Spiro heterocycles bearing piperidine moiety as potential scaffold for antileishmanial activity: synthesis, biological evaluation, and in silico studies

New spiro-piperidine derivatives were synthesised via the eco-friendly ionic liquids in a one-pot fashion. The in vitro antileishmanial activity against Leishmania major promastigote and amastigote forms highlighted promising antileishmanial activity for most of the derivatives, with superior activity compared to miltefosine. The most active compounds 8a and 9a exhibited sub-micromolar range of activity, with IC50 values of 0.89 µM and 0.50 µM, respectively, compared to 8.08 µM of miltefosine. Furthermore, the antileishmanial activity reversal of these compounds via folic and folinic acids displayed comparable results to the positive control trimethoprim. This emphasises that their antileishmanial activity is through the antifolate mechanism via targeting DHFR and PTR1. The most active compounds showed superior selectivity and safety profile compared to miltefosine against VERO cells. Moreover, the docking experiments of 8a and 9a against Lm-PTR1 rationalised the observed in vitro activities. Molecular dynamics simulations confirmed a stable and high potential binding to Lm-PTR1.

In silico screening of SARS-CoV2 helicase using African natural products: Docking and molecular dynamics approaches

In the current medical era, there is an urgent necessity to identify new effective drugs to enrich the COVID-19's therapeutic arsenal. The SARS-COV-2 NSP13/helicase enzyme has been identified as a potential target for developing novel COVID-19 inhibitors. In this work, we aimed at endorsing effective natural products with potential inhibitory action towards the NSP13 through the virtual screening of 1012 natural products of botanical and marine origin from the South African Natural Compounds Database (SANCDB). The molecules were docked into the NTPase active site, and the best twelve compounds were chosen for further analysis. Thereafter, a combination of molecular dynamics simulations and MM-GBSA free energy calculations were carried out for a subset of best hits complexed with NSP13 helicase. We believe that the findings of this work will pave the way for additional research and experimental validation of some natural products as viable NSP13 helicase inhibitors.

Tetrahydrobenzo[h]quinoline derivatives as a novel chemotype for dual antileishmanial-antimalarial activity graced with antitubercular activity: Design, synthesis and biological evaluation

Derivatives with tetrahydrobenzo[h]quinoline chemotype were synthesized via one-pot reactions and evaluated for their antileishmanial, antimalarial and antitubercular activities. Based on a structure-guided approach, they were designed to possess antileishmanial activity through antifolate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro antipromastigote and antiamastigote activity are promising for all candidates and superior to the reference miltefosine, in a low or sub micromolar range of activity. Their antifolate mechanism was confirmed via the ability of folic and folinic acids to reverse the antileishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Molecular dynamics simulations confirmed a stable and high potential binding of the most active candidates against leishmanial PTR1. For the antimalarial activity, most of the compounds exhibited promising antiplasmodial effect against P. berghei with suppression percentage of up to 97.78%. The most active compounds were further screened in vitro against the chloroquine resistant strain P. falciparum, (RKL9) and showed IC50 value range of 0.0198-0.096 μM, compared to IC50 value of 0.19420 μM for chloroquine sulphate. Molecular docking of the most active compounds against the wild-type and quadruple mutant pf DHFR-TS structures rationalized the in vitro antimalarial activity. Some candidates showed good antitubercular activity against sensitive Mycobacterium tuberculosis in a low micromolar range of MIC, compared to 0.875 μM of isoniazid. The top active ones were further tested against a multidrug-resistant strain (MDR) and extensively drug-resistant strain (XDR) of Mycobacterium tuberculosis. Interestingly, the in vitro cytotoxicity test of the best candidates displayed high selectivity indices emphasizing their safety on mammalian cells. Generally, this work introduces a fruitful matrix for new dual acting antileishmanial-antimalarial chemotype graced with antitubercular activity. This would help in tackling drug-resistance issues in treating some Neglected Tropical Diseases.

Engineered Microencapsulated Lactoferrin Nanoconjugates for Oral Targeted Treatment of Colon Cancer

Despite current progress in the development of targeted therapies for cancer treatment, there is a lack in convenient therapeutics for colorectal cancer (CRC). Lactoferrin nanoparticles (Lf NPs) are a promising drug delivery system in cancer therapy. However, numerous obstacles impede their oral delivery, including instability against stomach enzymes and premature uptake during passage through the small intestine. Microencapsulation of Lf NPs offer a great solution for these obstacles. It can protect Lf NPs and their drug payloads from degradation in the upper gastrointestinal tract (GIT), reduce burst drug release, and improve the release profile of the encapsulated NPs triggered by stimuli in the colon. Here, we developed nanoparticle-in-microparticle delivery systems (NIMDs) for the oral delivery of docetaxel (DTX) and atorvastatin (ATR). The NPs were obtained by dual conjugation of DTX and ATR into the Lf backbone, which was further microencapsulated into calcium-crosslinked microparticles using polysaccharide-protein hybrid copolymers. The NIMDs showed no detectable drug release in the upper GIT compared to NPs. Furthermore, sustained release of the NPs from the NIMDs in rat cecal content was observed. Moreover, the in vivo study demonstrated the superiority of the NIMDs over NPs in CRC treatment by suppressing p-AKT, p-ERK1/2, and NF-κB. This study provides the proof of concept for using NIMDs to enhance the effect of protein NPs in CRC treatment.

