Actin depolymerizing factor destrin governs cell migration in neural development during Xenopus embryogenesis.

The actin-based cytoskeleton is considered a fundamental driving force for cell differentiation and development. Destrin (Dstn), a member of the actin-depolymerizing factor family, regulates actin dynamics by treadmilling actin filaments and increasing globular actin pools. However, the specific developmental roles of dstn have yet to be fully elucidated. Here, we investigated the physiological functions of dstn during early embryonic development using Xenopus laevis as an experimental model organism. dstn is expressed in anterior neural tissue and neural plate during Xenopus embryogenesis. Depleting dstn promoted morphants with short body axes and small heads. Moreover, dstn inhibition extended the neural plate region, impairing cell migration and distribution during neurulation. In addition to the neural plate, dstn knockdown perturbed neural crest cell migration. Our data suggest new insights for understanding the roles of actin dynamics in embryonic neural development, simultaneously presenting a new challenge for studying the complex networks governing cell migration involving actin dynamics.

Early life exposure to perfluorooctanesulfonate (PFOS) impacts vital biological processes in Xenopus laevis: Integrated morphometric and transcriptomic analyses.

Perfluorooctanesulfonate (PFOS) is a ubiquitous environmental pollutant associated with increasing health concerns and environmental hazards. Toxicological analyses of PFOS exposure are hampered by large interspecies variations and limited studies on the mechanistic details of PFOS-induced toxicity. We investigated the effects of PFOS exposure on Xenopus laevis embryos based on the reported developmental effects in zebrafish. X. laevis was selected to further our understanding of interspecies variation in response to PFOS, and we built upon previous studies by including transcriptomics and an assessment of ciliogenic effects. Midblastula-stage X. laevis embryos were exposed to PFOS using the frog embryo teratogenesis assay Xenopus (FETAX). Results showed teratogenic effects of PFOS in a time- and dose-dependent manner. The morphological abnormalities of skeleton deformities, a small head, and a miscoiled gut were associated with changes in gene expression evidenced by whole-mount in situ hybridization and transcriptomics. The transcriptomic profile of PFOS-exposed embryos indicated the perturbation in the expression of genes associated with cell death, and downregulation in adenosine triphosphate (ATP) biosynthesis. Moreover, we observed the effects of PFOS exposure on cilia development as a reduction in the number of multiciliated cells and changes in the directionality and velocity of the cilia-driven flow. Collectively, these data broaden the molecular understanding of PFOS-induced developmental effects, whereby ciliary dysfunction and disrupted ATP synthesis are implicated as the probable modes of action of embryotoxicity. Furthermore, our findings present a new challenge to understand the links between PFOS-induced developmental toxicity and vital biological processes.

PCNB exposure during early embryogenic development induces developmental delay and teratogenicity by altering the gene expression in Xenopus laevis.

Pentachloronitrobenzene (PCNB) is an organochlorine fungicide commonly used to treat seeds against seedling infections and controlling snow mold on golf courses. PCNB has been demonstrated to be toxic to living organisms, including fish and several terrestrial organisms. However, only phenotypical deformities have been studied, and the effects of PCNB on early embryogenesis, where primary organogenesis occurs, have not been completely studied. In the current study, the developmental toxicity and teratogenicity of PCNB is evaluated by using frog embryo teratogenesis assay Xenopus (FETAX). Our results confirmed the teratogenic potential of PCNB revealing the teratogenic index of 1.29 during early embryogenesis. Morphological studies revealed tiny head, bent axis, reduced inter ocular distance, hyperpigmentation, and reduced total body lengths. Whole mount in situ hybridization and reverse transcriptase polymerase chain reaction were used to identify PCNB teratogenic effects at the gene level. The gene expression analyses revealed that PCNB was embryotoxic to the liver and heart of developing embryos. Additionally, to determine the most sensitive developmental stages to PCNB, embryos were exposed to the compound at various developmental stages, demonstrating that the most sensitive developmental stage to PCNB is primary organogenesis. Taken together, we infer that PCNB's teratogenic potential affects not just the phenotype of developing embryos but also the associated genes and involving the oxidative stress as a possible mechanism of toxicity, posing a hazard to normal embryonic growth. However, the mechanisms of teratogenesis require additional extensive investigation to be defined completely.

Physiological Functions of Thiol Peroxidases (Gpx1 and Prdx2) during Xenopus laevis Embryonic Development.

