Micropropagation and medicinal properties of Barleria greenii

Table 5.8: DPPH radical scavenging activity of different parts of Huernia hystrix
Plant part
DPPH radical scavenging
EC50 (µg/ml) R²
Stems 7.01 ± 0.183 a 0.9805
Roots 7.63 ± 0.154 a 0.9724
Whole plants 393.83 ± 7.364 b 0.9542
Ascorbic acid 6.17 ± 0.434 a 0.9550
Butylated hydroxytoluene 3.75 ± 0.764 a 0.9027
Mean values followed by different letters are significantly different (P = 0.05)
according to DMRT.
5.3.2.5.2 Ferric ion reducing power activity
The ferric ion reducing power assay (FRAP) is an assay based on an electron
transfer reaction (HUANG et al., 2005). In the assay, the presence of reductants
(antioxidants) in the tested extracts results in the reduction of the ferric
ion/ferricyanide complex to the ferrous form, with a characteristic formation of
Perl‟s Prussian blue, which is measured spectrophotometrically (CHUNG et al.,
2002). The degree of colour change is directly proportional to the antioxidant
concentrations in the extracts (HUANG et al., 2005).
Figures 5.7 and 5.8 show the reducing power of different extracts of three Barleria
species and H. hystrix, respectively. All the extracts evaluated showed an increase
in reducing power activity with an increase in extract concentration. However, the
reducing activities of the extracts were significantly lower than the ascorbic acid
and BHT standard controls. The ferric reducing power activity of the leaf and stem
extracts of both B. prionitis and B. greenii were significantly higher than that of
their root extracts (Figure 5.7), indicating a potential plant part substitution of the
leaves or stems for the roots.
118