The Mechanisms of GPR55 Receptor Functonal Selectivity

The objective of the project is to establish the mechanisms of multidirectional signal transmission through the same G-protein coupled receptor GPR55. Using the CRISPR-Cas9 system, clones of the MDA-MB-231 line knockout for the GPR55 (3 clones) and CB2 (CNR2 - 6 clones) receptor genes were obtained. On clones of the MDA-MB-231 line with a knockout CB2 receptor, the cytotoxic activity of the pro-apoptotic ligand docosahexaenoyldopamine (DHA-DA) did not change or slightly increased, while the pro-proliferative activity of the most active synthetic ligand of the GPR55 receptor (ML-184) completely disappeared. On the original line MDA-MB-231, the stimulatory effect of ML-184 is removed by the CB2 receptor blocker, but not by GPR55. At the same time, the stimulating effect of ML-184 is practically not manifested on cell lines knockout at the GPR55 receptor. Thus, it can be confidently assumed that when proliferation is stimulated with the participation of the GPR55 receptor, a signal is transmitted from the CB2 receptor to the GPR55 receptor due to the formation of a heterodimer. GPR18 and TRPV1 receptors are additionally involved in the implementation of the cytotoxic effect of DHA-DA, while the CB1 receptor is not involved. In the implementation of the cytotoxic action of DHA-DA, the predominant participation of one of the Ga subunits was not found, but the Ga13 subunit plays a decisive role in the implementation of the proproliferative action. The Gaq subunit is also important, although to a lesser extent than Ga13.

DNA Damage Repair: Predictor of Platinum Efficacy in Ovarian Cancer?

Ovarian cancer (OC) is the seventh most common type of cancer in women worldwide. Treatment for OC usually involves a combination of surgery and chemotherapy with carboplatin and paclitaxel. Platinum-based agents exert their cytotoxic action through development of DNA damage, including the formation of intra- and inter-strand cross-links, as well as single-nucleotide damage of guanine. Although these agents are highly efficient, intrinsic and acquired resistance during treatment are relatively common and remain a major challenge for platinum-based therapy. There is strong evidence to show that the functionality of various DNA repair pathways significantly impacts tumor response to treatment. Various DNA repair molecular components were found deregulated in ovarian cancer, including molecules involved in homologous recombination repair (HRR), nucleotide excision repair (NER), mismatch repair (MMR), non-homologous end-joining (NHEJ), and base excision repair (BER), which can be possibly exploited as novel therapeutic targets and sensitive/effective biomarkers. This review attempts to summarize published data on this subject and thus help in the design of new mechanistic studies to better understand the involvement of the DNA repair in the platinum drugs resistance, as well as to suggest new therapeutic perspectives and potential targets.

Antibacterial and cytotoxic activity of metronidazole and levofloxacin composites with silver nanoparticles

The aim of the work is to to ascertain their antibacterial activity, as well as the toxic effects toward human cells of composites of silver nanoparticles immobilized by electron-beam technology onto crystals of antimicrobial agents metronidazole and levofloxacin The assessment of antibacterial activity and cytotoxic action of silver naonparticled metronidazole and levofloxacin composites was carried out using the MTT-test. Objects of study of antibacterial activity were three strains of microorganisms: Staphylococcus aureus ATCC25923, Escherichia coli dH5α, Pseudomonas aeruginosa ATCC9027. For the investigation of cytotoxic action, cells of HEK 293 line obtained from human kidney embryos were used. Nanocomposites of metronidazole and levofloxacin were tested at concentrations known as the minimum toxic dose of antibiotics and at concentrations reduced/increased in 2 times. Immobilization of silver nanoparticles on the surface of metronidazole and levofloxacin by electron-beam technology gives a different effect on their antibacterial and cytotoxic activity. Nanocomposites of metronidazole exhibit a weaker antibacterial effect on E. coli than metronidazole alone, while levofloxacin nanocomposites have higher antibacterial activity compared to levofloxacin alone. Nanocomposites of the levofloxacin, compared to free levofloxacin, are characterized by a higher antibacterial effect towards gram-negative bacteria (E. coli), but practically do not differ in activity toward P. aeruginosa and S. aureus. Immobilization of silver nanoparticles on metronidazole crystals does not affect on its cytotoxicity relative to pseudonormal human cells line HEK 293, while the nanocomposites of levofloxacin with silver are more toxic to these cells than levofloxacin alone.

