Table 4.
Antioxidant activity of various forms of aloe
| Sample | Methods | Antioxidant activity | References |
|---|---|---|---|
| Gel extract | DPPH radical scavenging (%) | 11.93 | [42] |
|
Ferric reducing power (μM Fe(II)/kg) |
59.12 | ||
| Ethanol extract of gel | DPPH radical scavenging (%) | 6.56 | |
|
Ferric reducing power (μM Fe(II)/kg) |
26.51 | ||
| Ethanol extract of skin | DPPH radical scavenging (%) | 85.01 | |
|
Ferric reducing power (μM Fe(II)/kg) |
185.98 | ||
| Methanol extract of skin | DPPH radical scavenging (%) | 58.80 | [26] |
|
Ferric reducing power (mM of Fe(III) reduced to Fe(II)) |
2.40 | ||
| Methanol extract of flowers | DPPH radical scavenging (%) | 53.00 | |
|
Ferric reducing power (mM of Fe(III) reduced to Fe(II)) |
1.70 | ||
| Gel | DPPH radical scavenging (%) | 13.52 | [59] |
| Hydroxyl radical scavenging (%) | 11.74 | ||
| Superoxide radical scavenging (%) | 53.86 | ||
| Metal chelating activity (%) | 81.27 | ||
| Methanol extract of gel | DPPH radical scavenging (%) | 10.24 | [38] |
| Hydroxyl radical scavenging (%) | 48.01 | ||
| Superoxide radical scavenging (%) | 31.72 | ||
| Metal chelating activity (%) | 48.02 | ||
| Lyophilized leaf gel | Oxygen radical absorbance capacity (μM of TEa/g d.m.) | 59.00 | [31] |
| Ferric reducing power (μM/g d.m) | 2.63 | ||
| Aqueous ethanol leaf gel extracts | Oxygen radical absorbance capacity (μM of TE/g d.m.) | 83.00 | |
| Ferric reducing power (μM/g d.m) | 8.98 | ||
| Leaf extract | DPPH radical scavenging (IC50b mg/mL) | Methanol (0.086) > ethanol (0.288) = acetone (0.288) > aqueous extract (0.517) | [30] |
| ABTS cationic radicals scavenging (IC50 mg/mL) | Methanol (0.02) > acetone (0.033) > ethanol (0.062) > aqueous extracts (0.173) | ||
| Ferric reducing power (absorbance) | Ethanol > acetone > methanol > aqueous extracts | ||
| Nitric oxide scavenging (IC50 mg/mL) | Methanol (0.023) > ethanol (0.024) > aqueous (0.074) > acetone extracts (0.077) | ||
| Hydrogen peroxide scavenging (%) | Acetone < ethanol < methanol aqueous extract | ||
| Lipid peroxidation (TBARSc) (IC50 mg/mL) | Methanol (0.930) > ethanol (1.270) > acetone (1.492) aqueous extract (1.837) | ||
| Freeze-dried whole leaf | DPPH-HPLC method radical-scavenging (mM of TE/g) | 48.20 | [27] |
| Freeze-dried leaf skin | 35.00 | ||
| Boiled leaf skin | 61.60 | ||
| Lyophilized leaf gel | Oxygen radical absorbance capacity (μM of TE/g d.m.) | 53.00 | [28] |
| Ferric reducing power (μM/g d.m) | 4.90 | ||
| Ethanol leaf gel extracts | Oxygen radical absorbance capacity (μM of TE/g d.m.) | 136.00 | |
| Ferric reducing power (μM/g d.m) | 19.00 | ||
| Methanol extract of aloe leaves | DPPH radical scavenging (EC50d) (μg/mL) | 10.45 | [29] |
| Ferric reducing power (absorbance) | ~ 0.50 | ||
| Latex from the leaves of aloe | DPPH radical scavenging (IC50) (μg/mL) | 14.21 | [32] |
| 2-Deoxyribose degradation assay (IC50) (μg/mL) | 17.24 | ||
| Ethanol extract of leaf of aloe leaves | DPPH radical scavenging (IC50) (μg/mL) | 73.00 | [33] |
| Assay for inhibition of xanthine oxidase activity (IC50) (μg/mL) | 85.00 | ||
| Aloe gel | DPPH radical scavenging (IC50) (μg/mL) | 572.14 | [39] |
| ABTS cationic radicals scavenging (IC50) (μg/mL) | 105.26 | ||
| Nitric oxide scavenging (IC50) (μg/mL) | 46.36 | ||
| Ethanol extracts of leaf Aloe barbadensis | DPPH radical scavenging (μM of TE) | 108.00 | [40] |
| Oxygen radical absorbance capacity (μM of TE) | 1281.00 | ||
| Ethanol extracts of leaf Aloe arborescens | DPPH radical scavenging (μM of TE) | 71.00 | |
| Oxygen radical absorbance capacity (μM of TE) | 2671.00 | ||
| Water extract of aloe |
DPPH radical scavenging (mg of TE/g d.m.) |
8.87 | [43] |
| ABTS cationic radicals scavenging (mg of TE/g d.m.) | 0.87 | ||
|
Metal chelating activity (mg of EDTAe/g d.m.) |
8.76 | ||
| Emulsion system (Wo)f | 0.96 | ||
| Ethanol extract of flowers |
DPPH radical scavenging (IC50 mg/mL) |
0.25 | [60] |
| ABTS cationic radicals scavenging (IC50 mg/mL) | 0.30 | ||
|
Ferric reducing power (EC50 mg/mL) |
2.10 | ||
|
Nitrite scavenging (IC50 mg/mL) |
0.92 | ||
| Methanol extracts of leaf | DPPH radical scavenging (%) | 56.75–80.20 | [44] |
| Metal chelating activity (%) | 55.00–80.00 | ||
| Hydrogen peroxide scavenging (%) | 58.54–81.10 | ||
| Ferric reducing power (absorbance) | 0.6–0.8 | ||
| β carotene-linoleic assay (%) | 59.60–74.40 | ||
| Aloe barbadensis leaves | Ferric reducing power (absorbance) |
Extraction by shaker: Absolute methanol (2.01), Aqueous (80%) methanol (2.81), Absolute ethanol (1.56), Aqueous (80%) ethanol (2.16) |
[45] |
|
Extraction by reflux: Absolute methanol (2.18), Aqueous (80%) methanol (2.96), Absolute ethanol (1.72), Aqueous (80%) ethanol (1.88) | |||
| DPPH radical scavenging (%) |
Extraction by shaker: Absolute methanol (73.7), Aqueous (80%) methanol (80.1), Absolute ethanol (67.2), Aqueous (80%) ethanol (70.7) |
||
|
Extraction by reflux: Absolute methanol (72.9), Aqueous (80%) methanol (77.6), Absolute ethanol (68.0), Aqueous (80%) ethanol (71.9) | |||
| Inhibition of linoleic acid peroxidation (%) |
Extraction by shaker: Absolute methanol (66.2), Aqueous (80%) methanol (68.3), Absolute ethanol (63.7), Aqueous (80%) ethanol (65.9) |
||
|
Extraction by reflux: Absolute methanol (64.3), Aqueous (80%) methanol (67.9), Absolute ethanol (66.2), Aqueous (80%) ethanol (67.3) |
aTE – Trolox equivalents
bIC50 – The concentration at which 50% is inhibited
cTBARS – Thiobarbituric acid reactive substances
dEC50 – Effective concentration at which the absorbance is 0.5
eEDTA – Ethylenediaminetetraacetic acid equivalents
fWo – Antioxidant efficiency (Wo > 0 antioxidative properties, Wo < 0 prooxidative properties of the additive)