Novel VEGFR2 inhibitors with thiazoloquinoxaline scaffold targeting hepatocellular carcinoma with lower cardiotoxic impact.

Hepatocellular carcinoma (HCC) is a fatal tumor which is usually diagnosed at advanced stage. Molecular targeted drugs were used recently to treat HCC, however, due to serious side effects, mainly cardiotoxicity and emergence of resistance, there is demanding to explore new chemotherapeutics. 10 novel thiazoloquinoxaline derivatives coupled with different sulfonamide moieties 4(a-j) were designed and synthesized fulfilling pharmacophoric features of VEGFR-2 inhibition. Structures of all new compounds were verified via spectral and microanalytical data. After carrying in-vitro VEGFR-2 assay for compounds 4(a-j); sulfapyridine and sulfamethoxazole derivatives 4d and 4f showed potential inhibitory effect [61.04 and 83.35 nM], respectively, comparable to standard sorafenib [51.41 nM]. Both were then further evaluated for their cytocidal activity against HepG2 cell-line and against myocardium cells using H9C2 cell-line. As a result, only sulfapyridine derivative 4d exhibited a significant inhibition of HepG2 cells viability [IC50 = 4.31 µM]. Furthermore, it showed relatively lower cytotoxic impact against normal H9C2 myocardium cells [IC50, 33.47 µM] compared to that of sorafenib [IC50, 98.07 µM]. In-vivo study was carried out to determine myocardium safety of compound 4d on irradiated mice (8 Gy). In-vivo results of sulfapyridine derivative 4d showed normal cardiac enzyme function (CK) and serum catalase activity with significant reductions in LDH, cardiac TNF-α and caspase-9 levels, alongside with its efficacy in suppressing the expression of hepatic VEGF. In conclusion, sulfapyridine derivative 4d could be considered a promising candidate as VEGFR-2 inhibitor with less myocardium side effect.

Pyrazole-sulfonamide scaffold featuring dual-tail strategy as apoptosis inducers in colon cancer.

Dual-tail strategy has been successfully utilized in the development of novel carbonic anhydrase IX (CA IX) inhibitors. Herein we adopted this approach in the design and synthesis of a series of novel pyridine sulfonamide-pyrazole hybrid scaffold mimicking dual-tail inhibitors of CA IX. A library of 15 compounds was synthesized and assessed for their potential cytotoxic effects against colorectal cancer cells. Compounds 3, and 11 induced potential cytotoxic effects against the three cancer cell lines (HCT-116, HT-29, and SW-620) with IC50s' of 45.88, 28.27, and 16.57 uM, 25.01, 8.99, and 3.27 µM, respectively. Both compounds induced cellular apoptosis on HCT-116 and SW-620 cells, while compound 3 induced necrosis as well. In addition, both compounds induced cell cycle arrest on G0/G1, and S phases. Also, compound 11 showed potential autophagy induction on both colon cancer cell lines (HCT-116, and HT-29), and a little bit on metastatic type. Both compounds were less cytotoxic than the reference drug on normal epithelial cell. The migration rates of HCT-116 and the metastatic one SW-620 were reduced by both compounds. Finally, molecular docking of compounds 3 and 11 into the active site of CA IX confirmed in vitro inhibitory activity for both compounds.

Challenging breast cancer through novel sulfonamide-pyridine hybrids: design, synthesis, carbonic anhydrase IX inhibition and induction of apoptosis.

Background: Among the important key modulators of the tumor microenvironment and hypoxia is a family of enzymes named carbonic anhydrases. Herein, 11 novel sulfonamide-pyridine hybrids (2-12) were designed, synthesized and biologically evaluated for their potential use in targeting breast cancer. Methods & results: The para chloro derivative 7 reported the highest cytotoxic activity against the three breast cancer cell lines used. In addition, compound 7 was found to induce cell cycle arrest and autophagy as well as delaying wound healing. The IC50 of compound 7 against carbonic anhydrase IX was 253 ± 12 nM using dorzolamide HCl as control. Conclusion: This study encourages us to expand the designed library, where more sulfonamide derivatives would be synthesized and studied for their structure-activity relationships.