Glutathione peroxidase 1 (Gpx1) and peroxiredoxin 2 (Prdx2) belong to the thiol peroxidase family of antioxidants, and have been studied for their antioxidant functions and roles in cancers. However, the physiological significance of Gpx1 and Prdx2 during vertebrate embryogenesis are lacking. Currently, we investigated the functional roles of Gpx1 and Prdx2 during vertebrate embryogenesis using Xenopus laevis as a vertebrate model. Our investigations revealed the zygotic nature of gpx1 having its localization in the eye region of developing embryos, whereas prdx2 exhibited a maternal nature and were localized in embryonic ventral blood islands. Furthermore, the gpx1-morphants exhibited malformed eyes with incompletely detached lenses. However, the depletion of prdx2 has not established its involvement with embryogenesis. A molecular analysis of gpx1-depleted embryos revealed the perturbed expression of a cryba1-lens-specific marker and also exhibited reactive oxygen species (ROS) accumulation in the eye regions of gpx1-morphants. Additionally, transcriptomics analysis of gpx1-knockout embryos demonstrated the involvement of Wnt, cadherin, and integrin signaling pathways in the development of malformed eyes. Conclusively, our findings indicate the association of gpx1 with a complex network of embryonic developmental pathways and ROS responses, but detailed investigation is a prerequisite in order to pinpoint the mechanistic details of these interactions.

Xenopus gpx3 Mediates Posterior Development by Regulating Cell Death during Embryogenesis.

Glutathione peroxidase 3 (GPx3) belongs to the glutathione peroxidase family of selenoproteins and is a key antioxidant enzyme in multicellular organisms against oxidative damage. Downregulation of GPx3 affects tumor progression and metastasis and is associated with liver and heart disease. However, the physiological significance of GPx3 in vertebrate embryonic development remains poorly understood. The current study aimed to investigate the functional roles of gpx3 during embryogenesis. To this end, we determined gpx3's spatiotemporal expression using Xenopus laevis as a model organism. Using reverse transcription polymerase chain reaction (RT-PCR), we demonstrated the zygotic nature of this gene. Interestingly, the expression of gpx3 enhanced during the tailbud stage of development, and whole mount in situ hybridization (WISH) analysis revealed gpx3 localization in prospective tail region of developing embryo. gpx3 knockdown using antisense morpholino oligonucleotides (MOs) resulted in short post-anal tails, and these malformed tails were significantly rescued by glutathione peroxidase mimic ebselen. The gene expression analysis indicated that gpx3 knockdown significantly altered the expression of genes associated with Wnt, Notch, and bone morphogenetic protein (BMP) signaling pathways involved in tailbud development. Moreover, RNA sequencing identified that gpx3 plays a role in regulation of cell death in the developing embryo. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and phospho-histone 3 (PH3) staining confirmed the association of gpx3 knockdown with increased cell death and decreased cell proliferation in tail region of developing embryos, establishing the involvement of gpx3 in tailbud development by regulating the cell death. Furthermore, these findings are inter-related with increased reactive oxygen species (ROS) levels in gpx3 knockdown embryos, as measured by using a redox-sensitive fluorescent probe HyPer. Taken together, our results suggest that gpx3 plays a critical role in posterior embryonic development by regulating cell death and proliferation during vertebrate embryogenesis.

Dach1 regulates neural crest migration during embryonic development.

Dachshund 1(Dach1) is a key component of the retinal determination gene network that plays significant roles in cell fate regulation. The vertebrate homolog of Drosophila dachshund has gained considerable importance as an essential regulator of development, but its functions during embryonic development remain elusive. We investigated the functional significance of dach1 during Xenopus embryogenesis using loss-of-function studies. Reverse transcription-polymerase chain reaction demonstrated the maternal nature of dach1, showing enhanced expression at the neurula stage of development, and morpholino oligonucleotide injection of dach1 induced phenotypic anomalies of microcephaly and reduced body length. Animal cap assays followed by whole-mount in-situ hybridization indicated the perturbed expression of neural and neural crest (NC) markers. Our data suggest the prerequisite functions of dach1 in NC migration during Xenopus embryogenesis. However, the developmental pathways regulated by dach1 during embryogenesis require further elucidation.

Interplay Between Mitochondrial Peroxiredoxins and ROS in Cancer Development and Progression.