Modulating leishmanial pteridine metabolism machinery via some new coumarin-1,2,3-triazoles: Design, synthesis and computational studies

In accordance with WHO statistics, leishmaniasis is one of the top neglected tropical diseases, affecting around 700 000 to one million people per year. To that end, a new series of coumarin-1,2,3-triazole hybrid compounds was designed and synthesized. All new compounds exerted higher activity than miltefosine against L. major promastigotes and amastigotes. Seven compounds showed single digit micromolar IC₅₀ values whereas three compounds (13c, 14b and 14c) displayed submicromolar potencies. A mechanistic study to elucidate the antifolate-dependent activity of these compounds revealed that folic and folinic acids abrogated their antileishmanial effects. These compounds exhibited high safety margins in normal VERO cells, expressed as high selectivity indices. Docking simulation studies on the folate pathway enzymes pteridine reductase and DHFR-TS imparted strong theoretical support to the observed biological activities. Besides, docking experiments on human DHFR revealed minimal binding interactions thereby highlighting the selectivity of these compounds. Predicted in silico physicochemical and pharmacokinetic parameters were adequate. In view of this, the structural characteristics of these compounds demonstrated their suitability as antileishmanial lead compounds.

Marine Fish-Derived Lysophosphatidylcholine: Properties, Extraction, Quantification, and Brain Health Application

Long-chain omega-3 fatty acids esterified in lysophosphatidylcholine (LPC-omega-3) are the most bioavailable omega-3 fatty acid form and are considered important for brain health. Lysophosphatidylcholine is a hydrolyzed phospholipid that is generated from the action of either phospholipase PLA1 or PLA2. There are two types of LPC; 1-LPC (where the omega-3 fatty acid at the sn-2 position is acylated) and 2-LPC (where the omega-3 fatty acid at the sn-1 position is acylated). The 2-LPC type is more highly bioavailable to the brain than the 1-LPC type. Given the biological and health aspects of LPC types, it is important to understand the structure, properties, extraction, quantification, functional role, and effect of the processing of LPC. This review examines various aspects involved in the extraction, characterization, and quantification of LPC. Further, the effects of processing methods on LPC and the potential biological roles of LPC in health and wellbeing are discussed. DHA-rich-LysoPLs, including LPC, can be enzymatically produced using lipases and phospholipases from wide microbial strains, and the highest yields were obtained by Lipozyme RM-IM®, Lipozyme TL-IM®, and Novozym 435®. Terrestrial-based phospholipids generally contain lower levels of long-chain omega-3 PUFAs, and therefore, they are considered less effective in providing the same health benefits as marine-based LPC. Processing (e.g., thermal, fermentation, and freezing) reduces the PL in fish. LPC containing omega-3 PUFA, mainly DHA (C22:6 omega-3) and eicosapentaenoic acid EPA (C20:5 omega-3) play important role in brain development and neuronal cell growth. Additionally, they have been implicated in supporting treatment programs for depression and Alzheimer’s. These activities appear to be facilitated by the acute function of a major facilitator superfamily domain-containing protein 2 (Mfsd2a), expressed in BBB endothelium, as a chief transporter for LPC-DHA uptake to the brain. LPC-based delivery systems also provide the opportunity to improve the properties of some bioactive compounds during storage and absorption. Overall, LPCs have great potential for improving brain health, but their safety and potentially negative effects should also be taken into consideration.

Engineered Sericin-Tagged Layered Double Hydroxides for Combined Delivery of Pemetrexed and ZnO Quantum Dots as Biocompatible Cancer Nanotheranostics

Despite extensive progress in the field of cancer nanotheranostics, clinical development of biocompatible theranostic nanomedicine remains a formidable challenge. Herein, we engineered biocompatible silk-sericin-tagged inorganic nanohybrids for efficient treatment and imaging of cancer cells. The developed nanocarriers are anticipated to overcome the premature release of the chemotherapeutic drug pemetrexed (PMX), enhance the colloidal stability of layered double hydroxides (LDHs), and maintain the luminescence properties of ZnO quantum dots (QDs). Materials and Methods: PMX-intercalated LDHs were modified with sericin and coupled to ZnO QDs for therapy and imaging of breast cancer cells. Results: The optimized nanomedicine demonstrated a sustained release profile of PMX, and high cytotoxicity against MDA-MB-231 cells compared to free PMX. In addition, high cellular uptake of the engineered nanocarriers into MDA-MB-231 breast cancer cells was accomplished. Conclusions: Conclusively, the LDH-sericin nanohybrids loaded with PMX and conjugated to ZnO QDs offered a promising cancer theranostic nanomedicine.

Combined Cancer Immunotheranostic Nanomedicines: Delivery Technologies and Therapeutic Outcomes

Cancer is among the main causes of mortality all over the world. The delayed diagnosis is directly related to the decrease in survival rate. The use of immunotherapy has dramatically changed the treatment outcomes of different types of cancers. However, many patients still do not respond to immunotherapies, and many also suffer from severe immune-related side effects. Recent advances in the fields of nanomedicine bioengineering and in particular imaging offered new approaches which can enhance not only the safety but also the efficacy of immunotherapy. Theranostics has showed great progress as a branch of medicine which integrates both diagnosis and therapy in a single system. The outcomes from animal studies demonstrated an improvement in the diagnostic and immunotherapeutic potential of nanoparticles within the theranostic framework. Herein, we discuss the most recent developments in the application of nanotheranostics for combining tumor imaging and cancer immunotherapies.

New antileishmanial quinoline linked isatin derivatives targeting DHFR-TS and PTR1: Design, synthesis, and molecular modeling studies

In a search for new drug candidates for one of the neglected tropical diseases, leishmaniasis, twenty quinoline-isatin hybrids were synthesized and tested for their in vitro antileishmanial activity against Leishmaniamajor strain. All the synthesized compounds showed promising in vitro activity against the promastigote form in a low micromolar range (IC₅₀ = 0.5084-5.9486 μM) superior to the reference miltefosine (IC₅₀ = 7.8976 μM). All the target compounds were then tested against the intracellular amastigote form and showed promising inhibition effects (IC₅₀ = 0.60442-8.2948 μM versus 8.08 μM for miltefosine). Compounds 4e, 4b and 4f were shown to possess the highest antileishmanial activity against both promastigote and amastigote forms. The most active compounds were proven to exhibit their significant antileishmanial effects through antifolate mechanism, targeting DHFR-TS and PTR1. To evaluate the safety profile of the most active derivatives 4e, 4b and 4f, the in vitro cytotoxicity test was carried out and displayed higher selectivity indices than the reference miltefosine. Molecular docking within putative target protein PTR1 confirmed the high potentiality of the most active compounds 4e, 4b and 4f to block the catalytic activity of Lm-PTR1.

