Metabolomics analysis and biological investigation of three Malvaceae plants.

INTRODUCTION: Metabolomics is a fast growing technology that has effectively contributed to many plant-related sciences and drug discovery. OBJECTIVE: To use the non-targeted metabolomics approach to investigate the chemical profiles of three Malvaceae plants, namely Hibiscus mutabilis L. (Changing rose), H. schizopetalus (Dyer) Hook.f. (Coral Hibiscus), and Malvaviscus arboreus Cav. (Sleeping Hibiscus), along with evaluating their antioxidant and anti-infective potential. METHODOLOGY: Metabolic profiling was carried out using liquid chromatography coupled with high-resolution electrospray ionisation mass spectrometry (LC-HR-ESI-MS) for dereplication purposes. The chemical composition of the studied plants was further compared by principal component analysis (PCA). The antioxidant and anti-infective properties of their different extracts were correlated to their phytochemical profiles by orthogonal partial least square discriminant analysis (OPLS-DA). RESULTS: A variety of structurally different metabolites, mostly phenolics, were characterized. Comparing the distribution pattern of these tentatively identified metabolites among the studied plant species/fractions revealed the chemical uniqueness of the dichloromethane fraction of M. arboreus. Some extracts and fractions of these plants demonstrated noteworthy antioxidant and antitrypanosomal potential; the latter was partly attributed to their anti-protease activities. The active principles of these plants were pinpointed before any laborious isolation steps, to avoid the redundant isolation of previously known compounds. CONCLUSION: This study highlighted the use of the established procedure in exploring the metabolomes of these species, which could be helpful for chemotaxonomic and authentication purposes, and might expand the basis for their future phytochemical analysis. Coupling the observed biological potential with LC-MS data has also accelerated the tracing of their bioactive principles.

Recent Updates on Corals from Nephtheidae.

Marine natural products display a wide range of biological activities, which play a vital role in the innovation of lead compounds for the drug development. Soft corals have been ranked at the top in regard to the discovery of bioactive metabolites with potential pharmaceutical applications. Many of the isolated cembranoids revealed diverse biological activities, such as anticancer, antidiabetic and anti-osteoporosis. Likewise, sterols from soft corals exhibited interesting biological potential as anti-inflammatory, antituberculosis and anticancer. Consequently, investigating marine soft corals will definitely lead to the discovery of a large number of chemically varied secondary metabolites with countless bioactivities for possible applications in medicine and pharmaceutical industry. This review provides a complete survey of all metabolites isolated from the family Nephtheidae, from 2011 until November 2018, along with their natural sources and biological potential whenever possible.

Natural Product Potential of the Genus Nocardiopsis.

Actinomycetes are a relevant source of novel bioactive compounds. One of the pharmaceutically and biotechnologically important genera that attract natural products research is the genus Nocardiopsis, mainly for its ability to produce a wide variety of secondary metabolites accounting for its wide range of biological activities. This review covers the literature from January 2015 until February 2018 making a complete survey of all the compounds that were isolated from the genus Nocardiopsis, their biological activities, and natural sources, whenever applicable.

New Cytotoxic Cyclic Peptide from the Marine Sponge-Associated Nocardiopsis sp. UR67.

A new cyclic hexapeptide, nocardiotide A (1), together with three known compounds-tryptophan (2), kynurenic acid (3), and 4-amino-3-methoxy benzoic acid (4)-were isolated and identified from the broth culture of Nocardiopsis sp. UR67 strain associated with the marine sponge Callyspongia sp. from the Red Sea. The structure elucidation of the isolated compounds were determined based on detailed spectroscopic data including ¹D and ²D nuclear magnetic resonance (NMR) experimental analyses in combination with high resolution electrospray ionization mass spectrometry (HR-ESI-MS), while the absolute stereochemistry of all amino acids components of nocardiotide A (1) was deduced using Marfey's method. Additionally, ten known metabolites were dereplicated using HR-ESI-MS analysis. Nocardiotide A (1) displayed significant cytotoxic effects towards the murine CT26 colon carcinoma, human HeLa cervix carcinoma, and human MM.1S multiple myeloma cell lines. The results obtained revealed sponge-associated Nocardiopsis as a substantial source of lead natural products with pronounced pharmacological activities.

