5 mg/L). LPS stimulated astrocytes to produce and release a large number of inflammatory cytokines, on which the effects of different concentrations of total alkaloids, dendrobine and polysaccharide were examined. The cell viability was tested by MTS; the expressions of TNF-a, IL-6 mRNA in astrocytes were detected through real-time RT-PCR; the generation and release of TNF-a, IL-6 from astrocytes were evaluated via enzyme link immunosorbent assay (ELISA) assay. Results:1. LPS activated astrocytes resulting in significantly elevated absorbance tested by MTS, increased the level of NO, up-regulated the expressions of TNF-a and IL-6 mRNA and protein (compared with control group P<0.01); 2. The different concentrations of total alkaloids can decrease LPS-induced high absorbance, depress the high-level of NO, ameliorate the up-expression of TNF-a, IL-6 mRNA and protein by LPS (P<0.05); 3. The different concentrations of polysaccharides can significantly decrease the high-level of NO induced by LPS, whereas Dendrobine only at the high dose can depress the level of NO. Conclusion:1. Dendrobium total alkaloids can significantly inhibit the activation of astrocytes induced by LPS and reduce the release of inflammatory factors. These results indicated that Dendrobium total alkaloids exert neuroprotection through depressing the actived astrocytes.2. Dendrobine and polysaccharides can reduce the LPS-induced release of NO, this suggested the two components may play a role in anti-inflammatory effects of Dendrobium nobile.