Phytochemical Screening, Total Phenolic Content and Antioxidant Activity of Syzygium zeylanicum Leaves
Syzygium zeylanicum is a species that is rarely known especially among the present community. Although the plant is palatable, lack of research has been carried out on it benefits to human health. The leaves of Syzygium zeylanicum were extracted using hexane, ethanol and water; and evaluated for its phytochemicals, total phenolic content and antioxidant activities. Specific reagents were used in the phytochemical screening to check for the presence of secondary metabolites. Total phenolic content was determined using the Folin-Ciocalteu’s method and antioxidant activities using the DPPH free radical scavenging assay and ferric reducing antioxidant power (FRAP). The highest yield of extract was from the ethanol (64.52 ± 0.05%), followed by water (17.65 ± 0.84%) and hexane (4.61 ± 0.56%). Phytochemical screening on the leaves extracts showed the presence of flavonoids, saponins, tannins, alkaloids, terpenoids and steroids. Total phenolic content was highest in the extract of water (0.24 ± 0.02 ug/mL GAE), followed by ethanol (0.19 ± 0.01 ug/mL GAE) and hexane (0.02 ± 0.001 ug/mL GAE). Both free radical scavenging assays of ethanol and water extracts demonstrated stronger antioxidant activities in which the IC50 values were 79.48 ug/mL and 75.98 ug/mL respectively, than the commercial butylated hydroxyl toluene which was 197.60 ug/mL. A strong antioxidant capacity in both water (751.75 ± 12.36 mg/mL) and ethanol 741.64 ± 6.96 mg/mL) extracts were also shown in the FRAP method. The highest total phenolic content and antioxidant activities in the leaves extract of Syzygium zeylanicum indicated that the plant has the potential to be used as a functional food. Key Words: Syzygium Zeylanicum, Phytochemicals, Total Phenolics, Antioxidant.