Mutagenic and genotoxic in silico QSAR prediction of dimer impurity of gliflozins; canagliflozin, dapaglifozin, and emphagliflozin and in vitro evaluation by Ames and micronucleus test.

Canagliflozin, Dapagliflozin, and Empagliflozin, glucagon-like peptide-1 receptor agonists, are indicated for managing type II diabetes. Although the genotoxicity profiles of these drugs are well-explored, limited information exists regarding the genotoxic potential of their impurities. In this investigation, the dimer impurities of Canagliflozin, Dapagliflozin, and Empagliflozin underwent both in silico and in vitro assessments for mutagenic potential. Tester strains of Salmonella typhimurium and Escherichia coli were subjected to the Ames test, utilizing concentrations of up to 1 µg per plate, with and without the presence of metabolic activation. Evaluation of micronucleus induction in TK6 cells was conducted through a micronucleus test, exploring concentrations up to 500 µg/mL, with or without the presence of exogenous metabolic activation. Under the specific test conditions, the dimer impurities of Canagliflozin, Dapagliflozin, and Empagliflozin showed no evidence of mutagenicity or clastrogenicity, establishing their in vitro classification as nonmutagenic. These findings align with negative in silico predictions from quantitative structure-activity relationship (QSAR) analyses for mutagenicity and genotoxicity of the dimer impurities. Collectively, these studies contribute clinically relevant safety information by confirming that the dimer impurities of Canagliflozin, Dapagliflozin, and Empagliflozin are nonmutagenic and nongenotoxic, emphasizing the consistency between in silico and in vitro data.

Structural insight of glitazone for hepato-toxicity: Resolving mystery by PASS.

Troglitazone causes severe hepatic injury in certain individuals and multiple mechanisms related to hepato-toxicity has been reported creating confusion. In the present study, the mechanism for the hepatic injury of glitazones was investigated by PASS. The results suggest that chromane containing glitazones are apoptic agonist (activating p53 by intrinsic pathway leading to the apoptosis) and those which do not contain the chromane are devoid of this. In case of hepato-toxicity by non-chromane glitazone and their metabolite such as M-3, RM-3, rosiglitazone and pioglitazone; PASS suggest that these chemicals are not apoptic agonist but they are the substrate for CYP enzyme (Phase-I Oxidative Enzyme) and Phase-II conjugating enzymes; interfering with bile acid metabolism rendering bile acid more toxic (cholestasis). This unmetabolised bile salt further initiates the process apoptosis via intrinsic and extrinsic pathway leading to the apoptosis. Immunoblot analysis further confirm our hypothesis that troglitazone (chromane containing glitazone), but not rosiglitazone and pioglitazone (non-chromane containing glitazone) increased the levels of p53 in a time-dependent manner. Hence our prediction related to the mechanism of hepato-toxicity by apoptosis and structural insight of glitazone can be helpful in improving the drug profile of this category.

Novel synthetic organic compounds inspired from antifeedant marine alkaloids as potent bacterial biofilm inhibitors.

In this paper, we have reported seventeen novel synthetic organic compounds derived from marine bromopyrrole alkaloids, exhibiting potential inhibition of biofilm produced by Gram-positive bacteria. Compound 5f with minimumbiofilm inhibitory concentration(MBIC) of 0.39, 0.78 and 3.125 µg/mL against MSSA, MRSA and SE respectively, emerged as promising anti-biofilm lead compounds. In addition, compounds 5b, 5c, 5d, 5e, 5f, 5h, 5i and 5j revealed equal potency as that of the standard drug Vancomycin (MBIC = 3.125 µg/mL) against Streptococcus epidermidis. Notably, most of the synthesized compounds displayed better potency than Vancomycin indicating their potential as inhibitors of bacterial biofilm. The cell viability assay for the most active hybrid confirms its anti-virulence properties which need to be further researched.

Synthesis of novel 4-nitropyrrole-based semicarbazide and thiosemicarbazide hybrids with antimicrobial and anti-tubercular activity.

We report the synthesis and screening of forty novel 4-nitropyrrole-semicarbazide conjugates inspired from the reported bio-potential of bromopyrrole alkaloids and semicarbazide derivatives for antimicrobial activity. Herein, hybrids 5k-5o, 5r, 5s and 5t displayed four-fold increased activity (MIC=0.39 µg/mL) against Escherichia coli compared to standard ciprofloxacin. Eight hybrids, 5k-5o and 5r-5t displayed equal antibacterial activity (MIC=1.56 µg/mL) against Klebsiella pneumonia compared to standard ciprofloxacin. Hybrid, 5k-5o (MIC=0.195 µg/mL) displayed highly potent antibacterial activity against MSSA as compared to standard ciprofloxacin. Eight-fold superior activity was observed for four hybrids 5k-5m and 5o (MIC=0.39 µg/mL) against MRSA. Further, nine hybrids displayed four-fold superior antifungal activity (MIC=0.78 µg/mL) compared to standard Amphotericin B. Encouraging MICs of these hybrids recognize them as promising leads for development of potential antimicrobial drugs.

