Nuclear factor (NF)-cB is a transcription factor regulating the expression of inflammatory and immune genes. In the present study, an extract from stem bark of Cinnamomum cassia Blume(Lauraceae) was discovered to have an inhibitory effect on LPS-induced NF-KB transcriptional activity, which was determined using macrophages RAW 264.7 transfected stably with an alkaline phosphatase reporter construct containing four copies of the NF-KB binding KB sequence. Following activity-guided fractionation, trans-cinnamaldehyde and 2-methoxycinnamaldehyde were identified as the NF-KB inhibitors from C cassia with IC50 values of 43 MM and 31 pM, respectively. As a positive control, caffeic acid phenethyl ester (CAPE) showed an IC50 value of 2 uM on NF-KB transcriptional activity. Both trans-cinnamaldehyde and 2-methoxycinnamaldehyde inhibited LPS-induced DNA binding activity of NF-KB in addition to NF-KB transcription-al activity.

Inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT), which is a key enzyme in triglyceride synthesis in eukaryotic organisms, has been proposed as one of the drug targets for treating obesity, type II diabetes mellitus, and metabolic syndrome. Bioassay-guided fractionation of EtOH extract of the flower buds of Tussilago farfara , using an in vitro DGAT enzyme assay, resulted in the isolation of four known sesquiterpenoids, tussilagonone (1), tussilagone (2), 7beta-(3-ethyl-cis-crotonoyloxy)-1alpha-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (3), and 8-angeloylxy-3,4-epoxy-bisabola-7(14),10-dien-2-one (4). DGAT1 inhibitory activity was studied by in vitro DGAT assay using rat liver microsomes and HepG2 cell microsomes. They showed DGAT1 inhibition with IC(50) values of 99.2 (1), 18.8 (2), 47.0 (3), and 211.1 (4) microM (for rat liver microsomes) and >1 mM (1), 49.1 (2), 160.7 (3), and 294.4 (4) microM (for HepG2 cell microsomes), respectively. Compound 2 showed the most potent inhibition against microsomal DGAT1 derived from rat liver and human hepatocellular carcinoma HepG2 cells and also significantly inhibited triglyceride synthesis by suppressing incorporation of [(14)C]acetate or [(14)C]glycerol into triglycerides in HepG2 cells. These findings suggest that tussilagone is a potential lead compound in the treatment of obesity and type 2 diabetes.

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