RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Iris is the largest genus in the family Iridaceae. Iris plants are distributed in tropical regions of the world. They are used as ornamentals and traditionally used to treat a variety of ailments. AIM: This study aimed to evaluate the anti-inflammatory effect of flavonoids isolated from Iris spuria L. MATERIALS AND METHODS: The isolated flavonoids (1-4) were identified on the basis of different spectroscopic methods (1D- and 2D-NMR) and co-TLC with authentic samples. The anti-inflammatory effect was tested on lipopolysaccharide (LPS)-induced nitric oxide (NO) production from rat-isolated peritoneal macrophages. Modeling and docking simulations of the compounds were performed using Molecular Operating Environment software and the crystal structure of the murine inducible nitric oxide synthase (iNOS). RESULTS: Four flavonoids (1-4) had been isolated from the rhizomes of Iris spuria L. (Hocka Hoona) for the first time. They were characterized as 5,7,2'-trihydroxy-6-methoxyflavanone (1), tectorigenin 7-O-ß-D-glucopyranoside (2), tectorigenin 4'-O-ß-D-glucopyranoside (3), and tectorigenin 4'-O-[ß-D-glucopyranosyl(1 â 6)-ß-D-glucopyranoside] (4). The selective inducible NO synthase inhibitor; aminoguanidine was used as a positive control. The production of nitric oxide (NO) was inhibited in a dose-dependent manner of the isolated compounds along with isoflavonoids (5-9) previously isolated from Iris spuria L. (Calizona). A concentration of 60 µg/ml of all tested compounds showed a significant inhibitory effect compared to media with LPS. Molecular modeling experiments supported the obtained biological data. CONCLUSION: Our results reveal that flavonoids isolated from I. spuria L. (Hocka Hoona) and I. spuria L. (Calizona) appear to have a potential anti-inflammatory effect via inhibition of iNOS.