Mitochondria are multifunctional cellular organelles that are major producers of reactive oxygen species (ROS) in eukaryotes; to maintain the redox balance, they are supplemented with different ROS scavengers, including mitochondrial peroxiredoxins (Prdxs). Mitochondrial Prdxs have physiological and pathological significance and are associated with the initiation and progression of various cancer types. In this review, we have focused on signaling involving ROS and mitochondrial Prdxs that is associated with cancer development and progression. An upregulated expression of Prdx3 and Prdx5 has been reported in different cancer types, such as breast, ovarian, endometrial, and lung cancers, as well as in Hodgkin's lymphoma and hepatocellular carcinoma. The expression of Prdx3 and Prdx5 in different types of malignancies involves their association with different factors, such as transcription factors, micro RNAs, tumor suppressors, response elements, and oncogenic genes. The microenvironment of mitochondrial Prdxs plays an important role in cancer development, as cancerous cells are equipped with a high level of antioxidants to overcome excessive ROS production. However, an increased production of Prdx3 and Prdx5 is associated with the development of chemoresistance in certain types of cancers and it leads to further complications in cancer treatment. Understanding the interplay between mitochondrial Prdxs and ROS in carcinogenesis can be useful in the development of anticancer drugs with better proficiency and decreased resistance. However, more targeted studies are required for exploring the tumor microenvironment in association with mitochondrial Prdxs to improve the existing cancer therapies and drug development.

Comparative Analysis of the Developmental Toxicity in Xenopus laevis and Danio rerio Induced by Al2 O3 Nanoparticle Exposure.

Engineered aluminum oxide nanoparticles (Al2 O3 NPs) having high-grade thermal stability and water-dispersion properties are extensively used in different industries and personal care products. Toxicological response evaluation of these NPs is indispensable in assessing the health risks and exposure limits because of their industrial disposal into the aquatic environment. We assessed and compared the developmental toxicity of Al2 O3 NPs in Xenopus laevis and Danio rerio over a period of 96 h using the frog embryo teratogenic assay Xenopus and a fish embryo toxicity assay. Engineered Al2 O3 NP exposure produced dose-dependent embryonic mortality and decreased the embryo length, indicating a negative effect on growth. Moreover, Al2 O3 NPs induced various malformations, such as small head size, a bent/deformed axis, edema, and gut malformation, dose-dependently and altered the expression of heart- and liver-specific genes in both X. laevis and D. rerio, as revealed by whole-mount in-situ hybridization and reverse transcriptase polymerase chain reaction. In conclusion, the toxicological data suggest that Al2 O3 NPs are developmentally toxic and teratogenic and negatively affect the embryonic development of X. laevis and D. rerio. Our study can serve as a model for the toxicological evaluation of nanomaterial exposure on vertebrate development that is critical to ensure human and environmental safety. Environ Toxicol Chem 2019;38:2672-2681. © 2019 SETAC.

Peroxiredoxin5 Controls Vertebrate Ciliogenesis by Modulating Mitochondrial Reactive Oxygen Species.

AIMS: Peroxiredoxin5 (Prdx5), a thioredoxin peroxidase, is an antioxidant enzyme that is widely studied for its antioxidant properties and protective roles in neurological and cardiovascular disorders. This study is aimed at investigating the functional significance of Prdx5 in mitochondria and at analyzing its roles in ciliogenesis during the process of vertebrate development. RESULTS: We found that several Prdx genes were strongly expressed in multiciliated cells in developing Xenopus embryos, and their peroxidatic functions were crucial for normal cilia development. Depletion of Prdx5 increased levels of cellular reactive oxygen species (ROS), consequently leading to mitochondrial dysfunction and abnormal cilia formation. Proteomic and transcriptomic approaches revealed that excessive ROS accumulation on Prdx5 depletion subsequently reduced the expression level of pyruvate kinase (PK), a key metabolic enzyme in energy production. We further confirmed that the promotor activity of PK was significantly reduced on Prdx5 depletion and that the reduction in PK expression and its promoter activity led to ciliary defects observed in Prdx5-depleted cells. INNOVATION: Our data revealed the novel relationship between ROS and Prdx5 and the consequent effects of this interaction on vertebrate ciliogenesis. The normal process of ciliogenesis is interrupted by the Prdx5 depletion, resulting in excessive ROS levels and suggesting cilia as vulnerable targets of ROS. CONCLUSION: Prdx5 plays protective roles in mitochondria and is critical for normal cilia development by regulating the levels of ROS. The loss of Prdx5 is associated with excessive production of ROS, resulting in mitochondrial dysfunction and aberrant ciliogenesis.

Lysine demethylase 3a in craniofacial and neural development during Xenopus embryogenesis.