Ursolic acid inhibits NF-κB signaling and attenuates MMP-9/TIMP-1 in progressive osteoarthritis: a network pharmacology-based analysis.

Osteoarthritis (OA) is a degenerative joint disease, characterized by infiltration of monocytes into the synovial joint which promotes inflammation, stiffness, joint swelling, cartilage degradation and further bone destruction. The leaves of Ocimum forskolei have been used for inflammation-related disease management in traditional medicine. Additionally, the downregulation of NF-κB and the MMP/TIMP-1 ratio has been shown to protect against OA. The LC-HR-MS metabolic analysis of Ocimum yielded 19 putative compounds, among which ursolic acid (UA) was detected. Ursolic acid possesses significant anti-inflammatory effects and has been reported to downregulate oxidative stress and inflammatory biomarkers. It was tested on rats in a model of intra-articular carrageenan injection to investigate its efficacy on osteoarthritis progression. The UA emulgel exerted chondroprotective, analgesic and local anaesthetic efficacies confirmed via histopathological investigation and radiographical imaging. A network pharmacology followed by molecular docking highlighted TNF-α, TGF-ß and NF-κB as the top filtered genes. Quantitative real-time PCR analysis showed that UA significantly attenuated serum levels of TNF-α, IL-1ß, NF-κB, MMP-9/TIMP-1 and elevated levels of TGF-ß. Taken together, these results suggest that UA could serve as a functional food-derived phytochemical with a multi-targeted efficacy on progression of OA, regulating the immune and inflammatory responses, particularly, attenuating chondrocytes degeneration via suppression of NF-κB and MMP-9/TIMP-1. Accordingly, UA might be a promising alternative to conventional therapy for safe, easily applicable and effective management of OA.

Metabolic profiling and biological potential of the marine sponge associated Nocardiopsis sp. UR67 along with docking studies.

This work was performed to dig into the phytochemical composition and bioactivities of Nocardiopsis sp. UR67 associated with the marine sponge Callyspongia sp. It was fermented in suspension and immobilised in calcium alginate bead cultures. The ethyl acetate extracts, afforded from the broth in each case named EG-49 and J-48g, respectively, revealed 16 chemical principles mostly belonging to polyketides, macrolides, and peptides. EG-49 and J-48g displayed anti-Candida albicans activity with IC50 values of 8.1 and 8.3 µg/mL, and a substantial cytotoxic effect against lung adenocarcinoma H1650 at IC50 12.6 and 13.7 µg/mL, respectively. However, only EG-49 exhibited a noteworthy anti-trypanosomal activity at 7.5 µg/mL. Molecular docking of the characterised compounds against Trypanosoma brucei trypanothione reductase demonstrated the highest binding models of griseochelin-methyl ester (9) and filipin-II (11), which drew considerable significance of the metabolites derived from Nocardiopsis sp. UR67 developing potential T. brucei trypanothione reductase inhibitors.

Cytotoxic potential of Nephthea sp.-derived actinomycetes supported by metabolomics analysis.

Soft corals and associated microorganisms are known to produce leads for anticancer drugs. Keeping this in mind, Nephthea sp.; a Red Sea soft coral was investigated for the first time using the OSMAC approach. Two isolates, Streptomyces sp. UR63 and Micrococcus sp. UR67 were identified. Their extracts revealed the presence of alkaloids, macrolides, quinones, fatty acids and terpenoids. Further comparison through a set of multivariate data analyses revealed their unique chemical profiles. The extracts displayed inhibitory potencies against HepG-2, Caco-2 and MCF-7 tumor cell lines with IC50 values ranging from 11.4 to 38.7 µg/mL when compared with the positive control, doxorubicin. The study not only highlights the cytotoxic potential of soft coral-associated actinomycetes but also shows the advantage of using the OSMAC approach in this regard.

Natural metabolites from the soft coral Nephthea sp. as potential SARS-CoV-2 main protease inhibitors.