Synthesis of novel benzothiophene derivatives as protectors against cranial irradiation-induced neuroinflammation.

Aim: Cranial irradiation results in many deleterious effects to normal tissues, including neuroinflammation. There is a need to explore radioprotective agents that could be safely used to ameliorate these effects. Method: Nine novel benzothiophene derivatives bearing pyrimidinone, pyrazolidinone, triazole and other active moieties were synthesized and evaluated as antioxidants in an in vitro screening experiment. The most potent compounds were then tested as protectors against radiation-induced neuroinflammation and oxidative stress in rat brains following cranial irradiation. Results: The most potent antioxidant compounds were compounds 3-5 and 10 . P-fluro,p- bromo and pyrido benzothiophene derivatives offered good antioxidant and anti-inflammatory effects. Conclusion: Compounds 3-5 may be introduced as nontoxic candidates for adjuvant therapeutic protocols used in head and neck tumor radiotherapeutic management.

Green synthesis of novel antifungal 1,2,4-triazoles effective against γ-irradiated Candida parapsilosis.

This study reports the green synthesis of 11 novel 3-substituted-4-amino-5-mercapto-1,2,4-triazole derivatives using water as a readily available nontoxic solvent. Evaluation of their antimicrobial potential against several clinical pathogenic microorganisms was carried out. The newly synthesized cysteine derivative 6 showed promising antifungal activity against both γ-irradiated and nonirradiated Candida parapsilosis 216, with the lowest MIC (minimum inhibitory concentration) value of 3.125 µg/ml, probably through inhibition of 14α-demethylase. In addition, compound 6 showed complete inhibition of gelatinase, a virulence enzyme of C. parapsilosis. Also, scanning electron microscopy was carried out. Interestingly, compound 6 acted as a dual agent as it also showed good antibacterial activity against strains of Gram-positive bacteria used in the study. The synthesized compounds showed no cytotoxicity.

Design and synthesis of novel pyridazinoquinazoline derivatives as potent VEGFR-2 inhibitors: In vitro and in vivo study.

Worldwide, Hepatocellular Carcinoma (HCC) endures to be a prominent cause of cancer death. Treatment of HCC follows multiple therapies which are not entirely applicable for treatment of all patients. HCC usually arises contextual to chronic liver diseases and is often discovered at later stages which makes treatment options more complex. The present study aimed at design, synthesis & evaluation of new pyridazinoquinazoline derivatives as potential nontoxic anti-hepatocellular carcinoma (HCC) agents, through inhibition of Vascular endothelial growth factor -2 (VEGFR-2). Novel Pyridazino[3, 4, 5-de]quinazoline derivatives (2-6) were designed & synthesized. Their structures were confirmed via spectral and microanalytical data. They were tested for their in vitro VEGFR-2 inhibition & anticancer activity against human liver cancer cell line (HEPG-2). Molecular docking was investigated into VEGFR-2 site. In vivo studies of VEGRF-2 inhibition and the anti-apoptotic effect of the new compounds were determined in liver of irradiated rats. Toxicity of synthesized compounds was also assessed. The results showed that compounds 3-6 have significant antitumor activity and proved to be non-toxic. The ethoxy aniline derivative 6, exhibited the highest activity both in vitro and in vivo compared to the reference drug used, sorafenib. Compound 6 could be considered a promising nontoxic anti HCC agent and this could be partially attributed to its VEGFR-2 inhibition. Future preclinical investigation would be carried out to confirm the specific and exact mechanism of action of these derivatives especially compound 6 as an effective pharmaceutical agent after full toxicological and pharmacological assessment.

Semi-synthetic thymoquinone analogs: new prototypes as potential antihyperlipidemics in irradiated rats.

