الفهرس 
REVIEW OF LITERATURE
Hepatitis C virus (HCV) infectionOnly 14 pages are availabe for public view
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Abstract
Liver cancer or hepatocellular carcinoma (HCC) is one of the
most common cancer types worldwide, with a high prevalence and
a very low survival rate of 3–5%. Many factors play a role in the
etiology of HCC, but, most importantly, HCC can be caused by
hepatitis B and C viruses. HCC cells, unlike normal cells, are
resistant to death receptor-mediated apoptosis because their surface
death receptors are cross-linked with either agonistic antibodies or
soluble death ligand proteins. Several cell cycle proteins play a role
in the etiology of liver cancer.
So far, the development of chemotherapeutic drugs has
targeted molecules in HCC, but the results were not promising
because of drug resistance and systemic toxicity, specifically in the
advanced stage of this deadly malignancy.
Therefore, searching for new natural and nontoxic compounds
with the cytotoxic effects against HCC cells is of particular
interest. One of the less studied plants Origanum majorana L.
Origanum majorana is belongs to Lamiaceae family, commonly
known as sweet marjoram.
Reports indicate that Origanum majorana leaves contain
proteins, carbohydrates, iron, zinc, calcium, magnesium,
phosphorous, ascorbic acid and flavonoids. The Origanum majorana plant is utilized as spice and flavoring agent, and in
traditional medicine as well for treatment of chest infection, cough,
sore throat, rheumatic pain, nervous disorders, stomach disorders,
cardiovascular diseases, and skin care. There is increasing evidence
that O. majorana possesses extensive range of biological activity,
including antioxidant, antimicrobial, anti-inflammatory and
hepatoprotective activities.
This study was carried out in order evaluate the
antiproliferative effect of organic and water extracts of Origanum
majorana on Human hepatocellular carcinoma HepG2 cell line
which is a well-differentiated transformed cell line closely related
to HCC.
In this study, fresh O. majorana leaves were cleaned, dried,
and ground to a fine powder. The organic extract of Origanum
majorana was prepared from the air dried powder leaves (400 gm)
were macerated in 2L of 70% ethanol for 3 days and kept at 4°C in
a refrigerator without stirring. This process is repeated till
exhaustion. The filtration was done using a piece of cotton. the
filtrate was evaporated till dryness under reduced pressure using a
rotator evaporator at 45°C and 90 rpm until a semisolid residue was
obtained. The residue was converted to lyophilized powder using a
lyophilizer to give 16g extract/100g air dried powder leaves. The
aqueous extract as prepared from the air dried powder leaves (400 gm) substance was were macerated in 2L of distilled water and left
at 60°C for 1 hour with continuous shaking, the mixture was
cooled to room temperature. The filtration was done using a piece
of cotton the filtrate was evaporated till dryness under reduced
pressure using a rotatory evaporator at 45°C and 90 rpm till the
semisolid residue was obtained. The residue was left in lyophilizer
until dryness to give 18.5g extract/100g of dried powder leaves.
For bioassays, the residue of each extract was redissolved in 1ml of
dimethyl sulfoxide before use.
The HepG2 cells were maintained in RPMI- 1640 medium
supplemented with 10% heat inactivated fetal bovine serum (FBS),
100units/ml penicillin, 100 μg/ml streptomycin , and Amphotircin
B, culture medium was changed three times per week. Then, T-25
flasks of completely confluent HepG2 cells were treated with each
type of Origanum majorana extracts and cells treated with
dimethyl sulfoxide ( DMSO) were served as control. All flasks
were then maintained at 37ºC in a humidified incubator with 95%
air and 5% CO
2. After 24 ,48, and 72hrs respectively all flasks
were trypsinized with 1ml of trypsin-EDTA and counted under the
light microscope (100x) using trypan blue dye (0.04%) to count the
number of viable cells. The cell suspensions were centrifuged then,
the pellet was washed with PBS.RT-PCR was performed to detect nuclear factor kappa B gene
expression, as the following: total RNA was extracted from all of
the above cell-lysate, and then, in order to preserve RNA samples,
total RNA was transcribed into cDNA. RT-PCR was performed
using a Real time PCR 7500 fast thermal cycler.
Results obtained could be summarized as follows:
1-Origanum majorana L. extracts at concentration 150 µg/ml
significantly inhibited the growth and caused morphological
changes in HepG2 cells in a time-dependent manner at 24, 48,
and 72 hours post-treatment using water, and (EtOH) extracts
respectively as the number of viable cells which have
significantly decreased with the progress of time compared with
the untreated control cells .
2-Origanum majorana L. extracts inhibited the activity of nuclear
factor kappa B gene expression of HepG2 cells treated with
water, and EtOH extracts of Origanum majorana L. Leaves
compared with the control.
Therefore, the conclusion was that the water and organic
extracts of Origanum majorana L. leaves inhibit the growth of
HepG2 cells through suppressing the activity of NF-kB gene
expression and modulate the biochemical markers.