The ongoing spread of SARS-CoV-2 has created a growing need to develop effective antiviral treatments; therefore, this work was undertaken to delve into the natural metabolites of the Red Sea soft coral Nephthea sp. (family Nephtheidae) as a source of potential anti-COVID-19 agents. Overall, a total of 14 structurally diverse minor constituents were isolated and identified from the petroleum ether fraction of Nephthea sp. The characterised compounds were screened and compared for their inhibitory potential against SARS-CoV-2 main protease (Mpro) using Autodock Vina and MOE software. Interestingly, most compounds were able to bind effectively to the active site of Mpro, of which nephthoside monoacetate (1); an acylated tetraprenyltoluquinol glycoside, exhibited the highest binding capacity in both software with comparable interaction energies to the ligand N3 and moderately acceptable drug-likeness properties, which drew attention to the relevance of marine-derived metabolites from Nephthea sp., particularly compound (1), to develop potential SARS-CoV-2 protease inhibitors.

NS3 helicase inhibitory potential of the marine sponge Spongia irregularis.

In the current study, an investigation of the activity of the total extract of the marine sponge Spongia irregularis and its different fractions against the hepatitis C virus (HCV) was pursued. The results revealed that the ethyl acetate fraction exhibited the highest anti-HCV activity, with an IC50 value of 12.6 ± 0.05 µg ml-1. Chromatographic resolution of the ethyl acetate fraction resulted in the isolation of four known compounds, 1,3,7-trimethylguanine (1), 3,5-dihydroxyfuran-2(5H)-one (2), thymidine (3), and 1H-indazole (4). By using LC-HR-ESI-MS metabolic profiling, compounds 5-14 were also identified in the same fraction. Molecular docking calculations revealed the high binding affinity of compound 14 against the allosteric pocket of HCV NS3-NS4A and the active site of HCV NS3 helicase (-10.1 and -7.4 kcal mol-1, respectively). Molecular dynamics simulations, followed by molecular mechanics-generalized Born surface area energy calculations, demonstrated the structural and energetic stability of compound 14 in complex with HCV targets.

Multitarget in silico studies of Ocimum menthiifolium, family Lamiaceae against SARS-CoV-2 supported by molecular dynamics simulation.

The novel strain of human coronavirus, emerged in December 2019, which has been designated as SARS-CoV-2, causes a severe acute respiratory syndrome. Since then, it has arisen as a serious threat to the world public health. Since no approved vaccines or drugs has been found to efficiently stop the virulent spread of the virus, progressive inquiries targeting these viruses are urgently needed, especially those from plant sources. Metabolic profiling using LC-HR-ESI-MS of the butanol extract of Ocimum menthiifolium (Lamiaceae) aerial parts yielded 10 compounds including flavonoids, iridoids and phenolics. As it has been previously reported that some flavonoids can be used as anti-SARS drugs by targeting SARS-CoV-1 3CLpro, we chose to examine 14 flavonoids (detected by metabolomics and other compounds isolated via several chromatographic techniques). We investigated their potential binding interactions with the 4 main SARS-CoV-2 targets: Mpro, nsp16/nsp10 complex, ACE2-PD and RBD-S-protein via molecular docking. Docking results indicated that the nsp16/nsp10 complex has the best binding affinities where the strongest binding was detected with apigenin-7-O-rutinoside, prunin and acaciin with -9.4, -9.3 and -9.3 kcal/mol binding energy, respectively, compared to the control (SAM) with -8.2 kcal/mol. Furthermore, the stability of these complexes was studied using molecular dynamics of 150 ns, which were then compared to their complexes in the other three targets. MM-PBSA calculations suggested the high stability of acaciin-nsp16 complex with binding energy of -110 kJ/mol. This study sheds light on the structure-based design of natural flavonoids as anti-SARS-CoV-2 drugs targeting the nsp16/10 complex.Communicated by Ramaswamy H. Sarma.

The Red Sea marine sponge Spongia irregularis: metabolomic profiling and cytotoxic potential supported by in silico studies.

