Evaluation of the biological activity of novel monocationic fluoroaryl-2,2'-bichalcophenes and their analogues

New thiophene derivative augments the antitumor activity of γ-irradiation against colorectal cancer in mice via anti-inflammatory and pro-apoptotic pathways

BACKGROUND

Colorectal cancer (CRC) is one of the most common types of cancer worldwide and the second cause of cancer-related deaths. It usually starts as an inflammation that progresses to adenocarcinoma. The goal of the present study was to investigate the antitumor efficacy of a new thiophene derivative against CRC in mice and explore the possible associated molecular pathways. The potential of this thiophene derivative to sensitize the CRC tumor tissue to a low dose of gamma irradiation was also investigated.

METHODS

Adult male mice were divided into seven groups; control, group treated with dimethylhydrazine (DMH) for the induction of CRC. The DMH-group was further divided into six groups and treated with either cisplatin, thiophene derivative, γ-irradiation, cisplatin + γ-irradiation, thiophene derivative + γ-irradiation, or left untreated.

RESULTS

DMH induced CRC as evidenced by the macroscopic examination of colon tissues and histopathology, and elevated the activities of cyclooxygenase2 (COX2) and nitric oxide synthase (iNOS). DMH also elevated kirsten rat sarcoma (KRAS) and downregulated the peroxisome proliferator activated receptor (PPARγ) as shown by RT-PCR and Western blotting. DMH exerted anti-apoptotic activity by reducing the expression of phosphorylated p53 and cleaved caspase3 at the gene and protein levels. The flow cytometry analysis showed that DMH elevated the necrosis and reduced the apoptosis compared to the other groups. The colon tissue from DMH-treated mice showed hyperplasia, aberrant crypt foci, loss of cell polarity, typical CRC of grade 4 with lymphocytes and macrophages infiltrating mucosa, muscularis mucosa, and submucosa score 3. Treatment with thiophene derivative or γ-irradiation ameliorated most of these deleterious effects of DMH. The concomitant action of thiophene derivative + γ-irradiation was typified by the better amelioration of tumor incidence and multiplicity, iNOS, PPARγ, p53, caspase 3, and histopathology of colon.

CONCLUSION

Taken together, the new thiophene derivative is a promising therapeutic candidate for treatment of colorectal cancer in mice. It also sensitizes the CRC tumor to the ionizing radiation through anti-inflammatory and pro-apoptotic pathways.

Bithiophene derivative induced apoptosis and suppression of Akt pathway in mouse leukemic model

BACKGROUND: Bithiophene derivatives show a promising anti-cancer potential. We previously showed that Bithienyl Fluorobenzamidine (BFB) has an anti-proliferative effect against several leukemia cell lines. Acute myeloid leukemia (AML) accounts for 18% of the total leukemia cases worldwide with heavier burden during the past 30 years. Therefore, the main aim remains the discovery of safe and effective medications. OBJECTIVE: The current research aims to investigate the anti-cancer efficacy of BFB and its effect on the apoptosis in the 7,12-Dimethylbenz[a]anthracene (DMBA) induced AML in mice. METHODS: AML was induced in mice by DMBA and then treated by 2 different doses of BFB. After BFB treatment, the hematological and histological pattern changes was examined. Furthermore, the molecular effect of BFB on apoptosis, cell cycle markers and Protein kinase B (Akt) pathway was examined using qPCR, Western blotting and ELISA. RESULTS: BFB treatment ameliorates leukemia histological and hematological markers significantly, despite non-significant changes in normal mice. This improvement exhibits cell cycle arrest and apoptosis induction, represented by elevation of tp53/p53, p21/p21, Caspase3 and downregulation of ckk1/Cdk1 in the bone marrow, as well as Akt pathway suppression. CONCLUSIONS: Our results establishes BFB as a promising therapeutic candidate against AML through cell cycle arrest, apoptosis induction and Akt pathway modulation.

Novel cationic aryl bithiophene/terthiophene derivatives as corrosion inhibitors by chemical, electrochemical and surface investigations

Two novel bithienyl fluorobenzamidine derivatives namely, 4-([2,2′:5′,2′′-terthiophen]-5-yl)-2-fluorobenzamidine hydrochloride salt (MA-1615), 5′-(4-amidino-3-fluorophenyl)-[2,2′-bithiophene]-5-carboxamidine dihydrochloride salt (MA-1740) were synthesized, characterized and their corrosion inhibition properties were evaluated by electrochemical methods for carbon steel (C-steel) in 1 M HCl. Experimental investigations revealed that the inhibition effectiveness of the investigated inhibitors (INHs) by the Tafel polarization method followed the order: MA-1740 (96.9%) > MA-1615 (95.6%), demonstrating higher efficiency than inhibitors of similar structure reported in the literature. The investigated bithiophene derivatives exhibit mixed-type corrosion inhibition characteristics by blocking the active sites on the surface of C-steel. EIS study revealed that the INHs behave as interface-type corrosion inhibitors. UV–Visible spectrometric measurements confirmed a complex formation between the Fe²⁺ cation released during the corrosion reactions and inhibitor molecules.

