Galangal-Cinnamon Spice Mixture Blocks the Coronavirus Infection Pathway through Inhibition of SARS-CoV-2 MPro, Three HCoV-229E Targets; Quantum-Chemical Calculations Support In Vitro Evaluation

Natural products such as domestic herbal drugs which are easily accessible and cost-effective can be used as a complementary treatment in mild and moderate COVID-19 cases. This study aimed to detect and describe the efficiency of phenolics detected in the galangal-cinnamon mixture in the inhibition of SARS-CoV-2's different protein targets. The potential antiviral effect of galangal-cinnamon aqueous extract (GCAE) against Low Pathogenic HCoV-229E was assessed using cytopathic effect inhibition assay and the crystal violet method. Low Pathogenic HCoV-229E was used as it is safer for in vitro laboratory experimentation and due to the conformation and the binding pockets similarity between HCoV-229E and SARS-CoV-2 MPro. The GCAE showed a significant antiviral effect against HCoV-229E (IC50 15.083 µg/mL). Twelve phenolic compounds were detected in the extract with ellagic, cinnamic, and gallic acids being the major identified phenolic acids, while rutin was the major identified flavonoid glycoside. Quantum-chemical calculations were made to find molecular properties using the DFT/B3LYP method with 6-311++G(2d,2p) basis set. Quantum-chemical values such as EHOMO, ELUMO, energy gap, ionization potential, chemical hardness, softness, and electronegativity values were calculated and discussed. Phenolic compounds detected by HPLC-DAD-UV in the GCAE were docked into the active site of 3 HCoV-229E targets (PDB IDs. 2ZU2, 6U7G, 7VN9, and 6WTT) to find the potential inhibitors that block the Coronavirus infection pathways from quantum and docking data for these compounds. There are good adaptations between the theoretical and experimental results showing that rutin has the highest activity against Low Pathogenic HCoV-229E in the GCAE extract.

Anti-Alzheimer potential, metabolomic profiling and molecular docking of green synthesized silver nanoparticles of Lampranthus coccineus and Malephora lutea aqueous extracts

The green synthesis of silver nanoparticles (SNPs) using plant extracts is an eco-friendly method. It is a single step and offers several advantages such as time reducing, cost-effective and environmental non-toxic. Silver nanoparticles are a type of Noble metal nanoparticles and it has tremendous applications in the field of diagnostics, therapeutics, antimicrobial activity, anticancer and neurodegenerative diseases. In the present work, the aqueous extracts of aerial parts of Lampranthus coccineus and Malephora lutea F. Aizoaceae were successfully used for the synthesis of silver nanoparticles. The formation of silver nanoparticles was early detected by a color change from pale yellow to reddish-brown color and was further confirmed by transmission electron microscope (TEM), UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and energy-dispersive X-ray diffraction (EDX). The TEM analysis of showed spherical nanoparticles with a mean size between 12.86 nm and 28.19 nm and the UV- visible spectroscopy showed λmax of 417 nm, which confirms the presence of nanoparticles. The neuroprotective potential of SNPs was evaluated by assessing the antioxidant and cholinesterase inhibitory activity. Metabolomic profiling was performed on methanolic extracts of L. coccineus and M. lutea and resulted in the identification of 12 compounds, then docking was performed to investigate the possible interaction between the identified compounds and human acetylcholinesterase, butyrylcholinesterase, and glutathione transferase receptor, which are associated with the progress of Alzheimer's disease. Overall our SNPs highlighted its promising potential in terms of anticholinesterase and antioxidant activity as plant-based anti-Alzheimer drug and against oxidative stress.

Antiviral potential of green synthesized silver nanoparticles of Lampranthus coccineus and Malephora lutea

Background

Viral and microbial infections constitute one of the most important life-threatening problems. The emergence of new viral and bacterial infectious diseases increases the demand for new therapeutic drugs.

Purpose

The objective of this study was to use the aqueous and hexane extracts of Lampranthus coccineus and Malephora lutea F. Aizoaceae for the synthesis of silver nanoparticles, and to investigate its possible antiviral activity. In addition to the investigation of the phytochemical composition of the crude methanolic extracts of the two plants through UPLC-MS metabolomic profiling, and it was followed by molecular docking in order to explore the chemical compounds that might contribute to the antiviral potential.

Methods

The formation of SNPs was further confirmed using a transmission electron microscope (TEM), UV-Visible spectroscopy and Fourier transform infrared spectroscopy. The antiviral activity of the synthesized nanoparticles was evaluated using MTT assay against HSV-1, HAV-10 virus and Coxsackie B4 virus. Metabolomics profiling was performed using UPLC-MS and molecular docking was performed via Autodock4 and visualization was done using the Discovery studio.

