Cytotoxicity

The condensation of 2-hydrazino-4-phenyl thiazole and 3-formyl-2-hydroxyquinoline has led to the synthesis of a new Schiff base (L) and its series of mononuclear Co(II), Ni(II) and Cu(II) complexes have also been synthesized. The synthesized Schiff base and its metal complexes were characterized by elemental analyses, spectral techniques (FT-IR, 1H-NMR, 13C-NMR, GC-MS, ESI-MS, UV-Vis, etc;) and magnetic studies. Elemental analyses reveals the [M(L)2.(H2O)2] stoichiometry, where M= Co(II), Ni(II) and Cu(II); “L”= doubly deprotonated ligand. The synthesized metal complexes are completely soluble in DMF and DMSO. The molar conductivity values indicate that, the metal complexes are non-electrolytic in nature. The newly synthesized compounds are good anti-tuberculosis and cytotoxic agents. They have been screened for in-vitro antibacterial and antifungal activities by MIC method. The DNA cleavage activity is studied by agarose gel electrophoresis method using pBR322 Plasmid DNA.

Medicinal herbs are significant sources of chemotherapeutic drugs and play a vital role in the prevention and treatment of cancer. Mentha pulegium L. from Labiatae family was traditionally used as an anticancer agent. In this study, aerial parts including leaves of this plant were extracted by methanol and fractionated extracts have been produced by petroleum ether, ethyl acetate, acetone, methanol and distilled water. For the purpose of cytotoxic evaluation of methanolic extract and its fractions on human ovary carcinoma cells (C13), human hepatocarcinoma cells (HepG2) and human lung carcinoma cells (A549), clonogenic assay was performed. Briefly, 200 cells were seeded in each well of 6 well plates in RPMI 1640 with 10% FBS media. After 24 hours incubation, 0-50μg/ml of methanolic extract and its fractions were exposed to the cells. Finally, colonies with more than 50 cells were counted after 7 days. In each case, a control row was set by the exposure of cells to compounds-free solvents. LC50 values were calculated using nonlinear regression analysis on Graphpad prism® software. The result showed that the methanolic extract and its fractions are cytotoxic on all three studied human carcinoma cell lines at different degrees. Human ovary carcinoma cell line (C13), which is resistant to many other chemotherapeutic agents (e.g. cisplatin), is the most sensitive cell line to methanolic extract and its fractions compared to two other cell lines. Further complementary cellular and animal studies are recommended for these anticancer candidates.

Andrographolide is a diterpene lactone present in aerial parts of Andrographis paniculata especially in the leaves. It was reported to possess a wide variety of bioactivities. In the present research immunomodulatory effects of pure andrographolide have been studied on chicken spleenocytes in vitro. The immunological intervention of andrographolide was assayed using Nitro Blue Tetrazolium dye reduction assay, Inducible Nitric Oxide Synthase assay and Macrophage function test. Cytotoxic effects of andrographolide  on spleenocytes were tested using MTT assay. Andrographolide suppressed Nitro Blue Tetrazolium dye reduction assay response at all experimental concentrations. 45% reduction in immune response was observed when spleenocytes were treated with andrographolide at a concentration of 40µg/ml. The overall Inducible Nitric Oxide Synthase assay response of spleenocytes get decreased with incorporation of andrographolide in media. It was observed that when spleenocytes were mitogenically stimulated in presence of Covcanavalin A and Phytohaemagglutinin ,the suppression of Inducible Nitric Oxide Synthase assay response was observed. Andrographolide was found to enhance the phagocytic ability of spleenocytes upto 10 folds. It was found to be nontoxic at the concentration of 40µg/ml and 96% of spleenocytes remained viable as estimated by Trypan blue dye exclusion method. It was found to have immunosuppressive properties and it can be used to treat inflammatory disorders such as allergies, rheumatoid arthritis etc.

