A multidisciplinary approach to the antioxidant and hepatoprotective activities of Arbutus pavarii Pampan fruit; in vitro and in Vivo biological evaluations, and in silico investigations

The Libyan Strawberry, Arbutus pavarii Pampan (ARB), is an endemic Jebel Akhdar plant used for traditional medicine. This study presents the antioxidant and hepatoprotective properties of ARB fruit-extract. ARB phytochemical analysis indicated the presence of 354.54 GAE and 36.2 RE of the phenolics and flavonoids. LC-MS analysis identified 35 compounds belonging to phenolic acids, procyanidins, and flavonoid glycosides. Gallic acid, procyanidin dimer B3, β-type procyanidin trimer C, and quercetin-3-O-glucoside were the major constituents of the plant extract. ARB administration to paracetamol (PAR)-intoxicated rats reduced serum ALT, AST, bilirubin, hepatic tissue MDA and proinflammatory markers; TNF-α and IL-6 with an increase in tissue GSH level and SOD activity. Histological and immunohistochemical studies revealed that ARB restored the liver histology and significantly reduced the tissue expression of caspase 3, IL-1B, and NF-KB in PAR-induced liver damage. Docking analysis disclosed good binding affinities of some compounds with XO, COX-1, 5-LOX, and PI3K.

Comparative metabolic study of the chloroform fraction of three Cystoseira species based on UPLC/ESI/MS analysis and biological activities

This study aims to investigate the phytoconstituents of the chloroform fraction of three Cystoseira spp. namely C. myrica, C. trinodis, and C. tamariscifolia using UPLC/ESI/MS technique. The results revealed the identification of 19, 20 and 11 metabolites in C. myrica, C. trinodis, and C. tamariscifolia, respectively mainly terpenoids, flavonoids, phenolic acids and fatty acids. Also, an in vitro antioxidant study using FRAP and DPPH assays was conducted where the chloroform fraction of C. trinodis displayed the highest antioxidant activity in both assays, which would be attributed to its highest total phenolics and total flavonoids. Besides, the investigation of COX-1, α-glucosidase and α-amylase inhibitory activities were performed. Regarding C. trinodis, it showed the strongest inhibitory activity towards COX-1. Moreover, it showed potent inhibitory activity towards α-glucosidase and α-amylase enzymes. According to the molecular docking studies, the major compounds characterised showed efficient binding to the active sites of the target enzymes.

DFT and molecular simulation validation of the binding activity of PDEδ inhibitors for repression of oncogenic k-Ras

The development of effective drugs targeting the K-Ras oncogene product is a significant focus in anticancer drug development. Despite the lack of successful Ras signaling inhibitors, recent research has identified PDEδ, a KRAS transporter, as a potential target for inhibiting the oncogenic KRAS signaling pathway. This study aims to investigate the interactions between eight K-Ras inhibitors (deltarazine, deltaflexin 1 and 2, and its analogues) and PDEδ to understand their binding modes. The research will utilize computational techniques such as density functional theory (DFT) and molecular electrostatic surface potential (MESP), molecular docking, binding site analyses, molecular dynamic (MD) simulations, electronic structure computations, and predictions of the binding free energy. Molecular dynamic simulations (MD) will be used to predict the binding conformations and pharmacophoric features in the active site of PDEδ for the examined structures. The binding free energies determined using the MMPB(GB)SA method will be compared with the observed potency values of the tested compounds. This computational approach aims to enhance understanding of the PDEδ selective mechanism, which could contribute to the development of novel selective inhibitors for K-Ras signaling.

Phthalimide-tethered isatins as novel poly(ADP-ribose) polymerase inhibitors: Design, synthesis, biological evaluations, and molecular modeling investigations

Humanity is currently facing various diseases with significant mortality rates, particularly those associated with malignancies. Numerous enzymes and proteins have been identified as highly promising targets for the treatment of cancer. The poly(ADP-ribose) polymerases (PARPs) family comprises 17 members which are essential in DNA damage repair, allowing the survival of cancer cells. Unlike other PARP family members, PARP-1 and, to a lesser extent, PARP-2 show more than 90% activity in response to DNA damage. PARP-1 levels were shown to be elevated in various tumor cells, including breast, lung, ovarian, and prostate cancer and melanomas. Accordingly, novel series of phthalimide-tethered isatins (6a-n, 10a-e, and 11a-e) were synthesized as potential PARP-1 inhibitors endowed with anticancer activity. All the synthesized molecules were assessed against PARP-1, where compounds 6f and 10d showed nanomolar activities with IC50  = 15.56 ± 2.85 and 13.65 ± 1.42 nM, respectively. Also, the assessment of the antiproliferative effects of the synthesized isatins was conducted on four cancer cell lines: leukemia (K-562), liver (HepG2), and breast (MCF-7 and HCC1937) cancers. Superiorly, compounds 6f and 10d demonstrated submicromolar IC50 values against breast cancer MCF-7 (IC50  = 0.92 ± 0.18 and 0.67 ± 0.12 µM, respectively) and HCC1937 (IC50  = 0.88 ± 0.52 and 0.53 ± 0.11 µM, respectively) cell lines. In addition, compounds 6f and 10d induced arrest in the G2/M phase of the cell cycle as compared to untreated cells. Finally, in silico studies, including docking and molecular dynamic simulations, were performed to justify the biological results.

Novel indolinone-tethered benzothiophenes as anti-tubercular agents against MDR/XDR M. tuberculosis: Design, synthesis, biological evaluation and in vivo pharmacokinetic study

Joining the global effort to eradicate tuberculosis, one of the deadliest infectious killers in the world, we disclose in this paper the design and synthesis of new indolinone-tethered benzothiophene hybrids 6a-i and 7a-i as potential anti-tubercular agents. The MICs were determined in vitro for the synthesized compounds against the sensitive M. tuberculosis strain ATCC 25177. Potent compounds 6b, 6d, 6f, 6h, 7a, 7b, 7d, 7f, 7h and 7i were furtherly assessed versus resistant MDR-TB and XDR-TB. Structure activity relationship investigation of the synthesized compounds was illustrated, accordingly. Superlative potency was unveiled for compound 6h (MIC = 0.48, 1.95 and 7.81 µg/mL for ATCC 25177 sensitive TB strain, resistant MDR-TB and XDR-TB, respectively). Moreover, validated in vivo pharmacokinetic study was performed for the most potent derivative 6h revealing superior pharmacokinetic profile over the reference drug. For further exploration of the anti-tubercular mechanism of action, molecular docking was carried out for the former compound in DprE1 active site as one of the important biological targets of TB. The binding mode and the docking score uncovered exceptional binding when compared to the co-crystallized ligand suggesting that it maybe the underlying target for its outstanding anti-tubercular potency.