Results

The early signs of SNPs synthesis were detected by a color change from yellow to reddish brown color. The TEM analysis of SNPs showed spherical nanoparticles with mean size ranges between 10.12 nm to 27.89 nm, and 8.91 nm 14.48 nm for Lampranthus coccineus and Malephora lutea aqueous and hexane extracts respectively. The UV-Visible spectrophotometric analysis showed an absorption peak at λmax of 417 nm.The green synthesized SNPs of L. coccineus and M. lutea showed remarkable antiviral activity against HSV-1, HAV-10, and CoxB4 virus. Metabolomics profiling of the methanolic extract of L. coccineus and M. lutea resulted in identifying 12 compounds. The docking study predicted the patterns of interactions between the compounds of L. coccineus and M. lutea with herpes simplex thymidine kinase, hepatitis A 3c proteinase, and Coxsackievirus B4 3c protease, which was similar to those of the co-crystal inhibitors and this can provide a supposed explanation for the antiviral activity of the aqueous and nano extracts of L. coccineus and M. lutea.

Conclusion

These results highlight that SNPs of L. coccineus and M. lutea could have antiviral activity against HSV-1, HAV-10, and CoxB4 virus.

Euphosantianane A⁻D: Antiproliferative Premyrsinane Diterpenoids from the Endemic Egyptian Plant Euphorbia Sanctae-Catharinae

Euphorbia species are rich in diterpenes. A solvent extraction of Euphorbia sanctae-catharinae, a species indigenous to the Southern Sinai of Egypt, afforded several premyrsinane diterpenoids (1⁻4) as well as previously reported metabolites (5⁻13) that included three flavonoids. Isolated compounds were chemically characterized by spectroscopic analysis. Identified compounds were bioassayed for anti-proliferative activity in vitro against colon (Caco-2) and lung (A549) tumor cell lines. Compound 9 exhibited robust anti-proliferative activity against A549 cells (IC50 = 3.3 µM). Absolute configurations for 8 versus 9 were determined by experimental and TDDFT-calculated electronic circular dichorism (ECD) spectra.

Rutin as A Novel c-Met Inhibitory Lead for The Control of Triple Negative Breast Malignancies

Triple negative breast cancer (TNBC) has high metastatic and mortality potential and lacks effective and selective therapeutic options. Aberrant dysregulation of the receptor tyrosine kinase c-Met promotes TNBC progression, motility and survival and therefore considered a valid therapeutic target. Among various identified anticancer agents, plant polyphenols (PPs) including flavonoids, have been shown to be safe and proven for their antitumor activity through modulating diverse macromolecular targets. This study reports the bioassay-guided identification of the common flavonol glycoside rutin as breast cancer cell proliferation, migration and invasion inhibitor. The cell free Z'-LYTE kinase assay, Western blot and in silico docking experiments uncovered, for the first time, c-Met kinase as a potential mechanistic target for rutin-mediated anticancer effects on TNBC cell lines. Likewise, the intraperitoneal injection of rutin at 30 mg/kg, 3X/week, significantly reduced the growth of the TNBC MDA-MB-231/GFP orthotopic xenograft in nude mouse model. These results clearly designate the functional dietary flavonoid rutin as a potential lead for the prevention and control of c-Met-dependent breast malignancies.

Rationally designed hecogenin thiosemicarbazone analogs as novel MEK inhibitors for the control of breast malignancies

Natural products have documented oncology success history as valuable scaffolds for selective target modulation. Herein, the sapogenin hecogenin (1) was screened for its anti-breast cancer inhibitory capacity using in vitro assays, including proliferation, cytotoxicity, migration, invasion assays, and Western blotting. The results identified 1 as a propitious hit with modest activities attributed to the concurrent down-regulation of mitogen activated protein kinase kinase/extracellular signal-regulated kinase (MEK) distinctive downstream effectors. Guided by in silico 3D-structural insights of MAPK kinase domain, an extension strategy was adopted at 1's C-3 and C-12 aimed at the design of novel hecogenin-based analogs with improved target binding affinity. Thirty-three analogs were prepared and tested, among which hecogenin 12-(3'-methylphenyl thiosemicarbazone) (30) displayed the most potent selective anticancer effects. Analog 30 demonstrated antiproliferative, antimigratory and anti-invasive activities at low μM level, compared to the negligible effect on the non-tumorigenic MCF-10A mammary epithelial cells. Durable regression of breast tumor xenografts in athymic nude mice was observed after treatments with 30, compared to its parent hecogenin at the same dose regimen, confirmed the hit-to-lead promotion of this analog. Hecogenin-12-thiosemicarbazones, represented by 30, is a novel MEK inhibitory lead class to control breast neoplasms.