New pyrazolylpyrazoline derivatives as dual acting antimalarial-antileishamanial agents: synthesis, biological evaluation and molecular modelling simulations

Promising inhibitory activities of the parasite multiplication were obtained upon evaluation of in vivo antimalarial activities of new pyrazolylpyrazoline derivatives against Plasmodium berghei infected mice. Further evaluation of 5b and 6a against chloroquine-resistant strain (RKL9) of P. falciparum showed higher potency than chloroquine. In vitro antileishmanial activity testing against Leishmania aethiopica promastigote and amastigote forms indicated that 5b, 6a and 7b possessed promising activity compared to miltefosine and amphotericin B deoxycholate. Moreover, antileishmanial activity reversal of the active compounds via folic and folinic acids showed comparable results to the positive control trimethoprim, indicating an antifolate mechanism via targeting leishmanial DHFR and PTR1. The compounds were non-toxic at 125, 250 and 500 mg/kg. In addition, docking of the most active compound against putative malarial target Pf-DHFR-TS and leishmanial PTR1 rationalised the observed activities. Molecular dynamics simulations confirmed a stable and high potential binding of 7a against leishmanial PTR1.

Sequential Delivery of Novel Triple Drug Combination via Crosslinked Alginate/Lactoferrin Nanohybrids for Enhanced Breast Cancer Treatment

While breast cancer remains a global health concern, the elaboration of rationally designed drug combinations coupled with advanced biocompatible delivery systems offers new promising treatment venues. Herein, we repurposed rosuvastatin (RST) based on its selective tumor apoptotic effect and combined it with the antimetabolite pemetrexed (PMT) and the tumor-sensitizing polyphenol honokiol (HK). This synergistic three-drug combination was incorporated into protein polysaccharide nanohybrids fabricated by utilizing sodium alginate (ALG) and lactoferrin (LF), inspired by the stealth property of the former and the cancer cell targeting capability of the latter. ALG was conjugated to PMT and then coupled with LF which was conjugated to RST, forming core shell nanohybrids into which HK was physically loaded, followed by cross linking using genipin. The crosslinked HK-loaded PMT-ALG/LF-RST nanohybrids exhibited a fair drug loading of 7.86, 5.24 and 6.11% for RST, PMT and HK, respectively. It demonstrated an eight-fold decrease in the IC50 compared to the free drug combination, in addition to showing an enhanced cellular uptake by MCF-7 cells. The in vivo antitumor efficacy in a breast cancer-bearing mouse model confirmed the superiority of the triple cocktail-loaded nanohybrids. Conclusively, our rationally designed triple drug-loaded protein/polysaccharide nanohybrids offer a promising, biocompatible approach for an effective breast tumor suppression.

Engineered nanomedicines for augmenting the efficacy of colorectal cancer immunotherapy

Colorectal cancer (CRC) is one of the most devastating diseases worldwide. Immunotherapeutic agents for CRC treatment have shown limited efficacy due to the immunosuppressive tumor microenvironment (TME). In this context, various types of nanoparticles (NPs) have been used to reverse the immunosuppressive TME, potentiate the effect of immunotherapeutic agents and reduce their systemic side effects. Many advantages could be offered by NPs, related to drug-loading efficiency, particle size and others that can potentially aid the delivery of immunotherapeutic agents. The recent research on how nano-based immunotherapy can remodel the immunosuppressive TME of CRC and hence boost the antitumor immune response, as well as the challenges that face clinical translation of NPs and future perspectives, are summarized in this review article.

Synthesis and Antiproliferative Activity of a New Series of Mono- and Bis(dimethylpyrazolyl)-s-triazine Derivatives Targeting EGFR/PI3K/AKT/mTOR Signaling Cascades

Here, we synthesized a newseries of mono- and bis(dimethylpyrazolyl)-s-triazine derivatives. The synthetic methodology involved the reaction of different mono- and dihydrazinyl-s-triazine derivatives with acetylacetone in the presence of triethylamine to produce the corresponding target products in high yield and purity. The antiproliferative activity of the novel mono- and bis(dimethylpyrazolyl)-s-triazine derivatives was studied against three cancer cell lines, namely, MCF-7, HCT-116, and HepG2. N-(4-Bromophenyl)-4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-morpholino-1,3,5-triazin-2-amine 4f, N-(4-chlorophenyl)-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-amine 5c, and 4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-(4-methoxyphenyl)-1,3,5-triazin-2-amine 5d showed promising activity against these cancer cells: 4f [(IC₅₀ = 4.53 ± 0.30 μM (MCF-7); 0.50 ± 0.080 μM (HCT-116); and 3.01 ± 0.49 μM (HepG2)]; 5d [(IC₅₀ = 3.66 ± 0.96 μM (HCT-116); and 5.42 ± 0.82 μM (HepG2)]; and 5c [(IC₅₀ = 2.29 ± 0.92 μM (MCF-7)]. Molecular docking studies revealed good binding affinity with the receptor targeting EGFR/PI3K/AKT/mTOR signaling cascades. Compound 4f exhibited potent EGFR inhibitory activity with an IC₅₀ value of 61 nM compared to that of Tamoxifen (IC₅₀ value of 69 nM), with EGFR inhibition of 83 and 84%, respectively, at a concentration of 10 μM. Interestingly, 4f showed remarkable PI3K/AKT/mTOR inhibitory activity with 0.18-, 0.27-, and 0.39-fold decrease in their concentration (reduction in controls from 6.64, 45.39, and 86.39 ng/mL to 1.24, 12.35, and 34.36 ng/mL, respectively). Hence, the synthetic 1,3,5-triazine derivative 4f exhibited promising antiproliferative activity in HCT-116 cells through apoptosis induction by targeting the EGFR and its downstream pathway.

