## 4 Pharmacological Properties of _Elaeedendron_ Species
### Antioxidant Activity  
[PERSON] and [PERSON] used FRAP (reducing power), ABTS (2,2\({}^{\prime}\)-azinobis-3-ethylbenzothazoline-6-sulphonate), and DPPH (2,2-diphenyl-l-picrylhydrazyl) free radical scavenging tests to assess the antioxidant properties of _E. croceum_ stem bark and leaf acetone extracts [35]. Rutin, butylated hydroxytoluene (BHT), and ascorbic acid were used as reference antioxidant compounds. The leaf acetone extract IC\({}_{50}\) (Inhibitory Concentration) values were 0.1 mg/mL for the DPPH test, 2.5 mg/mL for FRAP, and 0.09 mg/mL for ABTS, whereas the IC\({}_{50}\) values of bark extract were 0.07 mg/mL for DPPH, 9.2 mg/mL for FRAP, and 0.2 mg/mL for ABTS. The reference medicines, ascorbic acid, BHT, and rutin, have IC\({}_{50}\) values ranging between 0.02 mg/mL to 3.5 mg/mL. This antioxidant activity demonstrated that the extracts have excellent ability with diverse free radical species, equivalent to ascorbic acid [35]. [PERSON] et al. used the TEAC, FRAP, ABTS, DPPH free radical scavenging tests with Trolox and ascorbic acid as standard medicines to assess the antioxidant properties of _E. croceum_ acetone extract. The extracts had strong DPPH and ABTS activity, with IC\({}_{50}\) values of 7.7 \(\upmu\)g/mL and 3.1 \(\upmu\)g/mL, respectively, which were also similar to Trolox and ascorbic acid, the two positive standards with IC\({}_{50}\) values in the range between 2.9 \(\upmu\)g/mL to 5.6 \(\upmu\)g/mL. The IC\({}_{50}\) for TEAC and FRAP were 1.3 \(\upmu\)g/mL and 1.0 \(\upmu\)g/mL respectively, whereas the values for Trolox and ascorbic acid ranged from 1.0 to 3.7 [36]. The antioxidant properties of _E. croceum_ extracts are most likely due to flavonoids and phenolics extracted from the plant. [PERSON] et al. examined the antioxidant properties of _E. transvaalensis_ ethanol and water root extracts, as well as 4\({}^{\prime}\)-O-methyl-epigallocatechin, a compound obtained from the plant, using a DPPH free radical scavenging experiment with ascorbic acid, rutin, and quercetin as standard drug. The ethanol extract had an 80% radical scavenging activity above 100 \(\upmu\)g/mL concentration, which was equivalent to the standard antioxidant substances ascorbic acid, rutin, and quercetin, while the water extract had 80% scavenging activity above 200 \(\upmu\)g/mL concentration. Between 25.0 \(\upmu\)g/mL and 50 \(\upmu\)g/mL concentration, the molecule 4\({}^{\prime}\)-O-methyl-epigallocatechin had a 65% radical scavenging activity, which was higher than the activity of both ethanol and water extracts. However, at levels more than 50 \(\upmu\)g/mL, the ethanol extract outperformed the chemical 4\({}^{\prime}\)-O-methyl-epigallocatechin [37]. [PERSON] et al., used the ABTS, iron chelating property assay, DPPH, sulphur hydryl content, hydroxyl radical scavenging, total antioxidant capacity, superoxide, and nitric oxide (NO) radical scavenging tests to examine the antioxidant effects of _E. transvaalense_ methanolic bark extracts. The IC\({}_{50}\) values for the superoxide was 1.6 \(\upmu\)g/mL, hydroxyl was 3.6 \(\upmu\)g/mL, ABTS was 4.1 \(\upmu\)g/mL, iron chelating was 3.9 \(\upmu\)g/mL, DPPH assay was 0.7 \(\upmu\)g/mL, and NO was 3.6 \(\upmu\)g/mL [38]. [PERSON] et al. used the DPPH radical scavenging activity test with ascorbic acid as the control sample to assess the antioxidant properties of _E. transvaalense_ methanolic leaf extracts. The extract had an EC\({}_{50}\) value of 2.8 \(\upmu\)g/mL, which was equivalent to the positive control, ascorbic acid (EC\({}_{50}\) = 2.3 \(\upmu\)g/mL) [39]. The antioxidant properties of _E. transvaalense_ crude extracts are most likely attributable to phenolics and flavonoids extracted from the species [39]. [PERSON] et al., used lipopolysaccharideaccharides (LPS)-induced intracellular reactive oxygen/nitrogen species measurement, ABTS\({}^{+}\) radical scavenging assay, and nitrite concentrations as a measure of reactive nitrogen species to assess the antioxidant activity of south African medicinal plant extracts including _E. croceum_ and _E.