Epigenetic modifier lysine demethylase 3a (Kdm3a) specifically demethylates mono­ and di­methylated ninth lysine of histone 3 and belongs to the Jumonji domain­containing group of demethylases. Kdm3a serves roles during various biological and pathophysiological processes, including spermatogenesis and metabolism, determination of sex, androgen receptor­mediated transcription and embryonic carcinoma cell differentiation. In the present study, physiological functions of Kdm3a were evaluated during embryogenesis of Xenopus laevis. Spatiotemporal expression pattern indicated that kdm3a exhibited its expression from early embryonic stages until tadpole stage, however considerable increase of kdm3a expression was observed during the neurula stage of Xenopus development. Depleting kdm3a using kdm3a antisense morpholino oligonucleotides induced anomalies, including head deformities, small­sized eyes and abnormal pigmentation. Whole­mount in situ hybridization results demonstrated that kdm3a knockdown was associated with defects in neural crest migration. Further, quantitative polymerase chain reaction revealed abnormal expression of neural markers in kdm3a morphants. RNA sequencing of kdm3a morphants indicated that kdm3a was implicated in mesoderm formation, cell adhesion and metabolic processes of embryonic development. In conclusion, the results of the present study indicated that Kdm3a may serve a role in neural development during Xenopus embryogenesis and may be targeted for treatment of developmental disorders. Further investigation is required to elucidate the molecular mechanism underlying the regulation of neural development by Kdm3a.

Physiological effects of KDM5C on neural crest migration and eye formation during vertebrate development.

BACKGROUND: Lysine-specific histone demethylase 5C (KDM5C) belongs to the jumonji family of demethylases and is specific for the di- and tri-demethylation of lysine 4 residues on histone 3 (H3K4 me2/3). KDM5C is expressed in the brain and skeletal muscles of humans and is associated with various biologically significant processes. KDM5C is known to be associated with X-linked mental retardation and is also involved in the development of cancer. However, the developmental significance of KDM5C has not been explored yet. In the present study, we investigated the physiological roles of KDM5C during Xenopus laevis embryonic development. RESULTS: Loss-of-function analysis using kdm5c antisense morpholino oligonucleotides indicated that kdm5c knockdown led to small-sized heads, reduced cartilage size, and malformed eyes (i.e., small-sized and deformed eyes). Molecular analyses of KDM5C functional roles using whole-mount in situ hybridization, ß-galactosidase staining, and reverse transcription-polymerase chain reaction revealed that loss of kdm5c resulted in reduced expression levels of neural crest specifiers and genes involved in eye development. Furthermore, transcriptome analysis indicated the significance of KDM5C in morphogenesis and organogenesis. CONCLUSION: Our findings indicated that KDM5C is associated with embryonic development and provided additional information regarding the complex and dynamic gene network that regulates neural crest formation and eye development. This study emphasizes the functional significance of KDM5C in Xenopus embryogenesis; however, further analysis is needed to explore the interactions of KDM5C with specific developmental genes.

KDM1A microenvironment, its oncogenic potential, and therapeutic significance.

The lysine-specific histone demethylase 1A (KDM1A) was the first demethylase to challenge the concept of the irreversible nature of methylation marks. KDM1A, containing a flavin adenine dinucleotide (FAD)-dependent amine oxidase domain, demethylates histone 3 lysine 4 and histone 3 lysine 9 (H3K4me1/2 and H3K9me1/2). It has emerged as an epigenetic developmental regulator and was shown to be involved in carcinogenesis. The functional diversity of KDM1A originates from its complex structure and interactions with transcription factors, promoters, enhancers, oncoproteins, and tumor-associated genes (tumor suppressors and activators). In this review, we discuss the microenvironment of KDM1A in cancer progression that enables this protein to activate or repress target gene expression, thus making it an important epigenetic modifier that regulates the growth and differentiation potential of cells. A detailed analysis of the mechanisms underlying the interactions between KDM1A and the associated complexes will help to improve our understanding of epigenetic regulation, which may enable the discovery of more effective anticancer drugs.

Peroxiredoxin1, a novel regulator of pronephros development, influences retinoic acid and Wnt signaling by controlling ROS levels.

