Nitrophenylpiperazine derivatives as novel tyrosinase inhibitors: design, synthesis, and in silico evaluations.

A novel series of 4-nitrophenylpiperazine derivatives (4a-m) was designed and synthesized as potential tyrosinase inhibitors. Comprehensive characterization using 1H-NMR, 13C-NMR, CNH, and IR techniques was performed for all target compounds. Subsequently, the derivatives were evaluated for their inhibitory activity against tyrosinase. Among them, compound 4l, featuring an indole moiety at the N-1 position of the piperazine ring, exhibited a significant tyrosinase inhibitory effect with an IC50 value of 72.55 µM. Enzyme kinetics analysis revealed that 4l displayed mixed inhibition of the tyrosinase enzymatic reaction. Molecular docking was carried out in the enzyme's active site to further investigate the enzyme-inhibitor interactions. Based on the findings, compound 4l shows promise as a lead structure for the design of potent tyrosinase inhibitors. This study paves the way for the development of more effective tyrosinase inhibitors for potential applications in various fields.

Preparation, Optimization and In Vitro Characterization of Fluticasoneloaded Mixed Micelles Based on Stearic Acid-g-chitosan as a Pulmonary Delivery System.

PURPOSE: The primary objective of this study was to optimize formulation variables and investigate the in vitro characteristics of fluticasone propionate (FP)-loaded mixed polymeric micelles, which were composed of depolymerized chitosan-stearic acid copolymer (DC-SA) in combination with either tocopheryl polyethylene glycol succinate or dipalmitoylphosphatidylcholine for pulmonary drug delivery. METHODS: A D-optimal design was employed for the optimization procedure, considering lipid/ polymer ratio, polymer concentration, drug/ polymer ratio, and lipid type as independent variables. Dependent variables included particle size, polydispersion index, zeta potential, drug encapsulation efficiency, and loading efficiency of the polymeric micelles. Additionally, the nebulization efficacy and cell viability of the optimal FP-loaded DC-SA micellar formulations were evaluated. RESULTS: The mixed polymeric micelles were successfully prepared with properties falling within the desired ranges, resulting in four optimized formulations. The release of FP from the optimal systems exhibited a sustained release profile over 72 hours, with 70% of the drug still retained within the core of the micelles. The nebulization efficiency of these optimal formulations reached up to 63%, and the fine particle fraction (FPF) ranged from 41% to 48%. Cellular viability assays demonstrated that FP-loaded DC-SA polymeric micelles exhibited lower cytotoxicity than the free drug but were slightly more cytotoxic than empty mixed micelles. CONCLUSION: In conclusion, this study suggests that DC-SA/ lipid mixed micelles have the potential to serve as effective carriers for nebulizing poorly soluble FP.

Thioquinoline derivatives conjugated to thiosemicarbazide as potent tyrosinase inhibitors with anti-melanogenesis properties.

In the present study, a series of aryl-substituted thioqunoline conjugated to thiosemicarbazide were rationally designed and synthesized. The formation of target compounds was confirmed by spectral characterization techniques such as IR, 1H-NMR, 13C-NMR, ESI-MS, and elemental analysis. Among the synthesized derivatives, compound 10g bearing para-chlorophenyl moiety was proved to be the most potent tyrosinase inhibitor with an IC50 value of 25.75 ± 0.19 µM. Compound 10g as the most potent derivative exhibited a noncompetitive inhibition pattern against tyrosinase in the kinetic study. Furthermore, the in silico cavity detection, as well as the molecular docking assessments, were performed to follow the behavior of 10g within the proposed binding site. Besides, the toxicity of 10g and its potency to reduce the melanin content on A375 cell lines were also measured. Consequently, aryl-substituted thioqunolines conjugated to thiosemicarbazide might be a promising candidate in the cosmetics, medicine, and food industry as tyrosinase inhibitors.

Ugi Bis-Amide Derivatives as Tyrosinase Inhibitor; Synthesis, Biology Assessment, and in Silico Analysis.

