الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Many marine organisms live in complex habitats exposed to extreme and harsh conditions so, to adapt to environmental changes, they produce a wide variety of secondary biologically active metabolites as a defense strategy against predators. It was revealed that among marine invertebrates, bioactive compounds; such as proteins, exhibit antibacterial and antitumor properties. Among marine organisms, invertebrates such as crustaceans and molluscans have proven to be rich natural bioactive resources of many biologically active compounds such as proteins that interfere with the disease pathogenesis and have pharmacological activities such as anti-bacterial and anti-tumor properties. Therefore, the present study aimed to evaluate the protein extracted from three marine invertebrates; Portunus pelagicus, Lithophaga lithophaga and Pinctada radiata, as antibacterial besides both In-vitro and In-vivo antitumor adjuavant therapy, expecting for applied later in pharmaceutical and medical purposes. The results of the present study could be summarized as follows: Inhibition concentration 50 (IC50) of three protein extracts was determined using MTT assay. The values of IC50 detected were 3695 μg/ml, 9756 μg/ml and 1587 μg/ml, for Portunus pelagicus, Lithophaga lithophaga and Pinctada radiata, respectively. Lethal doses 50 (LD50) of investigated three protein extracts was calculated which are 2244 mg/kg, 3221 mg/kg and 1639 mg/kg. 1/10 of LD50 was considered as (high dose) which equals 4.5 μg/mouse, 6.5 μg/mouse and 3.3 μg/mouse, and 1/20 of LD50 (low dose) which equals 2.25 μg/mouse, 3.25 μg/mouse and 1.65 μg/mouse of P. pelagicus, L. lithophaga and P. radiata, respectively. Doses were injected intraperitoneally (i.p.) to experimental mice. The investigated concentrations were tested against two Gram-positive bacteria; S. aureus and Streptomycs sp., and two Gram-negative bacteria; E. coli and P. aeruginosa to detect their antibacterial activity using disc diffusion assay. The three protein extracts have active antibacterial ingredients, which can inhibit the growth of tested bacterial strains. The highest anti-bacterial activity was recorded in P. radiata protein extract, followed by P. pelagicus protein extract and finally, L. lithophaga total protein extract. P. aeruginosa showed maximum sensitivity with the highest inhibition zone with high concentration of both P. pelagicus and P. radiata. Twelve groups of experimental (Swiss albino CD1) mice previously implanted with 0.5x106 Erlish ascites carcinoma (EAC) were intraperitoneally injected with three doses of low and high concentrations of one of the three investigates protein extracts or with three doses of the same previous concentrations combined with only single dose of the chemotherapeutic drug Cisplatin (Cis). All of the previous groups were compared with naïve nice without any treatment, negative control group (naïve tumor mice without any treatment), and positive control group (naïve tumor mice treated with single Cis dose). On day 14 post EAC implantation, mice were sacrificed and hematological, biochemical and immunological investigation were carried out and the results revealed that: The results of hematological analysis showed that injection with high dose of P. pelagicus and both low and high doses of L. lithophaga, elevated WBCs count, compared to control groups. The synergistic effect in WBCs count was obtained when mice injected with Cis combined with doses of P. radiata protein extract. Relative percentage of neutrophils count was significantly increased in EAC- bearing mice inoculated with high dose of P. pelagicus protein extract and low dose of L. lithophaga protein extract combined with Cis, compared with control groups. Cisplatin showed synergistic effect with both low and high doses of P. pelagicus and high dose of P. radiata extracts in elevating lymphocytes percentage. Hemoglobin content increased in EAC-bearing mice treated with single dose of Cis and low doses of L. lithophaga protein extract, compared to negative control group. High doses of both P. pelagicus and P. radiata showed an elevation in monocytes percentage, compared to control groups, with a clear antagonistic effect of chemotherapy with all protein extracts. Biochemical analysis showed that alanine aminotransferase (AST) reached to the minimum value in groups injected with high dose of both P. pelagicus and L. lithophaga and EAC-bearing mice treated with Cis combined with high dose of P. radiata, while all groups treated with three investigated protein groups with/without Cis showed significant decrease in the serum level of ALT. Kidney function was represented by creatinine and urea levels in serum of treated mice. The results showed that treatment of EAC-bearing mice with low dose of L. lithophaga protein extract or high dose of P. radiata protein extract combined with Cisplatin returned the elevation in creatinine level to become quite close to that in control mice. Obvious antagonistic effect of all protein extracts with Cisplatin was showed in urea concentration as all groups inoculated with different protein extracts without chemotherapy restored the level of urea to its normal level in naïve mice.