Biological Insights of Fluoroaryl-2,2'-Bichalcophene Compounds on Multi-Drug Resistant Staphylococcus aureus

Resistance of bacteria to multiple antibiotics is a significant health problem; hence, to continually respond to this challenge, different antibacterial agents must be constantly discovered. In this work, fluoroaryl-2,2'-bichalcophene derivatives were chemically synthesized and their biological activities were evaluated against Staphylococcus aureus (S. aureus). The impact of the investigated bichalcophene derivatives was studied on the ultrastructural level via scanning electron microscopy (SEM), molecular level via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method and on the biofilm inhibition via the electrochemical biosensors. Arylbichalcophenes' antibacterial activity against S. aureus was affected by the presence and location of fluorine atoms. The fluorobithiophene derivative MA-1156 displayed the best minimum inhibitory concentration (MIC) value of 16 µM among the tested fluoroarylbichalcophenes. Over a period of seven days, S. aureus did not develop any resistance against the tested fluoroarylbichalcophenes at higher concentrations. The impact of fluoroarylbichalcophenes was strong on S. aureus protein pattern showing high degrees of polymorphism. SEM micrographs of S. aureus cells treated with fluoroarylbichalcophenes displayed smaller cell-sizes, fewer numbers, arranged in a linear form and some of them were damaged when compared to the untreated cells. The bioelectrochemical measurements demonstrated the strong sensitivity of S. aureus cells to the tested fluoroarylbichalcophenes and an antibiofilm agent. Eventually, these fluoroarylbichalcophene compounds especially the MA-1156 could be recommended as effective antibacterial agents.

Synthesis, antimicrobial, and antiproliferative activities of substituted phenylfuranylnicotinamidines

This research work deals with the design and synthesis of a series of substituted phenylfuranylnicotinamidines 4a-i. Facile preparation of the target compounds was achieved by Suzuki coupling-based synthesis of the nitrile precursors 3a-i, followed by their conversion to the corresponding nicotinamidines 4a-i utilizing LiN(TMS)2. The antimicrobial activities of the newly synthesized nicotinamidine derivatives were evaluated against the Gram-negative bacterial strains Escherichia coli and Pseudomonas aeruginosa as well as the Gram-positive bacterial strains Staphylococcus aureus and Bacillus megaterium. The minimum inhibitory concentration values of nicotinamidines against all tested microorganisms were in the range of 10-20 μM. In specific, compounds 4a and 4b showed excellent minimum inhibitory concentration values of 10 μM against Staphylococcus aureus bacterial strain and were similar to ampicillin as an antibacterial reference. On the other hand, selected nicotinamidine derivatives were biologically screened for their cytotoxic activities against a panel of 60 cell lines representing nine types of human cancer at a single high dose at National Cancer Institute, Bethesda, MD, USA. Nicotinamidines showing promising activities were further assessed in a five-dose screening assay to determine their compound concentration causing 50% growth inhibition of tested cell (GI50), compound concentration causing 100% growth inhibition of tested cell (TGI), and compound concentration causing 50% lethality of tested cell (LC50) values. Structure-activity relationship studies demonstrated that the activity of members of this series can be modulated from cytostatic to cytotoxic based on the substitution pattern/nature on the terminal phenyl ring. The most active compound was found to be 4e displaying a submicromolar GI50 value of 0.83 μM, with TGI and LC50 values of 2.51 and 100 μM, respectively. Finally, the possible underlying mechanism of action of this series of compounds was investigated by determining their nuclease-like DNA degradation ability in addition to their antioxidant power and all monocations proved to be effective in all assays.

Anticancer, antioxidant activities, and DNA affinity of novel monocationic bithiophenes and analogues

A series of 15 monocationic bithiophenes and isosteres were prepared and subjected to in vitro antiproliferative screening using the full National Cancer Institute (NCI)-60 cell line panel, representing nine types of cancer. Among the nine types of cancer involved in a five-dose screen, non-small cell lung and breast cancer cell lines were the most responsive to the antiproliferative effect of the tested compounds, especially cell lines A549/ATCC, NCI-H322M, and NCI-H460, whereas compounds 1a, 1c, 1d, and 7 exhibited potent activity, with GI50 values (drug concentration that causes 50% inhibition of cell growth) from less than 10 nM to 102 nM. In addition, compounds 1c and 1d gave GI50 values of 73 nM and 79 nM, respectively, against the MDA-MB-468 breast cancer cell line. Structure-activity relationship findings indicated that the mononitriles were far less active than their corresponding monoamidines and, within the amidines series, the bioisosteric replacement of a thiophene ring by a furan led to a reduction in antiproliferative activity. Also, molecular manipulations, involving substitution on the phenyl ring, or its replacement by a pyridyl, or alteration of the position of the amidine group, led to significant alteration in antiproliferative activity. On the other hand, DNA studies demonstrated that these monoamidine bichalcophenes have promising ability to cleave the genomic DNA. These monoamidines show a wide range of DNA affinities, as judged from their DNA cleavage effect, which are remarkably sensitive to all kinds of structural modifications. Finally, the novel bichalcophenes were tested for their antioxidant property by the ABTS (2,2'-azino- bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt) assay, as well as lipid and nitric oxide scavenging techniques, and were found to exhibit good-to-potent antioxidant abilities.