AIM: Thymoquinone (TQ), has been reported to possess strong antihyperlipidemic properties. However, a variety of serious side effects has been reported for TQ. The present study aimed to evaluate the potential antihyperlipidemic activity of newly synthesized TQ analogs. METHODS & RESULTS: first, novel TQ derivatives were studied against radiation-induced dyslipidemia in male rats. Second, the most promising sulfur derivatives (4-7), were further tested to elucidate their possible mechanism(s) of actions. Results showed that they possess Hydroxymethyl Glutaryl-Co A reductase inhibitory activity, as well as stimulatory effects on the activities of each of plasma Lecithin-Cholesterol Acyltransferase and lipoprotein lipase enzymes. CONCLUSION: TQ derivatives (4-7), could be considered as promising agents in pathologies implicating impaired lipid metabolism, preclinical evaluation is warranted. [Formula: see text].

Novel 1,2,4-triazole derivatives as antitumor agents against hepatocellular carcinoma.

Fifteen novel 1,2,3-triazole derivatives were prepared in series of synthetic steps starting from 4-amino-5-hydrazino-4H-1,2,4-triazole-3-thiol 1. The structures of the obtained compounds were verified through micoanalytical and spectral data. All the compounds were screened for their anticancer activity against liver human cancer cell lines (HEPG2) using Doxorubicin as standard. The most promising triazolothiadiazine derivative 12 was further tested for its degree of toxicity by estimating the median lethal dose (LD 50) and its antitumor activity through inhibiting the angiogenesis and progression of tumor against diethylnitrosamine (DENA)/CCl4 induced hepatocellular carcinoma (HCC) in rats. To elucidate its mechanism of action, the following parameters were determined including: vascular endothelial growth factor (VEGF) as a marker of angiogenesis; hepatic tyrosine kinase (HTK) as a marker for tumor growth; serum alpha fetoprotein (AFP) as a marker for hepatocarcinoma; aspartate and alanine aminotransferases (AST & ALT) as liver function test; malondialdehyde (MDA) and glutathione (GSH) as markers of antioxidant activity. Liver histopathological analysis was also evaluated. Carcinogenic rats showed drastic elevation in all investigated parameters accompanied by reduction in hepatic glutathione. Administration of compound 12 into rats after induction of experimental HCC, improved the biochemical changes induced by DENA/CCl4. These observations were supported by histopathological study of liver sections. It was concluded that triazolothiadiazine compound 12 could be promising anti HCC agent after more investigations on higher animals.

Modulatory effects of new curcumin analogues on gamma-irradiation - Induced nephrotoxicity in rats.

In the present study, a new series of 2-amino-pyran-3-carbonitrile derivatives of curcumin 2-7 have been synthesized via one-pot simple and efficient protocol, involving the reaction of curcumin 1 with substituted-benzylidene-malononitrile to modify the 1,3-diketone moiety. The structures of the synthesized compounds 2-7 were elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. The nephroprotective mechanism of these new curcumin analogues was evaluated on the post-gamma-irradiation (7 Gy) - induced nephrotoxicity in rats. Activation of Nrf2 by these curcumin analogues is responsible for the amendment of the antioxidant status, impairment of NF-κB signal, thus attenuate the nephrotoxicity induced post-γ-irradiation exposure. 4-Chloro-phenyl curcumin analogue 7 showed the most potent activity. In conclusion, the results of the present study demonstrate a promising role of these new curcumin analogues to attenuate the early symptoms of nephrotoxicity induced by γ-irradiation in rats via activation of Nrf2 gene expression. These new curcumin analogues need further toxicological investigations to assess their therapeutic index.

Novel amino acid derivatives bearing thieno[2,3-d]pyrimidine moiety down regulate NF-κB in γ-irradiation mediated rat liver injury.

