Abstract Book - 3rd International Symposium on Medicinal Plants ...

hydroxyl radical scavenging and reducing power with IC 50 value of 0, 0068 ± 0, 0013 mg/ml, 0,16 ±
0,0082 mg/ml and 1,55±0,025 mg/ml respectively. Using β-carotene/linoleic acid bleaching assay,
crud extract had the highest antioxidant activity with 90 % inhibition. BHT was used as positive
control in this test. In addition, the ethyl acetate and crud extracts exhibited lipid peroxidation
inhibiting activity with 42.7% and 41%, respectively against the linoleic acid emulsion system. In
conclusion, Pistacia lentiscus extracts contain high amounts of phenolic compounds and exhibited
high antioxidant activity which is related to these compounds.
Key words: Antioxidant activity, free radicals scavenging activity, lipid peroxidation, Pistacia
lentiscus L, polyphenols.
1.31 Antiplasmodial and Immunomodulating Activity of Some Sudanese
Herbal Medicine with emphasis on Pristimerin as Antiplasmodial Agent
EL Tahir A 1,2 , SATTI G M H. 1 , THEANDER T 3 , CHRISTENSEN S B. 3 , and
KHALID S A. 4
1 Faculty of Medicine, King Fahad Medical City, Kingdom of Saudi Arabia. 2 Dept. of Biochemistry,
Faculty of Medicine, University of Gezira, Sudan. 3 Panum Institute, University of Copenhagen;
4 Faculty of Pharmacy University of Khartoum.
<strong>Abstract</strong>: Sudan is the largest country in Africa, covering an area of one million square miles
with different metrological and polyethnic, with a diverse flora. Most people in rural areas rely on
traditional medicine for the treatment of many infectious diseases. WHO has recently advocated
the use of traditional medicine where appropriate health services become inaccessible, therefore,
the study aims to investigate the potential antiplsmodial, antleishmanial activity of some medicinal
plants and to detect their effect on human lymphocytes proliferation which may imply the ability to
potentiate the human immune system. Forty-nine plant parts representing 26 species from 15
families were extracted and screened for their activity on chloroquine sensitive strains 3D7 and
Dd2. Plants were collected according to their traditional use and / or to their taxonomical affiliation
to their families that had been reported to have antimalarial activity. Thirty-four methanol extracts
(59%) exhibited significant activity against 3D7 with IC50 values ≤ 50 μg/ml, while twenty-one
extract (57%) showed antiplasmodial activity on Dd2 with IC50 values ≤ 50 μg/ml. On the other
hand, thirteen extracts (22%) and ten extracts (18%) only showed an activity with IC50 values ≤ 5
μg/ml on 3D7 and Dd2; respectively. Human lymphocytes treated with the most of extracts
demonstrated a minimum level of toxic inhibitory effect at concentration ≥ 100μg, whereas
Sonchous cornatus, Balanites aegyptiaca, Acacia nilotica and Tamarindus indica enhanced
lymphocytes proliferation. Bioactivity directed fractionation of the chloroform extract of the root
bark of Maytenus senegalensis resulted in the isolation and characterization of the
quinonemethide triterpene, (20α)-3-hydroxy-2-oxo-24-nor-friedela-1(10),3,5,7-tetraen-carboxylic
acid - (29)- methylester (pristimerin). The structure was elucidated by spectroscopic techniques.
The in vitro antiplasmodial activity of the isolated compound against chloroquine-resistant strain
(Dd2) of Plasmodium falciparum was IC50 = 0.5μg/ml and its in vitro antileishmanial activity
performed on promostigotes of Leishmania major was IC50 = 6.8 ± 0.8 μg/ml while the cytotoxicity
on lymphocyte proliferation model was detected at IC50= 6.8 ± 0.8 μg/ml. The promising response
of Acacia nilotica and Mayenus senegalensis conclude that some Sudanese plants used in
traditional medicine possess a potent antimalarial activity with minor effects on lymphocytes
proliferation. These plants have been subjected to long-term clinical trials in folk medicine and
hence we propose that these plants should be further investigated.
Key words: Antiplasmodial, immunomodulating activity, sudanese pristimerin.
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