Identification of sulphonamide-tethered N-((triazol-4-yl)methyl)isatin derivatives as inhibitors of SARS-CoV-2 main protease

SARS-CoV-2 pandemic in the end of 2019 led to profound consequences on global health and economy. Till producing successful vaccination strategies, the healthcare sectors suffered from the lack of effective therapeutic agents that could control the spread of infection. Thus, academia and the pharmaceutical sector prioritise SARS-CoV-2 antiviral drug discovery. Here, we exploited previous reports highlighting the anti-SARS-CoV-2 activities of isatin-based molecules to develop novel triazolo-isatins for inhibiting main protease (Mpro) of the virus, a crucial enzyme for its replication in the host cells. Particularly, sulphonamide 6b showed promising inhibitory activity with an IC50= 0.249 µM. Additionally, 6b inhibited viral cell proliferation with an IC50 of 4.33 µg/ml, and was non-toxic to VERO-E6 cells (CC50 = 564.74 µg/ml) displaying a selectivity index of 130.4. In silico analysis of 6b disclosed its ability to interact with key residues in the enzyme active site, supporting the obtained in vitro findings.

Discovery of pyrimidine-tethered benzothiazole derivatives as novel anti-tubercular agents towards multi- and extensively drug resistant Mycobacterium tuberculosis

In this study, new benzothiazole-pyrimidine hybrids (5a-c, 6, 7a-f, and 8-15) were designed and synthesised. Two different functionalities on the pyrimidine moiety of lead compound 4 were subjected to a variety of chemical changes with the goal of creating various functionalities and cyclisation to further elucidate the target structures. The potency of the new molecules was tested against different tuberculosis (TB) strains. The results indicated that compounds 5c, 5b, 12, and 15 (MIC = 0.24-0.98 µg/mL) are highly active against the first-line drug-sensitive strain of Mycobacterium tuberculosis (ATCC 25177). Thereafter, the anti-tubercular activity was evaluated against the two drug-resistant TB strains; ATCC 35822 and RCMB 2674, where, many compounds exhibited good activity with MIC = 0.98-62.5 3 µg/mL and 3.9-62.5 µg/mL, respectively. Compounds 5c and 15 having the highest anti-tubercular efficiency towards sensitive strain, displayed the best activity for the resistant strains by showing the MIC = 0.98 and 1.95 µg/mL for MDR TB, and showing the MIC = 3.9 and 7.81 µg/mL for XDR TB, consecutively. Finally, molecular docking studies were performed for the two most active compounds 5c and 15 to explore their enzymatic inhibitory activities.

Metabolomic profile, anti-trypanosomal potential and molecular docking studies of Thunbergia grandifolia

Trypanosomiasis is a protozoan disease transmitted via Trypanosoma brucei. This study aimed to examine the metabolic profile and anti-trypanosomal effect of methanol extract of Thunbergia grandifolia leaves. The liquid chromatography-high resolution electrospray ionisation mass spectrometry (LC-HRESIMS) revealed the identification of fifteen compounds of iridoid, flavonoid, lignan, phenolic acid, and alkaloid classes. The extract displayed a promising inhibitory activity against T. brucei TC 221 with MIC value of 1.90 μg/mL within 72 h. A subsequent in silico analysis of the dereplicated compounds (i.e. inverse docking, molecular dynamic simulation, and absolute binding free energy) suggested both rhodesain and farnesyl diphosphate synthase as probable targets for two compounds among those dereplicated ones in the plant extract (i.e. diphyllin and avacennone B). The absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling of diphyllin and avacennone were calculated accordingly, where both compounds showed acceptable drug-like properties. This study highlighted the antiparasitic potential of T. grandifolia leaves.

Chemical composition, seasonal variation and antiaging activities of essential oil from Callistemon subulatus leaves growing in Egypt

Callistemon is an aromatic genus of flowering plants belonging to family Myrtaceae. The essential oils of C. subulatus leaves were collected in four seasons and analyzed using GC/MS. The oils demonstrated monoterpenes as the predominant class. Eucalyptol was the main component in all seasons; summer (66.87%), autumn (58.33%), winter (46.74%) and spring (44.63%), followed by α-pinene; spring (31.41%), winter (28.69%), summer (26.34%) and autumn (24.68%). Winter oil, the highest yield (0.53 mL/100g), was further investigated for its inhibitory activity against enzymes associated with ageing; elastase and acetylcholinesterase. It remarkably inhibited elastase and acetylcholinesterase with IC₅₀ values of 1.05 and 0.20 µg/ml, respectively. A molecular docking study was conducted for the major oil components on the active sites of target enzymes. Eucalyptol revealed the best binding affinity for both enzymes. C. subualtus oil could be used as supplement for management of ageing disorders like skin wrinkles and dementia.

Novel N-Arylmethyl-aniline/chalcone hybrids as potential VEGFR inhibitors: synthesis, biological evaluations, and molecular dynamic simulations

Significant advancements have been made in the domain of targeted anticancer therapy for the management of malignancies in recent times. VEGFR-2 is characterised by its pivotal involvement in angiogenesis and subsequent mechanisms that promote tumour cells survival. Herein, novel N-arylmethyl-aniline/chalcone hybrids 5a-5n were designed and synthesised as potential anticancer and VEGFR-2 inhibitors. The anticancer activity was evaluated at the NCI-USA, resulting in the identification of 10 remarkably potent molecules 5a-5j that were further subjected to the five-dose assays. Thereafter, they were explored for their VEGFR-2 inhibitory activity where 5e and 5h emerged as the most potent inhibitors. 5e and 5h induced apoptosis with cell cycle arrest at the SubG0-G1 phase within HCT-116 cells. Moreover, their impact on some key apoptotic genes was assessed, suggesting caspase-dependent apoptosis. Furthermore, molecular docking and molecular dynamics simulations were conducted to explore the binding modes and stability of the protein-ligand complexes.

Berberine loaded thermosensitive lipid nanoparticles: in vitro characterization, in silico study, and in vivo anti-arthritic effect

Thermoresponsive drug delivery systems have been used to treat diseases that cause hyperthermia or elevated body tissue temperatures, viz., rheumatoid arthritis and different cancers. The aim of the study was to enhance berberine (BER) release using thermosensitive nanostructured lipid carriers (TNLCs) through intra-articular administration for the management of arthritis. TNLCs were prepared using binary mixtures of stearic acid and decanoic acid as solid and liquid lipids, respectively. Lipid mixtures with an optimum melting point were assessed using differential scanning calorimetry studies. In vitro characterization of the BER TNLCs included particle size, zeta potential, entrapment efficiency, and drug release at 37 °C and 41 °C. Joint diameter measurement, real-time polymerase chain reaction (RT-PC) analysis, enzyme-linked immunosorbent assay (ELISA) for inflammatory markers, and histological evaluation of the dissected joints were all performed in vivo on rats with adjuvant-induced arthritis. In vitro characterization revealed negatively charged BER-loaded TNLCs with a spherical shape, particle size less than 500 nm, BER entrapment efficiency up to 79%, and a high drug release rate at an elevated temperature of 41 °C. In silico studies revealed the affinity of BER to different formula components and to the measured biomarkers. In vivo assessment of the optimum TNLCs showed that BER TNLCs were superior to the BER solution suspension regarding their effect on inflammatory biomarkers, joint diameter, and histological studies.