A series of different amino acid-bearing thieno[2,3-d]pyrimidine moiety was synthesized via green chemistry aspects incorporating water as a solvent to give 2a-f, which were then acidified to attain the target compounds 3-9. Moreover, a tricyclic imidazothienopyrimidine of the glycine derivative (3) was synthesized to give (10). The title compounds were characterized by FT-IR, Mass, 13C-1HNMR spectroscopy and microanalysis. All the obtained amino acid-derivatives were screened for their post-irradiation protective efficacy in young rats. γ-Irradiation exposure was employed to induce oxidative stress. Radiation triggered significant alterations in the hematologic and blood - biochemical parameters. Further, a significant deterioration of hepatic antioxidant status was observed. Furthermore, a significant elevation of Nuclear Factor-kappa B (NF-κB) protein expression and level, which induced elevation in Cyclooxygenase-2 (COX-2) activity and cytochrome P450 2E1 (CYP2E1) gene expression were detected in hepatic tissues. Additionally, elevated levels of Tumor Necrosis Factor-alpha (TNF-α), and Interleukin-6 (IL-6) were perceived in serum of γ-irradiated young rats. However, most of the newly synthesized derivatives showed significant protective effects against injuries induced by γ-irradiation exposure, via ameliorating the altered hematopoietic system and activity of different biochemical parameters in blood. The results indicate that the antioxidant and anti-inflammatory mechanism of these compounds could be attributed to the significant down-regulation NF-κB protein expression in hepatic tissues. Subsequently, NF-κB could regulate TNF-α and IL-6 levels, COX-2 activity and CYP2E1 gene expression. Methionine derivative 8 was found to be the most active one. CONCLUSION: These new amino acid-derivatives showed promising outcomes as curative agents against γ-irradiation induced oxidative stress and physiological disturbance in different organs of young animals. Beyond, they may represent a novel selective class for treating liver injury induced by γ-irradiation in young rats, via down-regulation of NF-κB expression. Further investigations are warranted prior to the clinical use of these new compounds.

Radio-protective effect of some new curcumin analogues.

In the present study, novel symmetrical curcumin analogues (2-7) have been synthesized by substituting the phenolic OH of curcumin with different linkers providing additional keto-enol tautomerism, very essential for radioprotective activity. The structures of the synthesized compounds (2-7) were elucidated by elemental analysis, IR, (1)H-NMR, (13)C-NMR and mass spectral data and were found consistent with the assigned structures. The curative effect of these new compounds, against the oxidative stress due to exposure of rats to the whole body γ-irradiation (7Gy) was investigated. Gamma-irradiated rats exhibited elevations of ALT, AST activities, urea, creatinine, triglycerides, total cholesterol, malondialdehyde (MDA), nitric oxide (NO), Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α) and Nuclear Factor-kappa B (NF-κB) levels. Contrariwise, the total protein, albumin, total calcium level, SOD, CAT, GSH-Px, GST activities and GSH content were decreased. Treatment of gamma-irradiated rats with the new curcumin analogues (2-7) showed significant amelioration in the in-vivo antioxidant status, liver and kidney functions, as well as the anti-inflammatory markers (IL-6, TNF-α and NF-κB). Inhibition of NF-κB could be responsible for the improvement of the antioxidant and anti-inflammatory status in gamma-irradiated animals, by down-regulation of IL-1ß and TNF-α level. In conclusion, the new curcumin analogues (2-7) exhibited post-protective effect on gamma-irradiation, by NF-κB inhibition.

Novel thiophenes, thienopyrimidines, and triazolothienopyrimidines for the evaluation of anticancer and augmentation effects of gamma-radiation.

New derivatives of thiophenes 2, 12, iminoaminothieno[2,3-d]pyrimidines 3, 5, and 6, triazolothieno[2,3-d]pyrimidines 8-11, pyrazolo- and triazinothieno[2,3-d]pyrimidines 4, 7, respectively, have been prepared by different synthetic procedures. Structure elucidation of the newly synthesized compounds was carried out via elemental analyses and spectral data. The antitumor activity of compounds 2, 3, and 9-12 was evaluated against in-vitro cell lines (HEPG-2 and MCF-7). Compounds 2, 3, 10, 11, and 12 showed significant in-vitro cytotoxic activity against hepatocellular carcinoma (HEPG-2) compared to the reference drug Doxorubicin. Compound 2 showed significant in-vitro cytotoxic activity against breast cancer (MCF-7) cells compared to the reference drug Doxorubicin. The augmenting effect of gamma-radiation was assessed; here, compounds 2, 3, 10, and 11 showed the most potent in-vitro anticancer activity.