Antioxidant activities, cytotoxic properties and total phenolic content of Syzygium malaccense (L.) Merr. & LM Perry leaves extracts: A West Sumatera Indonesian plant

The purpose of this study was to determine the antioxidant activities and cytotoxic properties of the various extracts of Syzygium malaccense leaves and its correlation with total phenolic content. To deteunine the antioxidant properties 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide methods have been used while to determine cytotoxic properties brine shrimp lethality test method has been used. Furthermore, to determine total phenolic content the Folin-Ciocalteu method has been carried out. The results showed that all extracts have antioxidant activity both against DPPH and hydrogen peroxide. IC50 hexane, ethyl acetate and methanol extracts against DPPH were 181.26; 34.35; 36.87 mg/mL respectively and against hydrogen peroxide were 18.24; 12.03; and 13.04mg/mL, respectively. All extracts have also cytotoxicity properties on brine shrimp A. Salina where LC50 of hexane, ethyl acetate and methanol extracts were 204.69, 70.03 and 329.76 mu g/mL, respectively. Total phenolic content of hexane, ethyl acetate and methanol extracts were 587.17 +/- 19.48, 1617.47 +/- 4.63 and 1319.49 +/- 9.26 mu g of gallic acid equivalents (GAE)/10 mg extracts, respectively. Antioxidant activity of these extracts are increased if their phenolic content is increased with the regression equations between IC50 and phenolic content is y= -0.1529x +263.75 with R-2 = 0.9289 for DPPH method and y= 0.0062x + 21.745 with R-2 = 0.9825 for hydrogen peroxide method.