Triarylpyrazole Derivatives as Potent Cytotoxic Agents; Synthesis and Bioactivity Evaluation "Pyrazole Derivatives as Anticancer Agent".

BACKGROUND: During the last recent years, several anti-cancer agents were introduced for the treatment of diverse kinds of cancer. Despite their potential in the treatment of cancer, drug resistance and adverse toxicity such as peripheral neuropathy are some of the negative criteria of anti-cancer agents and for this reason, the design and synthesis of new anti-cancer agents are important. OBJECTIVE: Design, synthesis, and anticancer activity evaluation of some pyrazole derivatives. METHODS: A series of Target compounds were prepared using multistep synthesis. Their cytotoxic activity against three different human cancer cell lines namely human colon carcinoma cells (HT-29), epithelial carcinoma cells (U-87MG), pancreatic cancerous cells (Panc-1) as well as AGO1522 normal cell line using in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was investigated. RESULTS: 1,3-Diaryl-5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole and 1,3-Diaryl-5-(3,4,5-trimethoxyphenyl)- 1H-pyrazole were synthesized in good yields and their structure and purity were confirmed using 1H-NMR, 13C-NMR, and elemental analysis. Generally, the synthesized scaffolds exhibited good cytotoxicity against cancerous cell lines in comparison to the reference standard, paclitaxel. Compounds 3A: and 3C: , in Annexin V/ PI staining assay, exerted remarkable activity in apoptosis induction in HT-29 cell lines. Both of them also led to cell cycle arrest in the sub-G1 phase which is inconsistent with the results of apoptosis assay. CONCLUSION: Concerning obtained results, it is interesting to synthesis more pyrazole derivatives as anticancer agents.

Novel N-benzylpyridinium moiety linked to arylisoxazole derivatives as selective butyrylcholinesterase inhibitors: Synthesis, biological evaluation, and docking study.

A novel series of N-benzylpyridinium moiety linked to arylisoxazole ring were designed, synthesized, and evaluated for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Synthesized compounds were classified into two series of 5a-i and 5j-q considering the position of positively charged nitrogen of pyridinium moiety (3- or 4- position, respectively) connected to isoxazole carboxamide group. Among the synthesized compounds, compound 5n from the second series of compounds possessing 2,4-dichloroaryl group connected to isoxazole ring was found to be the most potent AChE inhibitor (IC50 = 5.96 µM) and compound 5j also from the same series of compounds containing phenyl group connected to isoxazole ring demonstrated the most promising inhibitory activity against BChE (IC50 = 0.32 µM). Also, kinetic study demonstrated competitive inhibition mode for both AChE and BChE inhibitory activity. Docking study was also performed for those compounds and desired interactions with those active site amino acid residues were confirmed through hydrogen bonding as well as π-π and π-anion interactions. In addition, the most potent compounds were tested against BACE1 and their neuroprotectivity on Aß-treated neurotoxicity in PC12 cells which depicted negligible activity. It should be noted that most of the synthesized compounds from both categories 5a-i and 5j-q showed a significant selectivity toward BChE. However, series 5j-q were more active toward AChE than series 5a-i.

Design and synthesis of novel coumarin-pyridinium hybrids: In vitro cholinesterase inhibitory activity.

A novel series of coumarin-pyridinium hybrids were synthesized and evaluated as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using Ellman's method. Among synthesized compounds, 1-(3-fluorobenzyl)-4-((2-oxo-2H-chromene-3-carboxamido)methyl)pyridinium bromide (7l) was found to be the most active compound toward AChE (IC50 = 10.14 µM), 1-(3-chlorobenzyl)-3-((2-oxo-2H-chromene-3-carboxamido)methyl)pyridinium bromide (7g) and 1-(2,3-dichlorobenzyl)-3-((2-oxo-2H-chromene-3-carboxamido)methyl)pyridinium chloride (7h) depicted the best BChE inhibitory activity (IC50s = 0.32 and 0.43 µM, respectively). Although most compounds showed moderate to good anti-AChE activity, their anti-BChE activity was more significant and compound 7g was found as the most selective BChE with SI of 101.18. Also, kinetic study of the compounds 7g and 7l displayed a mixed type inhibition for both AChE and BChE. Furthermore, they were evaluated against ß-secretase; however, they showed low inhibitory activity.

