Aruoma, O. I. 2003. Methodological
considerations for characterizing potential
antioxidant actions of bioactive components in
plant foods. Mutation. Research. 9: 523-524.
He, Y. Y and D. P. Häder. 2002. Reactive oxygen
species and UV-B: effect on Cyanobacteria.
Photochem. Photobiol. Sci. 1: 729-736.
Jacobi, R.A., B. J Burri, 1996. Oxidative damage
and defense. Am. J. Clin. Nutr., 63, 985-990.
Apel, K and H. Hirt. 2004. Reactive oxygen
species: metabolism, oxidative stress and signal
transduction. Annu. Rev. Plant. Biol. 55: 373-399.
Aruoma, O.I. 1998. Free radicals, oxidative stress,
and antioxidants in human health and disease. J.
Am. Oil Chem. Soc. 75: 199-212.
Prior, R. L and G. Cao. 2000. Antioxidant
phytochemicals in fruits and vegetables. Diet and
health implications. Hort. Sci. 35: 588-592.
Pryor, W.A. 1991. The antioxidant nutrient and
disease prevention-What do we know and what
we need to find out. Am. J. Clin. Nutr, 53: 391-
Cook, N. C and S. Samman. 1996. Flavonoids:
Chemistry, metabolism, cardioprotective effects,
and dietary sources. J.Nutr. Biochem. 7: 66-76.
Lien, E. J; S. Ren; S. H. H. Bui and R.Wang.
Quantitative structure activity analysis of
phenolic antioxidants. Free. Rad. Bio. Med. 26:
-294.
Rice-Evans, C.A; N.J. Miller and G. Paganga.
Antioxidant properties of phenolic
compounds. Trends. Plant. Sci. 2: 152-159.
Mashimbye, M. J; F. Mudau; P. Soundy and T.
Van Ree. 2006. A new flavonol fromAthrixia
phylicoides (Bush tea). S. Afri. J. Chem. 59: 1-2.
Mcgaw, L. J; V. Steenkamp and J. N. Eloff, 2007.
Evaluation of Athrixia bush tea for cytotoxicity,
antioxidant activity, caffeine content and presence
of pyrrolizidine alkaloids. J. Ethnopharmacol.
: 16-22.
Scalbert, A and G. Williamson. 2000. Dietary
intake and bioavailability of polyphenols. J. Nutr.
: 2073.
Rice-Evans, C.A; N.J. Miller and G. Paganga.
Structure-antioxidant activity relationships
of flavonoids and phenolic acids. Free. Radical.
Biol. Med. 20: 933âââ956.
Phippen, W.B and J. E. Simon. 2000.
Anthocyanin inheritance and instability in purple
basil (Ocimum basilicum L.). J. Hered. 91: 289âââ
Phippen, W.B and J. E. Simon. 1998.
Anthocyanins in basil (Ocimum basilicum L.). J.
Agr. Food Chem. 46: 1734-1738.
Blois, M. S. 1958. Antioxidant determinations by
the use of a stable free radical. Nature. 181: 1199-
Anderson, D; B. J. Phillips; T. Yu; A. J. Eduards;
R. Ayesh and K. R. Butterworth. 1997. The effect
of DPPH radical. Biochem. Pharmacol. 56: 213-
Johnson, C; S. Kaviarasan; H. Naik; R.
Gangabhagirathi; C. V. Anuradha and K. I.
Priyadarsini. 2007. In vitro studies on antiradical
and antioxidant activities of fenugreek (Trigonella
foenum graecum) seeds. Food. Chem. 103: 31-37.
Kumar, S. S; K. I. Priyadarsini and K. B. Sainis.
Free radical scavenging activity of vanillin
and O-vanillin using 1,1-diphenyl-2-
picrylhydrazyl (DPPH) radical. Redox. Rep. 7:
-40.
Wang, M; Y. Jin and C. T. Ho. 1999. Evaluation
of resveratrol derivatives as potential antioxidants
and identification of a reaction product of
resveratrol and 2, 2- diphenyl-1-picrylhydrazyl
radical. J. Agr. Food. Chem. 47: 3974-3977.
Yokozawa, T; C. P. Chen; E. Dong; T. Tanaka; G.
I. Nonaka and I. Nishioka. 1998. Study on the
inhibitory effect of tannins and flavonoids against
the 1, 1-diphenyl-2-picrylhydrazyl radical.
Biochem. Pharmacol. 56: 213-222.
Gazi, M. R; K. Kanda; M. Yasuda and F. Kato.
Optimisation of cultural conditions and
some properties of radical scavenging substances
from sporobolomyces salmonicolor Pak. J. Biol.
Sci. 7: 1365-1370.
Molyneux. P. 2004. The use of the stable free
radical diphenylpicryl-hydrazyl (DPPH) for
estimating antioxidant activity. Songklanakarin. J.
Sci. Technol. 26: 211-219.
Pavlov, A; P. Kovatcheva; V. Georgiev; I. Koleva
and M Ilieva. 2002. Biosynthesis and radical
scavenging activity of betalains during the
cultivation of red beet (Beta vulgaris) hairy root
cultures. Z. Naturforsch. 57c: 640-644.
Bray, T. M and W. J. Bettger. 1990. The
physiologic role of zinc as an antioxidant. Free.
Radic. Biol. Med. 8: 281-291