Phenolic constituents, anti-inflammatory and antidiabetic activities of Cyperus laevigatus L

Abstract

Background: Cyperus species are well known traditional plants and used for several diseases around the world. Aim of the Study: Our study aimed to identification of the phenolic constituents in addition to evaluation of different extracts of Cyperus laevigatus L as antioxidant, anti-inflammatory and antidiabetic agents. Materials and Methods: The phenolic constituents were identified using spectroscopic techniques. The antioxidant activity was evaluated using in vitro DPPH assay. Total extract, methanol and EtOAc fractions were evaluated for their anti-inflammatory activity using RAW 264.7 macrophages assay. Antidiabetic activity of the total extract was examined biochemically and histopathologically using streptozotocin-induced diabetic rats. Results: A new flavone, chrysoeriol 7-O-β-(6′-O-Acetyl-β-D-glucopyranosyl)-(1→4) glucopyranoside (1), along with seven knowns (2-8) were isolated from Cyperus laevigatus L. The structures of isolated compounds were established depending upon 1D, 2D-NMR and HR-ESI-MS. The MeOH and EtOAc fractions exhibited significant antioxidant activity while the isolated flavonoids exhibited from moderate to weak antioxidant activity. The total extract, MeOH and EtOAc fractions exhibited significant anti-inflammatory activity using LPS-stimulated RAW 264.7 macrophages model by decreasing of NO accumulation by 76 - 66% and 84 - 67%, of the original accumulation values with increasing concentrations in comparison with the reference drug, dexamethasone. The total extract exhibited antidiabetic activity in streptozotocin-induced diabetic rats and this effect was manifested by decreasing serum levels of glucose, glucagon and NO. It also increased level of insulin and promoted paraoxonase activity. Conclusion: These results proved that this plant may be multiple sources for medicinal natural drugs especially for anti-inflammatory and antidiabetic.