Rumex vesicarius L. boosts the effectiveness of sorafenib in triple-negative breast cancer by downregulating BCl2, mTOR, and JNK, and upregulating p21 expression

BACKGROUND/AIM

Triple-negative breast cancer (TNBC) is characterized by poor prognosis, rapid progression, serious clinical behavior, an elevated risk of metastasis, and resistance to standard treatments. Traditional medicine practitioners value Rumex vesicarius L. (RMV) for a variety of reasons, including the plant's antioxidant capabilities. Our study's goals were to ascertain the efficacy of RMV alone and in combination with sorafenib (SOR) against the aggressive TNBC cell line (MDA-MB-231) and use in vitro and in silico analysis to deduce the fundamental mechanism of action.

METHODS

In the current study, molecular operating environment (MOE, 2019.0102) software was used for performing molecular docking. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to determine the cytotoxicity of RMV, SOR or RMV/SOR combination against the TNBC cell line MDA-MB-231 cells. The effects of RMV, SOR, and RMV and SOR combining on mRNAs expressions of the target genes including mTOR, p21, JNK, and BCl2 were evaluated. In TNBC cells, the relative expressions of mRNAs of the genes were examined by using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

In our experiments, we discovered that both RMV extracts alone and in combination with SOR considerably reduced cancer cell proliferation (IC50 = 0.83 and 0.19 μM, respectively). Additionally, the expression of the tumor suppressor gene p21 was elevated whereas the expression of the invasion and anti-apoptosis genes BCl2, mTOR, and JNK were significantly decreased after treatment with RMV and SOR. Based on in silico analysis, it was found that RMV extract contains bioactive chemicals with a high affinity for inhibiting JNK and VEGFR-2.

CONCLUSION

In conclusion, in vitro and in silico investigations show that the RMV extract improves the anticancer efficiency of SOR through molecular processes involving the downregulation of mTOR, BCl2, and JNK1 and overexpression of p21 tumor suppressor gene. Finally, we suggest conducting additional in vivo investigations on RMV and its bioactive components to verify their potential in cancer therapy.

Novel hydrazone-isatin derivatives as potential EGFR inhibitors: Synthesis and in vitro pharmacological profiling

Merging isatin and arylhydrazone moieties constitutes an efficient strategy to access new potential anticancer derivatives. Consequently, 14 hydrazone-isatin derivatives were synthesized and evaluated for their antiproliferative activity against the NCI-60 cancer cell line panel. A kinase assay demonstrated that compound VIIIb inhibited the epidermal growth factor receptor (EGFR), which was confirmed by docking studies, molecular dynamics, and binding free energy calculations. Further characterizations showed that this compound possesses drug-likeness properties, showed a significant decrease of the cell population in the G2/M phase and led to a significant increase in early and late apoptosis, comparable to erlotinib. Also, VIIIb increased the expression of caspase-3 and Bax and decreased the expression of Bcl-2, confirming its potential as a new proapoptotic compound.

The Potential Roles of Ficus carica Extract in the Management of COVID-19 Viral Infections: A Computer-Aided Drug Design Study

INTRODUCTION

The conventional processes of drug discovery are too expensive, time-consuming and the success rate is limited. Searching for alternatives that have evident safety and potential efficacy could save money, time and improve the current therapeutic regimen outcomes.

METHOD

Clinical phytotherapy implies the use of extracts of natural origin for prophylaxis, treatment, or management of human disorders. In this work, the potential role of common Fig (Ficus carica) in the management of COVID-19 infections has been explored. The antiviral effects of Cyanidin-3-rhamnoglucoside which is abundant in common Figs have been illustrated on COVID-19 targets. The immunomodulatory effect and the ability to ameliorate the cytokine storm associated with coronavirus infections have also been highlighted. This work involves various computational studies to investigate the potential roles of common figs in the management of COVID-19 viral infections.

RESULTS

Two molecular docking studies of all active ingredients in common Figs were conducted starting with MOE to provide initial insights, followed by Autodock Vina for further confirmation of the results of the top five compounds with the best docking score.

CONCLUSION

Finally, Molecular dynamic simulation alongside MMPBSA calculations were conducted using GROMACS to endorse and validate the entire work.

Synergistic antiviral activity of Lactobacillus acidophilus and Glycyrrhiza glabra against Herpes Simplex-1 Virus (HSV-1) and Vesicular Stomatitis Virus (VSV): experimental and In Silico insights

BACKGROUND

The emergence of different viral infections calls for the development of new, effective, and safe antiviral drugs. Glycyrrhiza glabra is a well-known herbal remedy possessing antiviral properties.

OBJECTIVE

The objective of our research was to evaluate the effectiveness of a newly developed combination of the probiotics Lactobacillus acidophilus and G. glabra root extract against two viral models, namely the DNA virus Herpes simplex virus-1 (HSV-1) and the RNA virus Vesicular Stomatitis Virus (VSV), with regards to their antiviral properties.

METHODOLOGY

To examine the antiviral impacts of various treatments, we employed the MTT assay and real-time PCR methodology.

RESULTS

The findings of our study indicate that the co-administration of L. acidophilus and G. glabra resulted in a significant improvement in the survival rate of Vero cells, while also leading to a reduction in the titers of Herpes Simplex Virus Type 1 (HSV-1) and Vesicular Stomatitis Virus (VSV) in comparison to cells that were not treated. Additionally, an investigation was conducted on glycyrrhizin, the primary constituent of G. glabra extract, utilizing molecular docking techniques. The results indicated that glycyrrhizin exhibited a greater binding energy score for HSV-1 polymerase (- 22.45 kcal/mol) and VSV nucleocapsid (- 19.77 kcal/mol) in comparison to the cocrystallized ligand (- 13.31 and - 11.44 kcal/mol, respectively).

CONCLUSIONS

The combination of L. acidophilus and G. glabra extract can be used to develop a new, natural antiviral agent that is safe and effective.

Morphologic Design of Nanogold Carriers for a Carbonic Anhydrase Inhibitor: Effect on Ocular Retention and Intraocular Pressure

Morphologic design of nanomaterials for a diversity of biomedical applications is of increasing interest. The aim of the current study is to construct therapeutic gold nanoparticles of different morphologies and investigate their effect on ocular retention and intraocular pressure in a glaucoma rabbit model. Poly(lactic-co-glycolic acid) (PLGA)-coated nanorods and nanospheres have been synthesized and loaded with carbonic anhydrase inhibitor (CAI), and characterized in vitro for their size, zeta potential and encapsulation efficiency. Nanosized PLGA-coated gold nanoparticles of both morphologies demonstrated high entrapment efficiency (˃ 98%) for the synthesized CAI and the encapsulation of the drug into the developed nanoparticles was confirmed via Fourier transform-infrared spectroscopy. In vivo studies revealed a significant reduction in intraocular pressure upon instillation of drug-loaded nanogold formulations compared to the marketed eye drops. Spherical nanogolds exhibited a superior efficacy compared to the rod-shaped counterparts, probably due to the enhanced ocular retention of spherical nanogolds within collagen fibers of the stroma, as illustrated by transmission electron microscopy imaging. Normal histological appearance was observed for the cornea and retina of the eyes treated with spherical drug-loaded nanogolds. Hence, incorporation of a molecularly-designed CAI into nanogold of tailored morphology may provide a promising strategy for management of glaucoma.

