الفهرس 
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Abstract
The present work aimed to study the antitumor efficacy of the biosynthesized gallium nanoparticles by using a natural polyphenol
( Ellagic acid (EA)) by a simple and green method forming gallium nanoparticles coated with Ellagic acid (EA-GaNPs).
The antitumor efficacy of (EA-GaNPs) was studied in vitro against human breast carcinoma cell line (MCF-7) and in vivo against 7, 12 Dimethyl benz[a]anthracene (DMBA)-induced mammary gland carcinogenesis of female Swiss albino rat model.
The biosynthesized gallium nanoparticles (EA-GaNPs) were characterized by using dynamic light scattering (DLS) , scanning electron microscope (SEM), ultraviolet-visible absorption and FT-IR spectroscopies, the results revealed that EA-GaNPs were of spherical shape with relatively narrow particle size distribution and size ranging from 5.8 - 10.5 nm. The UV/VIS scan showed 2 narrow peaks at wave lengths 360 and 380 nm. As well as the FT-IR results confirmed the presence of bioactive molecules and functional groups in both of EA and EA-GaNPs which means that there was no chemical interaction interfered with the synthesis of EA-GaNPs and the prepared NPs were capped by physical interaction with organic molecules.
In vitro study of EA-GaNPs on human breast carcer cell line (MCF-7) showed toxicity with IC50 of 2.86 μg/ml. while the in vivo study, a narrow scale experiment was performed to determine the LD50 of EA-GaNPs which was found to be 10 mg/kg b. w. and the safe dose was calculated by dividing LD50 by 10 to be used as a safe dose in the in vivo study. Forty female Swiss albino rats weighing (120 ± 20 gm) were equally divided randomly into the following 4 groups:
group I (control healthy group): rats were received 1.0 ml of physiological saline solution orally.
group II (DMBA- induced mammary gland carcinogenesis group): rats were received a single dose of 20.0 mg of DMBA/kg b. w. dissolved in 1.0 ml of olive oil by oral gastric intubation then animals were palpated weekly to monitor changes in the mammary glands.
group III (EA-GaNPs group): at the 7th month, rats were received a daily oral dose of 1.0 mg of EA-GaNPs /kg b.w. by gastric intubation for one month.
group IV (DMBA+EA-GaNPs): rats were received a single dose of 20.0 mg of DMBA/kg b. w. dissolved in 1.0 ml of olive oil by oral gastric intubation 7 months earlier for cancer induction then they were received a daily oral dose of 1.0 mg of EA-GaNPs /kg b.w. by gastric intubation for one month.
At the end of the experiment (after 8 months), rats were anesthetized and sacrificed, blood samples were obtained via heart puncture and mammary glands were excised for evaluation of several biochemical and molecular parameters in addition to the histopathological study.
Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were measured as markers for liver function; serum urea and creatinine were measured as markers for kidney function. in addition to evaluation of the value of total iron binding capacity (TIBC) and calcium levels in serum. Also, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, reduced glutathione (GSH) content, concentration of caspase-3 and protein intensity of phosphatidylinositol 3-kinases (PI3K) and protein kinase B (AKT) were measured in 10% mammary gland tissue homogenates.
The obtained results of the current work revealed that administration of DMBA resulted in significant elevations of ALT and AST activities as well as urea and creatinine levels in an indicating manner of occurrence of damage to those internal organs (liver and kidney) which could be due to the produced reactive oxygen species by DMBA which also was manifested clearly in significant increasing of MDA content and significant decreasing of the activity of SOD and GSH content. Also a significant increase in the concentration of caspase-3 was noted indicating the induction of apoptosis by DMBA. In the same time, DMBA administration resulted in a significant increase of both of AKT &PI3K protein intensity indicating the staking of PI3K/ Akt signaling pathway in “on” position which resulting in cellular surviving.
Furthermore, significant increasing of TIBC was noted indicating the ability of malignant cell to uptake much more iron which was in line with their far greater requirement for iron for proliferation , while there was a significant decrease of Ca levels.
Also histopathological alterations in the architecture of the mammary glands were appeared clear in proliferative hyperplasia of the lining epithelial cells of the acini and lactiferous ducts with cystic dilatation as well as stratification.
The treating of the induced mammary gland carcinogensis with EA-GaNPs resulted in amelioration of the investigated biochemical parameters which was manifested clearly in significant decreasing of the activities of ALT&AST, levels of urea and creatinine indicating the reflection of the damage action induced by DMBA. Also, improving of antioxidant state occured by increasing SOD activity and GSH content and decreasing of oxidative stress state by depletion of lipid peroxidation marker (MDA content).
Treating with EA-GaNPs also induced the apoptotic process by increasing of caspase-3 concentration and decreasing of AKT &PI3K protein intensity indicating the down regulation of AKT &PI3K signaling pathway.
Competition of gallium with serum iron resulted in decreasing of TIBC level to impede the dependence of the malignant cell on iron for surviving and proliferation. Also, a significant increase of serum Ca levels was noted.
A mild recurrence of normal mammary gland tissue was histopathologically appeared by treating of EA-GaNPs as there was no hyperplastic changes were noted, only a mild stratification of the acinar lining epithelium was found.