English

Abstract

The aim of this study was to determine the content of phenolic compounds and flavonoids, the antibacterial, antioxidant and cytotoxicity activities of hydroethanolic extracts of root, stem, leaf and fruit of Euphorbia cotinifolia. Phytochemical screening was performed using spectrophotometric methods (phenolic and flavonoid content) and liquid cromatography. The antibacterial activity was determined by agar diffusion and broth microdilution technique. Additionally, antioxidant activity was determined by diphenylpicrylhydrazyl (DPPH) radical scavenging method and cytotoxicity by the MTT method using BHK-21 (newborn hamster’s kidney) cells. All extracts presented notable content of phenolic compounds, flavonoids and tannins. The high-performance liquid chromatography with photodiode array detection (HPLC-DAD) analysis showed higher concentration of phenolic compounds in dried leaves than in fresh leaves and it indicated the presence of caffeic acid. The extracts of leaf, stem, root and fruit showed activity against five gram-positive bacteria, six gram-negative bacteria and two yeasts, but not for mycobacterial. The highest antioxidant activity was exhibited in the extract of dried leaf (EC50 = 7.32 μg/ml). Extracts showed no cytotoxicity at the concentrations tested. All extracts showed antibacterial, antifungal and antioxidant activities, phenolic compounds, tannins and flavonoids. The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents. Key words: Euphorbia cotinifolia, antimibacterial, antioxidant, phenolic compounds, flavonoids.