Insights into targeting SARS-CoV-2: design, synthesis, in silico studies and antiviral evaluation of new dimethylxanthine derivatives

Aiming to achieve efficient activity against severe acute respiratory syndrome coronavirus (SARS-CoV-2), the expansion of the structure- and ligand-based drug design approaches was adopted, which has been recently reported by our research group. Purine ring is a corner stone in the development of SARS-CoV-2 main protease (Mpro) inhibitors. The privileged purine scaffold was elaborated to achieve additional affinity based on hybridization and fragment-based approaches. Thus, the characteristic pharmacophoric features that are required for the inhibition of Mpro and RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 were utilized along with the crystal structure information of both targets. The designed pathways involved rationalized hybridization with large sulfonamide moieties and a carboxamide fragment for the synthesis of ten new dimethylxanthine derivatives. The synthesis was performed under diverse conditions to afford N-alkylated xanthine derivatives, and cyclization afforded tricyclic compounds. Molecular modeling simulations were used to confirm and gain insights into the binding interactions at both targets' active sites. The merit of designed compounds and the in silico studies resulted in the selection of three compounds that were evaluated in vitro to estimate their antiviral activity against SARS-CoV-2 (compounds 5, 9a and 19 with IC50 values of 38.39, 8.86 and 16.01 μM, respectively). Furthermore, oral toxicity of the selected antiviral candidates was predicted, in addition to cytotoxicity investigations. Compound 9a showed IC50 values of 8.06 and 3.22 μM against Mpro and RdRp of SARS-CoV-2, respectively, in addition to promising molecular dynamics stability in both target active sites. The current findings encourage further specificity evaluations of the promising compounds for confirming their specific protein targeting.

Immunomodulatory, apoptotic and anti-proliferative potentials of sildenafil in Ehrlich ascites carcinoma murine model: In vivo and in silico insights

Sildenafil is a potent phosphodiesterase-5 (PDE5) inhibitor that effectively inhibits cGMP and increases the strength of nitric oxide. PDE5 was overexpressed in several carcinomas, including breast cancer, which inhibited tumor growth and cell division. The current research aims to investigate the in vivo sildenafil's immunomodulatory and antineoplastic potentials against Ehrlich Ascites Carcinoma. This study looked at the effects of sildenafil mono-treatment and co-treatment with cisplatin; tumor cell count, viability and the inhibition rate were determined. Apoptosis, cell cycle distribution, alterations in tumor cells and splenocytes proliferation, changes in splenocytes immunophenotyping using flowcytometry, plasma levels of malondialdehyde (MDA), reduced glutathione (GSH), interferone (IFN)-γ, granzyme B, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine and hematological alterations were detected. Additionally, docking study was conducted to get further insights on how Sildenafil exerts its activity. Sildenafil mono-treatment and co-treatment with cisplatin markedly reduced tumor cell count, viability, growth rate and proliferative capability accompanied by apoptosis enhancement and G₀/G₁ and sub G₁ cells cycle arrest. Fortunately, sildenafil evoked efficient cellular immune response by increasing plasma levels of granzyme B and IFN-γ, proportion of splenic T cytotoxic (CD3⁺CD8⁺) and T helper (CD3⁺CD4⁺), accompanied by decrease in the proportion of splenic regulatory T cells. . Moreover, in silico data suggest LcK and MAPKs as the potential targets of sildenafil. Furthermore, sildenafil rebalanced the oxidant-antioxidant status by decreasing MDA and increasing GSH plasma levels. Sildenafil successfully retrieved various hematological values besides renal and hepatic functions in EAC-bearing animals. In conclusion, our results suggest that sildenafil could be potential safe anti-tumor agent with immuno-modulatory properties against Ehrlich ascites carcinoma.

1-Benzyl-5-bromo-3-hydrazonoindolin-2-ones as Novel Anticancer Agents: Synthesis, Biological Evaluation and Molecular Modeling Insights

Human health is experiencing several obstacles in the modern medical era, particularly cancer. As a result, the cancer therapeutic arsenal should be continually expanded with innovative small molecules that preferentially target tumour cells. In this study, we describe the development of two small molecule series (7a–d and 12a–e) based on the 1-benzyl-5-bromoindolin-2-one scaffold that connected through a hydrazone linker to a 4-arylthiazole (7a–d) or 4-methyl-5-(aryldiazenyl)thiazole (12a–e) moiety. The anticancer activity of all the reported indolin-2-one derivatives was assessed against breast (MCF-7) and lung (A-549) cancer cell lines. The 4-arylthiazole-bearing derivatives 7c and 7d revealed the best anticancer activity toward MCF-7 cells (IC50 = 7.17 ± 0.94 and 2.93 ± 0.47, respectively). Furthermore, the VEGFR-2 inhibitory activity for 7c and 7d was evaluated. Both molecules disclosed good inhibitory activity, and their IC50 values were equal to 0.728 µM and 0.503 µM, respectively. Additionally, the impacts of 7d on the cell cycle phases as well as on the levels of different apoptotic markers (caspase-3, caspase-9, Bax, and Bcl-2) were assessed. Molecular docking and dynamic simulations are carried out to explore the binding mode of 7d within the VEGFR-2 active site.

Synergistic Effect of Sophora japonica and Glycyrrhiza glabra Flavonoid-Rich Fractions on Wound Healing: In Vivo and Molecular Docking Studies

Glycyrrhiza glabra and Sophora japonica (Fabaceae) are well-known medicinal plants with valuable secondary metabolites and pharmacological properties. The flavonoid-rich fractions of G. glabra roots and S. japonica leaves were prepared using Diaion column chromatography, and the confirmation of flavonoid richness was confirmed using UPLC-ESI-MS profiling and total phenolics and flavonoids assays. UPLC-ESI-MS profiling of the flavonoid-rich fraction of G. glabra roots and S. japonica leaves resulted in the tentative identification of 32 and 23 compounds, respectively. Additionally, the wound healing potential of topical preparations of each fraction, individually and in combination (1:1) ointment and gel preparations, were investigated in vivo, supported by histopathological examinations and biomarker evaluations, as well as molecular docking studies for the major constituents. The topical application of G. glabra ointment and gel, S. japonica ointment and gel and combination preparations significantly increase the wound healing rate and the reduction of oxidative stress in the wound area via MDA reduction and the elevation of reduced GSH and SOD levels as compared to the wound and Nolaver®-treated groups. The molecular docking study revealed that that major compounds in G. glabra and S. japonica can efficiently bind to the active sites of three proteins related to wound healing: glycogen synthase kinase 3-β (GSK3-β), matrix metalloproteinases-8 (MMP-8) and nitric oxide synthase (iNOS). Consequently, G. glabra roots and S. japonica leaves may be a rich source of bioactive metabolites with antioxidant, anti-inflammatory and wound healing properties.

