Antioxidant and hypoglycemic activities of extract and fractions of Rambutan seeds (Nephelium lappaceum L.)

Sylvia Soeng (Faculty of Medicine, Maranatha Christian University, West Java, Indonesia)
Endang Evacuasiany (Faculty of Medicine, Maranatha Christian University, West Java, Indonesia)
Wahyu Widowati (Faculty of Medicine, Maranatha Christian University, West Java, Indonesia)
Nurul Fauziah (Bimolecular and Biomedical Research Center, Aretha Medika Utama, Bandung, West Java, Indonesia)

Biomedical Engineering
Vol 1, No 1 (2014)

Objective : This research was done  to measure the antioxidants and hypoglycemic activities of Nephelium lappaceum L. seed (NLS) extract and fractions. Methods: The ethanol extract of rambutan seeds were prepared by maseration method and the fractions (n-hexane, ethyl acetate, buthanol and water) by separation of extract based on the polarity. The antioxidant activity was determined by using  superoxide dismutase value (SOD), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity. The hypoglycemic activity was determined by using inhibition of α-glucosidase test. The DPPHscavenging and hypoglycemic activities were analized by median of Inhibitory Concentration (IC-50). Results: The highest SOD activity showed that ethyl acetate and aqueous fraction of NLS were 3.3771 µg/ml and 3.0374 µg/ml. Meanwhile DPPH assay showed that both NLS extract and fractions had low DPPH scavenging activity. Hypoglycemic activity showed that extract of NLS had highest activity as α-glucosidase inhibitor. Conclusion: Nephelium lappaceum L. seed extract and fractions have high SOD antioxidantvalue but low DPPH scavenging activity and can be used as potential hypoglycemic agent. Key Words: antidiabetic; antioxidants; α-glucosidase; hypoglycemic; scavenging