Methotrexate-Lactoferrin Targeted Exemestane Cubosomes for Synergistic Breast Cancer Therapy

While the treatment regimen of certain types of breast cancer involves a combination of hormonal therapy and chemotherapy, the outcomes are limited due to the difference in the pharmacokinetics of both treatment agents that hinders their simultaneous and selective delivery to the cancer cells. Herein, we report a hybrid carrier system for the simultaneous targeted delivery of aromatase inhibitor exemestane (EXE) and methotrexate (MTX). EXE was physically loaded within liquid crystalline nanoparticles (LCNPs), while MTX was chemically conjugated to lactoferrin (Lf) by carbodiimide reaction. The anionic EXE-loaded LCNPs were then coated by the cationic MTX–Lf conjugate via electrostatic interactions. The Lf-targeted dual drug-loaded LCNPs exhibited a particle size of 143.6 ± 3.24 nm with a polydispersity index of 0.180. It showed excellent drug loading with an EXE encapsulation efficiency of 95% and an MTX conjugation efficiency of 33.33%. EXE and MTX showed synergistic effect against the MCF-7 breast cancer cell line with a combination index (CI) of 0.342. Furthermore, the Lf-targeted dual drug-loaded LCNPs demonstrated superior synergistic cytotoxic activity with a combination index (CI) of 0.242 and a dose reduction index (DRI) of 34.14 and 4.7 for EXE and MTX, respectively. Cellular uptake studies demonstrated higher cellular uptake of Lf-targeted LCNPs into MCF-7 cancer cells than non-targeted LCNPs after 4 and 24 h. Collectively, the targeted dual drug-loaded LCNPs are a promising candidate offering combinational hormonal therapy/chemotherapy for breast cancer.

Investigation of the anti-inflammatory and analgesic activities of promising pyrazole derivative

The development of new COX-2 inhibitors with analgesic and anti-inflammatory efficacy as well as minimal gastrointestinal, renal and cardiovascular toxicity, is of vital importance to patients suffering from chronic course pain and inflammatory conditions. This study aims at evaluating the therapeutic activity and adverse drug reactions associated with the use of the newly synthesized pyrazole derivative, compound AD732, E-4-[3-(4-methylphenyl)-5-hydroxyliminomethyl-1H-pyrazol-1-yl]benzenesulfonamide, as compared to indomethacin and celecoxib as standard agents. Anti-inflammatory activity was assessed using carrageenan-induced rat paw edema and cotton pellet granuloma tests; formalin-induced hyperalgesia and hot plate tests were done to study analgesic activity. In vitro tests to determine COX-1/COX-2 selectivity and assessment of renal and gastric toxicity upon acute exposure to AD732 were also conducted. Compound AD732 exhibited promising results; higher anti-inflammatory and analgesic effects compared to standard agents, coupled with the absence of ulcerogenic effects and minimal detrimental effects on renal function. Additionally, compound AD732 was a less potent inhibitor of COX-2 in vitro than celecoxib, which may indicate lower potential cardiovascular toxicity. It may be concluded that compound AD732 appears to be a safer and more effective molecule with promising potential for the management of pain and inflammation.

Design and synthesis of 2-Substituted-4-benzyl-5-methylimidazoles as new potential Anti-breast cancer agents to inhibit oncogenic STAT3 functions

STAT3 signaling is known to be associated with tumorigenesis and further cancer cell-intrinsic activation of STAT3 leads to altered regulation of several oncogenic processes. Given the importance of STAT3 in cancer development and progression particularly breast cancer, it is crucial to discover new chemical entities of STAT3 inhibitor to develop anti-breast cancer drug candidates. Herein, 4-benzyl-2-benzylthio-5-methyl-1H-imidazole (2a) and 4-benzyl-5-methyl-2-[(2,6-difluorobenzyl)thio]-1H-imidazole (2d) from a group of thirty imidazole-bearing compounds showed greater STAT3 inhibition than their lead compounds VS1 and the oxadiazole derivative MD77. Within all tested compounds, ten derivatives effectively inhibited the growth of the two tested breast cancer cells with IC₅₀ values ranging from 6.66 to 26.02 µM. In addition, the most potent derivatives 2a and 2d inhibited the oncogenic function of STAT3 as seen in the inhibition of colony formation and IL-6 production of breast cancer cell lines. Modeling studies provided evidence for the possible interactions of the synthesized compounds with the key residues of the STAT3-SH2 domain. Collectively, our present study suggests 2-substituted-4-benzyl-5-methylimidazoles are a new class of anti-cancer drug candidates to inhibit oncogenic STAT3 function.

Potential anti-COVID-19 activity of Egyptian propolis using computational modeling

Aim: To investigate the prospective anti COVID-19 activity of Egyptian propolis. Material & methods: Propolis samples were collected from different Egyptian geographical areas and characterized using standardized methods, scanning electron microscope and gas chromatography/mass spectrometry along with computational modeling to predict the anti-COVID-19 activity. Results & conclusion: Gas chromatography/mass spectrometry analysis of Menoufia propolis proved the presence of Octatriacontyl pentafluoropropionate (4.2%). Docking analyses declared that Octatriacontyl pentafluoropropionate is well oriented inside the enzyme pockets, in addition to excellent binding manner with the active site of the target macromolecules (RNA-dependent RNA polymerase, Spike protein S1 and main protease) in relation to some broad-spectrum antiviral agents. Menoufia propolis could be a promising candidate in the combat against the pandemic COVID-19.

