Free radical-scavenging activity of sequential leaf extracts of Embothrium coccineum

The aim of this study was to evaluate the influence of phenolic, flavonoid, and anthraquinones from sequential extracts (n-hexane, dichloromethane, ethyl acetate, and ethanol) of Embothrium coccineum leaves on the antioxidant capacity, cell viability, and toxicity of the same, in order to find possible sources for novel antioxidants for food and pharmaceutical formulations. Antioxidant potential of sequential extracts was analyzed by five different assays: 2,2-diphenyl-1- picrylhydrazyl radical scavenging activity assay (DPPH), hydrogen peroxide scavenging activity (H2O2), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and total reactive antioxidant potential (TRAP). An in vitro growth inhibition assay was performed using sulphorhodamine dye to quantify cell viability, while an in vivo brine shrimp lethality test was used to quantify toxicity. The dichloromethane extract has a greater efficiency in scavenging free radicals, combined with low toxicity, and no effect exhibited on healthy cells, compared to observations for the other extracts tested. Further research is in progress to identify and separate the active compounds of active extracts and investigate the protective effect of extracts on human dermal fibroblast injury induced by hydrogen peroxide.