Table 3

Effect of long-term storage on the free radical scavenging activity of 21 South African medicinal plants
Plant species Plant part Radical scavenging activity (%) at 100 μg/ml EC50(μg/ml) Antioxidant activity index
Stored Fresh Stored Fresh Stored Fresh
Acokanthera oppositifoliaδ Roots 93.3 ± 0.03 ** 92.6 ± 0.10 26.8 ± 2.43 * 18.0 ± 0.34 0.7 ± 0.06 ** 1.1 ± 0.02
Artemisia afra# Aerial parts 93.8 ± 0.11 * 92.7 ± 0.34 9.3 ± 0.07 *** 12.4 ± 0.15 2.1 ± 0.02 *** 1.6 ± 0.02
Artemisia afraδ Aerial parts 94.0 ± 0.07 * 92.7 ± 0.34 6.8 ± 0.50 *** 12.4 ± 0.15 2.9 ± 0.21 ** 1.6 ± 0.02
Buddleja salviifolia# Leaves 96.2 ± 0.06 *** 93.0 ± 0.40 15.5 ± 0.47 ** 10.0 ± 0.61 1.3 ± 0.04 ** 2.0 ± 0.12
Buddleja salviifolia# Twigs 94.2 ± 0.13 ns 94.3 ± 0.15 17.2 ± 0.32 ns 17.5 ± 0.40 1.1 ± 0.02 ns 1.1 ± 0.03
Clausena anisata# Leaves & Twigs 70.8 ± 0.28 ns 72.6 ± 6.21 33.2 ± 3.89 ns 26.8 ± 2.06 0.6 ± 0.07 ns 0.7 ± 0.06
Cussonia spicata# Leaves 93.7 ± 0.07 *** 61.6 ± 1.67 14.3 ± 0.22 ** 43.6 ± 5.73 1.4 ± 0.02 *** 0.5 ± 0.07
Dombeya rotundifolia# Leaves 96.5 ± 0.56 ** 93.6 ± 0.27 5.9 ± 0.12 ns 6.1 ± 0.32 3.3 ± 0.07 ns 3.2 ± 0.16
Ekebergia capensisδ Leaves & Twigs 94.2 ± 0.42 * 92.8 ± 0.30 4.7 ± 0.37 ** 25.5 ± 4.99 4.3 ± 0.32 *** 0.8 ± 0.14
Leonotis intermediaδ Leaves 93.3 ± 0.09 * 88.5 ± 1.73 10.6 ± 0.37 *** 51.7 ± 0.32 1.9 ± 0.06 *** 0.4 ± 0.00
Leonotis leonurusδ Leaves 93.7 ± 0.18 ** 91.6 ± 0.43 16.8 ± 0.06 *** 30.3 ± 0.92 1.2 ± 0.00 *** 0.7 ± 0.02
Merwilla plumbeaδ Bulbs 8.2 ± 0.61 ** 2.6 ± 0.97 ND ND ND ND
Ocotea bullataδ Bark 95.0 ± 0.25 ** 93.8 ± 0.02 3.2 ± 0.14 ** 4.3 ± 0.10 6.3 ± 0.28 ** 4.6 ± 0.11
Olea europaea# Leaves 94.9 ± 0.20 ** 93.2 ± 0.09 14.0 ± 0.48 *** 20.0 ± 0.16 1.4 ± 0.05 *** 1.0 ± 0.01
Pittosporum viridiflorum# Leaves & Twigs 93.6 ± 0.10 ns 93.8 ± 0.29 17.9 ± 0.25 ns 17.5 ± 0.27 1.1 ± 0.02 ns 1.1 ± 0.02
Plumbago auriculataδ Leaves 50.6 ± 3.97 ns 54.6 ± 1.15 ND ND ND ND
Protorhus longifoliaδ Leaves 95.8 ± 0.24 ** 97.3 ± 0.21 2.2 ± 0.16 ns 2.3 ± 0.14 9.1 ± 0.71 ns 8.5 ± 0.49
Solanum mauritianumδ Leaves 34.4 ± 0.73 *** 19.8 ± 1.53 ND ND ND ND
Spirostachys africana# Leaves & Twigs 96.6 ± 0.06 *** 91.8 ± 0.34 2.0 ± 0.07 *** 14.4 ± 0.58 10.0 ± 0.35 *** 1.4 ± 0.06
Synadenium cupulareδ Leaves 90.9 ± 0.70 *** 46.0 ± 5.30 55.7 ± 0.35 ND 0.4 ± 0.02 ND
Tetradenia ripariaδ Leaves 68.5 ± 1.39 *** 23.8 ± 2.44 41.0 ± 5.29 ND 0.5 ± 0.06 ND
Trichilia dregeana# Leaves & Twigs 95.8 ± 0.46 ** 92.3 ± 0.16 5.3 ± 0.02 *** 14.6 ± 0.24 3.7 ± 0.01 *** 1.3 ± 0.02
Ziziphus mucronata# Leaves 90.7 ± 0.42 ns 89.0 ± 2.20 29.7 ± 1.02 ns 30.9 ± 1.94 0.7 ± 0.02 ns 0.6 ± 0.04
Ziziphus mucronataδ Leaves 91.1 ± 0.18 ns 89.0 ± 2.20 18.1 ± 0.29 ** 30.9 ± 1.94 1.1 ± 0.02 *** 0.6 ± 0.04
Ascorbic acid 96.6 ± 0.04 2.1 ± 0.05 9.4 ± 0.23
Butylated hydroxytoluene 93.2 ± 0.34 3.0 ± 0.04 6.5 ± 0.09

ns = not significant; P = 0.05 (*); P = 0.01 (**); P = 0.001 (***).

ND = not determined.

δ = Plant material stored for 16 years.

# = Plant material stored for 12 years.

Amoo et al.

Amoo et al. BMC Complementary and Alternative Medicine 2012 12:87   doi:10.1186/1472-6882-12-87

Open Data