Antimicrobial, Antioxidant and Antihemolytic Activities of Two Daphne gnidium Leaves Extracts

Abstract

In this study, Daphne gnidium leaves extracts were screened for their Phenolic content, antimicrobial, antioxidant and antihemolitic activities. Decoction and maceration were used to obtain the aqueous (Aq E) and the ethanolic extract (Et E), respectively. Total phenolic content was determined using Folin–Ciocalteu reagent. Moreover, a disc diffusion assay and inhibition of mycelial growth test were applied to evaluate the antibacterial and antifungal activity. The extracts were also tested for their antioxidant effects in terms of DPPH, OH, H2O2, β-carotene, and ferrous ion chelating assays. To investigate antihemolytic activity, the 2,2,-azobis (2-amidinopropane) dihydrochloride (AAPH) was used to induce erythrocyte oxidative hemolysis. Results indicated that ethanolic extract (Et E) contains the highest polyphenol content (775.25 μg GAE/mg extract). The Et E inhibited the growth of bacterial strains with inhibition zone diameters from 7 to 15 mm. In contrast, no activities have been found against all fungal strains. In antihemolytic test, aqueous and ethanolic extracts showed almost the same effect with an HT50 value of 106 min. Ethanolic extract was found to be more active in DPPH and β-carotene assays (IC50: 5.76 μg/ml and 70% inhibition respectively). However, the aqueous extract showed a greater effect than the ethanolic one in metal chelating activity assay (IC50: 170 μg/ml), OH scavenging effect assay (IC50: 9.67 μg/ml) and H2O2 scavenging assay (IC50: 133.2 μg/ml).