Synthesis and biological evaluation of new nicotinic acid derivatives as potential anti-inflammatory agents with enhanced gastric safety profile.

Two innovative series derived from nicotinic acid scaffold were synthesized and evaluated for their anti-inflammatory activity. Ibuprofen, celecoxib and indomethacin were used as standard drugs. All the newly synthesized compounds were in vitro screened for their anti-inflammatory activity adopting 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide dye (MTT), as well as Griess assays. The results showed that all compounds exhibited significant anti-inflammatory activity without affecting the viability of the macrophages compared to ibuprofen. In addition, compounds 4d, 4f, 4g, 4h and 5b exhibited the most potent nitrite inhibition activity and consequently superior anti-inflammatory activity with MTT results ranging between values 86.109 ± 0.51 to 119.084 ± 0.09. The most active compounds were subjected to evaluation of TNF-α, IL-6, iNOS and COX-2 levels in LPS/INF γ-stimulated RAW 264.7 macrophage cells in comparison to ibuprofen as a reference compound. The five compounds showed comparable inhibition potency of these inflammatory cytokines compared to ibuprofen. Same compounds were further in vivo evaluated for their anti-inflammatory activity via carrageenan induced arthritis in rats. Regarding the ulcerogenic profile, compound 4h showed mild infiltration of gastric mucosa superb to compound 5b displayed severe gastritis. Molecular docking of 4h and 5b in the COX-2 active site was performed to evaluate their preferential COX-2 inhibitory potency. The docking results were in accordance with the biological findings.

Semi-supervised learning and bidirectional decoding for effective grammar correction in low-resource scenarios.

The correction of grammatical errors in natural language processing is a crucial task as it aims to enhance the accuracy and intelligibility of written language. However, developing a grammatical error correction (GEC) framework for low-resource languages presents significant challenges due to the lack of available training data. This article proposes a novel GEC framework for low-resource languages, using Arabic as a case study. To generate more training data, we propose a semi-supervised confusion method called the equal distribution of synthetic errors (EDSE), which generates a wide range of parallel training data. Additionally, this article addresses two limitations of the classical seq2seq GEC model, which are unbalanced outputs due to the unidirectional decoder and exposure bias during inference. To overcome these limitations, we apply a knowledge distillation technique from neural machine translation. This method utilizes two decoders, a forward decoder right-to-left and a backward decoder left-to-right, and measures their agreement using Kullback-Leibler divergence as a regularization term. The experimental results on two benchmarks demonstrate that our proposed framework outperforms the Transformer baseline and two widely used bidirectional decoding techniques, namely asynchronous and synchronous bidirectional decoding. Furthermore, the proposed framework reported the highest F1 score, and generating synthetic data using the equal distribution technique for syntactic errors resulted in a significant improvement in performance. These findings demonstrate the effectiveness of the proposed framework for improving grammatical error correction for low-resource languages, particularly for the Arabic language.

Design and synthesis of novel hexahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives as potential anticancer agents with antiangiogenic activity via VEGFR-2 inhibition, and down-regulation of PI3K/AKT/mTOR signaling pathway.

New thieno[2,3-d]pyrimidine derivatives were designed and synthesized. The National Cancer Institute (NCI) evaluated the synthesized novel compounds against a panel of 60 tumor cell lines for their antiproliferative activity. Compounds 6b, 6f, and 6g showed potent anticancer activity at 10 µM dose, with mean GI of 20.86%, 76.41%, and 31.49%, respectively. Compound 6f was selected for five-dose concentrations evaluation. Compound 6f scored a submicromolar range of GI50 values against 10 cancer cell lines, indicating broad-spectrum and potent antiproliferative activity. Compound 6f TGI values were recorded in the cytostatic range of 4.02-95.1 µM. In comparison to sorafenib, the tested compounds 6b, 6f, and 6g inhibited VEGFR-2 with IC50 values of 0.290 ± 0.032, 0.066 ± 0.004, and 0.16 ± 0.006 µM, correspondingly. Compound 6f significantly reduced the total VEGFR-2 expression and its phosphorylation. Additionally, 6f reduced the phosphorylation of PI3K, Akt, and mTOR pathway proteins. Moreover, the migratory potential of HUVECs was significantly reduced, after 72 h of treatment with compound 6f, resulting in disrupted wound healing patterns which verified the angiogenesis suppression properties of compound 6f. Compound 6f increased the total apoptosis percentage by 21.27-fold compared to sorafenib, which caused a 24.11-fold increase in the total apoptosis percentage. This apoptotic activity was accompanied by a 7.81-fold increase in the level of apoptotic caspase-3. Furthermore, the cell cycle analysis revealed that the target derivative 6f reduced cellular proliferation and induced an arrest in HCT-15 colon cancer cell cycle at the S phase. Molecular modeling was used to determine the binding profile and affinity of derivative 6f toward the VEGFR-2 active site.

