In vitro biological propensities and chemical profiling of Euphorbia milii Des Moul (Euphorbiaceae): A novel source for bioactive agents

The plants of Euphorbia genus have been extensively studied for their nutritive and therapeutic purposes. The present research is the foremost effort to investigate and compare the biological activities and chemical composition of dichloromethane (DCM) and methanol (MeOH) solvent extracts of Euphorbia milii Des Moul aerial and root parts. Antioxidant potential was determined using six different (FRAP, CUPRAC, Phosphomolybdenum, DPPH, ABTS and ferrous chelation) methods. The enzyme inhibition effects of the tested extracts were evaluated against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), alpha-glucosidase, alpha-amylase and tyrosinase. Similarly, the amount of total phenolic and flavonoid contents were assessed via spectrophotometric methods and individual secondary metabolites were also determined using UHPLC-MS analysis. Methanolic extracts from both aerial and root parts contained the highest contents for phenolic and flavonoids which tends to correlate with their significant DPPH, ABTS (radical scavenging), FRAP, CUPRAC (reducing power) and alpha-glucosidase inhibition potentials. While, both the DCM extracts containing the lowest bioactive contents were most active in the phosphomolybdenum assay, cholinesterases and tyrosinase inhibition. The root extracts proved to be a better source of bioactive antioxidant molecules. Additionally, UHPLC-MS profiling of both the methanolic extracts revealed the presence of total 16 secondary metabolites belonging to five major groups (phenolic, flavonoid, coumarin, glycoside and alkaloid). To conclude, our results suggest that E. milii can be considered as a promising lead origin for natural bioactive enzyme inhibitory and antioxidant compounds which could pave the way for industrial applications.