Free Radical Scavenging Activity of
Some Malaysian Medicinal Plants
Muhammad Taher
Faculty of Pharmacy, International Islamic University Malaysia
19th CPA-MPS 2007, KUALA LUMPUR
Presentation layout





Introduction
Objective
Methodology
Results and discussion
Conclusion
INTRODUCTION
Antioxidant
“Any substance, when present at low
concentrations compared with those
of an oxidizable substrate,
significantly delays or prevents
oxidation of that substrate “
Free Radicals in Biological Medicine, 3rd ed. 1999
Antioxidant action

The antioxidant can act by the
following mechanisms: reducing
activity, free radical-scavenging,
potential complexing of pro-oxidant
metals and quenching of singlet
oxygen.
Effect of free radical

Tissue damage resulting from free
radical may cause a variety of
disorders, including degenerative
disorders of the CNS, such as
Alzheimer’s disease, cancer,
atherosclerosis, diabetes mellitus,
hypertension, AIDS and aging
(Halliwell and Gutteridge, 1998 and Mantle et al., 2000).
Plant materials
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Andrographis paniculata (leaves),
Averrhoa belimbi (fruits),
Eurycoma longifolia (roots),
Dipteris lobbiana (leaves),
Ficus deltoidea (leaves),
Fagrea obovata (roots),
Momordica subanguenta (fruits),
Morinda citrifolia (fruits),
Orthosiphon stamineus (leaves),
Smilax myosotiflora (rhizome)
Traditional Uses


Aphrodisiac and energy enhancer
Eurycoma longifolia, Smilax myosotiflora,
Dipteris lobbiana, Ficus deltoidea and
Fagrea obovata
Antidiabetes mellitus
Momordica subanguenta, Orthosiphon
stamineus, Andrographis paniculata,
Averrhoa belimbi and Morinda citrifolia:
Eurycoma longifolia
Tongkat Ali/Malaysian ginseng

Traditional uses: tonic,
poultice for
headaches, wounds &
ulcers, febrifuge,
hepatitis, aphrodisiac
Andrographis paniculata
Hempedu bumi (‘bile of the earth’), akar
cerita

Traditional uses: Roots
and leaves used
against snake bites,
decoction of leaves
against stomach-ache,
dysentery, typhus and
bronchitis, as a
poultice on swollen
legs, vitiligo, piles and
antidiabetes
Orthosiphon aristatus
Misai kucing, kumis kucing, ruku hutan

Traditional uses:
diabetes and kidney
related diseases,
diuretic, regulate
blood pressure
Morinda citrifolia
noni, mengkudu

Traditional Uses: to
treat diabetes,
haemorrhages and
coughs.
Objective
The research is aimed to study the
relationship of traditional usage of
medicinal plants and their free radical
scavenging activity
METHODOLOGY
1. Extraction
50 g of powdered plants were extracted with
EtOH:Water (50:50) (500 mL) and freeze dryed
2. Phenolic contents was determined by FolinCiocalteu reagent (McDonald et al., 2001)
3. Flavonoid contents was determined by aluminum
chloride colorimetric method (Siddhuraju and
Becker, 2003)
4. Free radical scavenging activity was determined by 2,2-diphenyl-1picrylhydrazyl radical (DPPH· ) scavenging
a. Spectrophotometric assay
% Scavenging
X 
 1    x100 %
Y 
X= Absorbance of sample at 517 nm
Y= Absorbance of control at 517 nm
b. Thin layer chromatography test
(yellow spots against purple background)
RESULTS AND DISCUSSION
Table 1. Percentage of soluble materials
extracted from the plants
Sample (Abbreviation)
Local name
Yield (% w/w)
Averrhoa belimbi (AB)
Belimbing buloh
39.8
Fagrea obovata (FO)
Tengkuk biawak
24.3
Dipteris lobbiana(DL)
Janggut ali
17.9
Momordica subanguenta (MS)
Peria katak
16.6
Andrographis paniculata (AP)
Hempedu bumi
14.4
Orthosiphon stamineus (OS)
Misai kucing
11.4
Ficus deltoidea(FD)
Mas cotek
8.9
Smilax myosotiflora (SM)
Ubi jaga
7.9
Morinda citrifolia (MC)
Mengkudu
7.7
Eurycoma longifolia (EL)
Tongkat ali
2.8
Table 2. Total phenolic and flavonoids contents of
the samples
Sample
Total phenolic (mg /g)
Total flavonoid (mg/g) % DPPH
Andrographis
paniculata
43.58
2.47
19.0
Averrhoa belimbi
40.68
14.88
14.8
Eurycoma longifolia
53.75
3.37
24.0
Dipteris lobbiana
54.92
81.75
92.0
Ficus deltoidea
53.93
42.45
61.1
Fagrea obovata
54.58
74.13
91.6
Momordica subanguenta 48.30
0.15
22.9
Morinda citrifolia
53.75
11.80
46.1
Orthosiphon stamineus
54.54
56.75
87.5
Smilax myosotiflora
54.63
16.19
32.6
Scavenging activity
% Scavenging of plant extract
Percent scavenging
100
80
60
% Scavenging
40
20
0
Ap
Ab
El
Dl
Fd
Fo
Ms
Mc
Os
Sm
Sample
Ap=Andrographis paniculata, Ab=Averrhoa belimbi, El=Eurycoma longifolia,
Dl=Dipteris lobbiana, Fd=Ficus deltoidea, Fo=Fagrea obovata, Mo=Momordica
subanguenta, Mc=Morinda citrifolia, Os=Orthosiphon stamineus and Sm=Smilax
myosotiflora
Flavonoid contents and scavenging activity
Flavonoid content (mg/g)
and scavenging (%)
Correlation of flavonoid contents and % scavenging
100
80
60
Series1
40
Series2
20
0
Ap
Ab
El
Dl
Fd
Fo
Ms
Mc
Os
Sm
Que BHA
Sample
Ap=Andrographis paniculata, Ab=Averrhoa belimbi, El=Eurycoma longifolia,
Dl=Dipteris lobbiana, Fd=Ficus deltoidea, Fo=Fagrea obovata, Mo=Momordica
subanguenta, Mc=Morinda citrifolia, Os=Orthosiphon stamineus and Sm=Smilax
myosotiflora, Que= Quercetin
TLC test
F. obovata
D. lobbiana
F. deltoidea
O. aristatus
Conclusion
1.
2.
There is correlation between
flavonoid content and radical
scavenging activity.
F.obovata, D.lobbiana and
O.aristatus exhibited highest free
radical scavenging activity.
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