Synthesis, pharmacological screening and in silico studies of new class of Diclofenac analogues as a promising anti-inflammatory agents.

A novel series of 5-[2-(2,6-dichlorophenylamino)benzyl]-3-(substituted)-1,3,4-oxadiazol-2(3H)-thione (4a-k) derivatives have been synthesized by the Mannich reaction of 5-[2-(2,6-dichlorophenylamino)benzyl]-1,3,4-oxadiazol-2(3H)-thione (3) with an appropriately substituted primary/secondary amines, in the presence of formaldehyde and absolute ethanol. Structures of these novel compounds were characterized on the basis of physicochemical, spectral and elemental analysis. The title compounds (4a-k) were screened for in vivo acute anti-inflammatory and analgesic activities at a dose of 10mg/kg b.w. Compound 4k exhibited the most promising and significant anti-inflammatory profile while compounds 4a, 4d, 4e, 4i, and 4j showed moderate to good inhibitory activity at 2nd and 4thh, respectively. These compounds were also found to have considerable analgesic activity (acetic acid induced writhing model) and antipyretic activity (yeast induced pyrexia model). In addition, the tested compounds were also found to possess less degree of ulcerogenic potential as compared to the standard NSAIDs. Compounds that displayed promising anti-inflammatory profile were further evaluated for their inhibitory activity against cyclooxygenase enzyme (COX-1/COX-2), by colorimetric COX (ovine) inhibitor screening assay method. The results revealed that the compounds 4a, 4e, 4g and 4k exhibited effective inhibition against COX-2. In an attempt to understand the ligand-protein interactions in terms of the binding affinity, docking studies were performed using Molegro Virtual Docker (MVD-2013, 6.0) for those compounds, which showed good anti-inflammatory activity. It was observed that the binding affinities calculated were in agreement with the IC50 values.

Design, synthesis and antistaphylococcal activity of marine pyrrole alkaloid derivatives.

A novel set of 16 hybrids of bromopyrrole alkaloids with aroyl hydrazone were designed, synthesized and evaluated for antibacterial and antibiofilm activities against methicillin-resistant Staphylococcus aureus (MRSA; ATCC 43866), methicillin-susceptible Staphylococcus aureus (MSSA; ATCC 35556) and Staphylococcus epidermidis (SE, S. epidermidis ATCC 35984). Of the 16 tested hybrids, 14 exhibited equal or superior antibiofilm activity against MSSA and MRSA relative to standard vancomycin. Compound 4m showed highest potency with antibiofilm activity of 0.39 µg/mL and 0.78 µg/mL against MSSA and MRSA, respectively. Thus, this compound could act as a potential lead for further development of new antistaphylococcal drugs.

CRISPR/Cas9 Gene Editing: A Novel Approach Towards Alzheimer's Disease Treatment.

In defiance of the vast amount of information regarding Alzheimer's disease (AD) that has been learned over the past thirty years, progress toward developing an effective therapy has been difficult. A neurological ailment that progresses and cannot be reversed is Alzheimer's disease, which shows neurofibrillary tangles, beta-amyloid plaque, and a lack of cognitive processes that is created by tau protein clumps with hyperphosphorylation that finally advances to neuronal damage without a recognized treatment, which has stimulated research into new therapeutic strategies. The protein CAS9 is linked to CRISPR, which is a clustered Regularly Interspaced Short Palindromic Repeat that inactivates or corrects a gene by recognizing a gene sequence that produces a doublestranded break has enchanted a whole amount of interest towards its potency to cure gene sequences in AD. The novel CRISPR-Cas9 applications for developing in vitro and in vivo models to the benefit of AD investigation and therapies are thoroughly analyzed in this work. The discussion will also touch on the creation of delivery methods, which is a significant obstacle to the therapeutic use of CRISPR/Cas9 technology. By concentrating on specific genes, such as those that are significant early-onset AD risk factors and late-onset AD risk factors, like the apolipoprotein E4 (APOE4) gene, this study aims to evaluate the potential application of CRISPR/Cas9 as a possible treatment for AD.

Improved Pharmacokinetic and Pharmacodynamic Profile of Deuterium-Reinforced Tricyclic Antidepressants Doxepin, Dosulepin, and Clomipramine in Animal Models.