Thalidomide attenuates development of morphine dependence in mice by inhibiting PI3K/Akt and nitric oxide signaling pathways.

Morphine dependence and the subsequent withdrawal syndrome restrict its clinical use in management of chronic pain. The precise mechanism for the development of dependence is still elusive. Thalidomide is a glutamic acid derivative, recently has been reconsidered for its clinical use due to elucidation of different clinical effects. Phosphoinositide 3-kinase (PI3K) is an intracellular transducer enzyme which activates Akt which in turns increases the level of nitric oxide. It is well established that elevated levels of nitric oxide has a pivotal role in the development of morphine dependence. In the present study, we aimed to explore the effect of thalidomide on the development of morphine dependence targeting PI3K/Akt (PKB) and nitric oxide (NO) pathways. Male NMRI mice and human glioblastoma T98G cell line were used to study the effect of thalidomide on morphine dependence. In both models the consequent effect of thalidomide on PI3K/Akt and/or NO signaling in morphine dependence was determined. Thalidomide alone or in combination with PI3K inhibitor, Akt inhibitor or nitric oxide synthase (NOS) inhibitors significantly reduced naloxone induced withdrawal signs in morphine dependent mice. Also, the levels of nitrite in hippocampus of morphine dependent mice were significantly reduced by thalidomide in compared to vehicle treated morphine dependent mice. In T98G human glioblastoma cells, thalidomide alone or in combination with PI3K and Akt inhibitors significantly reduced iNOS expression in comparison to the morphine treated cells. Also, morphine-induced p-Akt was suppressed when T98G cells were pretreated with thalidomide. Our results suggest that morphine induces Akt, which has a crucial role in the induction of NOS activity, leading to morphine dependence. Moreover, these data indicate that thalidomide attenuates the development of morphine dependence in vivo and in vitro by inhibition of PI3K/Akt and nitric oxide signaling pathways.

Synthesis, docking study and neuroprotective effects of some novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety.

Novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety were synthesized and evaluated against acetylcholinestrase (AChE) and butylcholinestrase (BuChE). Among the synthesized compounds, N-(3-cyano-4-(4-methoxyphenyl)-5-oxo-4,5-dihydropyrano[3,2-c]chromen-2-yl)-2-(4-phenylpiperazin-1-yl)acetamide (6c) exhibited the highest acetylcholinestrase inhibitory (AChEI) activity (IC50=1.12µM) and most of them showed moderate butylcholinestrase inhibitory activity (BChEI). Kinetic study of compound 6c confirmed mixed type of inhibition towards AChE which was in covenant with the results obtained from docking study. Also, it was evaluated against ß-secretase which demonstrated low activity (inhibition percentage: 18%). It should be noted that compounds 6c, 7b, 6g, and 7d showed significant neuroprotective effects against H2O2-induced PC12 oxidative stress.

A review on tacrine-based scaffolds as multi-target drugs (MTDLs) for Alzheimer's disease.

Alzheimer's disease (AD) is a multifactorial neurological disorder among elderly people and combinatorial factors such as genetic, lifestyle, and environmental are involved in onset and disease progression. It has been demonstrated that loss of cholinergic transmission is one of the most significant causes of AD. One strategy currently being investigated for the development of new therapeutics relates to the enhancement of cholinergic system through several ways. At this juncture, anticholinesterase inhibitors have absorbed lots of attention and different marketed drugs such as donepezil, rivastigmine, tacrine, and galantamine have been developed. 9-Amino-1,2,3,4-tetrahydroacridine known as tacrine was introduced in 1945 as an efficient anticholinesterase agent. The mechanism of action of tacrine was proved to inhibit the metabolism of acetylcholine and therefore extending its activity and raising levels in the cerebral cortex. However, extensive use of tacrine was limited since it showed various side effects and toxicity. Thus, lots of efforts were carried out to prepare tacrine analogues to overcome the related adverse effects. This review describes differently synthesized tacrine-based scaffolds as cholinesterase inhibitors to manage Alzheimer's disease (AD).