Total phenolic content, in vitro antioxidant activity and chemical composition of plant extracts from semiarid Mexican region

Objective: To determine the extraction suitable conditions of total phenolic content (TPC) by heat reflux system, antioxidant activities and HPLC characterization of the aqueous-ethanolic extracts of Jatropha dioica (J. dioica) (Dragon's blood), Flourensia cernua (F. cernua) (Tar bush), Eucaljptus camaldulensis (E. canialdulensis) (Eucalyptus) and Turrtera diffusa (T. diffusa) (Damianm. Methods: TPC was evaluated by the well known colorimetric assay using Folin Ciocalteu reagent. The antioxidant activities were assayed by three methods based on scavenging of DPPH, ABTS and by lipid oxidation inhibition. The chemical composition of the extracts obtained was subject to HPLC analysis. Results: 'ITC in the plant extracts ranged from 2.3 to 14.12 mg gal lie acid equivalents/g for J. dioica and E. camaldulensis, respectively. The plant extracts of F. centua, E. camaldulensis and 7'. diffusa showed similar strong antioxidant activities on scavenging of DPPH and lipid oxidation inhibition. In contras!, J. dioica extracts had lowest potential antioxidant in three assays used. HPLC assay showed the presence of several phenolic compounds in the extracts used. Conclusions: The results obtained suggest that F. cernua, E. camaldulensis and T. diffitsa are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.