BACKGROUND AND OBJECTIVES: Doxepin, dosulepin, and clomipramine are tricyclic antidepressants (TCAs) that act as serotonin and noradrenaline reuptake inhibitors. The metabolites formed by N-dealkylation of these tricyclic antidepressants contribute to overall poor pharmacokinetics and efficacy. Deuteration of the methyl groups at metabolically active sites has been reported to be a useful strategy for developing more selective and potent antidepressants. This isotopic deuteration can lead to better bioavailability and overall effectiveness. The objective is to study the effect of site-selective deuteration of TCAs on their pharmacokinetic and pharmacodynamic profile by comparison with their nondeuterated counterparts. METHODS: In the current study, the pharmacokinetic profile and antidepressant behavior of deuterated TCAs were evaluated using the forced swim test (FST) and tail suspension test (TST), using male Wistar rats and male Swiss albino mice, respectively; additionally, a synaptosomal reuptake study was carried out. RESULTS: Compared with the nondeuterated parent drugs, deuterated forms showed improved efficacy in the behavior paradigm, indicating improved pharmacological activity. The pharmacokinetic parameters indicated increased maximum concentration in the plasma (Cmax), elimination half-life (t1/2), and area under the concentration-time curve (AUC)  in deuterated compounds. This can have a positive clinical impact on antidepressant treatment. Synaptosomal reuptake studies indicated marked inhibition of the reuptake mechanism of serotonin (5-HT) and norepinephrine. CONCLUSIONS: Deuterated TCAs can prove to be potentially better molecules in the treatment of neuropsychiatric disorders as compared with nondeuterated compounds. In addition, we have demonstrated a concept that metabolically active, site-selective deuteration can be beneficial for improving the pharmacokinetic and pharmacodynamic profiles of TCAs. A further toxicological study of these compounds is needed to validate their future clinical use.

Discovery of Novel Diesters Incorporating Kojic Acid With NSAIDs and Palmitic Acid as Dual Inhibitor of Melanogenesis and Inflammation.

Our study focuses on creating hybrid compounds and assessing their suitability for use in skincare products. The synergistic combination of Kojic acid, NSAIDs, and Palmitic acid proved to be an effective approach in inhibiting melanin production, making it a promising solution for individuals with hyperpigmentation concerns with Kojic acid (KA) Ibuprofen monoester (IBUM) and Ibuprofen-Kojic acid-Palmitic acid diester (IBUD) exhibiting a potential tyrosinase (38 % and 49 % inhibition at 200 µM) and anti-melanogenesis activity (77 % and 79 % inhibition at 100 µM). Furthermore, these compounds exhibited potent anti-inflammatory effects, Kojic acid-Diclofenac monoester (DICM) and Diclofenac-Kojic acid-Palmitic acid diester (DICD) offering potential benefits for inflammation by lowering the paw volume. A stability study under chemical conditions and enzymatic conditions was also performed, wherein DICM and DICD showed a better half-life of 515, 593 h under chemical stability and 6.3, 7.5 h under enzymatic stability studies respectively. The diester hybrids IBUD, DICD, Naproxen-Kojic acid-Palmitic acid diester (NAPD) showed a better permeation and penetration profiles compared to their parent drugs. In-vitro cell line studies were conducted to assess the safety and efficacy of these hybrid esters, with promising results. The dual inhibitor demonstrated minimal cytotoxicity and remarkable anti-melanogenic and anti-inflammatory activities, showing its potential as a versatile agent in addressing both melanogenesis and inflammation.

Levothyroxine synthesis impurities are neither mutagenic nor genotoxic: Insilico, Ames test and micronucleus test studies.

In vitro and in silico tests were used to assess the possible genotoxicity and mutagenicity of five impurities that may be present in levothyroxine, a drug used for thyroid hormone replacement therapy. Neither ToxTree nor VEGA (Virtual Models for evaluating the properties of chemicals within a global architecture) identified cause for concern for any of the impurities. Ames test results (doses up to 1 mg per plate), with or without metabolic activation, were negative. The micronucleus test with TK6 (human lymphoblastoid) cells, at doses up to 500 µg/mL, with or without metabolic activation, also gave negative results.

Synthesis and evaluation of novel 1,3,4-oxadiazole derivatives of marine bromopyrrole alkaloids as antimicrobial agent.