Schiff bases as linker in the development of quinoline-sulfonamide hybrids as selective cancer-associated carbonic anhydrase isoforms IX/XII inhibitors: A new regioisomerism tactic.

A novel set of quinoline tailored with the sulfonamide as zinc-binding group (ZBG) has been rationalized and synthesized as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. Such hybrids were decorated by a novel elongated imine linker with/without ethylene spacer with variable hydrophobic and lipophilic pockets. Therefore, a regioisomeric tactic has been established, most of which act as efficient inhibitors of the tumor-associated CA isoforms IX and XII. Interestingly, one hybrid 10b displayed an appreciable activity in MCF-7 cell line under normoxic condition (IC50 of 8.42 µM) in comparison to the standard staurosporine (IC50 = 5.34 µM) and excellent activity under hypoxic conditions (IC50 = 1.56 µM) in comparison to staurosporine (IC50 = 4.45 µM). Furthermore, hybrids 8a and 10b encouraged MCF-7 and MDA-MB-231 cell apoptosis alongside promising Bax/Bcl expression ratio change. Docking studies were also, performed and agreed with the biological results. Our SAR study suggested that our regiosiomerization tactic for the quinoline based-sulfonamide molecules led to effective inhibition of tumuor-relevant hCAs IX/XII.

Recent Modifications of Anti-dementia Agents Focusing on Tacrine and/or Donepezil Analogs.

Alzheimer's Disease (AD) is a multifactorial incurable neurodegenerative disorder. It is characterized by a decline of cholinergic function in parallel with ß-amyloid fibril deposition. Such an imbalance causes severe loss in memory and cognition, leading to behavioral disturbances, depression, and ultimately death. During the last decades, only a few approved drugs were launched onto the market with indications for treating initial and moderate stages of AD. To date, cholinesterase inhibitors (ChEI) are the mainstay line of treatment to ameliorate AD symptoms. Tacrine and Donepezil are the most commonly prescribed anti-dementia drugs, given their potent inhibitory effects. Therefore, many trials have focused on both drugs' structures to synthesize new anti-dementia agents. This paper discusses recent trends of new AD-treating anti-dementia agents focusing on Tacrine and Donepezil analogs and multifunctional hybrid ligands.

Evaluation of different bacterial honey isolates as probiotics and their efficient roles in cholesterol reduction.

Continue to hypothesize that honey is a storehouse of beneficial bacteria, and the majority of these isolates are levansucrase producers. Accordingly, ten bacterial strains were isolated from different honey sources. Four honey isolates that had the highest levansucrase production and levan yield were identified by the partial sequencing of the 16S rRNA gene as Achromobacter sp. (10A), Bacillus paralicheniformis (2M), Bacillus subtilis (9A), and Bacillus paranthracis (13M). The cytotoxicity of the selected isolates showed negative blood hemolysis. Also, they are sensitive to the tested antibiotics (Amoxicillin + Flucloxacillin, Ampicillin, Gentamicin, Benzathine benzylpenicillin, Epicephin, Vancomycin, Amikacin, and Zinol). The isolates had strong alkaline stability (pHs 9, 11) and were resistant to severe acidic conditions (29-100 percent). The tested isolates recorded complete tolerance to both H2O2 and the bile salt (0.3% Oxgall powder) after 24 h incubation. The cell-free supernatant of the examined strains had antifungal activities against C. Albicans with varying degrees. Also, isolates 2M and 13M showed strong activities against S. aureus. The isolates showed strong adhesion and auto-aggregation capacity. Isolate 10A showed the highest antioxidant activity (91.45%) followed by 2M (47.37%). The isolates recorded different catalase and protease activity. All isolates produced cholesterol oxidase and lipase with different levels. Besides, the four isolates reduced LDL (low-density lipoprotein) to different significant values. The cholesterol-reducing ability varied not only for strains but also for the time of incubation. The previous results recommended these isolates be used safely in solving the LDL problem.

