Investigation of the composition and antioxidant activity of daphne sericea and daphne gnidioides

The aim of the study is to investigate the composition of the extracts obtained from Daphne sericea L. ve Daphne gnidioides L, belonging to Thymelaeaceae family, and their antioxidant activities by various methods. Crude extracts were isolated using acetone, methanol and n-hexane by shaking for three days at room temperature after being harvested and dried. Chemical composition of the plant extracts was investigated by performing phenolic composition profile analysis using HPLC-DAD, chlorophyll a, chlorophyll b, total carotenoid, flavanoid and phenolic content analyses. DPPH., ABTS.+, hydroxyl (.OH) and superoxide anion radical (O2.-) scavenging and oxygen radical absorption (ORAC) assays were performed to determine in vitro antioxidant (radical scavenging) activities. Antioxidant activity tests measuring lipid oxidation inhibiting capacity were carried using follow up of thiobarbituric acid reactive substances (TBARS) and measuring lipid oxidation inhibition capacity in low density lipoprotein (LDL) and bovine brain lipozomes (BBE). The results obtained showed that methanol and acetone extracts containing phenolic compounds at important levels generally exhibited radical scavenging activities at levels not to be underestimated. They were found to have effects as lipid oxidation inhibitors comparable with some of the positive control antioxidants, BHT, α-tocopherol, ferulic acid and quercetin, used to compare with them under the same conditions. Methanolic crude extract of D. gnidioides, especially, was found to exhibit in vitro antioxidant activity and lipid oxidation inhibiting properties similar to one or more of the positive controls in most cases.