In an attempt to identify new potential lead as antimicrobial agent, twenty hybrids of marine bromopyrrole alkaloids with 1,3,4-oxadiazole were designed based on molecular hybridization technique and synthesized. Synthesized molecules were evaluated for their antibacterial, antifungal and antitubercular activities. Hybrids 5d, 5i, 5j and 5k exhibited equivalent antibacterial activity (MIC of 1.56 µg/mL) compared with standard drug ciprofloxacin against Staphylococcus aureus and Escherichia coli. Equal antifungal activity (MIC of 1.56 µg/mL) was shown by of hybrids 5j, 5k and 7d compared with standard Amphotericin-B. The inhibition of Mycobacterium tuberculosis at concentrations as low as 1.6 and 1.5 µg/mL by compounds 5f and 7d respectively indicates that these compounds can act as leads for development of newer anti-TB compounds.

Synthesis and antibiofilm activity of marine natural product-based 4-thiazolidinones derivatives.

4-Thiazolidinones derivatives of marine bromopyrrole alkaloids were synthesized as potential antibiofilm compounds. Among the synthesized compounds, some showed promising antibiofilm activity. Biological data revealed that 1,3-thiazolidin-4-one derivatives are more potent antibiofilm agents compared to 1,3-thiazinan-4-ones. Antibiofilm activity of compound 4b, 4c (MIC=0.78 µg/ml) was 3-fold superior than standard vancomycin (MIC=3.125 µg/ml) while activity of compound 4d, 4f, 4g and 4h was 2-fold (MIC=1.56 µg/ml) against Staphylococcus aureus biofilm. Compound 4b-4h showed equal antibiofilm activity against Staphylococcus epidermidis compared to standard Vancomycin (MIC=3.125 µg/ml).

Synthesis and evaluation of novel chloropyrrole molecules designed by molecular hybridization of common pharmacophores as potential antimicrobial agents.

In an attempt to identify new potential lead as antimicrobial agent, 31 novel chloropyrrole derivatives of aroyl hydrazones and chalcones incorporating common pharmacophore of pyoluteorin derivatives were synthesized. Antimicrobial activity of the synthesized compounds was evaluated using broth dilution technique. Based on biological evaluation data it was observed that activity increases as the number of chlorines on pyrrole core increases. Few 1H-pyrrole-2-carbohydrazide derivatives shows activity equivalent to the standard drug ciprofloxacin. Thus, these compounds can act as potential lead for further antibacterial studies.

A Recent Perspective on Discovery and Development of Diverse Therapeutic Agents Inspired from Isatin Alkaloids.

Isatin as an alkaloidal framework have consistently attracted attention of medicinal chemist towards development of wide range of novel therapeutic agents. This review report has discussed significant isatin lead molecules and their derivatives which have shown promising biological potential in recent times. The substituted isatins showing a potent pharmacological activities such as antimicrobial, antitubercular, anticancer, antioxidant, anti-histaminic, anti-HIV, antiviral, anti-inflammatory, anti-Parkinson's and antidiabetic have been described in this review. The mechanism of action leading to therapeutic activity of the respective isatin derivation has also been recorded. This review reveals that the systematic and rational modifications on isatin motif exhibited significant bio-activities which can be exploited for the development of potent novel therapeutic agents in the future studies. Hence the quest to investigate more structural alterations on isatin scaffold should be continued.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin: a recent perspective.

Overexpression of epidermal growth factor receptor (EGFR) is seen in a number of human tumors like prostate, colon, breast and ovarian. Their expression is correlated with vascularity and often difficult to diagnose. Though a number of active inhibitors and anticancer drugs against EGFR-tyrosine kinase are known, increase in resistance together with many side effects designate the need for new and improved treatments. Natural products and their analoges have significant contribution in the cancer drug discovery and development process. Therefore in the current review we mainly discuss design, synthesis and structural activity relationship of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin.

Novel series of coumarinyl substituted-thiazolidin-2,4-dione analogs as anticancer agents: design, synthesis, spectral studies and cytotoxicity evaluation.

In this research work, a series of eighteen novel coumarinyl substituted thiazolidin-2,4-dione analogs (4a-4r) have been designed by molecular hybridization approach, synthesized and their structures were established on the basis of FTIR, 1H NMR, 13C NMR and elemental (CHN) analysis. These title compounds were screened for their cytotoxicity using MTT assay methodology against five different mammalian cancer cell lines viz. hormone dependant breast adenocarcinoma (MCF7), cervical carcinoma (HeLa), colorectal carcinoma (HT29), lung cancer (A549) and prostate adeno carcinoma (PC3). The cytotoxicity screening studies revealed that MCF-7, HeLa and A549 cancer cell lines were sensitive to all the tested compounds. Though the compounds showed varying degrees of cytotoxicity in the tested cell lines, most significant effect was observed for compounds 4i (1.06, 2.4 and 3.06 µM) and 4o (0.95, 3.2 and 2.38 µM) against MCF7, HeLa and A549 cell lines respectively. In conclusion, the anticancer results of these promising leads strongly encouraged us for additional lead optimization with the aim of developing more potential anticancer agents.

