الفهرس 
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Abstract
Silver is a nontoxic inorganic agent and it exhibits vital functions as an antiseptic due to its efficiency against about 650 types of microorganisms caused diseases. It was recently documented that silver plant nano-extracts showed wide range of possible applications. This might refer to enhancing the active phytoconstituents which exhibit present with antioxidant potentials and free radical scavenging activities higher than those of the crude extracts.
1. Study on M. oleifera leaves before and after incorporating Ag-NPs
1.1. Preparation of silver M. oleifera leaves nano-extract
The present study postulated that M. oleifera leaves extract found to be more effective than extract of the plant seeds. This was represented by the higher concentration of the total polyphenolic compounds, total antioxidant capacity, iron reducing power and free radical scavenging activity in addition to the lower extract concentration required to kill 50 % of colon cancer cells. Therefore, M. oleifera leaves were selected to be incorporated by Ag-NPs during the current study.
The plant leaves extract utilized as reducing for synthesis of Ag-NPs by mean of green nano-technology. The synthesized nanoparticles characterized by various confirmatory advanced techniques including UV-visible spectroscopy, DLS and TEM.
1.2. characterization of the synthesized Ag-NPs
It was observed that the Ag-NPs were predominantly spherical in shape, while some of the NPs were irregular in shape. No aggregations were detected. Presence of the Ag-NPs maintained homogeneity and uniformity of Ag-NPs distribution in the particles size ranged between 5-10 nm.
Based on the data obtained using the UV-visible spectroscopy, it was confirmed that Ag-NPs were prepared within the chemical reduction method. The Ag-NPs generate strongly interrelate with exact wavelengths of light.
1.3. In vitro antioxidant and cytotoxic activities of the different extracts
It was noticed that incorporation of Ag-NPs enhanced the total antioxidant capacity, concentration of total polyphenolic compounds, reducing power and scavenging activity against free radicals initiated by ABTS and DPPH in addition to increasing the cytotoxicity against growth of the colon cancer cells.
1.4. chromatographic analysis of total phenolics
The GC/MS analysis showed that the phenolic compounds increased as a result of incorporating Ag-NPs. It was noticed that 40 phenolic compounds were identified in the aqueous M. oleifera leaves extract before incorporating of Ag-NPs and three common compounds identified as 3-Octanol, 2-Butanol and 2-Methyl-2-hexanol at Rts 38.80, 41.88 and 56.25 min, respectively represent the highest percents in the extract (8.61, 34.27 and 7.11%, respectively). In silver M. oleifera leaves nano-extract, 50 phenolic compounds were identified and three common compounds identified as 3-methyl-2,4-pentanediol, Butanal and Bis[(2,4,6-tritertbutylphenyl)amino]phenylchlorosilane at Rts 38.82, 41.87 and 48.21 min, respectively) represent the highest percents in the extract (6.17, 34.43 and 4.75%, respectively).
1.5. Fourier Transform Infrared (FT-IR) Spectroscopy
The FT-IR spectrum showed that 7 phenolic compounds were identified in the M. oleifera leaves extract before incorporating Ag-NPs. As regard to silver M. oleifera leaves nano-extract, it was noticed that 17 phenolic compounds were identified.
Consequently, enhancement of these compounds found to be related to the total antioxidant capacity, iron reducing power and free radicals scavenging activity and hence increasing the anticancer activity.
1.6. Median lethal dose of different extracts (LD50)
It was found that there was no wide gap in value of the LD50 between M. oleifera leaves extract and silver M. oleifera leaves nano-extract. It was found that the LD50 values of the M. oleifera leaves extract and nano-extract were about 14250 and 13750 mg/Kg, respectively. Moreover, the therapeutic doses (1/20 LD50) for both extracts were about 712.50 and 687.50, respectively. Incorporation of Ag-NPs into the extract caused no toxicity when administrated by stomach tube.
The present study was designed to reveal efficiency of M. oleifera leaves extract after incorporating Ag-NPs against colon cancer induced by AOM but it was found that AOM caused different deleterious effects at the hematological and biochemical levels during the induction process.
2. Effect of silver M. oleifera leaves nano-extract against AOM induced colon cancer on hematological measurements
AOM caused no significant alterations in the hematological measurements related to indices of red blood cells (RBCs, HB, HCT, MCV, MCH and MCHC). Furthermore, it caused significant (P≤0.05) elevation in levels of RDW, MPV and PLT as compared to control group. As regard to WBCs and its differential count (Lymp., Mono. and Gran.), it caused significant (P≤0.05) elevation in levels of these measurements as compared to control group.
The M. oleifera leaves nano-extract could not affect RDW level in the pre-treated group when compared to AOM induced colon cancer group but it restored its level to normal values in the simult-treated and post-treated groups. Moreover, it decreased levels of MPV and PLT significantly (P≤0.05) in all nano-extract treated groups as compared to AOM induced colon cancer group and restored these measurements to normal values in the simult-treated and post-treated groups. Also, it decreased levels of WBCs and its differential count significantly (P≤0.05) as compared to AOM induced colon cancer group and restored these measurements to normal values in all nano-extract treated groups.
3. Effect of silver M. oleifera leaves nano-extract against AOM induced colon cancer on different biochemical measurements
3.1. Liver and kidney functions
Activities of liver enzymes (ALT, AST and ALP) in addition to levels of TC and T.Gs elevated significantly (P≤0.05) in sera of AOM induced colon cancer group as compared to control group. The M. oleifera nano-extract caused significant (P≤0.05) restored their levels to normalcy in all nano-extract treated groups.
As regard to the renal functions, it was found that AOM increased levels of urea and creatinin associated with lowering levels of T.P and albumin significantly (P≤0.05). The treatment with nano-extract exhibited the same therapeutic effect in all nano-extract treated groups through lowering levels of urea and creatinin significantly (P≤0.05) with restoring levels of T.P and albumin into normal values.