Antioxidative and Free Radical Scavenging Activities of Some Plants Used in Thai Folk Medicine

Figures & data

Table 1 The parts of seven medicinal plants used for preparing crude extracts in this study.

Botanical name	Common name	Part tested	Medical uses
1. Angiopteris evecta.	King fern	Rhizome	Astringent for buccal ulcer, antidiarrhetic, analgesic, antemetic, diuretic
2. Citrus hystrix.	Kiffir lime	Leaf	Antitussive, antihemorrhage
		Fruit peel	antiflatulent, antiscurvy, antidandruff
3. Laurentia longiflora.	Star of Bethlehem	Whole plant	antivenereal diseases (VD), antiasthma, antibronchitis, antiepileptic
4. Nelumbo nucifera.	Sacred lotus	Leaf	Antidiarrhetic
		Pollen	Cardiac tonic
		Seeds head	Antidiarrhetic
5. Piper sarmentosum.	Wild betel leaf	Whole plant	Expectorant, antidiabetic
6. Portulaca oleracea.	Pigweed	Whole plant	Antidysenteric, antiasthma, cardiac and hepatic tonic, laxative, antipruritic insect bite treatment
7. Stachytarphera indica.	Common snake weed	Whole plant	Antipyretic, diaphoretic, diuretic, antiphlogistic, antigonorrhea, antidote

Figure 1 Comparison of IC₅₀ values of the plant extracts against (A) DPPH, (B) , and (C) free radicals. Each bar represents the mean ±SD of triplicate values. Those bars with the same letter are not statistically different from each other (p > 0.05).

Table 2 The Fe²⁺-chelating activities of the plant extracts.

	Concentration
Sample	0.5 mg/ml	1 mg/ml	2 mg/ml
A. evecta. rhizome extract	4.31 ± 1.70	29.6 ± 1.78	71.2 ± 0.51
C. hystrix. leaf extract	6.89 ± 1.05	10.9 ± 0.68	23.7 ± 1.31
C. hystrix. peel extract	10.1 ± 1.02	16.8 ± 0.34	33.1 ± 1.21
L. longiflora. extract	9.31 ± 2.04	15.6 ± 0.79	18.5 ± 1.95
N. nucifera. leaf extract	10.8 ± 0.25	61.1 ± 1.01	99.6 ± 0.19
N. nucifera. pollen extract	3.25 ± 0.10	7.10 ± 0.51	18.0 ± 1.56
N. nucifera. seeds head extract	3.86 ± 0.44	10.9 ± 0.61	20.1 ± 0.70
P. sarmentosum. extract	9.30 ± 0.59	12.0 ± 0.26	20.0 ± 1.69
P. oleracea. extract	5.21 ± 0.44	8.63 ± 0.10	11.2 ± 0.35
S. indica. extract	16.8 ± 0.68	28.8 ± 0.79	38.0 ± 3.75
0.2 M citric acid (positive control)		96.9 ± 0.26

Data are presented as the mean±SD of each triplicate test. All values are expressed as percentage of chelation calculated from the equation stated in the “Materials and Methods” section.

Table 3 Total amounts of phenolics in the plant extracts.

Extract	Total phenolics (µ mole of cathechin-equivalent/mg of dried extract)
A. evecta. rhizome	9.31 ± 0.40
C. hystrix. leaf	8.19 ± 0.40
C. hystrix. peel	6.58 ± 0.14
L. longiflora.	1.01 ± 0.38
N. nucifera. leaf	15.98 ± 0.16
N. nucifera. pollen	5.28 ± 0.26
N. nucifera. seeds head	0.23 ± 0.14
P. sarmentosum.	6.41 ± 0.14
P. oleracea.	4.34 ± 0.16
S. indica.	5.97 ± 0.14

Data are presented as the mean ± SD of each triplicate test.

Table 4 Effect of the plant extracts on lipid peroxidation in a rat brain homogenate.

	Concentration
Sample	250 µg/ml	500 µg/ml
A. evecta. rhizome extract	74.58 ± 0.26	77.58 ± 0.14
C. hystrix. leaf extract	45.26 ± 0.41	70.18 ± 0.46
C. hystrix. peel extract	26.06 ± 0.15	45.30 ± 0.27
L. longiflora. extract	27.20 ± 0.14	32.36 ± 0.13
N. nucifera. leaf extract	74.32 ± 0.39	75.46 ± 0.14
N. nucifera. pollen extract	70.73 ± 0.41	76.16 ± 0.38
N. nucifera. seeds head extract	64.76 ± 0.45	75.08 ± 0.51
P. sarmentosum. extract	69.29 ± 0.33	72.80 ± 0.32
P. oleracea. extract	49.19 ± 0.60	70.64 ± 0.19
S. indica. extract	69.08 ± 0.27	70.30 ± 0.26
BHT	77.96 ± 0.08	79.36 ± 0.19

Data are presented as the mean ± S.D of each triplicate test. All values are expressed as percent inhibition of lipid peroxidation calculated from the equation stated in the “Materials and Methods” section.

Table 5 Effects of the plant extracts on hemolysis of human erythrocytes.

	Concentration
Sample	250 µg/ml	500 µg/ml
A. evecta. rhizome extract	56.08 ± 0.55	63.80 ± 0.69
C. hystrix. leaf extract	90.02 ± 0.85	98.14 ± 0.19
C. hystrix. peel extract	87.47 ± 0.73	98.06 ± 0.13
L. longiflora. extract	69.77 ± 2.03	78.84 ± 0.25
N. nucifera. leaf extract	93.82 ± 0.13	98.87 ± 0.07
N. nucifera. pollen extract	64.60 ± 1.02	67.14 ± 0.43
N. nucifera. seeds head extract	52.50 ± 0.27	57.17 ± 0.65
P. sarmentosum. extract	80.08 ± 0.30	97.41 ± 0.07
P. oleracea. extract	67.35 ± 0.49	81.21 ± 0.25
S. indica. extract	85.57 ± 0.12	93.77 ± 0.26
Ascorbic acid	94.03 ± 0.30	96.47 ± 0.61

Data are presented as the mean ± SD of each triplicate test. All values are expressed as percent inhibition of hemolysis calculated from the equation stated in the “Materials and Methods” section.

Table 6 Pro-oxidant effects of the plant extracts on ferric bleomycin induced DNA damage.

	Concentration
Sample	100 µg/ml	200 µg/ml
Blank	0.006 ± 0.001
A. evecta. rhizome extract	0.031 ± 0.001	0.059 ± 0.001
C. hystrix. leaf extract	0.037 ± 0.001	0.066 ± 0.001
C. hystrix. peel extract	0.022 ± 0.001	0.030 ± 0.002
L. longiflora. extract	0.019 ± 0.001	0.029 ± 0.001
N. nucifera. leaf extract	0.064 ± 0.002	0.123 ± 0.003
N. nucifera. pollen extract	0.018 ± 0.001	0.023 ± 0.001
N. nucifera. seeds head extract	0.016 ± 0.001	0.021 ± 0.001
P. sarmentosum. extract	0.039 ± 0.001	0.079 ± 0.003
P. oleracea. extract	0.087 ± 0.002	0.031 ± 0.001
S. indica. extract	0.033 ± 0.001	0.061 ± 0.001
BHT	0.066 ± 0.002	0.013 ± 0.001
Ascorbic acid	0.631 ± 0.002	1.231 ± 0.002

Data are presented as the mean ± SD of each triplicate test. All values represent the extent of DNA damage and are expressed as the absorbance (O.D.) at 532 nm.