Abstract:
Protection against free radicals can be impeded by improving the dietary intake of
antioxidants. Wild fruits and their products are a valuable source of antioxidant.
Therefore, objectives of this study were to determine and compare different mode
of antioxidant activities of six different underutilized wild fruits i.e. Calophyllum
calaba (Keena), Syzygium cumini (Madan),Drypetes sepiaria (Weera), Syzygium
caryophyllatum (Dan), Ficus racemose (Attikka) and Careya arborea
(Kahata)found in natural habitats of Sri Lanka. Antioxidant properties of wild fruits
were tested using different in vitro assays using 96 well micro plates. Free radical
scavenging activity (FRSA), Ferric reducing antioxidant power (FRAP) and oxygen
radical absorbance capacity (ORAC), total phenolic contents (TPC) and total
flavonoid content (TFC) was determined by using standard procedures. Softmax Pro
5.2 v software was used to calculate antioxidant values. Results showed that 2,2-
azinobis3ethylbenzothiozoline-6-sulfonic (ABTS+
) and 1-diphenyl-2-
picrylhydrazyl (DPPH) radical scavenging activity in all fruit types. DPPH and
ABTS+
radical scavenging activity of selected wild fruits were in the range of
30.49±4.87 to 585.40±6.43 mg Trolox equivalents (TE)/g of extract and
43.08±02.89 into 435.30±6.62 mg (TE)/g of extract respectively. Calophyllum
calaba recorded the lowest FRSA with the highest IC50 value in each assay. Total
reducing potential of fruit extracts that was measured using FRAP revealed that
significantly (P<0.05) higher value in Careya arborea (455.91 ± 33.94 mg TE/g of
extract) while the lowest in Calophyllum calaba (12.35 ± 0.10 mg TE/g of extract).
ORAC of selected fruit extracts were ranged from 7 to 25 mg TE/g extract. The
highest TPC was recorded in Careya arborea (590.95 ± 22.17 mg gallic acid eq/g
extract) followed by Ficus racemose (180.04 ± 5.09 mg gallic acid eq/g extract).
Syzygium caryophyllatum recorded the highest TFC (13.56 ± 0.26 quercertin/g of
International Conference of Sabaragamuwa University of Sri Lanka - 2017
Copyright © ICSUSL-Sabaragamuwa University of Sri Lanka 2017 325
extract) while Calophyllum calaba and Syzygium cumini showed the lowest TPC
and TFC respectively. Overall results suggested that selected fresh wild fruits
possess marked antioxidant activities and Careya arborea and Calophyllum calaba
L recorded the highest and the lowest antioxidant activity showing the use of these
wild fruits for prevention and management of oxidative stress associated chronic
diseases in Sri Lanka.