Chemical Constituents, Antioxidant, and Enzyme Inhibitory Activities Supported by In-Silico Study of n-Hexane Extract and Essential Oil of Guava Leaves

Psidium guajava (Guava tree) is one of the most widely known species in the family Myrtaceae. The Guava tree has been reported for its potential antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities. In the current study, the chemical compositions of the n-hexane extract and the essential oil of P. guajava were investigated using the GC/MS analysis, along with an evaluation of their antioxidant potential, and an investigation into the enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BchE), tyrosinase, α-amylase, and α-glucosidase. Moreover, molecular docking of the major identified active sites of the target enzymes were investigated. The chemical characterization of the n-hexane extract and essential oil revealed that squalene (9.76%), α-tocopherol (8.53%), and γ-sitosterol (3.90%) are the major compounds in the n-hexane extract. In contrast, the major constituents of the essential oil are D-limonene (36.68%) and viridiflorol (9.68%). The n-hexane extract showed more antioxidant potential in the cupric reducing antioxidant capacity (CUPRAC), the ferric reducing power (FRAP), and the metal chelating ability (MCA) assays, equivalent to 70.80 ± 1.46 mg TE/g, 26.01 ± 0.97 mg TE/g, and 24.83 ± 0.35 mg EDTAE/g, respectively. In the phosphomolybdenum (PM) assay, the essential oil showed more antioxidant activity equivalent to 2.58 ± 0.14 mmol TE/g. The essential oil demonstrated a potent BChE and tyrosinase inhibitory ability at 6.85 ± 0.03 mg GALAE/g and 61.70 ± 3.21 mg KAE/g, respectively. The α-amylase, and α-glucosidase inhibitory activity of the n-hexane extract and the essential oil varied from 0.52 to 1.49 mmol ACAE/g. Additionally, the molecular docking study revealed that the major compounds achieved acceptable binding scores upon docking with the tested enzymes. Consequently, the P. guajava n-hexane extract and oil can be used as a promising candidate for the development of novel treatment strategies for oxidative stress, neurodegeneration, and diabetes mellitus diseases.

Discovery of novel thiazolyl-pyrazolines as dual EGFR and VEGFR-2 inhibitors endowed with in vitro antitumor activity towards non-small lung cancer

New series of thiazolyl-pyrazoline derivatives (7a–7d, 10a–10d and 13a–13f) have been synthesised and assessed for their potential EGFR and VEGFR-2 inhibitory activities. Compounds 10b and 10d exerted potent and selective inhibitory activity towards the two receptor tyrosine kinases; EGFR (IC₅₀ = 40.7 ± 1.0 and 32.5 ± 2.2 nM, respectively) and VEGFR-2 (IC₅₀ = 78.4 ± 1.5 and 43.0 ± 2.4 nM, respectively). The best anti-proliferative activity for the examined thiazolyl-pyrazolines was observed against the non-small lung cancer cells (NSCLC). Compounds 10b and 10d displayed pronounced efficacy against A549 (IC₅₀ = 4.2 and 2.9 µM, respectively) and H441 cell lines (IC₅₀ = 4.8 and 3.8 µM, respectively). Moreover, our results indicated that 10b and 10d were much more effective towards EGFR-mutated NSCLC cell lines (NCI-H1650 and NCI-H1975 cells) than gefitinib. Finally, compounds 10b and 10d induce G2/M cell cycle arrest and apoptosis and inhibit migration in A549 cancerous cells.

Multi-stage structure-based virtual screening approach towards identification of potential SARS-CoV-2 NSP13 helicase inhibitors

On account of its crucial role in the virus life cycle, SARS-COV-2 NSP13 helicase enzyme was exploited as a promising target to identify a novel potential inhibitor using multi-stage structure-based drug discovery approaches. Firstly, a 3D pharmacophore was generated based on the collected data from a protein-ligand interaction fingerprint (PLIF) study using key interactions between co-crystallised fragments and the NSP13 helicase active site. The ZINC database was screened through the generated 3D-pharmacophore retrieving 13 potential hits. All the retrieved hits exceeded the benchmark score of the co-crystallised fragments at the molecular docking step and the best five-hit compounds were selected for further analysis. Finally, a combination between molecular dynamics simulations and MM-PBSA based binding free energy calculations was conducted on the best hit (compound FWM-1) bound to NSP13 helicase enzyme, which identified FWM-1 as a potential potent NSP13 helicase inhibitor with binding free energy equals -328.6 ± 9.2 kcal/mol.

Identification of Novel Cyanopyridones and Pyrido[2,3-D]Pyrimidines as Anticancer Agents with Dual VEGFR-2/HER-2 Inhibitory Action: Synthesis, Biological Evaluation and Molecular Docking Studies

In the current work, we designed and synthesized three families of non-fused and fused compounds based on cyanopyridone: derivatives of 6-amino-1,2-dihydropyridine-3,5-dicarbonitrile (5a-f) and 3,4,7,8-tetrahydro pyrimidine-6-carbonitrile (6a-b and 7a-e). The newly synthesized compounds’ structure were determined using a variety of techniques, including ¹H NMR, ¹³C NMR, mass spectrum, infrared spectroscopy, and elemental analysis. The developed compounds were tested for the ability to inhibit the growth of breast adenocarcinoma (MCF-7) and hepatic adenocarcinoma (HepG2) cell lines using MTT assay. Some of the synthesized compounds were more effective towards the cancer cell lines than the standard treatment taxol. The best antiproliferative activities were demonstrated by non-fused cyanopyridones 5a and 5e against the MCF-7 cell line (IC₅₀ = 1.77 and 1.39 μM, respectively) and by compounds 6b and 5a against the HepG2 cell line (IC₅₀ = 2.68 and 2.71 μM, respectively). We further explored 5a and 5e, the two most potent compounds against the MCF-7 cell line, for their ability to inhibit VEGFR-2 and HER-2. Finally, docking and molecular dynamics simulations were performed as part of the molecular modeling investigation to elucidate the molecular binding modes of the tested compounds, allowing for a more thorough comprehension of the activity of compounds 5a and 5e.

LC/MS analysis of Viscum cruciatum Sieber ex Boiss. extract with anti-proliferative activity against MCF-7 cell line via G0/G1 cell cycle arrest: An in-silico and in-vitro study

ETHNOPHARMACOLOGICAL RELEVANCE

Viscum cruciatum Sieb is a well-known medicinal plant in Jordan containing various secondary metabolites. It has traditionally been used to treat many ailments, most notably cancer. However, there is a significant gap between scientific research and its value in traditional medicine.

AIM OF THE WORK

To evaluate the antiproliferative activity of different V. cruciatum extracts against MCF-7 breast cancer cell lines and recognize the affected cell cycle phase. Besides, identifying the bioactive components present in the active extract using LC/MS technique. Also, to determine the possible mechanism of action by in silico and in-vitro study.