Triterpene Glycosides from the Far Eastern Sea Cucumber Psolus chitonoides: Chemical Structures and Cytotoxicities of Chitonoidosides E1, F, G, and H

Four new triterpene disulfated glycosides, chitonoidosides E1 (1), F (2), G (3), and H (4), were isolated from the Far-Eastern sea cucumber Psolus chitonoides and collected near Bering Island (Commander Islands) at depths of 100–150 m. Among them there are two hexaosides (1 and 3), differing from each other by the terminal (sixth) sugar residue, one pentaoside (4) and one tetraoside (2), characterized by a glycoside architecture of oligosaccharide chains with shortened bottom semi-chains, which is uncommon for sea cucumbers. Some additional distinctive structural features inherent in 1–4 were also found: the aglycone of a recently discovered new type, with 18(20)-ether bond and lacking a lactone in chitonoidoside G (3), glycoside 3-O-methylxylose residue in chitonoidoside E1 (1), which is rarely detected in sea cucumbers, and sulfated by uncommon position 4 terminal 3-O-methylglucose in chitonoidosides F (2) and H (4). The hemolytic activities of compounds 1–4 and chitonoidoside E against human erythrocytes and their cytotoxic action against the human cancer cell lines, adenocarcinoma HeLa, colorectal adenocarcinoma DLD-1, and monocytes THP-1, were studied. The glycoside with hexasaccharide chains (1, 3 and chitonoidoside E) were the most active against erythrocytes. A similar tendency was observed for the cytotoxicity against adenocarcinoma HeLa cells, but the demonstrated effects were moderate. The monocyte THP-1 cell line and erythrocytes were comparably sensitive to the action of the glycosides, but the activity of chitonoidosides E and E1 (1) significantly differed from that of 3 in relation to THP-1 cells. A tetraoside with a shortened bottom semi-chain, chitonoidoside F (2), displayed the weakest membranolytic effect in the series.

Erythrocytic antioxidant system in the administration of new coordination compounds thiosemicarbazide derivatives

Background: Currently, there is a growing interest in new local coordination compounds (CC), which demonstrated antitumor properties, but their influence on the erythrocyte antioxidant system has not been studied. The aim of the study: to study the effects of CC, thiosemicarbazide derivatives –TIA-160, CMT-67 and CMJ-33 on indices of the antioxidant system indicators in erythrocytes peripheral blood in vivo experiments. Material and methods: The action of CC on superoxide dismutase, catalase, total antioxidant capacity was evaluated on a group of 34 white rats, randomly divided into 4 groups: the first control group was injected subcutaneously with saline. The other groups (2 – TIA-160, 3 – CMT-67 and 4 – CMJ-33) were given subcutaneously 3 times a week for 30 days, 0.1µM / kg CC. Results: It was established that the TIA-160 compound demonstrated the highest capacity to induce the expression of erythrocyte catalase that exceeded the control level of 1.8, which did not correlate with the enzymatic superoxide dismutase (SOD) activity. Thus, this study showed that there are differences in the mechanisms of action of thiosemicarbazone derivatives. Conclusions: The influence of tested CC on the indices of the antioxidant system is selective. This selectivity may be the base to their strong selective antiproliferative and cytotoxic action on tumor cells, but not on healthy ones.

Identification and Isolation of lupeol and β-sitosterol from Iraqi Bauhinia variegata and determination the cytotoxic activity of the hexane extract of its leaves, stems and flowers

Objective: Bauhinia variegata is evergreen small medicinal tree grows all over the world especially in the tropical regions. The aims of the study were detection, isolation quantification and identification of β-sitosterol and lupeol of Iraqi B. variegata stem using various chromatographic and spectroscopic methods, beside the cytotoxic investigation of hexane extract of different aerial parts. Methods: detection by GC mass spectroscopy, isolated by preparative TLC. The identification and the structural elucidation of isolated β-sitosterol and lupeol were performed by 1H nuclear magnetic resonance and FTIR. While the cytotoxic activity was performed against MCF-7 cells line. Results: Results highlighted that β-sitosterol and lupeol present in Iraqi B. variegata stem that confirmed by different chromatographic and spectroscopic analysis. Also the leaves extract has the superior action on MCF-7 cells followed by stem extract and end up by flower extract. Conclusions: The plant has a good content of both β-sitosterol and lupeol and the good cytotoxic action of aerial parts hexane extract confirm the successful plantation of B. variegata. These isolated compounds are a suitable candidate for further pharmacological study.

