Screening of Chinese medicinal plants for inhibition of NF-κB1 gene expression

Patients suffering from widespread chronic inflammatory diseases – like rheumatoid arthritis and asthma – have to endure serious side-effects due to long-term therapy based on the first-line therapeutics non-steroidal anti-inflammatory drugs (NSAIDs) or corticosteroids. Therefore, research into alternative therapies has been intensified in recent years, especially into the Traditional Chinese Medicine (TCM), that comprises a huge variety of anti-inflammatory plants. A crucial mediator of cellular inflammation is the Nuclear Transcription Factor kappa B (NF-κB) leading to transcription of various pro-inflammatory genes. In this study 68 TCM plants have been examined regarding their potential to decrease the mRNA-level of NF-κB1 in an in vitro gene expression assay. THP-1 cells were incubated with herbal extracts (20µg/ml) and stimulated with LPS, whereas parthenolide served as positive control. The expression level of NF-κB1 mRNA was determined by relative quantification using real-time PCR. The following extracts showed considerable inhibitory effects (>40%) on NF-κB1 gene expression: Aristolochia debilis DCM and MeOH, Asari species DCM, Cassia species MeOH and Chrysanthemum indicum DCM. These extracts were further investigated with a cell viability assay (XTT). The extracts of Asari species and Aristolochia debilis showed a high toxicity, whereas those of Cassia species and Chrysanthemum indicum did not affect cell survival. Since the inhibitory effect on NF-κB1 gene expression may contribute to the anti-inflammatory activity, further investigations of the active compounds are in progress.

Acknowledgements: This work was granted by the Austrian Science Foundation (NFN: Drugs from Nature Targeting Inflammation, S10705-B03).