|Free Radic Biol Med. 2015 Jan;78:135-46. |
|Identification of heme oxygenase-1 stimulators by a convenient ELISA-based bilirubin quantification assay.[Pubmed: 25462643 ]|
|The upregulation of heme oxygenase-1 (HO-1) has proven to be a useful tool for fighting inflammation. In order to identify new HO-1 inducers, an efficient screening method was developed which can provide new lead structures for drug research. |
METHODS AND RESULTS:
We designed a simple ELISA-based HO-1 enzyme activity assay, which allows for the screening of 12 compounds in parallel in the setting of a 96-well plate. The activity of known HO-1 inducers was confirmed, while the chalcones cardamonin, flavokawain A, calythropsin, 2',3,4'-trihydroxy-4-methoxychalcone (4-O-Methylbutein,THMC), and 2',4'-dihydroxy-3,4-dimethoxychalcone (DHDMC) were identified as new potent HO-1 inducers. The highest inductive power after 6h incubation was found at 10 uM for DHDMC (6.1-fold), carnosol (3.9-fold), butein (3.1-fold), THMC (2.9-fold), and zerumbone (2.5-fold). Moreover, the time dependence of HO-1 protein production for DHDMC was compared to its enzyme activity, which was further evaluated in the presence of lipopolysaccharide and the specific HO-1 inhibitor tin protoporphyrin IX.
Taken together, we developed a convenient and highly sensitive ELISA-based HO-1 enzyme activity assay, allowing the identification and characterization of molecules potentially useful for the treatment of inflammatory and autoimmune diseases.
|Flavonoids and polyacetylenes in Dahlia tenuicaulis[Reference: WebLink]|
METHODS AND RESULTS:
5,7,4′-Trimethoxyflavanone,5-hydroxy-7,4′-dimethoxyflavanone,2′-hydroxy-4,4′,6′-trimeth-oxychalcone, and a new naturally occurring compound, 5,7,4′-trimethoxyflavan-4-ol have been isolated from the leaves of Dahlia tenuicaulis Sorensen. Two chalcones, 4,2′,4′-trihydroxychalcone and 3,2′,4′-trihydroxy-4-methoxychalcone(4-O-Methylbutein), and 5-hydroxy-7,4′-dimethoxyflavanone have been isolated from the flower heads.
Minute amounts of the polyacetylene 1,3-diacetoxy-tetradeca-4,6-diene-8,10,12-triyne have been found in both leaves and flower heads, whereas 1-acetoxy-tetradeca-4,6-diene-8,10,12-triyne was present only in the flower heads.