MATERIALS AND METHODS

V. cruciatum was extracted using solvents with increasing polarity. The antiproliferative effects of the extracts against MCF-7 cell lines were evaluated using SRB assay. Further, flow cytometry was used to identify the inhibited phase of the cell cycle, while LC/MS-MS technique was used to analyze the chemical composition of the most active extract. After that, the putative mechanism of action was investigated through in-silico docking, molecular dynamic simulation for compounds with the highest docking scores, and Western blot analysis of cyclin-dependent kinases (CDK2/4/6).

RESULTS

The chloroform/methanol 90/10 (ChMe) extract showed the most potent antiproliferative effect against MCF-7 cells (IC₅₀ = 23.8 μg/mL), and cell cycle arrest at the G0/G1phase. Furthermore, LC-MS/MS analysis revealed the presence of several polyphenolics belonging to the flavonoids and phenolic acids classes. Additionally, quercetin-4'-glucoside, 3, 5, 7-trihydroxy-4'-methoxy flavone, and hesperetin-7-O-neohesperidoside demonstrated the highest docking binding scores and stable complexes against CDK2 and CDK4/6. Moreover, RMSD (root-mean-square deviation), RMSF (root-mean-square fluctuation), Rg (radius of gyration), and energy analysis during molecular dynamic simulation indicated the stable binding of the studied complexes. These results were supported by Western blot analysis, which revealed the downregulation of CDK2, CDK4, and CDK6 protein expression in MCF-7 cell lines.

CONCLUSION

These findings emphasized the potential breast anticancer activity of the V. cruciatum ChMe extract by arresting the G0/G1 phase of the cell cycle, which could be related to its flavonoid content. Moreover, the results provided experimental support for the traditional anticancer activity of V. cruciatum, and its ChMe extract might be a source of chemoprotective or chemotherapeutic isolates.

Development of 4-((3-oxo-3-phenylpropyl)amino)benzenesulfonamide derivatives utilizing tail/dual-tail approaches as novel carbonic anhydrase inhibitors

In the current work, we adopted the tail/dual tail approaches to design and synthesize the benzenesulfonamide derivatives 6a-b, 8, 10a-b, 12a-b, 14, and 16 as new SLC-0111 analogs endowed with carbonic anhydrase (CA) inhibitory activity. All the prepared benzenesulfonamide derivatives were tested for their inhibitory action towards hCA isoforms; hCA I, II, IX, and XII. The results revealed their ability to affect the examined isoforms in variable degrees with KI ranges: 49.3-6459 nM for CA I, 5.1-4171 nM for CA II, 9.4-945.1 nM for CA IX, and 5.2-1159 nM for CA XII. As expected, appending a second hydrophilic tail (ethanolamine) in compound 16 significantly enhanced the inhibitory activities towards hCA IX and hCA XII isoforms by about 5-fold in comparison to its single tail analogue 6c (KI = 51.5 and 28.2 nM for 6cvs. 10.2 and 5.2 nM for 16, respectively). Moreover, SAR analysis pointed out the significance of grafting the sulfamoyl functionality at para-position, as well as the incorporation of a bulky hydrophobic tail for CA inhibitory activity. The most potent hCA IX inhibitors (6f and 16) displayed efficient cell growth inhibitory activity against breast cancer cell lines; T-47D (IC50 = 19 and 10.9 μM, respectively) and MCF-7 (IC50 = 7.5 and 5.7 μM, respectively).

Design, synthesis, in vitro biological assessment and molecular modeling insights for novel 3-(naphthalen-1-yl)-4,5-dihydropyrazoles as anticancer agents with potential EGFR inhibitory activity

Currently, the humanity is in a fierce battle against various health-related challenges especially those associated with human malignancies. This created the urge to develop potent and selective inhibitors for tumor cells through targeting specific oncogenic proteins possessing crucial roles in cancer progression and survive. In this respect, new series of pyrazole-thiazol-4-one hybrids (9a–p) were synthesized as potential anticancer agents. All the synthesized molecules exhibited potent antiproliferative actions against breast cancer (BC) T-47D and MDA-MB-231 cell lines with IC₅₀ ranges 3.14–4.92 and 0.62–58.01, respectively. Moreover, the most potent anti-proliferative counterparts 9g and 9k were assessed against EGFR. They displayed nanomolar inhibitory activity, IC₅₀ 267 ± 12 and 395 ± 17 nM, respectively. Worth noting, both compounds 9g and 9k induced apoptosis in MDA-MB-231 cells, and resulted in a cell cycle arrest at G2/M phase. Furthermore, an in silico analysis including docking and molecular dynamic simulations was performed.

GC/MS analysis and potential synergistic effect of mandarin and marjoram oils on Helicobacter pylori

Helicobacter pylori can cause chronic gastritis, peptic ulcer, and gastric carcinoma. This study compares chemical composition and anti-H. pylori activity of mandarin leaves and marjoram herb essential oils, and their combined oil. GC/MS analysis of mandarin oil revealed six compounds (100% identified), mainly methyl-N-methyl anthranilate (89.93%), and 13 compounds (93.52% identified) of marjoram oil, mainly trans-sabinene hydrate (36.11%), terpinen-4-ol (17.97%), linalyl acetate (9.18%), and caryophyllene oxide (8.25%)). Marjoram oil (MIC = 11.40 µg/mL) demonstrated higher activity than mandarin oil (MIC = 31.25 µg/mL). The combined oil showed a synergistic effect at MIC of 1.95 µg/mL (same as clarithromycin). In-silico molecular docking on H. pylori urease, CagA, pharmacokinetic and toxicity studies were performed on major compounds from both oils. The best scores were for caryophyllene oxide then linalyl acetate and methyl-N-methyl anthranilate. Compounds revealed high safety and desirable properties. The combined oil can be an excellent candidate to manage H. pylori.

Olive Leaves as a Potential Phytotherapy in the Treatment of COVID-19 Disease; A Mini-Review

Beginning from December 2019, widespread COVID-19 has caused huge financial misfortunes and exceptional wellbeing emergencies across the globe. Discovering an effective and safe drug candidate for the treatment of COVID-19 and its associated symptoms became an urgent global demand, especially due to restricted information that has been discharged with respect to vaccine efficacy and safety in humans. Reviewing the recent research, olive leaves were selected as a potential co-therapy supplement for the treatment and improvement of clinical manifestations in COVID-19 patients. Olive leaves were reported to be rich in phenolic compounds such as oleuropein, hydroxytyrosol, verbascoside, apigenin-7-O-glucoside, and luteolin-7-O-glucoside and also triterpenoids such as maslinic, ursolic, and oleanolic acids that have been reported as anti-SARS-CoV-2 metabolites in recent computational and in vitro studies. In addition, olive leaf extract was previously reported in several in vivo studies for its anti-inflammatory, analgesic, antipyretic, immunomodulatory, and antithrombotic activities which are of great benefit in the control of associated inflammatory cytokine storm and disseminated intravascular coagulation in COVID-19 patients. In conclusion, the described biological activities of olive leaves alongside their biosafety, availability, and low price make them a potential candidate drug or supplement to control COVID-19 infection and are recommended for clinical investigation.

