Schiff base complexes of copper and zinc as potential anti-colitic compounds

The design, synthesis and activity of polymodal compounds for the treatment of inflammatory bowel disease are reported. The compounds, being based on a metal-Schiff base motif, are designed to degrade during intestinal transit to release the bioactive components in the gut. The compounds have been developed sequential with the biomodal compounds combining copper or zinc with a salicylaldehyde adduct. These compounds were tested in a formalin induced colonic inflammation model in BK:A mice. From these studies a trimodal compound based on a zinc Schiff base analogue of sulfasalazine was designed. This was tested against a trinitrobenzenesulfonic acid (TNB) induced colitic model in Wistar rats. The use of two models allows us to test our compounds in both an acute and a chronic model. The trimodal compound reported is observed to provide anticolitic properties in the chronic TNB induced colitis model commensurate with that of SASP. However, the design of trimodal compound still has the capacity for further development. This the platform reported may offer a route into compounds which can markedly outperform the anti-colitic properties of SASP.

Schiff Base-Poloxamer P85 Combination Prevents Prostate Cancer Progression in C57/Bl6 Mice

BACKGROUND

Prostate cancer which is the second most common cause of death among men has a high incidence in recent years. Current therapeutic regimens should be improved to overcome drug resistance. At the metastatic stage, tumors become refractory to established chemotherapeutic treatments and cause serious problems at the clinics. Development of new drug molecules that are able to transport through the membrane easily and kill tumor cells rapidly is of great interest.

METHOD

In the current study, a novel Heterodinuclear copper(II)Mn(II) Schiff base complex combined with P85 was used for prostate cancer treatment in vivo. Tramp-C1 cells injected animals were subjected to chemotherapeutic formulation treatment and results were analyzed by toxicology analysis, tumor volume measurements, and histopathological analysis. 0.5 mg/kg Schiff base was selected and combined with 0.05% P85 according to the toxicology analysis showing the enzyme levels, blood parameters, and multiple organ toxicity.

RESULTS

Results demonstrated that Heterodinuclear copper(II)Mn(II) complex-P85 combination decreased tumor formation and tumor volume steadily over the course of experiments.

CONCLUSIONS

Overall, Heterodinuclear copper(II)Mn(II) complex-P85 exerted remarkable anti-cancer activity in vivo in C57/B16 mice. Prostate 76:1454-1463, 2016. © 2016 Wiley Periodicals, Inc.

Chemoprevention of Colonic Aberrant Crypt Foci by Novel Schiff Based Dichlorido(4-Methoxy-2-{[2-(Piperazin-4-Ium-1-Yl)Ethyl]Iminomethyl}Phenolate)Cd Complex in Azoxymethane-Induced Colorectal Cancer in Rats

Schiff-based complexes as a source of cancer chemotherapeutic compounds have been subjected to the variety of anticancer studies. The in-vitro analysis confirmed the CdCl2(C14H21N3O2) complex possess cytotoxicity and apoptosis induction properties in colon cancer cells, so lead to investigate the inhibitory efficiency of the compound on colonic aberrant crypt foci (ACF). Five groups of adult male rats were used in this study: Vehicle, cancer control, positive control groups and the groups treated with 25 and 50 mg/kg of complex for 10 weeks. The rats in vehicle group were injected subcutaneously with 15 mg/kg of sterile normal saline once a week for 2 weeks and orally administered with 5% Tween-20 (5 ml/kg) for 10 weeks, other groups were injected subcutaneously with 15 mg/kg azoxymethane once a week for 2 weeks. The rats in positive groups were injected intra-peritoneally with 35 mg/kg 5-Flourouracil four times in a month. Administration of the complex suppressed total colonic ACF formation up to 73.4% (P < 0.05). The results also showed that treatment with the complex significantly reduced the level of malondialdehyde while increasing superoxide dismutase and catalase activities. Furthermore, the down-regulation of PCNA and Bcl2 and the up-regulation of Bax was confirmed by immunohistochemical staining.