Peroxiredoxin1 (Prdx1) is an antioxidant enzyme belonging to the peroxiredoxin family of proteins. Prdx1 catalyzes the reduction of H2O2 and alkyl hydroperoxide and plays an important role in different biological processes. Prdx1 also participates in various age-related diseases and cancers. In this study, we investigated the role of Prdx1 in pronephros development during embryogenesis. Prdx1 knockdown markedly inhibited proximal tubule formation in the pronephros and significantly increased the cellular levels of reactive oxygen species (ROS), which impaired primary cilia formation. Additionally, treatment with ROS (H2O2) severely disrupted proximal tubule formation, whereas Prdx1 overexpression reversed the ROS-mediated inhibition in proximal tubule formation. Epistatic analysis revealed that Prdx1 has a crucial role in retinoic acid and Wnt signaling pathways during pronephrogenesis. In conclusion, Prdx1 facilitates proximal tubule formation during pronephrogenesis by regulating ROS levels.

NSrp70 is significant for embryonic growth and development, being a crucial factor for gastrulation and mesoderm induction.

NSrp70 (nuclear speckle-related protein 70), a recently discovered protein and it belongs to the serine/arginine (SR) rich related protein family. NSrp70 is recognized as an important splicing factor comprising RNA recognition motif (RRM) and arginine/serine (RS)-like regions at the N- and C-terminus respectively, along with two coiled coil domains at each terminus. However, other functions of NSrp70 remain unelucidated. In this study, we investigated the role of NSrp70 in Xenopus embryogenesis and found that its maternal expression plays a critical role in embryonic development. Knockdown of NSrp70 resulted in dramatic reduction in the length of developing tadpoles and mild to severe malformation in Xenopus embryos. In addition, knockdown of NSrp70 resulted in an extremely short axis by blocking gastrulation and convergent extension. Further, animal cap assays along with activin A treatment revealed that NSrp70 is an essential factor for dorsal mesoderm induction as knockdown of NSrp70 caused a dramatic down-regulation of dorsal mesoderm specific genes and its loss significantly shortened the elongation region of animal caps. In conclusion, NSrp70 is crucial for early embryonic development, influencing gastrulation and mesoderm induction.

The splicing factor SRSF1 modulates pattern formation by inhibiting transcription of tissue specific genes during embryogenesis.

Alternative splicing is a major mechanism regulating pattern of gene expression through the production of multiple mRNAs from a single gene transcript. Any misregulation can cause various human diseases and also have severe effects on embryogenesis. SRSF1 is one of the critical factors regulating alternative splicing at many stages of vertebrate development and any disturbance in SRSF1 leads to serious consequences. In current study, we investigated the effects of loss of the SRSF1 gene using antisense morpholino oligonucleotides (MO) in Xenopus embryogenesis. It is evident from the results of RT-PCR and whole-mount in situ hybridization that SRSF1 is a maternal gene having strong expression in head, eyes and central nervous system. Moreover, SRSF1 morphants exhibited malformed phenotypes, including miscoiled guts, heart and cartilage formation, edema in the head and heart, and small eyes. Especially, in SRSF1 morphants, bone cartilage formation was reduced in the brain and Nkx-2.5 expression was dramatically reduced in the heart of SRSF1 morphants. In addition, a dramatic reduction in functional chordin RNA in SRSF1 morphants was observed suggesting that chordin is one of the targets of SRSF1. Thus, we concluded that SRSF1 is an essential factor for pattern formation including heart, cartilage and germ layers through the regulation of specific genes.

IFT46 plays crucial roles in craniofacial and cilia development.

The intraflagellar transport (IFT) system is essential for bidirectional movement of ciliary components from the basal body to the tip beneath the ciliary sheath and is conserved for cilia and flagella formation in most vertebrates. IFT complex A is involved in anterograde trafficking, whereas complex B is involved in retrograde trafficking. IFT46 is well known as a crucial component of IFT complex B, however, its developmental functions are poorly understood. In this study, we investigated the novel functions of IFT46 during vertebrate development, especially, ciliogenesis and neurogenesis, because IFT46 is strongly expressed in both multiciliated cells of epithelial and neural tissues. Knockdown of IFT46 using morpholino microinjections caused shortening of the body axis as well as the formation of fewer and shorter cilia. Furthermore, loss of IFT46 down-regulated the expression of the neural plate and neural tube markers, thus may influence Wnt/planar cell polarity and the sonic hedgehog signaling pathway during neurogenesis. In addition, loss of IFT46 caused craniofacial defects by interfering with cartilage formation. In conclusion, our results depict that IFT46 plays important roles in cilia as well as in neural and craniofacial development.

New lipoxygenase and cholinesterase inhibitory sphingolipids from Carthamus oxyacantha.

