somaye shahraki

Cressa cretica L., due to producing of some various compounds, which could be used as a source of many herbal medicines. The present research were studied in antioxidant, antibacterial properties and the ability of interaction with human serum albumin (HSA) of Cressa cretica L. So the leaves of the plant were collected in vegetative stage from Sistan in 2015. Three kinds of extraction such as aquatic, methanolic and ethanolic extracts were obtained by using maceration method. The antioxidant activity were measured by DPPH method. The interaction of ethanolic extraction with HSA was performed by UV-Vis spectroscopy. The Anti-bacterial properties of extracts against Staphylococcus aureus, and Escherichia coli were investigated by MIC and MBC methods. The results were showed that the lowest and highest extraction efficiency were related to the aquatic and ethanolic, respectively. The ethanolic extract had the highest antioxidant activity in inhibition percentage of DPPH than other extracts (56, 38 and 34%) respectively. Study of the interaction with HSA demonstrated the changes in protein secondary structure and the binding constant in that obtained 0.49 × 102 ppm-1.This plant showed acceptable bactericidal activity and MIC values were higher than the MBC.

In many diseases such as cancer, simultaneous use of two or more pharmacologically active agents will be more effective and have fewer side effects. In this study a new palladium(II) complex with formula of [Pd(phen)(py-dtc)]NO3 (where is phen 1,10-phenanthroline and py-dtc is n-propyldithiocarbamate), was synthesized. The cytotoxic activity of this complex was tested against leukemia K562 cell lines. The cytotoxic concentration (Cc50) value of above Pd(II) complex was 53.06 μM. In the presence of vitamin K3, Cc50 value dramatically decreased to 32.95 μM and encouraged us to study DNA interaction of Pd (II) complex in the absence and presence of vitamin K3. Interaction of above Pd(II) complex in two modes (in the absence and presence of vitamin K3) with calf thymus DNA was evaluated using spectroscopic methods. UV-Vis results showed that in the presence of VK3, Pd(II) complex unexpectedly denatures CT-DNA at very low concentration. Fluorescence results showed that quenching of the intrinsic fluorescence of EBr-DNA system by Pd(II) complex is static quenching mechanism and type of mechanism does not change in the presence of vitamin. Also, in the absence and presence of vitamin, the mode of intercalation might play a major role in the interactions of Pd(II) complex with DNA. Several binding and thermodynamic parameters are also presented. We hope that these results provide a basis for additional studies and clinical use of combined anticancer drugs to be useful.

The ability of small molecules to perturb the natural structure and dynamics of nucleic acids is intriguing and has potential applications in cancer therapeutics. This work reports the synthesis, characterization, cytotoxicity and DNA-binding studies of two cytotoxic and intercalative [M(bpy)(pyrr-dtc)]NO3 complexes (where M = Pt(II) and Pd(II), bpy = 2,2´-bipyridine and pyrr-dtc = pyrrolidinedithio-carbamate). Binding interaction of these complexes with calf thymus DNA (CT-DNA) was investigated by spectrophotometric, spectrofluorometric and gel filtration techniques. Gel filtration studies indicate that the binding of these complexes with CT-DNA is strong enough not to readily break. The binding constant and the thermodynamic parameters have been determined using absorption measurements. The fluorescence studies indicate that the two complexes bind to CT-DNA through an intercalative mode. The cytotoxic activity of these metal complexes has been tested against chronic myelocytic leukemia K562 cell lines and revealed much lower 50% cytotoxic concentration (Cc50) than that of cisplatin. We hope that such spectroscopic studies to be indeed helpful in studying the pharmacological response of drugs and design of dosage forms.

In depth interaction studies between calf thymus deoxyribonucleic acid (CT-DNA) and a series of four structurally relative palladium(II) complexes [Pd(en)(HB)](NO3)2 (a-d), where en is ethylenediamine and heterocyclic base (HB) is 2,2''-bipyridine (bpy, a); 1,10-phenanthroline (phen, b); dipyridoquinoxaline (dpq, c) and dipyridophenazine (dppz, d) (Figure 1), were performed. These studies have been investigated by utilizing the electronic absorption spectroscopy, fluorescence spectra and ethidium bromide (EBr) displacement and gel filtration techniques. a-d complexes cooperatively bind and denature the DNA at low concentrations. Their concentration at midpoint of transition, L1/2, follows the order a >> b > c > d. Also the g, the number of binding sites per 1000 nucleotides, follows the order a >> b ~ c > d. EBr and Scatchard experiments for a-d complexes suggest efficient intercalative binding affinity to CT-DNA giving the order: d > c > b > a. Several binding and thermodynamic parameters are also described. The biological activity of these cationic and water soluble palladium complexes were tested against chronic myelogenous leukemia cell line, K562. b, c and d complexes show cytotoxic concentration (Cc50) values much lower than cisplatin.