Abstract

ANTIOXIDANT AND ANTI-INFLAMMATORY POTENTIAL OF THE AQUEOUS EXTRACT OF THE PEEL OF A SRI LANKAN VARIETY OF NEPHELIUM LAPPACEUM LINN.

Uduwelage Dona Harshani Kaushalya Uduwela, *Srianthie A. Deraniyagala and Gobika Thiripuranathar

Abstract

Plant-based remedies play a significant role in healthcare due to low side effects compared to that of synthetic drugs. Excess free radicals generated in the human body are implicated in numerous diseases as well as in aging. This study involves the determination of antioxidant and anti-inflammatory activities of the aqueous extract of the peel of a Sri Lankan variety of rambutan (AEPR); Malwana special. The AEPR was prepared according to “kasaya” preparation method in Ayurvedic medicine. The total phenolic content and the total flavonoid content of AEPR were 463.5±5.2 mg (PGE)/g and 375.0±13.2 mg (QE)/g respectively. (PGE=Pyrogallol Equivalence, QE=Quercetin Equivalence). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of AEPR was 3.9-64.5% for concentrations of 10–500 μg/ml. Ascorbic acid gave values of 6.5-96.4%. The hydroxyl radical scavenging activity of AEPR ranged from 10.3-35.0% for concentrations of 1000–1500 ppm. Ascorbic acid showed values of 22.6-51.1%. The extract exhibited a good reducing power in the iron reducing power assay. Nitric oxide radical scavenging activity of AEPR was 4.1-31.7% for concentrations of 100– 500 μg/ml. Ascorbic acid gave values of 30.1-43.3%. The protection reported for Human Red Blood Cell (HRBC) assay was 17.1-34.8% for concentrations from 35.5-250.0 ppm. Aspirin protection ranged from 32.3-54.5%. These results show that the AEPR prepared from peel waste has a potential to be used as an antioxidant and also it possesses anti-inflammatory activity.

Keywords: Nephelium lappaceum, antioxidant, anti-inflammatory, HRBC.