Synthesis and antimicrobial activity of some novel 1,2-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines bearing amino acid moiety

A new series of [1,2,4]-triazole bearing amino acid derivatives 2a-d-9a-d were synthesized under green chemistry conditions via multicomponent reaction using lemon juice as an acidic catalyst. The obtained compounds were characterized by different spectral and elemental analyses. The obtained candidates showed promising antibacterial activity against some standard bacteria and multidrug resistant (MDR) clinical isolates. In contrast to the reference drugs cephalothin and chloramphenicol, the tested compounds showed substantial better MIC values towards the tested MDR strains. The most active compounds 3c, 8a and 9d against MDR bacteria were tested for MBC and MIC index, the results indicted the bacteriostatic activity of these compounds. The most active compounds 2c, 2d, 3c, 8a, 8b, 9a, 9b, 9c and 9d showed a high selectivity index towards antimicrobial activity against K. pneumoniae and MRSA1 compared to mammalian cells, suggesting a good safety profile.

Supporting SARS-CoV-2 Papain-Like Protease Drug Discovery: In silico Methods and Benchmarking

The coronavirus disease 19 (COVID-19) is a rapidly growing pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Its papain-like protease (SARS-CoV-2 PLpro) is a crucial target to halt virus replication. SARS-CoV PLpro and SARS-CoV-2 PLpro share an 82.9% sequence identity and a 100% sequence identity for the binding site reported to accommodate small molecules in SARS-CoV. The flexible key binding site residues Tyr269 and Gln270 for small-molecule recognition in SARS-CoV PLpro exist also in SARS-CoV-2 PLpro. This inspired us to use the reported small-molecule binders to SARS-CoV PLpro to generate a high-quality DEKOIS 2.0 benchmark set. Accordingly, we used them in a cross-benchmarking study against SARS-CoV-2 PLpro. As there is no SARS-CoV-2 PLpro structure complexed with a small-molecule ligand publicly available at the time of manuscript submission, we built a homology model based on the ligand-bound SARS-CoV structure for benchmarking and docking purposes. Three publicly available docking tools FRED, AutoDock Vina, and PLANTS were benchmarked. All showed better-than-random performances, with FRED performing best against the built model. Detailed performance analysis via pROC-Chemotype plots showed a strong enrichment of the most potent bioactives in the early docking ranks. Cross-benchmarking against the X-ray structure complexed with a peptide-like inhibitor confirmed that FRED is the best-performing tool. Furthermore, we performed cross-benchmarking against the newly introduced X-ray structure complexed with a small-molecule ligand. Interestingly, its benchmarking profile and chemotype enrichment were comparable to the built model. Accordingly, we used FRED in a prospective virtual screen of the DrugBank database. In conclusion, this study provides an example of how to harness a custom-made DEKOIS 2.0 benchmark set as an approach to enhance the virtual screening success rate against a vital target of the rapidly emerging pandemic.

Combination of magnetic targeting with synergistic inhibition of NF-κB and glutathione via micellar drug nanomedicine enhances its anti-tumor efficacy

Breast cancer is not only one of the most prevalent types of cancer, but also it is a prime cause of death in women aged between 20 and 59. Although chemotherapy is the most common therapy approach, multiple side effects can result from lack of specificity and the use of overdose as safe doses may not completely cure cancer. Therefore, we aimed in this study is to combine the merits of NF-κB inhibiting potential of celastrol (CST) with glutathione inhibitory effect of sulfasalazine (SFZ) which prevents CST inactivation and thus enhances its anti-tumor activity. Inspired by the CD44-mediated tumor targeting effect of the hydrophilic polysaccharide chondroitin sulphate (ChS), we chemically synthesized amphiphilic zein-ChS micelles. While the water insoluble SFZ was chemically coupled to zein, CST was physically entrapped within the hydrophobic zein/SFZ micellar core. Moreover, physical encapsulation of oleic acid-capped SPIONs in the hydrophobic core of micelles enabled both magnetic tumor targeting as well as MRI theranostic capacity. Combining magnetic targeting to with the active targeting effect of ChS resulted in enhanced cellular internalization of the micelles in MCF-7 cancer cells and hence higher cytotoxic effect against MCF-7 and MDA-MB-231 breast cancer cells. In the in vivo experiments, magnetically-targeted micelles (154.4 nm) succeeded in achieving the lowest percentage increase in the tumor volume in tumor bearing mice, the highest percentage of tumor necrosis associated with significant reduction in the levels of TNF-α, Ki-67, NF-κB, VEGF, COX-2 markers compared to non-magnetically targeted micelles-, free drug-treated and positive control groups. Collectively, the developed magnetically targeted micelles pave the way for design of cancer nano-theranostic drug combinations.

PHNQ from Evechinus chloroticus Sea Urchin Supplemented with Calcium Promotes Mineralization in Saos-2 Human Bone Cell Line

Polyhydroxylated naphthoquinones (PHNQs), known as spinochromes that can be extracted from sea urchins, are bioactive compounds reported to have medicinal properties and antioxidant activity. The MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay showed that pure echinochrome A exhibited a cytotoxic effect on Saos-2 cells in a dose-dependent manner within the test concentration range (15.625-65.5 µg/mL). The PHNQ extract from New Zealand sea urchin Evechinus chloroticus did not induce any cytotoxicity within the same concentration range after 21 days of incubation. Adding calcium chloride (CaCl2) with echinochrome A increased the number of viable cells, but when CaCl2 was added with the PHNQs, cell viability decreased. The effect of PHNQs extracted on mineralized nodule formation in Saos-2 cells was investigated using xylenol orange and von Kossa staining methods. Echinochrome A decreased the mineralized nodule formation significantly (p < 0.05), while nodule formation was not affected in the PHNQ treatment group. A significant (p < 0.05) increase in mineralization was observed in the presence of PHNQs (62.5 µg/mL) supplemented with 1.5 mM CaCl2. In conclusion, the results indicate that PHNQs have the potential to improve the formation of bone mineral phase in vitro, and future research in an animal model is warranted.

