Morinda citrifolia (noni) fruit juice inhibits SARS-CoV-2 spike protein binding of angiotensin receptor type 2

Covid-19 is a global pandemic that has claimed millions of lives. This disease is caused by a coronavirus, SARS-CoV-2, which requires the binding of its spike protein to angiotensin-converting enzyme 2 (ACE2) for infection of the host cell. Morinda citrifolia (noni) fruit juice has antiviral activity that involves enhancement of immune system function. SARS-CoV-2 spike-ACE2 interaction experiments were carried out to further investigate the antiviral properties of noni juice and its major iridoids. Noni juice inhibited binding by approximately 69%. Scandoside was the most active of the three iridoids evaluated, reducing average spike protein-ACE2 interaction by 79.25%. The iridoids worked synergistically towards inhibiting spike protein binding when assayed together, improving activity by more than 22% above the expected level. But the modest activity of the most abundant iridoid, deacetylasperulosidic acid, indicates that other phytochemicals (i.e. scopoletin, quercetin, rutin and kaempferol) are also involved. Our results suggest that the presence of several biological active phytochemicals in noni juice enhances resistance to SARS-CoV-2 by interfering with its ability to bind ACE2. This is a new and significant anti-viral mechanism of noni juice that does not directly involve its immunomodulatory properties.

Endogenous and combination retinoids are active in myelomonocytic leukemias

Retinoid therapy transformed response and survival outcomes in acute promyelocytic leukemia (APL), but has demonstrated only modest activity in non-APL forms of acute myeloid leukemia (AML). The presence of natural retinoids in vivo could influence the efficacy of pharmacologic agonists and antagonists. We found that natural RXRA ligands, but not RARA ligands, were present in murine MLL-AF9-derived myelomonocytic leukemias in vivo and that the concurrent presence of receptors and ligands acted as tumor suppressors. Pharmacologic retinoid responses could be optimized by concurrent targeting RXR ligands (e.g. bexarotene) and RARA ligands (e.g. all-trans retinoic acid, ATRA), which induced either leukemic maturation or apoptosis depending on cell culture conditions. Co-repressor release from the RARA:RXRA heterodimer occurred with RARA activation, but not RXRA activation, providing an explanation for the combination synergy. Combination synergy could be replicated in additional, but not all, AML cell lines and primary samples, and was associated with improved survival in vivo, although tolerability of bexarotene administration in mice remained an issue. These data provide insight into the basal presence of natural retinoids in leukemias in vivo and a potential strategy for clinical retinoid combination regimens in leukemias beyond acute promyelocytic leukemia.

Screening of FDA-Approved Drugs Using a 384-Well Plate-Based Biofilm Platform: The Case of Fingolimod

In an effort to find new repurposed antibacterial compounds, we performed the screening of an FDA-approved compounds library against Staphylococcus aureus American Type Culture Collection (ATCC) 25923. Compounds were evaluated for their capacity to prevent both planktonic growth and biofilm formation as well as to disrupt pre-formed biofilms. One of the identified initial hits was fingolimod (FTY720), an immunomodulator approved for the treatment of multiple sclerosis, which was then selected for follow-up studies. Fingolimod displayed a potent activity against S. aureus and S. epidermidis with a minimum inhibitory concentration (MIC) within the range of 12–15 µM at which concentration killing of all the bacteria was confirmed. A time–kill kinetic study revealed that fingolimod started to drastically reduce the viable bacterial count within two hours and we showed that no resistance developed against this compound for up to 20 days. Fingolimod also displayed a high activity against Acinetobacter baumannii (MIC 25 µM) as well as a modest activity against Escherichia coli and Pseudomonas aeruginosa. In addition, fingolimod inhibited quorum sensing in Chromobacterium violaceum and might therefore target this signaling pathway in certain Gram-negative bacteria. In conclusion, we present the identification of fingolimod from a compound library and its evaluation as a potential repurposed antibacterial compound.