Herein, a straightforward synthetic strategy mediated by Ugi reaction was developed to synthesize novel series of compounds as tyrosinase inhibitors. The structures of all compounds were confirmed by FT-IR, 1 H-NMR, 13 C-NMR, and CHNOS techniques. The tyrosinase inhibitory activities of all synthesized derivatives 5a-m were determined against mushroom tyrosinase and it was found that derivative 5c possesses the best inhibition with an IC50 value of 69.53±0.042 µM compared to the rest of the synthesized derivatives. Structure-activity relationships (SARs) showed that the presence of 4-MeO or 4-NO2 at the R2 position plays a key role in tyrosinase inhibitory activities. The enzyme kinetics studies showed that compound 5c is an noncompetitive inhibitor. For in silico study, the allosteric site detection was first applied to find the appropriate binding site and then molecular docking and molecular dynamic studies were performed to reveal the position and interactions of 5c as the most potent inhibitor within the tyrosinase active site. The results showed that 5c bind well with the proposed binding site and formed a stable complex with the target protein.

In vitro cell-based models of drug-induced hepatotoxicity screening: progress and limitation.

Drug-induced liver injury (DILI) is one of the major causes of post-approval withdrawal of therapeutics. As a result, there is an increasing need for accurate predictive in vitro assays that reliably detect hepatotoxic drug candidates while reducing drug discovery time, costs, and the number of animal experiments. In vitro hepatocyte-based research has led to an improved comprehension of the underlying mechanisms of chemical toxicity and can assist the prioritization of therapeutic choices with low hepatotoxicity risk. Therefore, several in vitro systems have been generated over the last few decades. This review aims to comprehensively present the development and validation of two-dimensional (2D) and three-dimensional (3D) culture approaches on hepatotoxicity screening of compounds and highlight the main factors affecting predictive power of experiments. To this end, we first summarize some of the recognized hepatotoxicity mechanisms and related assays used to appraise DILI mechanisms and then discuss the challenges and limitations of in vitro models.

Design, Synthesis, in Vitro, and in Silico Evaluation of N-Phenylacetamide-Oxindole-Thiosemicarbazide Hybrids as New Potential Tyrosinase Inhibitors.

A novel series of N-phenylacetamide-oxindole-thiosemicarbazide hybrids were synthesized and evaluated for their tyrosinase inhibitory activity. According to tyrosinase inhibition results, all the synthesized compounds showed high tyrosinase inhibitory activity with IC50 values ranging from 0.8 to 3.88 µM in comparison to positive control kojic acid with IC50 value of 36.32 µM. Among tested compounds, analog 7o, containing the 2-methyl-4-nitrophenyl on N-phenylacetamide moiety displayed superior tyrosinase inhibition. This compound was around 45-fold more potent than kojic acid. The kinetic analysis of compound 7o demonstrated that this compound is a competitive inhibitor against tyrosinase. Docking study of this compound demonstrated that compound 7o interacted with critical histidine residues within tyrosinase active site.

Therapeutic applications of biosimilar monoclonal antibodies: Systematic review of the efficacy, safety, and immunogenicity in autoimmune disorders.

PURPOSE: Biosimilars are biological products that could be used instead of reference biological drugs to provide a less costly option for treating patients with autoimmune disorders. With the introduction of biosimilar monoclonal antibodies into the drug market, the main concern is confirming the similarity in terms of efficacy, safety, and immunogenicity of these biosimilars with their reference products. The presence of valuable comparative clinical trials to demonstrate these similarities with analytical methods is challenging. This review discusses the similarity between biosimilar mAbs and reference products as candidates for autoimmune diseases. METHODS: Data on efficacy endpoints, adverse events, production of anti-drug antibodies (ADAs), and neutralizing antibodies (nAbs) were collected from trials. FINDINGS: Overall, these data suggest the similarity between biosimilar mAbs and reference products in terms of safety and efficacy. IMPLICATIONS: Biosimilars are used in a wider range of diseases, and by examining their similarities in all those diseases with reference drugs, more comprehensive results can be obtained.

HPLC methods for quantifying anticancer drugs in human samples: A systematic review.