This dissertation describes the biological investigations of Diospyros peregrina gurke; a plant belonging to the family Ebenaceae.Present study was designed to test the cytotoxic activity and antimicrobial effect of crude extract. The study protocol consists cold extraction of powdered unripe fruit and seed of Diospyros peregrina gurke for cytotoxicity effect using Brine shrimp bioassay lethality and tested against four Gram negative and three Gram positive bacteria for antimicrobial activity. From the results of the brine shrimp lethality bioassay it can be well predicated that crude extracts of Diospyros peregrina gurke possess cytotoxic principles (with LD50  9.12011µg/ml and 10.8893µg/ml).For antimicrobial activity, the extracts were tested against standard microbial strains of gram positive and gram-negative, by means of Agar-Disc Diffusion Method and minimum inhibitory concentration (MIC) was noted.Although, both extracts were found to be effective in inhibiting pathogens to varying degrees to the tested organisms, the unripe fruit pulp extract of Diospyros peregrina gurke was found to be more effective than seed extract of Diospyros peregrina gurke .When both extracts were used in combination, they have shown strong synergistic effect against all the pathogens tested in the present study. Plant extracts  can be used to source antitumor and antibiotic substances for possible treatment.

The crude methanol extract of leaf of Tiliacora acuminata Miers as well as organic solvent (n-hexane, carbon tetrachloride and chloroform) fractions and methanolic fraction (aqueous) were subjected to screening for total phenolic content, antioxidant, cytotoxic, thrombolytic and antimicrobial activity. In total phenolic content analysis, the n-hexane soluble fraction of leaf was found to contain highest amount of phenolic content (TPC, 132.18 mg/gm of dry weight of extract, expressed as gallic acid equivalents). In the DPPH assay, the n-hexane soluble fraction of leaf displayed the highest free radical scavenging activity with IC50 value 64.54 μg/ml as compared to 27.5 μg/ml produced by butylated hydroxyl toluene.  A positive correlation was evident between total phenolic content and free radical scavenging activity of T. acuminata having correlation coefficient (R2) of 0.91. In cytotoxicity screening, the crude methanol extract of leaf demonstrated strong cytotoxic activity with LC50 value of 2.40 μg/ml as compared to 0.451 μg/ml produced by vincristine sulphate. During assay for thrombolytic activity, the crude methanol extract revealed 32.5% lysis of clot while standard streptokinase and water, used as positive and negative controls, demonstrated 70.4% and 3.62% lysis of clot, respectively. In antimicrobial assay by disc diffusion method, all the samples exhibited moderate to significant antimicrobial activity (zone of inhibition = 10.0-20.0 mm) against all the test organisms. Among all the samples, the carbon tetrachloride soluble fraction displayed strong antimicrobial activity against Escherichia coli (20.0 mm).

The use of microbial products in drug discovery is an ancient and well-established practice. Actinomycetes are known producers of pharmacological and anti-viral agents. This study aimed to screen the crude extract of Actinomycetes some Egyptian collection for their anti (Hepatitis A Virus (HAV-H10), Coxsackie B4 virus (COX B4) and Herpes Simplex Virus (HSV-1)) then, select the most potent actinomycete crude extract (having highest antiviral activity) for processes of purification, identification and mechanism of action. The maximum non toxic dose (MNTD) of each actinomycete extract was determined then antiviral activity against fast growing viral strains replicating in African green monkey kidney (VERO) cells was studied by the reduction in the number of plaques formed by the viruses. A total of 18 extracts Actinomycete isolates with antimicrobial potential against bacteria and fungi was screened for their antiviral activity. The results indicated that; Mnf-21kt extract showed the most promising antiviral activity against three virus strains while extracts from kfs-1ss and kfs-7ss showed inhibition activity against HAV-H10 and HSV-1 only. After purification of extract Mnf-21kt then the analysis of physico-chemical, elemental and spectroscopic analysis (UV, IR, H.NMR, Mass spectroscopy) indicated that; the active compound has the nature of nucleoside analog. On other hand, when the purified active substance was tested for its mechanism of action against HAV-H10, the result indicated that it has induced significant anti-infectivity and anti-replicative effect. The purified compound has promising broad spectrum antiviral activity in an in vitro system.