Recent green approaches for the synthesis of pyrazolo[3,4-d]pyrimidines: A mini review.

Pyrazolo[3,4-d]pyrimidine as a bioisostere of purine has drawn considerable attention as a privileged scaffold for the design and discovery of novel drugs. Green synthesis is an emerging area in the field of chemistry that provides economic and environmental benefits as an alternative to traditional methods. The present mini review reflects recent advances in the green synthesis of pyrazolo[3,4-d]pyrimidines, published in the time frame from 2006 to 2019.

New promising levofloxacin derivatives: Design, synthesis, cytotoxic activity screening, Topo2ß polymerase inhibition assay, cell cycle apoptosis profile analysis.

Newly designed levofloxacin analogues were synthesized to act as topoisomerase II beta inhibitors (Topo2ß). Their cytotoxic activity was screened against breast, liver, and leukemia cancer cell lines. The best activity against liver cancer cell line (Hep3B) was exhibited by the target compounds 3c, 3e, 4a, and 6d (IC50 = 2.33, 1.38, 0.60 and 0.43, respectively). (L-SR) leukemia cancer cell line was pronouncedly affected by compounds 3b, 3g and 4a (IC50 = 1.62, 1.41 and 1.61, sequentially). 3c possessed the best activity against breast cancer cell line (MCF-7) with IC50 = 0.66. Compounds 3c, 3e, 3g, 4a and 4c exhibited Topo2ß inhibition activities exceeding etoposide and levofloxacin as reference drugs and variant cell lines. In DNA-Flow cytometry cell cycle analysis, compound 3c arrested the cell cycle at G2/M phase like etoposide and levofloxacin, while compounds 3e and 4a exhibit its arrest at S phase. In addition, 3c, 3e and 4a showed a significant elevation in active caspase-3 levels (10.01, 8.98 and 10.71 folds, respectively). The effect of the new compounds on normal cells was also investigated including breast (MCF10a), liver (THLE2), and lymphocytic (PCS-800-011) normal cell lines.

Novel Pyrazolo[3,4-d]pyrimidines as Potential Cytotoxic Agents: Design, Synthesis, Molecular Docking and CDK2 Inhibition.

BACKGROUND: Pyrazolo[3,4-d]pyrimidine scaffold was reported to possess potent cytotoxic and CDK2 inhibitory activity as analogue of roscovitine. OBJECTIVE: To design and synthesize novel 1-(4-flourophenyl)pyrazolo[3,4-d]pyrimidine derivatives as bioisosters of roscovitine with potential cytotoxic and CDK2 inhibitory activity. METHODS: A series of novel 1-(4-flourophenyl)pyrazolo[3,4-d]pyrimidines were designed and synthesized. Structural elucidation for all the newly synthesized compounds was achieved through performing MS, 1H NMR, 13C NMR and IR spectral techniques. Eight compounds were screened for their cytotoxic activity by National Cancer Institute (USA) against 60 different human cancer cell lines. Compounds 2a, 4, 6, 7b, 8a and 8b were further studied through the determination of their IC50 values against the most sensitive cell lines. The inhibitory activities of compounds 2a and 4 were evaluated against CDK2 enzyme. RESULTS: Compound 4 exhibited the most prominent broad-spectrum cytotoxic activity against 42 cell lines representing all human cancer types showing growth inhibition percentages from 53.19 to 99.39. Compound 2a showed promising selectivity against several cell lines. Moreover, all the test compounds exhibited potent cytotoxic activity in nanomolar to micromolar range with IC50 values ranging from 0.58 to 8.32µM. Compound 2a showed significant cytotoxic activity against CNS (SNB-75), lung (NCI-H460) and ovarian (OVCAR-4) cancer cell lines with IC50 values 0.64, 0.78 and 1.9µM, respectively. Compound 4 showed promising potency against leukemia (HL-60) and CNS (SNB-75) cell lines (IC50 = 0.58 and 0.94µM, sequentially). Moreover, the antiproliferative activities of compounds 2a and 4 appeared to correlate well with their ability to inhibit CDK2 at sub-micromolar level (IC50 = 0.69 and 0.67µM, respectively) that were comparable to roscovitine (IC50=0.44µM). The Molecular docking results revealed that compound 4 interacted with the same key amino acids as roscovitine in the active site of CDK2 enzyme with a marked docking score (-14.1031 kcal/mol). CONCLUSION: 1-(4-Flourophenyl)pyrazolo[3,4-d]pyrimidine is a promising scaffold for the design and synthesis of potent cytotoxic leads.