Enhanced retinoid response by a combination of the vitamin A ester retinyl propionate with niacinamide and a flavonoid containing Ceratonia siliqua extract in retinoid responsive in vitro models

OBJECTIVESRetinoids have been used for decades as efficacious topical agents to treat photoaged skin. The purpose of our present research is to evaluate whether the activity of the Vitamin A ester retinyl propionate (RP) can be enhanced by niacinamide (Nam) and a flavonoid containing Ceratonia siliqua (CS) fruit extract in retinoid responsive in vitro models.METHODSRP was tested alone and in combination with Nam and CS in an RARα reporter cell line for promoter activation and compared to trans-retinoic acid (tRA) activation. These treatments were also tested in keratinocytes for gene expression profiling by qPCR using a panel of 40 retinoid responsive genes.RESULTStRA or RP elicited RARα reporter activation in a dose dependent manner. The combination of 0.5 μM or 2 μM RP with 10 mM Nam had a 56% and 95% signal increase compared to RP, respectively. The addition of 1% CS to 0.5 μM or 2 μM RP with 10 mM Nam elicited a further increase of 114% and 156%, respectively, over RP and Nam combinations. All retinoids elicited an increase in expression of 40 retinoid sensitive genes over control levels. Of the 40 genes 27 were enhanced by either 0.5 μM RP or 2 μM RP with 10 mM Nam and 1% CS. Nam or CS had very modest activity in both models.CONCLUSIONThe combination of RP with Nam and CS showed a higher retinoid response than RP in two separate retinoid responsive in vitro models. We hypothesize Nam and CS enhances RP activity by modulating metabolism to tRA via increasing NAD+ pools and inhibiting reduction of retinal (RAL) back to retinol, respectively. The findings provide evidence that this combination may have enhanced efficacy for treating the appearance of photoaged skin.

Synthesis of bioactive quinazolin-4(3H)-one derivatives via microwave activation tailored by phase-transfer catalysis

A series of nine new 2,3-disubstituted 4(3H)-quinazolin-4-one derivatives was furnished starting from the 2-propyl-4(3H)-quinazo-line-4-one (2). The reinvestigation of the key starting quinazolinone 2 was performed under microwave irradiation (MW) and solvent-free conditions. Combination of MW and phase-transfer catalysis using tetrabutylammonium benzoate (TBAB) as a novel neutral ionic catalyst was used for carrying out N-alkylation and condensation reactions of compound 2 as a simple, efficient and eco-friendly technique. The structure of the synthesized compounds was elucidated using different spectral and chemical analyses. In vitro antimicrobial activity of the compounds was investigated against four bacterial and two fungal strains; very modest activity was achieved. Some of the synthesized compounds were screened for their antitumor activity against different human tumor cell lines. The screened compounds exhibited a significant antitumor activity on some of the cancer cell lines, melanoma (SK-MEL-2), ovarian cancer (IGROV1), renal cancer (TK-10), prostate cancer (PC-3), breast cancer (MCF7) and colon cancer (HT29). The most active, even more active than the reference 5-fluorouracil, were found to be ethyl 4-[(4-oxo-2-propylquinazolin-3(4H)-yl)methyl]benzoate (3c), 3-{2-[6-(pyrrolidin-1-yl-sulfonyl)-1,2,3,4-tetrahydroquinoline]-2-oxoethyl}-2-propylquinazolin--4(3H)-one (3e), N’-[(E)-(2H-1,3-benzodioxo-5-yl)methylidene]-2-(4-oxo-2-propylquinazolin-3(4H)-yl)acetohydrazide (10a), N’-[(E)-(4-hydroxyphenyl)methylidene]-2-(4-oxo-2-propylquinazo-lin-3(4H) -yl)acetohydrazide (10b) and N’-[(E)-(4-nitrophenyl)methyl idene]-2-(4-oxo-2-propylquinazolin-3(4H)-yl)acetohydrazide (10c).

Comparative Antiviral Activity of Remdesivir and Anti-HIV Nucleoside Analogs against Human Coronavirus 229E (HCoV-229E)

Remdesivir is a nucleotide prodrug that is currently undergoing extensive clinical trials for the treatment of COVID-19. The prodrug is metabolized to its active triphosphate form and interferes with the action of RNA-dependent RNA polymerase of SARS-COV-2. Herein, we report the antiviral activity of remdesivir against human coronavirus 229E (HCoV-229E) compared to known anti-HIV agents. These agents included tenofovir (TFV), 4′-ethynyl-2-fluoro-2′-deoxyadenosine (EFdA), alovudine (FLT), lamivudine (3TC), and emtricitabine (FTC), known as nucleoside reverse-transcriptase inhibitors (NRTIs), and a number of 5′-O-fatty acylated anti-HIV nucleoside conjugates. The anti-HIV nucleosides interfere with HIV RNA-dependent DNA polymerase and/or act as chain terminators. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. The study revealed that remdesivir exhibited an EC50 value of 0.07 µM against HCoV-229E with TC50 of > 2.00 µM against MRC-5 cells. Parent NRTIs were found to be inactive against (HCoV-229E) at tested concentrations. Among all the NRTIs and 5′-O-fatty acyl conjugates of NRTIs, 5′-O-tetradecanoyl ester conjugate of FTC showed modest activity with EC50 and TC50 values of 72.8 µM and 87.5 µM, respectively. These data can be used for the design of potential compounds against other coronaviruses.