Increasing the efficiency of precise genome editing with CRISPR-Cas9 by inhibition of nonhomologous end joining

Methods to introduce targeted double-strand breaks (DSBs) into DNA enable precise genome editing by increasing the rate at which externally supplied DNA fragments are incorporated into the genome through homologous recombination. The efficiency of these methods is limited by nonhomologous end joining (NHEJ), an alternative DNA repair pathway that competes with homology-directed repair (HDR). To promote HDR at the expense of NHEJ, we targeted DNA ligase IV, a key enzyme in the NHEJ pathway, using the inhibitor Scr7. Scr7 treatment increased the efficiency of HDR-mediated genome editing, using Cas9 in mammalian cell lines and in mice for all four genes examined, up to 19-fold. This approach should be applicable to other customizable endonucleases, such as zinc finger nucleases and transcription activator-like effector nucleases, and to nonmammalian cells with sufficiently conserved mechanisms of NHEJ and HDR.

[The influence of aromatic amino acid derivatives on the complement system under ionizing radiation]

Activities of the complement classical, alternative and lectin pathways were determined under conditions of X-radiation in the blood of rats treated and none-treated with synthetic Schiffbase aromatic amino acid derivatives, nicotinyl-L-tyrosinate or nicotinyl-L-tryptophanate, before irradiation. In case of activities of the alternative and lectin pathways no significant changes between irradiated animals and none-irradiated control animals were detected. However, the data obtained demonstrate significantly elevated activity of the classical complement cascade in the blood of irradiated animals (1 day after irradiation), as compared to those none-irradiated. This effect was less pronounced in rats treated with nicotinyl-L-tyrosinate or nicotinyl-L-tryptophanate 1 hour before irradiation. Based on the results obtained the ability of nicotinyl-L-tyrosinate and nicotinyl-L-tryptophanate to act as cyto-protectors is concluded.

Antioxidant, pro-oxidant effect of the thiosemicarbazone derivative Schiff base (4-(1-phenylmethylcyclobutane-3-yl)-2-(2-hydroxybenzylidenehydrazino) thiazole) and its metal complexes on rats

Adverse biological activities of thiosemicarbazone (TSC) and Schiff base (SB) derivatives have been widely studied in rats and in other animal species using different doses, times and routes of administration. However, there are few studies describing changes in some biochemical parameters in vivo which are indicative of oxidative stress in biological systems and of morphological changes of tissues. In this study, the rats were injected subcutaneously with a new thiosemicarbazone thiazole ring containing a Schiff base (LH) and its Cu(L)2 and Zn(L)2 complexes (25 mg kg(-1) body weight) and then sacrificed after 1, 2, 4, 8, 16, 32 and 64 days. The aim of this study was to determine the effect of the new compounds on the serum antioxidant vitamins (A, E, C), selenium (Se), malondialdehyde (MDA) levels, erythrocyte GSH-Px enzyme activity and morphological changes in the liver, kidney and adrenal gland tissues. It was observed that erythrocyte GSH-Px activity, serum MDA and vitamins A, E concentrations were statistically changed (p < 0.02), but serum levels of selenium, and vitamin C were not changed. In conclusion, the parameters measured show that Cu(L)2 caused considerable oxidative stress and Zn(L)2 behaved as an antioxidant. No oxidative stress in LH was observed compared to the control group.

[Changes in the brain GABA system after repeated injections of pyridoxal-5'-phosphate and its Schiff base with GABA]

A state of the gamma-aminobutyric acid (GABA) system (glutamate, glutamate decarboxylase, GABA, GABA-alpha-ketoglutarate aminotransferase) and the coupled reactions (alpha-ketoglutarate dehydrogenase complex, aspartate- and alanine aminotransferases) was studied in three brain structures (cerebellum, brain cortex and truncus cerebri) after multiple administration of pyridoxal-5'-phosphate (PALP) and its Shiff base with GABA (5 injections at doses 10.0 and 15.0 mg/kg of body mass, respectively). Non-coenzymatic effects of PALP were found to prevail within 1 hr after its last administration: inhibition of PALP-dependent aminotransferases and activation of the alpha-keto-glutarate oxidative decarboxylation were observed. The opposite effects were detected after addition of PALP to brain homogenates in vitro. Administration of the PALP-GABA complex exhibited qualitatively similar to those of PALP effects on the reactions studied in brain. The data obtained suggest that parenteral administration of the coenzyme preparation caused a number of metabolic effects, which are sometimes far from unambigously predicted theoretical considerations. The similarity of PALP and PALP-GABA effects appears to demonstrate ready biotransformation of the Shiff base with liberation of PALP and GABA.