Novel Siwa propolis and colistin-integrated chitosan nanoparticles: elaboration; in vitro and in vivo appraisal

Aim: The present study aimed to formulate novel cremophore-decorated chitosan nanoparticles of colistin, integrated with Siwa propolis extract, to solve bacterial resistance to colistin. Materials & methods: The novel nanoformula was prepared using an incorporation method. Physicochemical assessment and in vivo studies of the selected nanoformulations were performed. Results: The nanoformulation exhibited a nanosize of 48.3 nm, high ζ potential (43.6 mV), high entrapment efficiency (75%) and complete bacterial growth eradication within 2 h (minimum inhibitory concentration = 6.25 μg/ml). Histological examination showed that incorporation of colistin into the nanoformulation could successfully prevent its nephrotoxicity. Conclusion: Tailoring of proper nanocarrier could successfully revert bacteria from being colistin-resistant to colistin-sensitive. The developed nanoformulation can be considered as a potential antibacterial agent in pneumonia treatment.

Co-Administration of Tretinoin Enhances the Anti-Cancer Efficacy of Etoposide via Tumor-Targeted Green Nano-Micelles

Herein we report promoted anti-cancer activity via a combination strategy of synergistic chemotherapy/retinoid-based breast cancer therapy with shell-stabilized micellar green nanomedicine. Amphiphilic zein-chondroitin sulfate (ChS)-based copolymeric micelles (PMs) were successfully developed via carbodiimide coupling for concomitant delivery of etoposide (ETP) and all-trans retinoic acid (ATRA) to breast cancer. The micelles exhibited low critical micellar concentration (CMC) of 0.008 mg/mL with high encapsulation efficiencies of ETP and ATRA (61.2 and 84.29%, respectively). Calcium-mediated crosslinking of the anionic ChS micellar shell resulted in prolonged drug release with small micellar size of 222.7 nm. The micelles exhibited augmented internalization into MCF-7 breast cancer cells by virtue of ChS binding affinity to CD44 receptors overexpressed by cancer cells. Consequently, the ETP/ATRA-loaded micelles exhibited synergistic cytotoxicity against breast cancer cells as revealed by their significantly lower IC50, combination index (CI), and higherdose reduction index (DRI) in comparison to the free ETP and free ATRA or their combination. Micelles displayed superiority in reducing tumor volume, decreasing proliferation, and promoting necrosis in mice bearing Ehrlich Ascites Tumor (EAT) upon comparison to free ETP and free ATRA or their combination. Overall, the developed green zein-ChS micelles offer a promising platform for tumor-targeted delivery of hydrophobic therapeutic agents.

Synthesis, in vitro biological evaluation and in silico studies of certain arylnicotinic acids conjugated with aryl (thio)semicarbazides as a novel class of anti-leishmanial agents

Herein we introduce new compounds as conjugates of arylnicotinic acids with aryl (thio)semicarbazide derivatives. Based on a structure-guided approach, they were designed to possess anti-leishmanial activity through anti-folate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro anti-promastigote and anti-amastigote activity were promising for many thiosemicarbazide derivatives and superior to the reference miltefosine. The most active compounds 8i and 8j exhibited their anti-amastigote activity with IC₅₀ values of 4.2 and 3.3 μM, respectively, compared to reference miltefosine (IC₅₀ value of 7.3). Their anti-folate mechanism was confirmed via the ability of folic and folinic acids to reverse the anti-leishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Interestingly, the in vitro cytotoxicity test of the most active compounds displayed higher selectivity indices than that of miltefosine emphasizing their safety on mammalian cells. Furthermore, the docking experiments on Lm-PTR1 as a putative target rationalized the in vitro anti-leishmanial activity. The in silico predictions exhibited promising pharmacokinetics and drug-likeness profiles of the most active compounds. Generally, this work introduces a fruitful matrix for new anti-leishmanial chemotype which would extend the chemical space for the anti-leishmanial activity.

Lactobionic/Folate Dual-Targeted Amphiphilic Maltodextrin-Based Micelles for Targeted Codelivery of Sulfasalazine and Resveratrol to Hepatocellular Carcinoma

In this study, promising approaches of dual-targeted micelles and drug-polymer conjugation were combined to enable injection of poorly soluble anticancer drugs together with site-specific drug release. Ursodeoxycholic acid (UDCA) as a hepatoprotective agent was grafted to maltodextrin (MD) via carbodiimide coupling to develop amphiphilic maltodextrin-ursodeoxycholic acid (MDCA)-based micelles. Sulfasalazine (SSZ), as a novel anticancer agent, was conjugated via a tumor-cleavable ester bond to MD backbone to obtain tumor-specific release, whereas resveratrol (RSV) was physically entrapped within the hydrophobic micellar core. For maximal tumor-targeting, both folic acid (FA) and lactobionic acid (LA) were coupled to the surface of micelles to obtain dual-targeted micelles. The decrease of critical micelle concentration (CMC) from 0.012 to 0.006 mg/mL declares the significance of a dual hydrophobicized core of micelles by both UDCA and SSZ. The dual-targeted micelles showed a great hemocompatibility, as well as enhanced cytotoxicity and internalization into HepG-2 liver cancer cells via binding to overexpressed folate and asialoglycoprotein receptors. In vivo, the micelles demonstrated superior antitumor effects revealed as reduction in the liver/body weight ratio, inhibition of angiogenesis, and enhanced apoptosis. Overall, combined strategies of dual active targeted micelles with bioresponsive drug conjugation could be utilized as a promising approach for tumor-targeted drug delivery.