A Review of Immune Checkpoint Blockade Therapy in Endometrial Cancer

Approximately 30% of primary endometrial cancers are microsatellite instability high/hypermutated (MSI-H), and 13% to 30% of recurrent endometrial cancers are MSI-H or mismatch repair deficient (dMMR). Given the presence of immune dysregulation in endometrial cancer as described, immune checkpoint blockade (ICB) has been explored as a therapeutic mechanism, both as monotherapy and in combination with cytotoxic chemotherapy, other immunotherapy, or targeted agents. In MSI-H or dMMR advanced endometrial cancers, PD-1 inhibitors dostarlimab and pembrolizumab have shown response rates of 49% and 57%, respectively, whereas PD-L1 inhibitors avelumab and durvalumab have shown response rates of 27% and 43%, respectively. In microsatellite stable (MSS) or PD-L1–positive advanced endometrial cancers, modest activity of PD-1 inhibitors nivolumab and dostarlimab and PD-L1 inhibitors atezolizumab, avelumab, and durvalumab has been seen, with response rates ranging from 3% to 23%. Based on substantial activity in a phase Ib/II study, the U.S. Food and Drug Administration (FDA) granted lenvatinib and pembrolizumab combination therapy accelerated approval in 2019 for the treatment of advanced endometrial cancer that is not MSI-H or dMMR and has progressed following prior therapy. Although these developments have been highly impactful, a more robust understanding of the molecular and immunologic drivers of response and resistance will be critical to optimally design next-generation studies in endometrial cancer.

MAP kinase dysregulation by Coronaviruses

An opinion on what may cause complications displayed by the current coronavirus whereby it seems MAP kinase is 'overworking' in the process of virulence. Although the virus is completely inactivated in the presence of known chemicals such as acetone and zinc it is by accessing the lungs that it manages to cause respiratory distress. The virus is quite an amphiphilic molecule which makes its absorption easy to achieve particularly at an alveolar level where gas exchange occurs; however this amphilicity has been reached by mimicking human genome rather than by its own developmental sophistication. There is a wide range of therapeutic options for map kinase regulations. Some antimalarials and low dose aspirin even have demonstrated modest activity and according to recent news they have helped in difficult cases but prompt antiviral management should be addressed prior to the skyrocketing immune phase where the body may fail to recognise itself and self-attack. By targeting the virus initially the map kinase may react non-disproportionately.

Nicotinamide Limits Replication of Mycobacterium tuberculosis and Bacille Calmette-Guérin Within Macrophages

Novel antimicrobials for treatment of Mycobacterium tuberculosis are needed. We hypothesized that nicotinamide (NAM) and nicotinic acid (NA) modulate macrophage function to restrict M. tuberculosis replication in addition to their direct antimicrobial properties. Both compounds had modest activity in 7H9 broth, but only NAM inhibited replication in macrophages. Surprisingly, in macrophages NAM and the related compound pyrazinamide restricted growth of bacille Calmette-Guérin but not wild-type Mycobacterium bovis, which both lack a functional nicotinamidase/pyrazinamidase (PncA) rendering each strain resistant to these drugs in broth culture. Interestingly, NAM was not active in macrophages infected with a virulent M. tuberculosis mutant encoding a deletion in pncA. We conclude that the differential activity of NAM and nicotinic acid on infected macrophages suggests host-specific NAM targets rather than PncA-dependent direct antimicrobial properties. These activities are sufficient to restrict attenuated BCG, but not virulent wild-type M. bovis or M. tuberculosis.

Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO

Currently, the most active electrocatalysts for the conversion of CO2 to CO are gold-based nanomaterials, whereas non–precious metal catalysts have shown low to modest activity. Here, we report a catalyst of dispersed single-atom iron sites that produces CO at an overpotential as low as 80 millivolts. Partial current density reaches 94 milliamperes per square centimeter at an overpotential of 340 millivolts. Operando x-ray absorption spectroscopy revealed the active sites to be discrete Fe3+ ions, coordinated to pyrrolic nitrogen (N) atoms of the N-doped carbon support, that maintain their +3 oxidation state during electrocatalysis, probably through electronic coupling to the conductive carbon support. Electrochemical data suggest that the Fe3+ sites derive their superior activity from faster CO2 adsorption and weaker CO absorption than that of conventional Fe2+ sites.