Two new sphingolipids: oxyacanthin A [(2S,3S,4R)-2-{[(2R,5E)-2-hydroxyoctadec-5-enoyl]amino}hexaeicosane-1,3,4-triol; 1] and B [(2S,3S,4R)-2-{[(2R,5E)-2-hydroxyoctadec-5-enoyl]amino}hexaeicosane-1,3,4-triol-1-O-ß-D-glucopyranoside; 2], together with 1-octacosanol, ß-sitosterol, ß-sitosterol 3-O-ß-D-glucopyranoside and luteolin 7-O-ß-glucopyranoside were isolated from the methanolic extract of the whole plant of Carthamus oxyacantha. Their structures were elucidated using (1)H and (13)C NMR spectra and 2D NMR analyses (HMQC, HMBC and COSY) in combination with mass spectrometry (EI-MS, HR-EI-MS, FAB-MS and HR-FAB-MS) experiments and in comparison with the literature data of the related compounds. Both the compounds 1 and 2 showed inhibitory potential against lipoxygenase (LOX) in a concentration-dependent manner with IC50 values 83.3 ± 1.3 and 245.7 ± 1.1 µM, whereas compound 2 showed inhibition against enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values 65.3 ± 0.1 and 93.6 ± 0.1 µM, respectively.

Synthesis, biological screening and molecular docking studies of some ethylated sulfonamides having 1,4-Benzodioxane moiety.

The presented study comprises the synthesis of a new series of ethylated sulfonamides in which 1,4-benzodioxane moiety has been incorporated. The reaction of 1,4-benzodioxane-6-amine (1) with ethane sulfonyl chloride (2) yielded N-(2,3-dihydrobenzo[1,4]dioxin-6-yl)ethanesulfonamide (3), which further on treatment with various alkyl/aralkyl halides, 4a-r, in N,Nꞌ-dimethylformamide (DMF) and in the presence of lithium hydride (LiH) acting as a weak base and catalyst; yielded derivatives of N-alkyl/aralkyl substituted N-(2,3-dihydrobenzo[1,4]dioxin-6-yl)ethanesulfonamides (5a-r). The characterization of these derivatives was carried out by different spectroscopic techniques like infra red, proton-NMR and mass spectrometry; then screened against various enzymes i.e. acetylcholinesterase, butyrylcholinesterase, lipoxygenase and α-glucosidase enzymes and five different bacterial strains. The synthesized compounds were found to be good inhibitors of lipoxygenase but moderate inhibitors of AChE, BChE and α-glucosidase; whereas compounds 3, 5a, 5f, 5n and 5r were found good antibacterial compounds. The interaction between inhibitors and target enzymes (cholinestrases and lipoxygenase) was computationally observed which correlated with the experimental results.

Synthesis of novel triazoles and a tetrazole of escitalopram as cholinesterase inhibitors.

A novel serie of escitalopram triazoles (60-88) and a tetrazole (89) have been synthesized and subjected to a study to establish the inhibitory potential of these compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Some selectivity in inhibition has been observed. The 4-chlorophenyl- (75, IC50, 6.71 ± 0.25 µM) and 2-methylphenyl- (70, IC50, 9.52 ± 0.23 µM) escitalopram triazole derivatives depicted high AChE inhibition, while 2-fluorophenyl- (76, IC50 = 4.52 ± 0.17 µM) and 4-fluorophenyl- (78, IC50 = 5.31 ± 0.43 µM) have found to be excellent BChE inhibitors. It has also been observed that ortho, meta and para substituted electron donating groups increase the inhibition, while electron withdrawing groups reduce the inhibition. Docking analyses of inhibitors with AChE have depicted the binding energies for 70 and 75 as ΔG(bind) -6.42 and -6.93 kcal/mol, respectively, while ligands 76 and 78 have shown the binding affinity ΔG(bind) -9.04 and -8.51 kcal/mol, respectively, for BChE.

Design and Synthesis of New Dual Binding Site Cholinesterase Inhibitors: in vitro Inhibition Studies with in silico Docking.

Cholinesterases (ChEs) play a vital role in the regulation of cholinergic transmission. The inhibition of ChEs is considered to be involved in increasing acetylcholine level in the brain and thus has been implicated in the treatment of Alzheimer's disease. We have designed and synthesized a series of novel indole derivatives and screened them for inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Most of the tested compounds exhibited inhibitory activity against AChE and BChE. Among them 4f and 6e showed the highest AChE inhibitory activity with IC50 91.21±0.06 and 68.52±0.04 µM, respectively. However compound 5a exhibited the highest inhibitory activity against BChE (IC50 55.21±0.12 µM).