Synthesis and Biological Evaluation of Some Novel Pyrrole Derivatives

The Pyrrole is one of the significant classes of heterocyclic mixes having pharmacological and natural exercises, for example, antibacterial, antifungal, anthelmintic. The subbed pyrroles with chose functionalities at various position fill in as antecedents for the combination of different new functionalities. Pyrrole has additionally indicated wide organic exercises, for example, treatment of hyperlipidemias, mitigating, COX1/COX-2 inhibitors, 6 cytotoxic action against strong tumor model and assortment of marine and human models. A progression of new Schiff base (E)- N'- Substituted benzylidene-1H-pyrrole-2-carbohydrazide subsidiary (3a-3j) were combined by the response of 1H-pyrrole-2-carbohydrazide and fragrant aldehyde within the sight of ethanol with barely any drops of frosty acidic corrosive. The response blend was observed by TLC and recrystallized from wanted dissolvable. FTIR, 1HNMR, mass spectral and natural investigation were affirmed the structure of the blended mixes. All orchestrated mixes were screened against traditional strains for their antibacterial, antifungal and anthelmintic tasks: gram positive is B.subtilis, and S.aureus and gram negative are E. coli. Antifungal movement was screened against C. Albicans and A. niger and anthelmintic movement was screened against M. konkanensis and P. corethruses. The outcomes uncovered that 3f, 3g and 3i display increasingly strong action against the both two microorganism (gram negative and gram positive bacteria) on the opposite side compound 3a, 3g and 3h show progressively intense movement against the two growths (C. Albicans and A. niger) and compound 3c and 3d having most powerful movement with mean paralyzing time of 11.27 mins and 15.83 mins and mean death time of 19.25 mins and 24.45 mins individually when contrasted with standard medication.

Naturally occurring heterocyclic anticancer compounds

Naturally occurring heterocyclic scaffolds are key ingredients for the development of various therapeutics employed for biomedical applications. Heterocyclic pharmacophores are widely disseminated and have been befallen in almost all categories of drugs for the alleviation of myriad ailments including diabetes, neurodegenerative, psychiatric, microbial infections, disastrous cancers etc. Countless fused heterocyclic anticancerous templates are reported to display antimetabolite, antioxidant, antiproliferative, cytostatic etc. pharmacological actions via targeting different signaling pathways (cell cycle, PI-3kinase/Akt, p53, caspase extrinsic pathway etc.), overexpressive receptors (EGRF, HER2, EGF, VEGF etc.) and physiological enzymes (topoisomerase I and II, cyclin dependent kinase etc.). A compiled description on various natural sources (plants, microbes, marine) containing anticancer agents comprising heterocyclic ring specified with presence of nitrogen (vincristine, vinblastine, indole-3-carbinol, meridianins, piperine, lamellarins etc.), oxygen (paclitaxel, halichondrin B, quercetin, myricetin, kaempferol etc.) and sulphur atoms (brugine, fucoidan, carrageenan etc.) are displayed here along with their molecular level cytotoxic action and therapeutic applications.

Targeted Nano-Drug Delivery System to Colon Cancer

Cancer has been considered as the most cause of death in world. Employing of nanocarriers as drug delivery systems provide a platform for delivering drugs with increasing the anti-cancer efficacy, enhancing bioavailability of drugs, reducing side effects, enhancing the circulation half-life of drugs, improving the distribution of drugs and overcoming drug resistance. A number of nanocarriers have been studied as drug delivery systems for improving the treatment of cancer including liposomes, micelle, polymeric nanoparticles, carbon nanotubes, dendrimers, solid lipid nanoparticle (SLN) and nanostructure lipid carrier (NLC). In order to enhance recognition and internalization of nanocarriers by the target tissues, their surfaces can be modified with targeting ligands such as integrins, transferrin, folic acid, polysaccharides and antibodies. In this chapter, we are going to introduce the targeted nanocarriers for improving the cytotoxic action of drugs with further attempt of decreasing dose to achieve higher anticancer activity. Targeted nanocarriers would provide a promising therapeutic approach for cancer.

Cytotoxicity of snake venom Lys49 PLA2-like myotoxin on rat cardiomyocytes ex vivo does not involve a direct action on the contractile apparatus

Viperid snake venoms contain a unique family of cytotoxic proteins, the Lys49 PLA2 homologs, which are devoid of enzymatic activity but disrupt the integrity of cell membranes. They are known to induce skeletal muscle damage and are therefore named ‘myotoxins’. Single intact and skinned (devoid of membranes and cytoplasm but with intact sarcomeric proteins) rat cardiomyocytes were used to analyze the cytotoxic action of a myotoxin, from the venom of Bothrops asper. The toxin induced rapid hypercontraction of intact cardiomyocytes, associated with an increase in the cytosolic concentration of calcium and with cell membrane disruption. Hypercontraction of intact cardiomyocytes was abrogated by the myosin inhibitor para-aminoblebbistatin (AmBleb). No toxin-induced changes of key parameters of force development were observed in skinned cardiomyocytes. Thus, although myosin is a key effector of the observed hypercontraction, a direct effect of the toxin on the sarcomeric proteins -including the actomyosin complex- is not part of the mechanism of cytotoxicity. Owing to the sensitivity of intact cardiomyocytes to the cytotoxic action of myotoxin, this ex vivo model is a valuable tool to explore in further detail the mechanism of action of this group of snake venom toxins.