Fenticonazole nitrate loaded trans-novasomes for effective management of tinea corporis: design characterization, in silico study, and exploratory clinical appraisal

The current investigation aimed for loading fenticonazole nitrate (FTN), an antifungal agent with low aqueous solubility, into trans-novasomes (TNs) for management of tinea corporis topically. TNs contain Brij^® as an edge activator besides the components of novasomes (cholesterol, Span 60, and oleic acid) owing to augment the topical delivery of FTN. TNs were fabricated applying ethanol injection method based on D-optimal experiment. TNs were evaluated with regard to entrapment efficiency percent (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). Further explorations were conducted on the optimum formulation (F7). F7 showed spherical appearance with EE%, PS, PDI, and ZP of 100.00 ± 1.10%, 358.60 ± 10.76 nm, 0.51 ± 0.004, and −30.00 ± 0.80 mV, respectively. The in silico study revealed the ability of the FTN–cholesterol complex to maintain favorable interactions throughout the molecular dynamics simulation (MDS) study. Moreover, Trichophyton mentagrophytes growth was inhibited effectively by F7 than by FTN suspension applying 2,3-bis(2-methyloxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay. Furthermore, a clinical appraisal on patients with tinea corporis fungal lesions confirmed the superiority of F7 compared to Miconaz^® cream in the magnitude of clinical cure of tinea corporis. Thereby, TNs could be considered as promising vesicles for enhancing the antifungal potential of FTN for the topical management of tinea corporis.

GC/MS Profiling, Anti-Collagenase, Anti-Elastase, Anti-Tyrosinase and Anti-Hyaluronidase Activities of a Stenocarpus sinuatus Leaves Extract

Today, skin care products and cosmetic preparations containing natural ingredients are widely preferred by consumers. Therefore, many cosmetic brands are encouraged to offer more natural products to the market, such as plant extracts that can be used for their antiaging, antiwrinkle, and depigmentation properties and other cosmetic purposes. In the current study, the volatile constituents of the hexane-soluble fraction of a Stenocarpus sinuatus (family Proteaceae) leaf methanol extract (SSHF) were analyzed using GC/MS analysis. Moreover, the antiaging activity of SSHF was evaluated through in vitro studies of anti-collagenase, anti-elastase, anti-tyrosinase, and anti-hyaluronidase activities. In addition, an in silico docking study was carried out to identify the interaction mechanisms of the major compounds in SSHF with the active sites of the target enzymes. Furthermore, an in silico toxicity study of the identified compounds in SSHF was performed. It was revealed that vitamin E (α-tocopherol) was the major constituent of SSHF, representing 52.59% of the extract, followed by γ-sitosterol (8.65%), neophytadiene (8.19%), β-tocopherol (6.07%), and others. The in vitro studies showed a significant inhibition by SSHF of collagenase, elastase, tyrosinase, and hyaluronidase, with IC₅₀ values of 60.03, 177.5, 67.5, and 38.8 µg/mL, respectively, comparable to those of the positive controls epigallocatechin gallate (ECGC, for collagenase, elastase, hyaluronidase) and kojic acid (for tyrosinase). Additionally, the molecular docking study revealed good acceptable binding scores of the four major compounds, comparable to those of ECGC and kojic acid. Besides, the SSHF identified phytoconstituents showed no predicted potential toxicity nor skin toxicity, as determined in silico. In conclusion, the antiaging potential of SSHF may be attributed to its high content of vitamin E in addition to the synergetic effect of other volatile constituents. Thus, SSHF could be incorporated in pharmaceutical skin care products and cosmetics after further studies.

Development of potent nanosized isatin-isonicotinohydrazide hybrid for management of Mycobacterium tuberculosis

Inspired by the antitubercular activity of isoniazid (INH) and 5-bromoisatin, isatin-INH hybrid (WF-208) has been synthesized as a potent agent against multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of M. tuberculosis. In silico molecular docking studies indicated that DprE1, a critical enzyme in the synthesis of M. tuberculosis cell wall, is a potential enzymatic target for WF-208. The synthesized WF-208 was incorporated into a nanoparticulate system to enhance stability of the compound and to sustain its antimicrobial effect. Nanosized spherical niosomes (hydrodynamic diameter of ca. 500-600 nm) could accommodate WF-208 at a high encapsulation efficiency of 74.2%, and could impart superior stability to the compound in simulated gastric conditions. Interestingly, WF-208 had minimal inhibitory concentrations (MICs) of 7.8 and 31.3 µg/mL against MDR and XDR M. tuberculosis, respectively, whereas INH failed to demonstrate bacterial growth inhibition at the range of the tested concentrations. WF-208-loaded niosomes exhibited a 4-fold increase in the anti-mycobacterial activity as compared to the free compound (MIC of 1.9 vs. 7.8 µg/mL) against H37Rv M. tuberculosis, after three weeks of incubation with WF-208-loaded niosomes. Incorporation of the compound into nanosized vesicles allowed for a further increase in stability, potency and sustainability of the anti-mycobacterial activity, thus, providing a promising strategy for management of tuberculosis.

Development of novel isatin-nicotinohydrazide hybrids with potent activity against susceptible/resistant Mycobacterium tuberculosis and bronchitis causing-bacteria

Joining the global fight against Tuberculosis, the world's most deadly infectious disease, herein we present the design and synthesis of novel isatin-nicotinohydrazide hybrids (5a-m and 9a-c) as promising anti-tubercular and antibacterial agents. The anti-tubercular activity of the target hybrids was evaluated against drug-susceptible M. tuberculosis strain (ATCC 27294) where hybrids 5d, 5g and 5h were found to be as potent as INH with MIC = 0.24 µg/mL, also the activity was evaluated against Isoniazid/Streptomycin resistant M. tuberculosis (ATCC 35823) where compounds 5g and 5h showed excellent activity (MIC = 3.9 µg/mL). Moreover, the target hybrids were examined against six bronchitis causing-bacteria. Most derivatives exhibited excellent antibacterial activity. K. pneumonia emerged as the most sensitive strain with MIC range: 0.49-7.81 µg/mL. Furthermore, a molecular docking study has proposed DprE1 as a probable enzymatic target for herein reported isatin-nicotinohydrazide hybrids, and explored the binding interactions within the vicinity of DprE1 active site.