Pharmacokinetic (PK) study of anticancer drugs in cancer patients is highly crucial for dose selection and dosing intervals in clinical applications. Once an anticancer drug is administered, it undergoes various metabolic pathways; to determine these pathways, it is necessary to follow the administered drug in biological samples via different analytical methods. In addition, multi-drug quantification methods in patients undergoing multi-drug regimens of cancer therapy can have several benefits, such as reduced sampling time and analysis costs. In order to collect and categorize these studies, we conducted a systematic review of HPLC methods reported for the analysis of anticancer drugs in biological samples. A systematic search was performed on PubMed Medline, Scopus, and Web of Science databases, and 116 studies were included. In summary of included studies, when the objective of a method was to quantify a single drug, MS, or UV detectors were utilized equivalently. On the other hand, in methods with the aim of quantifying drug and metabolite(s) in a single run, MS detectors were the most utilized. This review can provide a comprehensive insight for researchers prior to developing a quantification method and selecting a detector.

Design, synthesis, molecular modeling and anticholinesterase activity of benzylidene-benzofuran-3-ones containing cyclic amine side chain.

AIM: A series of 2-benzylidene-benzofuran-3-ones were designed from the structures of Ebselen analogs and aurone derivatives and synthesized in good yields. MATERIALS & METHODS: The target compounds were prepared by the condensation reaction between appropriate benzofuranones with amino alkoxy aldehydes and evaluated as cholinesterase inhibitors by Ellman's method. RESULTS: The in vitro anti-acetylcholinesterase (AChE)/butyrylcholinesterase activities of the synthesized compounds revealed that 7e (IC50 = 0.045 µM) is the most active compound against AChE. Furthermore, the docking study confirmed the results obtained through in vitro experiments and predicted the possible binding conformation. CONCLUSION: The anticholinesterase activities of benzylidene-benzofurane-3-ones as aurone analogs revealed that the compounds bearing piperidinylethoxy residue showed better activities against AChE, introducing these compounds for further drug discovery developments. [Formula: see text].

Synthesis and biological evaluation of novel imidazopyrimidin-3-amines as anticancer agents.

Groebke-Blackburn-Bienayme reaction has been utilized for the synthesis of new imidazo[1,2-a]pyrimidine derivatives as novel anticancer agents. The cytotoxic activities of compounds were evaluated against human cancer cell lines including MCF-7, T-47D, and MDA-MB-231, compared with etoposide as the standard drug. Among the tested compounds, hydroxy- and/or methoxy-phenyl derivatives (6a-c and 6k) with IC50 values of 6.72-14.36 µm were more potent than etoposide against all cell lines. The acridine orange/ethidium bromide double staining and DNA fragmentation studies demonstrated that the cytotoxic effect of 3-hydroxy-4-methoxyphenyl derivative 6c is associated with apoptosis in cancer cells.

Novel Tacrine-Based Pyrano[3',4':5,6]pyrano[2,3-b]quinolinones: Synthesis and Cholinesterase Inhibitory Activity.

In order to develop effective anti-cholinesterase compounds, a novel series of pyrano[3',4':5,6]pyrano[2,3-b]quinolinones were designed, synthesized, and evaluated in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). All derivatives showed very good AChE inhibitory (AChEI) activity (IC50 = 0.37-5.62 µM) compared with rivastigmine (IC50 = 11.07 µM). Among them, 11-amino-12-(2,3-dichlorophenyl)-3-methyl-7,8,9,10-tetrahydropyrano[3',4':5,6]pyrano[2,3-b]quinolin-1(12H)-one (6f) displayed the best inhibitory activity. However, most of the synthesized compounds showed no anti-BChE activity and compounds 6b and 6f were found to be only moderate inhibitors. The most potent anti-AChE compound 6f had low and moderate inhibitory activity and neuroprotective effects against beta-secretase (BACE1) and oxidative stress-induced cell death, respectively. Also, kinetic and molecular docking studies of binding interactions elucidated that compound 6f bound to both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE.

Medicinal Plants Used in Iranian Traditional Medicine (ITM) as Contraceptive Agents.