Discovery, optimization, and pharmacophore modeling of oleanolic acid and analogues as breast cancer cell migration and invasion inhibitors through targeting Brk/Paxillin/Rac1 axis

Bioassay-guided fractionation of Terminalia bentzoe L. leaves methanol extract identified the known triterpene oleanolic acid (1) as its major breast cancer cell migration inhibitor. Further chemical optimization afforded five new (9-12 and 15) and seven known (4-8, 13, and 14) semisynthetic analogues. All compounds were tested for their ability to inhibit human breast cancer MDA-MB-231 cells migration, proliferation, and invasion. The results revealed that 3-O-[N-(3'-chlorobenzenesulfonyl)-carbamoyl]-oleanolic acid (11) and 3-O-[N-(5'-fluorobenzenesulfonyl)-carbamoyl]-oleanolic acid (12) were the most active hits at low μM concentration. Western blot analysis indicated the activity of 1, 11, and 12 might be related, at least in part, to the suppression of Brk/Paxillin/Rac1 signaling pathway. Pharmacophore modeling study was conducted to better understand the common structural binding epitopes important for the antimigratory activity. The sulfonyl carbamoyl moiety with an optimal bulkiness electron-deficient phenyl ring is associated with improved activity. This study is the first to discover the antimigratory and anti-invasive activities of oleanolic acid and analogues through targeting the Brk/Paxillin/Rac1 axis.

Antioxidant and cytotoxic activity of polyphenolic compounds isolated from the leaves of Leucenia leucocephala

CONTEXT

Cancer is a serious clinical problem to the health care system. Anticancer drugs have been extracted from plants containing phenolic compounds. Leucenia species (Fabaceae) contain a variety of bioactive components of numerous biological and pharmacological properties.

OBJECTIVE

This study explored the constitutive polyphenols of Leucenia leucocephala Lam. growing in Egypt and evaluated the antioxidant and cytotoxic activity.

MATERIALS AND METHODS

Chemical structures of the isolated compounds from the leaves of L. leucocephala were established by spectral techniques (UV, (1)H, and (13)C NMR, MS).

RESULTS

Chromatographic separation of 80% MeOH extract of the leaves of L. leucocephala have resulted in a novel flavonoid-galloyl glycoside [myricetin 3-O-(2',3'4'-tri-O-galloyl)-α-L-rhamnopyranoside] with three known polyphenolic compounds isolated for the first time from this species (apigenin 7-O-β-D-glucuronopyranoside methyl ester, luteolin 7-O-β-D-glucuronopyranoside methyl ester, and 1,3,6-tri-O-galloyl-β-D-glucopyranose) and seven known previously isolated compounds. Also, 80% methanol extract exhibited high antioxidant activity (SC(50) = 3.94 µg/ml), which is correlated with its phenolic content. The extract also showed cytotoxic activity against Hep G2 (IC(50) value 1.41 µg/ml) confirming its anticancer activity against hepatocellular carcinoma. Among the tested compounds (4-8) for antioxidant property, compound 7 was the most active compound (SC(50) = 2.49 µg/ml). Also compounds 7 and 8 exhibited high cytotoxic activity (IC(50) = 2.41 and 2.81 µg/ml, respectively).

DISCUSSION AND CONCLUSION

These findings demonstrate that the leaves of L. leucocephala contain a considerable amount of polyphenolic compounds with high antioxidant properties, thus it has great potential as a source for natural health products.

Antioxidant flavonol glycosides from Schinus molle

Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

The effect of a herbal water-extract on histamine release from mast cells and on allergic asthma

A water extract of a mixture of eight herbs (chamomile, saffron, anise, fennel, caraway, licorice, cardomom and black seed) was tested for its inhibitory effect on histamine released from rat peritoneal mast cells stimulated either by compound 48/80 or be IgE/anti-IgE. The effect of the herb extract was compared to that of the flavonoid quercetin. The herbal water-extract inhibited histamine released from chemically- and immunologically-induced cells by 81% and 85%, respectively; quercetin treated cells were inhibited by 95% and 97%, respectively. The clinical results showed significant improvements of sleep discomfort, cough frequency and cough intensity in addition to increased percentages of FEV1/FVC in patients suffering from allergic asthma, who used the herbal tea compared to those who used the placebo tea.