In silico identification of novel SARS-COV-2 2'-O-methyltransferase (nsp16) inhibitors: structure-based virtual screening, molecular dynamics simulation and MM-PBSA approaches

The novel coronavirus disease COVID-19, caused by the virus SARS CoV-2, has exerted a significant unprecedented economic and medical crisis, in addition to its impact on the daily life and health care systems all over the world. Regrettably, no vaccines or drugs are currently available for this new critical emerging human disease. Joining the global fight against COVID-19, in this study we aim at identifying a potential novel inhibitor for SARS COV-2 2'-O-methyltransferase (nsp16) which is one of the most attractive targets in the virus life cycle, responsible for the viral RNA protection via a cap formation process. Firstly, nsp16 enzyme bound to Sinefungin was retrieved from the protein data bank (PDB ID: 6WKQ), then, a 3D pharmacophore model was constructed to be applied to screen 48 Million drug-like compounds of the Zinc database. This resulted in only 24 compounds which were subsequently docked into the enzyme. The best four score-ordered hits from the docking outcome exhibited better scores compared to Sinefungin. Finally, three molecular dynamics (MD) simulation experiments for 150 ns were carried out as a refinement step for our proposed approach. The MD and MM-PBSA outputs revealed compound 11 as the best potential nsp16 inhibitor herein identified, as it displayed a better stability and average binding free energy for the ligand-enzyme complex compared to Sinefungin.

Development of isatin-thiazolo[3,2-a]benzimidazole hybrids as novel CDK2 inhibitors with potent in vitro apoptotic anti-proliferative activity: Synthesis, biological and molecular dynamics investigations

In the current medical era, human health is experiencing numerous challenges, particularly the human malignancies. Therefore, the therapeutic arsenal for these malignancies is to be inexorably enhanced with new treatments that target tumor cells in a selective manner. In this regard, the present work aims at developing a new set of small molecules featuring the privileged isatin scaffold conjugated with a thiazolo[3,2-a]benzimidazole (TBI) motif through a cleavable hydrazide linker (7a-e and 10a-i) as potential anticancer CDK2 inhibitors. The large tricyclic TBI motif is anticipated to achieve a plethora of hydrophobic interactions within the CDK2 binding site. The growth of the two examined cell lines was significantly inhibited by most the prepared hybrids with IC₅₀ ranges; (2.60 ± 1.47-20.90 ± 1.17 µM, against MDA-MB-231) and (1.27 ± 0.06-16.83 ± 0.95 µM, against MCF-7). In particular, hybrids 7a, 7d and 10a displayed potent dual activity against the examined cell lines, and thus selected for further investigations. They exerted a significance alteration in the cell cycle progression, in addition to an apoptosis induction within both MDA-MB-231 and MCF-7 cells. Furthermore, 7a, 7d and 10a displayed potent CDK2 inhibitory action (IC₅₀ = 96.46 ± 5.3, 26.24 ± 1.4 and 42.95 ± 2.3 nM, respectively). The docking simulations unveiled, as expected, the ability of the TBI ring to well-accommodate and establish several hydrophobic interactions within a hydrophobic pocket in the CDK2 binding site. Also, the docking simulations highlighted the significance of incorporation of the hydrazide linker and isatin unsubstituted (NH) functionality in the H-bonding interactions. Interestingly, the most potent CDK2 inhibitor 7d achieved the best binding score (-11.2 Kcal/mole) and formed the most stable complex with CDK2 enzyme (RMSD = 1.24 Å) in a 100 ns MD simulation. In addition, the MM-PBSA calculations ascribed the lowest binding free energy to the 7d-CDK2 complex (-323.69 ± 15.17 kJ/mol). This could be attributed to an incorporation of the 5-OCH₃ group that was engaged in an extra hydrogen bonding with key THR14 amino acid residue. Finally, these results suggested hybrid 7d as a good candidate for further optimization as promising breast cancer antitumor agent and CDK2 inhibitor.

In silico identification of potential SARS COV-2 2′-O-methyltransferase inhibitor: fragment-based screening approach and MM-PBSA calculations

In the present era, there are many efforts trying to face the emerging and successive waves of the COVID-19 pandemic. This has led to considering new and unusual targets for SARS CoV-2. 2′-O-Methyltransferase (nsp16) is a key and attractive target in the SARS CoV-2 life cycle since it is responsible for the viral RNA protection via a cap formation process. In this study, we propose a new potential inhibitor for SARS COV-2 2′-O-methyltransferase (nsp16). A fragment library was screened against the co-crystal structure of the SARS COV-2 2′-O-methyltransferase complexed with Sinefungin (nsp16 – PDB ID: 6WKQ), and consequently the best proposed fragments were linked via a de novo approach to build molecule AP-20. Molecule AP-20 displayed a superior docking score to Sinefungin and reproduced the key interactions in the binding site of 2′-O-methyltransferase. Three molecular dynamic simulations of the 2′-O-methyltransferase apo structure and its complexed forms with AP-20 and Sinefungin were performed for 150 nano-seconds to provide insights on the dynamic nature of such setups and to assess the stability of the proposed AP-20/enzyme complex. AP-20/enzyme complex demonstrated better stability for the ligand–enzyme complex compared to Sinefungin in a respective setup. Furthermore, MM-PBSA binding free energy calculations showed a better profile for AP-20/enzyme complex compared to Sinefungin/enzyme complex emphasizing the potential inhibitory effect of AP-20 on SARS COV-2 2′-O-methyltransferase. We endorse our designed molecule AP-20 to be further explored via experimental evaluations to confront the spread of the emerging COVID-19. Also, in silico ADME profiling has ascribed to AP-20 an excellent safety and metabolic stability profile.

The identification of AP-20 as a potential SARS COV-2 2′-O-methyltransferase inhibitor: fragment-based screening approach and MM-PBSA calculations.

Identification of a New Potential SARS-COV-2 RNA-Dependent RNA Polymerase Inhibitor via Combining Fragment-Based Drug Design, Docking, Molecular Dynamics, and MM-PBSA Calculations

The world has recently been struck by the SARS-Cov-2 pandemic, a situation that people have never before experienced. Infections are increasing without reaching a peak. The WHO has reported more than 25 million infections and nearly 857,766 confirmed deaths. Safety measures are insufficient and there are still no approved drugs for the COVID-19 disease. Thus, it is an urgent necessity to develop a specific inhibitor for COVID-19. One of the most attractive targets in the virus life cycle is the polymerase enzyme responsible for the replication of the virus genome. Here, we describe our Structure-Based Drug Design (SBDD) protocol for designing of a new potential inhibitor for SARS-COV-2 RNA-dependent RNA Polymerase. Firstly, the crystal structure of the enzyme was retrieved from the protein data bank PDB ID (7bv2). Then, Fragment-Based Drug Design (FBDD) strategy was implemented using Discovery Studio 2016. The five best generated fragments were linked together using suitable carbon linkers to yield compound MAW-22. Thereafter, the strength of the binds between compound MAW-22 and the SARS-COV-2 RNA-dependent RNA Polymerase was predicted by docking strategy using docking software. MAW-22 achieved a high docking score, even more so than the score achieved by Remdesivir, indicating very strong binding between MAW-22 and its target. Finally, three molecular dynamic simulation experiments were performed for 150 ns to validate our concept of design. The three experiments revealed that MAW-22 has a great potentiality to inhibit the SARS-COV-2 RNA-dependent RNA Polymerase compared to Remdesivir. Also, it is thought that this study has proven SBDD to be the most suitable avenue for future drug development for the COVID-19 infection.