EVALUATION OF Syzygium travancoricum Gamble LEAF EXTRACTS FOR ITS PHYTOCHEMICALS, ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES

Syzygium travancoricum Gamble leaves crude extract (petroleum ether, chloroform and ethanol) were investigated for phytochemical constituents, antimicrobial assay and antioxidant activity. The results of qualitative phytochemical analysis showed the absence of saponins and presence of alkaloids, tannins and phenols, sterols, terpenoids, flavonoids, cardiac glycosides, carbohydrates, oils and fats in all three solvent extracts. Anthroquinones and glycosides were present in petroleum ether extract and ethanol extract but absent in chloroform. Proteins and amino acids were present in chloroform and ethanol extracts but absent in petroleum ether extract. Antimicrobial study revealed that the fungal pathogens (Candida albicans, Fusarium oxysporum and Aspergillus niger) and bacterial pathogens (Staphylococcus aureus, Listeria monocytogenes, E. coli, Klebsiella sp and Pseudomonas sp) were resistant to all the extracts. Micrococcus luteus, Shigella flexneri and Enterococcus faecalis were resistant to petroleum ether extract but sensitive to ethanol extract than chloroform extract with an inhibition zone of 14, 14.5 and 12.3 mm diameter respectively. The total phenolic content of the petroleum ether, chloroform and ethanol extracts of S. travancoricum was determined to be 5.70, 23.34 and 27.76 µg of GAE respectively. Total antioxidant activity and reducing capacity of ethanol extracts showed a maximum absorbance of 1.60 and 2.31 at 1000 µg/ mL concentration followed by chloroform (1.13 and 2.05) and petroleum ether (0.25 and 0.88). Among the three solvent extracts tested ethanol extract showed highest percent inhibition of 96.11%, 97.11% and 96.16% in DPPH, nitric oxide and ABTS scavenging assay respectively, followed by chloroform and petroleum ether extract. The percent scavenging activity of the three extracts increased with increase in concentration of the crude extracts.