BACKGROUND: In recent years, rapid population growth and unsafe abortions have emerged as controversial health issues in some countries. Hence, safe and effective contraceptive methods or agents have attracted a great deal of attention and the corresponding market has been widely expanded. OBJECTIVE: In this study, we present a review profiting from Iranian Traditional Medicine (ITM) to introduce expedient plants as efficient contraceptive agents. METHODS: Medicinal plants suggested as contraceptive agents were obtained from ITM text books and they were also investigated using search engines to confirm their in vitro and in vivo efficacy. RESULTS: According to credible Iranian medical literature a wide spectrum of plants possesses contraceptive activity and among them, Ruta graveolens, Ricinus communis, Piper nigrum, and Physalis alkekengi were found to be more efficient. CONCLUSION: Complementary and Alternative Medicine (CAM), particularly herbal remedies have received a lot of attention because of their truly healing properties. Focusing on ITM knowledge, there are various comments based on medicinal plants to reduce unsafe abortions leading to better public health in the society.

The development of biomarkers to reduce attrition rate in drug discovery focused on oncology and central nervous system.

INTRODUCTION: The task of discovery and development of novel therapeutic agents remains an expensive, uncertain, time-consuming, competitive, and inefficient enterprise. Due to a steady increase in the cost and time of drug development and the considerable amount of resources required, a predictive tool is needed for assessing the safety and efficacy of a new chemical entity. AREAS COVERED: This study is focused on the high attrition rate in discovery and development of oncology and central nervous system (CNS) medicines, because the failure rate of these medicines is higher than others. Some approaches valuable in reducing attrition rates are proposed and the judicious use of biomarkers is discussed. EXPERT OPINION: Unlike the significant progress made in identifying and characterizing novel mechanisms of disease processes and targeted therapies, the process of novel drug development is associated with an unacceptably high attrition rate. The application of clinically qualified predictive biomarkers holds great promise for further development of therapeutic targets, improved survival, and ultimately personalized medicine sets for patients. Decisions such as candidate selection, development risks, dose ranging, early proof of concept/principle, and patient stratification are based on the measurements of biologically and/or clinically validated biomarkers.

Design and synthesis of novel anti-Alzheimer's agents: Acridine-chromenone and quinoline-chromenone hybrids.

A novel series of acridine-chromenone and quinoline-chromenone hybrids were designed, synthesized, and evaluated as anti-Alzheimer's agents. All synthesized compounds were evaluated as cholinesterases (ChEs) inhibitors and among them, 7-(4-(6-chloro-2,3-dihydro-1H-cyclopenta[b]quinolin-9-ylamino)phenoxy)-4-methyl-2H-chromen-2-one (8e) exhibited the most potent anti-acetylcholinesterase (AChE) inhibitory activity (IC50=16.17µM) comparing with rivastigmine (IC50=11.07µM) as the reference drug. Also, compound 8e was assessed for its ß-secretase (BACE1) inhibitory and neuroprotective activities which demonstrated satisfactory results. It should be noted that both kinetic study on the inhibition of AChE and molecular modeling revealed that compound 8e interacted simultaneously with both the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE.

Treatment of Helicobacter pylori infection: Current and future insights.

Helicobacter pylori (H. pylori) is an important major cause of peptic ulcer disease and gastric malignancies such as mucosa-associated lymphoid tissue lymphoma and gastric adenocarcinoma worldwide. H. pylori treatment still remains a challenge, since many determinants for successful therapy are involved such as individual primary or secondary antibiotics resistance, mucosal drug concentration, patient compliance, side-effect profile and cost. While no new drug has been developed, current therapy still relies on different mixture of known antibiotics and anti-secretory agents. A standard triple therapy consisting of two antibiotics and a proton-pump inhibitor proposed as the first-line regimen. Bismuth-containing quadruple treatment, sequential treatment or a non-bismuth quadruple treatment (concomitant) are also an alternative therapy. Levofloxacin containing triple treatment are recommended as rescue treatment for infection of H. pylori after defeat of first-line therapy. The rapid acquisition of antibiotic resistance reduces the effectiveness of any regimens involving these remedies. Therefore, adding probiotic to the medications, developing anti-H. pylori photodynamic or phytomedicine therapy, and achieving a successful H. pylori vaccine may have the promising to present synergistic or additive consequence against H. pylori, because each of them exert different effects.

