TITLE:
Potentials of Two Nigerian Spices—Piper nigrum and Monodora myristica as Sources for Cheap Natural Antioxidants
AUTHORS:
Edak A. Uyoh, Peter N. Chukwurah, Roseline C. Akarika, Victoria A. Antia
KEYWORDS:
Antioxidant; Piper nigrum; Monodora myristica; Spices; Free Radicals
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.5,
May
29,
2013
ABSTRACT:
Two commonly consumed spices in Nigeria—Piper nigrum (leaf and seed) and Monodora myristica (seed) were evaluated
for natural antioxidant potentials in complementary in vitro assay systems. Extracts of the tested plant parts contained
low amounts of antioxidant compounds: 4.00 - 6.65 μg GAE/mg
and 2.50 - 10.38 μg RE/mg for phenols and flavonoids respectively. The extracts
scavenged DPPH and hydroxyl radicals in the range of 4.32% - 37.37%
(inferior to ascorbic acid and gallic acid used as standards) and 6.43% - 17.10%
respectively. In the reducing power and phosphomolybdenum
assays, the extracts showed ability to reduce Fe (III) and Mo (VI)
ions to their lower valence states of Fe (II) and Mo (V) respectively, although
these activities were inferior to those of the standards used. Comparatively, Monodora myristica seed
extract was superior to Piper nigrum leaf and seed extracts in antioxidant
potential, but all the extracts generally showed dose-dependent antioxidant
activities. Evidently, the studied spice plants are not without some natural
antioxidant capacity and would contribute appreciably in combating free radical
damages when consumed.