Bioactive Compounds and Antioxidant Activity of Ethanolic Extracts from the Leaves of Tetraclinis Articulate (Vahl) Masters

Abstract

Tetraclinis articulata (Vahl) masters is an endemic plant from the south-western Mediterranean. This species was widely used in Algeria for its medicinal virtues. In this work, dried leaves of T. articulata have been analyzed for their polyphenol and flavonoid composition, and antioxidant activity. The influence of extraction time (30–240 min) and concentration of ethanol (40, 60 and 80%) on the extraction yield of phenolic and flavonoid compounds of extracts were investigated. The extraction yield of T. articulata ranged from 10.03 to 40.45% and the maximum extraction yield was obtained at 240 min with 60% of ethanol. The evaluation of total phenolic compounds was realized by the method of the Folin–Ciocalteu and the estimation of total flavonoid compounds was determined using a method of aluminum chloride. In addition, the antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity method. The highest extraction yield of total phenolic (95.28 mg GAE/g) and flavonoid (36.70 mg QE/g) compounds was obtained with 60% ethanol concentration for an extraction time of 210 min and 120 min, respectively. The best antioxidant activity was obtained from the T. articulata leaves extracted for an extraction time of 120 min with 60% ethanol concentration. The results demonstrated that an ethanol concentration of 60% was better to obtain extracts of T. articulata with greater amount of bioactive compounds and antioxidant activity.