Design, synthesis, in vitro cytotoxic activity evaluation, and apoptosis-induction study of new 9(10H)-acridinone-1,2,3-triazoles.

A new series of 9(10H)-acridinone-1,2,3-triazole derivatives were designed, synthesized and evaluated for their cytotoxic activity against human breast cancer cell lines. The acridone skeleton was prepared through the Ullman condensation of 2-bromobenzoic acid and anilines. Subsequently, it was functionalized with propargyl bromide. Then, a click reaction of the latter compound and in situ prepared 1-(azidomethyl)-4-methoxybenzene derivatives led to the formation of the desired triazole products. Finally, all products were investigated for their capability to cause cytotoxicity against MCF-7, T-47D, and MDA-MB-231 cell lines. Among them, 2-methoxy-10-((1-(4-methoxybenzyl)-1H-1,2,3-triazol-4-yl)methyl)acridin-9(10H)-one 8c exhibited the most potency [Formula: see text] against MCF-7 cells, being more potent than etoposide [Formula: see text]. Also, apoptosis induced by compound 8c was confirmed via acridine orange/ethidium bromide and Annexin V-FITC/propidium iodide (PI) double staining.

Design, Synthesis, Biological Evaluation, and Docking Study of Acetylcholinesterase Inhibitors: New Acridone-1,2,4-oxadiazole-1,2,3-triazole Hybrids.

In this study, novel acridone-1,2,4-oxadiazole-1,2,3-triazole hybrids were designed, synthesized, and evaluated for their acetylcholinesterase and butyrylcholinesterase inhibitory activity. Among various synthesized compounds, 10-((1-((3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)acridin-9(10H)-one 10b showed the most potent anti-acetylcholinesterase activity (IC50  = 11.55 µm) being as potent as rivastigmine. Also docking outcomes were in good agreement with in vitro results confirming the dual binding inhibitory activity of compound 10b.

Synthesis and cytotoxic activity of novel poly-substituted imidazo[2,1-c][1,2,4]triazin-6-amines.

A novel series of 3,4-diphenyl-7-(hetero)arylimidazo[2,1-c][1,2,4]triazin-6-amine derivatives were synthesized via three-component reaction of 5,6-diphenyl-1,2,4-triazin-3-amine, various aromatic aldehydes, and cyclohexyl isocyanide. All synthesized compounds were tested against HL60 (human promyelocytic leukemia), MOLT-4 (human T lymphoblastic leukemia), and MCF-7 (human breast adenocarcinoma) cell lines, as cytotoxic agents. The structure-activity relationships study revealed that the introduction of hydroxyl and methoxy groups on the 7-phenyl ring can modulate the cytotoxic activity of these compounds. Among the 7-aryl derivatives, 3-hydroxyphenyl and 3-hydroxy-4-methoxyphenyl derivatives (6h and 6o) were the most potent compounds against HL60 and MCF-7 cells (IC(50s) = 9.8 - 20.4 µM). However, the replacement of the 7-aryl moiety with pyridyl or furan-2-yl resulted in compounds 6p or 6r with more promising cytotoxicity against MOLT-4 cell line (IC50 values 12.1 and 13.0 µM, respectively). Also, the acridine orange/ethidium bromide staining assay in MCF-7 cells suggested that the cytotoxic activity of compound 6r occurs via apoptosis.

Potent acetylcholinesterase inhibitors: design, synthesis, biological evaluation, and docking study of acridone linked to 1,2,3-triazole derivatives.

A novel series of acridone linked to 1,2,3-triazole derivatives have been synthesized and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. The synthetic approach was started from the reaction of 2-bromobenzoic acid with aniline derivatives and subsequent cyclization reaction to give acridone derivatives. Then, reaction of the later compounds with propargyl bromide followed by azide-alkyne cycloaddition reaction (click reaction) led to the formation of the title compounds in good yields. Among the synthesized compounds, 10-((1-(4-chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)-2-methoxyacridin-9(10H)-one 9g, depicted the most potent anti-AChE activity (IC50 = 7.31 µM). Also, docking study confirmed the results obtained through in vitro experiments and predicted possible binding conformation.