ABTS AND DPPH ANTIOXIDANT EFFECT OF EXTRACTS FROM GUAVA LEAVES AND FRUITS

Kyu Byn Lee, Da Kyung Yang, So Hee Yang, Sue Jeong Im, Eun Ji Choi and Man Kyu Huh*

ABSTRACT

Guava (Psidium guajava L.) is an important fruit in tropical regions such as South Asia and South America. The aim of this study was to assess the antioxidant capacity of their extracts. Two antioxidant properties of guava leaves and fruits were analyzed using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity. ABTS scavenging activity of fruits varied from 38.0% at 0.25 mg/ml for ethanol extract to 59.4% at 1.0 mg/ml. There was a significant difference between ethanol and water extracts (t = 5.842 for fruits and 9.571 for leaves, p < 0.05). DPPH scavenging activity of ethanol extract of leaves varied from 34.4% at 0.25 mg/ml for ethanol extract to 66.5% at 1.0 mg/ml. There was no significant difference in DPPH scavenging activity between leaves and fruits (p > 0.05). Although DPPH activity of ethanol extracts was slightly higher than that of water extracts, there was no significant difference (p > 0.05). Generally, the fruits had slightly higher antioxidant activity than leaves.

Keywords: Antioxidant, ABTS, DPPH, guava (Psidium guajava L.).