Polyphenol uses in biomaterials engineering

Polyphenols are micronutrients obtained from diet that have been suggested to play an important role in health. The health benefits of polyphenols and their protective effects in food systems as antioxidant compounds are well known and have been extensively investigated. However, their functional roles as a "processing cofactor" in tissue engineering applications are less widely known. This review focuses on the functionality of polyphenols and their application in biomaterials. Polyphenols have been used to stabilize collagen and to improve its resistance to degradation in biological systems. Therefore, they have been proposed to improve the performance of biomedical devices used in cardiovascular systems by improving the mechanical properties of grafted heart valves, enhancing microcirculation through the relaxation of the arterial walls and improving the capillary blood flow and pressure resistance. Polyphenols have been found to stimulate bone formation, mineralization, as well as the proliferation, differentiation, and the survival of osteoblasts. These effects are brought about by the stimulatory effect of polyphenols on osteoblast cells and their protective effect against oxidative stress and inflammatory cytokines. In addition, polyphenols inhibit the differentiation of the osteoclast cells. Collectively, these actions lead to promote bone formation and to reduce bone resorption, respectively. Moreover, polyphenols can increase the cross-linking of dentine and hence its mechanical stability. Overall, polyphenols provide interesting properties that will stimulate further research in the bioengineering field.

Folate conjugated vs PEGylated phytosomal casein nanocarriers for codelivery of fungal- and herbal-derived anticancer drugs

Aim: Monascin and ankaflavin, the major fractions of the fungal-derived monascus yellow pigments, were incorporated with the herbal drug, resveratrol (RSV) within the core of folate-conjugated casein micelles (FA–CAS MCs, F1) for active targeting. PEGylated RSV-phospholipid complex bilayer enveloping casein-loaded micelles (PEGPC–CAS MCs) were also developed as passive-targeted nanosystem. Results: FA– and PEGPC–CAS MCs demonstrated a proper size with monomodal distribution, sustained drug release profiles and good hemocompatibility. The coloaded MCs showed superior cytotoxicity to MCF-7 breast cancer cells compared with free drugs. Both nanosystems exerted excellent in vivo antitumor efficacy in breast cancer bearing mice with PEGylated MCs showing comparable tumor regression to folate-conjugated MCs. Conclusion: Evergreen nanoplatforms coloaded with monascus yellow pigments and RSV were effective for breast cancer treatment.

Keratin: dissolution, extraction and biomedical application

Keratinous materials such as wool, feathers and hooves are tough unique biological co-products that usually have high sulfur and protein contents. A high cystine content (7-13%) differentiates keratins from other structural proteins, such as collagen and elastin. Dissolution and extraction of keratin is a difficult process compared to other natural polymers, such as chitosan, starch, collagen, and a large-scale use of keratin depends on employing a relatively fast, cost-effective and time efficient extraction method. Keratin has some inherent ability to facilitate cell adhesion, proliferation, and regeneration of the tissue, therefore keratin biomaterials can provide a biocompatible matrix for regrowth and regeneration of the defective tissue. Additionally, due to its amino acid constituents, keratin can be tailored and finely tuned to meet the exact requirement of degradation, drug release or incorporation of different hydrophobic or hydrophilic tails. This review discusses the various methods available for the dissolution and extraction of keratin with emphasis on their advantages and limitations. The impacts of various methods and chemicals used on the structure and the properties of keratin are discussed with the aim of highlighting options available toward commercial keratin production. This review also reports the properties of various keratin-based biomaterials and critically examines how these materials are influenced by the keratin extraction procedure, discussing the features that make them effective as biomedical applications, as well as some of the mechanisms of action and physiological roles of keratin. Particular attention is given to the practical application of keratin biomaterials, namely addressing the advantages and limitations on the use of keratin films, 3D composite scaffolds and keratin hydrogels for tissue engineering, wound healing, hemostatic and controlled drug release.

Phytosomal bilayer-enveloped casein micelles for codelivery of monascus yellow pigments and resveratrol to breast cancer

Aim: Multireservoir nanocarriers were fabricated for delivering antineoplastic drug cocktail from herbal and fungal origin. Monascus yellow pigments (MYPs), monascin and ankaflavin, were isolated from red-mold rice, and incorporated within casein micelles (CAS MCs) along with the herbal drug, resveratrol (RSV). Both drugs (MYPs and RSV) were simultaneously incorporated into the hydrophobic core of CAS MCs. Alternatively, MYPs-loaded CAS MCs were enveloped within RSV-phytosomal bilayer elaborating multireservoir nanocarriers. Results: Cytotoxicity studies confirmed the superiority of multireservoir nanocarriers against MCF-7 breast cancer cells. The in vivo antitumor efficacy was revealed by reduction of the tumor volume and growth biomarkers. Conclusion: Multireservoir CAS nanocarriers for codelivery of both MYPs and RSV may be promising alternative to traditional breast cancer therapy.

1,3,5-Triazino Peptide Derivatives: Synthesis, Characterization, and Preliminary Antileishmanial Activity

A library of short di-, tri-, and tetra-peptides with an s-triazine moiety at the N terminus and either an amide or ethyl ester C terminus was prepared in solution and on the solid phase. The two remaining positions of the s-triazine moiety were substituted with methoxy, morpholino, or piperidino groups. All the synthesized peptide derivatives were analyzed by HPLC and fully characterized by IR spectroscopy, ¹ H and ¹³ C NMR spectroscopy, elemental analysis, and mass spectrometry (MALDI TOF/TOF). A preliminary study of the antileishmanial activity of the 1,3,5-triazinyl peptide derivatives revealed that four dipeptide amide derivatives showed higher antipromastigote or antiamastigote activity than the reference standard drug miltefosine with no significance acute toxicity.