Recent advancement in discovery and development of natural product combretastatin-inspired anticancer agents.

The natural stilbenoids combretastatin A-4 (CA4) and combretastatin A-1 (CA1) are potent antitubulin agents demonstrating antimitotic activity as well as tumor vascular disruption property. Due to structural simplicity and potent cytotoxicity of CA4 and CA1, they are considered as promising leads for the development of potent anticancer agents. In fact, scientific fraternity is motivated to synthesize several derivatives of CA4 and CA1 as novel therapeutic agents. In the literature, several studies have been carried out to evaluate the medicinal chemistry, pharmacology and structure-activity relationships (SAR) of a variety of modified combretastatin derivatives. The present report aimed at comprehensively revising the recent advancements (2006-2014) in the medicinal chemistry and SAR of diversified combretastatin analogues. The published data concerning new combretastatin A-4 analogues as antimitotic anticancer agents are presented and SAR is reviewed and discussed.

Synthesis of Novel Hybrids Inspired from Bromopyrrole Alkaloids Inhibiting MMP-2 and -12 as Antineoplastic Agents.

Synthesis of novel set of forty semicarbazide/thiosemicarbazide hybrids inspired from marine bromopyrrole alkaloids is reported. Biological screening of these hybrids against a panel of five human cancer cell lines identified a number of hits endowed with interesting cytotoxicity profile. Compounds 5c and 5e (IC50  = 0.03 µm), 5t (IC50  = 0.03 µm), 4s (IC50  = 0.07 µm), and 5n (IC50  = 0.01 µm) displayed maximum cytotoxicity toward hormone-dependent breast cancer cells MCF7, hepatic cancer cells WRL68, colon cancer cells CaCO2 and mouth and oral cancer cells KB403, respectively. The most active hits were further investigated for their potential to inhibit MMP-2 and MMP-12. Compound 5e showed maximum activity (IC50  = 1.8 µm) toward MMP-2. Further, we preformed anti-invasive assay on the most active compounds, where CaCO2 tumor cell migration was significantly decreased (77.9%) by hybrid 5e. The non-toxicity toward human VERO cells (IC50  = 83.1 to 231.8 µm) indicated the selectivity of most active hits (5c, 5e, 5t and 5n) toward cancer cells.

Synthesis of novel amides based on acridone scaffold with interesting antineoplastic activity.

In search of novel cytotoxic agents based on acridone scaffold, twenty five derivatives of acridone-2- carboxamide were synthesized and evaluated against a panel of eleven cancer cell lines by using MTT assay. Amides, A5 and A8 (IC50 = 0.3 µM) exhibited good cytotoxicity against MCF7. Compound A22 (IC50 = 4.3 µM) was found to be selectively cytotoxic against cancer cell line MCF7 and KB403. Particularly, promising cytotoxic activities were shown by amides A6 (IC50 = 0.7 µM), A16 (IC50 = 6.3 µM), A8 (IC50 = 0.9 µM ), A21 (IC50 = 1.3 µM), A5 (IC50 = 2.9 µM), A8 (IC50 = 2.8 µM), A14 (IC50 = 0.8 µM), A9 (IC50 = 0.8 µM) and A8 (IC50 = 0.4 µM) against cell lines; PA1, WRL68, CaCO2, TK-10, K-562, PC-3, HOP-92, ECV-304 and UACC-257, respectively. The favorable cytotoxic profile and non-toxicity towards normal human cells displayed by the derivative revealed their potential for further anticancer drug developments.

Design and synthesis of novel antineoplastic agents inspired from marine bromopyrrole alkaloids.

Azetidin-2-one, a ß -lactam four-membered heterocyclic ring is widely identified for its diverse medicinal properties. Ezetimibe a cholesterol absorption inhibitor and Aztreonam a potent cephalosporinase inhibitor proved the medicinal value of azetidin-2-ones. On the other hand marine bromopyrrole alkaloids are well known for their diverse biological significance. Hence twenty novel conjugates of azetidin-2-ones integrated with 4,5-dibromopyrrole motif were synthesized and screened for antineoplastic activity using MTT assay. Synthesized hybrids displayed good antineoplastic profile particularly towards breast cancer cell line MCF7, where hybrid 5e displayed maximum cytotoxicity (IC50 = 0.5 µM). The selective cytotoxicity displayed by these conjugates towards tested cancer cells with non-toxicity against normal human VERO cells indicated their potential for further antineoplastic drug development.