Novel pyrazolo[3,4-d]pyrimidines: design, synthesis, anticancer activity, dual EGFR/ErbB2 receptor tyrosine kinases inhibitory activity, effects on cell cycle profile and caspase-3-mediated apoptosis.

A series of novel pyrazolo[3,4-d]pyrimidines was synthesised. Twelve synthesised compounds were evaluated for their anticancer activity against 60 human tumour cell lines by NCI (USA). Compound 7d proved prominent anticancer activity. It showed 1.6-fold more potent anti-proliferative activity against OVCAR-4 cell line with IC50 = 1.74 µM. It also exhibited promising potent anticancer activity against ACHN cell line with IC50 value 5.53 µM, representing 2.2-fold more potency than Erlotinib. Regarding NCI-H460 cell line, compound 7d (IC50 = 4.44 µM) was 1.9-fold more potent than Erlotinib. It inhibited EGFR and ErbB2 kinases at sub-micromolar level (IC50 = 0.18 and 0.25 µM, respectively). Dual inhibition of EGFR and ErbB2 caused induction of apoptosis which was confirmed by a significant increase in the level of active caspase-3 (11-fold). It showed accumulation of cells in pre-G1 phase and cell cycle arrest at G2/M phase.

Impact of microRNA-375 and its target gene SMAD-7 polymorphism on susceptibility of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) has a high morbidity and mortality. Many studies reported that mir-375 is frequently down-regulated in many cancers including esophageal cancer, hepatocellular carcinoma, breast cancer and leukemias. AIM: Our aim was to study the expression of microRNA-375 and its target gene SMAD-7 polymorphisms (rs4939827) in CRC patients in comparison to control subjects and to correlate these results with clinical data of patients to elucidate their role in pathogenesis and early diagnosis of CRC. MATERIAL AND METHODS: The present study was conducted on 122 subjects divided into 86 patients with CRC and 36 age- and sex-matched controls. The followings were done to all subjects: full history taking, full clinical examination, complete blood picture, serum (ALT, AST), serum albumin, CEA, TLC, PLT, and creatinine. Gene expression of miRNA-375 from serum was done by real-time PCR. Gene polymorphism SNPs of SMAD7 (rs4939827) was also done in DNA extracted from blood by real-time PCR. RESULTS: As regards the polymorphism of SMAD7, we found that CC (wild) genotype has high percentage in controls compared to CRC cases (36.1% vs 15.1%). Meanwhile, the mutant and heterozygotes genotypes showed high percentage among cases compared to controls (33.7%, and 51.2% respectively) vs (22.2%, and 41.7% respectively) with no significant statistical analysis. There was a statistically significant high T-allelic frequency among cases and C-allelic frequency among controls. There was a statistically significant association between fold change in micro RNA (-375) and the susceptibility to CRC as there is down-regulation of the microRNA-375 in CRC group with fold change in 0.42±0.27. CONCLUSION: Micro RNA-375 and rs4939827 SNP in SMAD7 could be considered as potential markers for detecting and early diagnosing CRC patients.

Efficacy and Safety of Rituximab for Refractory and Relapsing Thrombotic Thrombocytopenic Purpura: A Cohort of 10 Cases.

OBJECTIVE: Idiopathic thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder mediated by autoantibodies directed against ADAMTS13. This provides a rationale for the use of rituximab in this disorder. We report our experience and the outcome of 10 cases of TTP (9 refractory and 1 relapsing) successfully treated with rituximab in combination with plasma exchange (PE) and other immunosuppressive treatments. METHODS: The diagnosis of TTP was based on clinical criteria and supported by severe deficiency of ADAMTS13 activity and presence of inhibitors in seven cases. Rituximab was started after a median of 18.6 sessions of PE (range: 5-35) at the dose of 375 mg/m(2)/week for 4-8 weeks. RESULTS: Complete remission was achieved in all patients after a median time of 14.4 days of the first dose (range: 6-30). After a median follow-up of 30 months (range: 8-78), eight patients were still in remission and two developed multiple relapses, treated again with the same therapy, and achieved complete responses; they are alive, and in complete remission after a follow-up of 12 and 16 months. CONCLUSION: Rituximab appears to be a safe and effective therapy for refractory and relapsing TTP. However, longer follow-up is recommended to assess relapse and detect possible long-term side effects of this therapy.