Synthesis and characterization of novel dimerics-triazine derivatives as potential anti-bacterial agents against MDR clinical isolates

Several dimerics-triazine Schiff bases displayed more potent anti-bacterial activity compared with ampicillin trihydrate. They revealed significantly low MIC values towards the tested MDR strains and showed a high selectivity index towards antimicrobial activity againstK. pneumoniaeandMRSA1compared to mammalian cells.

Design and synthesis of new s-triazine polymers and their application as nanoparticulate drug delivery systems

The feasibility ofs-triazine polyamides to fabricate celecoxib-loaded nanoparticles.

Quantification of total polyphenols, catechin, caffeine, L-theanine, determination of antioxidant activity and effect on antileishmanial drugs of ethiopian tea leaves extracts

Objective:

In this study four tea samples Gumero black, Wushwush black and Wushwush green from Agri- Ceft Plc and East Africa black tea leaves from East African Agribusiness Plc were investigated for total polyphenols, caffeine, catechin and L-theanine content.

Materials and Methods:

The aqueous extracts were investigated for their antioxidant and antileishmanial property and effect on amphotericin B, miltefocine and sodium stibogluconate, the commonly used antileishmanial drugs. Antileishmanial studies were conducted on L. aethiopica.

Results:

Wushwush green tea had the highest content of polyphenol (19.98 ± 1.15 mg gallic acid equivalent /100 g dry leaf weight), catechin (37.06 mg/g) and L-theanine (48.54 mg/g but the lowest caffeine content). It exhibited the highest antioxidant activity. The highest antioxidant effect of Wushwush green tea may be attributed to the highest polyphenol content. East African black tea had the lowest L-theanine (20.72 mg/g) and antioxidant activity but the highest caffeine (16.60 mg/g) content.

Conclusion:

Wushwush green tea showed slight inhibitory effect on L. aethiopica while the lack tea extracts (Gumero, East Africa and Wushwush) exhibited no antileishmanial activity. Wushwush green tea did not show any synergistic or antagonistic effect on the antileishmanial drugs used in this study while Gumero, East Africa and Wushwush black tea extracts exhibited dose dependant inhibitory activity to the commonly used antileishmanial drugs included in this study.

Persistent organochlorine pesticides residues in cow and goat milks collected from different regions of Ethiopia

The present study investigated the bioaccumulation of organochlorines in two milk-producing animals (goats and cows) grazed on the same feed to explore the extent of organochlorines availability in milk and any species effect on the bioaccumulation pattern. Six organochlorine pesticides: aldrin, α-endosulfan, β-endosulfan, p,p'-DDE, o,p'-DDT and p,p'-DDT were determined in samples collected from four regions in Ethiopia. Aldrin (11.6μgkg(-1)) was detected only in one cow milk sample and α-endosulfan was detected in one goat milk sample at a level of 142.1μgkg(-1), and in one cow milk sample (47.8μgkg(-1)) from the same region. p,p'-DDE was detected in 40% of the milk samples analyzed while o,p'-DDT and p,p'-DDT were found in high amounts in almost all samples. The average total DDT (excluding DDD) in the samples was 328.5μgkg(-1). Regions known for their malaria epidemics were the most contaminated with DDT residue. The accumulation pattern in both species was not clear under natural sampling.

Antifungal and antiviral products of marine organisms

Marine organisms including bacteria, fungi, algae, sponges, echinoderms, mollusks, and cephalochordates produce a variety of products with antifungal activity including bacterial chitinases, lipopeptides, and lactones; fungal (-)-sclerotiorin and peptaibols, purpurides B and C, berkedrimane B and purpuride; algal gambieric acids A and B, phlorotannins; 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol, spongistatin 1, eurysterols A and B, nortetillapyrone, bromotyrosine alkaloids, bis-indole alkaloid, ageloxime B and (-)-ageloxime D, haliscosamine, hamigeran G, hippolachnin A from sponges; echinoderm triterpene glycosides and alkene sulfates; molluscan kahalalide F and a 1485-Da peptide with a sequence SRSELIVHQR; and cepalochordate chitotriosidase and a 5026.9-Da antifungal peptide. The antiviral compounds from marine organisms include bacterial polysaccharide and furan-2-yl acetate; fungal macrolide, purpurester A, purpurquinone B, isoindolone derivatives, alterporriol Q, tetrahydroaltersolanol C and asperterrestide A, algal diterpenes, xylogalactofucan, alginic acid, glycolipid sulfoquinovosyldiacylglycerol, sulfated polysaccharide p-KG03, meroditerpenoids, methyl ester derivative of vatomaric acid, lectins, polysaccharides, tannins, cnidarian zoanthoxanthin alkaloids, norditerpenoid and capilloquinol; crustacean antilipopolysaccharide factors, molluscan hemocyanin; echinoderm triterpenoid glycosides; tunicate didemnin B, tamandarins A and B and; tilapia hepcidin 1-5 (TH 1-5), seabream SauMx1, SauMx2, and SauMx3, and orange-spotted grouper β-defensin. Although the mechanisms of antifungal and antiviral activities of only some of the aforementioned compounds have been elucidated, the possibility to use those known to have distinctly different mechanisms, good bioavailability, and minimal toxicity in combination therapy remains to be investigated. It is also worthwhile to test the marine antimicrobials for possible synergism with existing drugs. The prospects of employing them in clinical practice are promising in view of the wealth of these compounds from marine organisms. The compounds may also be used in agriculture and the food industry.