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

general pain. It can be used as beverage, mouth wash, local drug delivery or chewing gum. The
aim of this study is to investigate the antioxidant effect of aqueous green tea extracts. Infusion and
decoction are used to obtain water extracts from green tea leaves, Moreover, the DPPH (1,1-
diphenyl-2-picrylhydrazyl) radical scavenging assay, the β-carotene bleaching test and the ferrous
ions chelating assay are applied to evaluate the antioxidant activity of the extracts. The obtained
results show that both tea extracts have exhibited a strong scavenging effect on DPPH radical
comparable with ascorbic acid (reference antioxidant) with an IC 50 of 3µg/ml. The maximum of
inhibition reached 88%. Our results also indicated that 88% and 93% of linoleic acid oxidation was
inhibited by tea extracts prepared by infusion and decoction respectively. These results are similar
to those exhibited by the standard antioxidant (BHT) witch produce an inhibition percent of 96%. In
terms of FIC ability, the two types of tea extracts produced a good chelating power on Fe 2+ with
chelating level of 75%. Infusion and decoction extracts have the same antioxidant activities without
significant differences. The present study provides additional data for supporting the use and
consumption of aqueous green tea extracts as natural antioxidant agents.
Key words: Antioxidant activity, oxidative stress, tea.
1.42 Greco-Arab-Based Medicinal Plants Diminishe Insulin Resistance in
Skeletal Muscle Cell Line
Kadan Sleman 1,2 Saad Bashar 1,3 , Kmail Abdalsalam 3 , Khasib S 3 ., and Zaid
H. 1,3
1 Qasemi Research Center- Al-Qasemi Academic College, P.O Box 124, Baqa El-Gharbia 30100.
2 Casali Institute for Applied Chemistry, Faculty of Mathematics and Sciences, The Hebrew
University of Jerusalem, 3 Faculty of Arts and Sciences, Arab American University Jenin, P.O Box
240, Jenin, Palestine.
<strong>Abstract</strong>: Hypoglycemic herbs are widely used as non-prescription treatment for diabetes
(mainly type II)). Palestinian herbs have been used for hundreds of years in treatment and
prevention of diverse diseases including diabetes. However, Palestinian herbal anti-diabetic
medicines action mechanisms are not well characterized as those of Western drugs. This study
aimed at investigating safety and efficacy of one of these plants that is still in the process of
patenting it; herein named HIBAS. The largest site for glucose disposal in the mammalian body is
skeletal muscle, and Glucose Transporter-4 (GLUT4) is the major glucose carrier in muscle
mediating most of the glucose influx. Insulin triggers GLUT4 translocation to the plasma
membrane, where it can mediate glucose influx into the cell. Here, we focused on identifying the
mechanism of action of HIBAS in curing insulin resistance (type II diabetes) in an in-vitro skeletal
muscle cell line model by detecting the relative amount of GLUT4 on the plasma membrane. We
had also tested the toxicity of the HIBAS leave extracts (50% H 2 O, 50% Ethanol) on human
fibroblasts and skeletal muscle cells. No sign of toxic effects were seen in cultured human
fibroblasts and skeletal muscle cells treated with increasing concentrations of the Plant mixture up
to 1mg/ml. Anti-diabetic effects were evidenced by measuring the relative amount of GLUT4
translocation to the plasma membrane in the presence and absence of insulin. Skeletal muscle
(L6) cells stably expressing myc-tagged GLUT4. have been repeatedly shown to display insulin
regulated GLUT4 traffic. HIBAS led to increase in surface GLUT4myc when L6 myoblasts were
pre-treated with increasing concentrations of the plant extract for 20h, followed by 3h serumdeprivation
and insulin stimulation for 20 min. Exposing L6 muscle cell cultures to high glucose and
high insulin (25 mM, 100 nM, respectively, for 24h), followed by 3h in control medium, renders
them refractory to subsequent acute stimulation by insulin. This experimental paradigm has also
been tested. Consistent with the previous finding, 0.5mg/ml of HIBAS for 3h was able to overcome
the induced Insulin insensitivity. Collectively, our results demonstrate safety, tolerability and
efficacy of a herbal Palestinian plant that seems to be safe for use and regulates glucose
homeostasis.
Key words: Diabetes, insulin triggers, mechanism, myoblasts, Palestinian herbs.
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