Characterization of phenolic compounds isolated from the Fraxinus angustifolia plant and several associated bioactivities

In Algeria, Fraxinus angustifolia Vahl (Oleaceae) is a prominent ingredient for the treatment of inflammatory diseases caused by oxidative stress. This study aimed to make a comparison between the phenolic compound compositions of the ethanolic and aqueous extracts (decoction and infusion) of this plant and to test the antioxidant, cytotoxic and anti-pancreatic lipase activities of the ethanolic extracts from the leaf and bark. The identification and quantification of phenolic compounds was carried out by HPLC-DAD-MS and the antioxidant activity was assessed according to three methods: Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging activity and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity. The cytotoxic effect was investigated using the human colon adenocarcinoma cell line HCT-116; while pancreatic lipase inhibitory activity was examined using 4-nitrophenyl butyrate (NPB) as a substrate. A large variety of phenolic compounds were detected and the content of the leaf was much higher than that of the bark. The ethanolic extracts from the leaf had a higher antioxidant capacity than those of the bark, however, the latter showed greater antilipase activity and cytotoxicity than the former. These results suggest that this plant may be an important source of active compounds with a variety of biological activities which justify its use in traditional medicine.