The current study discusses the chemical composition of the marine sponge Spongia irregularis using LC-HRESIMS. The metabolomic profiling resulted in the annotation of 17 metabolites of different chemical classes. Additionally, evaluation of the cytotoxic activities of the total extract and different fractions were carried out against three different cell lines where the n-butanol fraction exhibited the highest cytotoxic effects against HepG-2, MCF-7 and CACO-2 cell lines with IC50 values of 9.6 ± 0.02, 4.3 ± 0.10 and 5.6 ± 0.03 µg/mL, respectively. Also, the study was supported by docking study of the identified compounds for binding affinity to MSK1.

Local anaesthetic potential, metabolic profiling, molecular docking and in silico ADME studies of Ocimum forskolei, family Lamiaceae.

The present study aimed to detect the bioactive metabolites from Ocimum forskolei aerial parts which are responsible for the local anaesthetic activity of the ethyl acetate fraction. Following a bioassay-guided fractionation, twelve compounds were dereplicated from the ethyl acetate fraction which was the most potent one with a mean onset of action (1.43 ± 0.07****) min compared to tetracaine as a positive control (1.37 ± 0.07****) min. These compounds, along with seven other compounds (isolated by diverse chromatographic techniques) were subjected to a molecular docking study to declare the top scoring compounds predicted to be responsible for such activity. The results highlighted Rabdosiin and Apigenin-7-O-rutinoside as the main bioactive leaders of the local anaesthesia via forming multiple H- bonding with the sodium ion channels leading to their blockade and loss of pain sensation, which strongly supports the use of O. forskolei as a local anaesthetic agent.

Chemical and biological studies on the soft coral Nephthea sp.

Soft corals belonging to the family Nephtheidae have been appreciated as marine sources of diverse metabolites with promising anticancer potential. In view of that, the current work investigates the anti-proliferative potential of the crude extract, different fractions, and green synthesized silver nanoparticles (AgNPs) of the Red Sea soft coral, Nephthea sp. against a panel of tumor cell lines. The metabolic pool of the soft coral under study was also explored via an LC-HR-ESI-MS metabolomics approach, followed by molecular docking analysis of the characterized metabolites against the target proteins, EGFR, VEGFR, and HER2 (erbB2) that are known to be involved in cancer cell proliferation, growth, and survival. Overall, the n-butanol fraction of Nephthea sp. exhibited the highest inhibitory activities against MCF7 (breast cancer) and A549 (lung cancer) cell lines, with interesting IC50 values of 2.30 ± 0.07 and 3.12 ± 0.10 µg ml-1, respectively, whereas the maximum growth inhibition of HL60 (leukemia) cells was recorded by the total extract (IC50 = 2.78 ± 0.09 µg ml-1). More interestingly, the anti-proliferative potential of the total soft coral extract was evidently improved when packaged in the form of biogenic AgNPs, particularly against A549 and MCF7 tumor cells, showing IC50 values of 0.72 ± 0.06 and 9.32 ± 0.57 µg ml-1, respectively. On the other hand, metabolic profiling of Nephthea sp. resulted in the annotation of structurally diverse terpenoids, some of which displayed considerable binding affinities and molecular interactions with the studied target proteins, suggesting their possible contribution to the anti-proliferative properties of Nephthea sp. via inhibition of tyrosine kinases, especially the EGFR type. Taken together, the present findings highlighted the relevance of Nephthea sp. to future anticancer drug discovery and provided a base for further work on the green synthesis of a range of bioactive NPs from marine soft corals.

Anti-epileptic potential, metabolic profiling and in silico studies of the aqueous fraction from Ocimum menthiifolium benth, family Lamiaceae.

The current study aimed to investigate the anti-epileptic potential of the ethanol extract and its different fractions from the Lamiaceous plant, Ocimum menthiifolium. The results revealed that the aqueous fraction with the latest onset of myoclonic convulsions (1095 ± 45**** s) was the most biologically active one. This was followed by LC-HR-MS-coupled metabolic profiling which led to dereplication of 8 compounds from that fraction. A molecular docking study was performed on the dereplicated compounds to discover the main responsible ones for the activity. The results highlighted Apigenin-7,4'-di-O-glucoside as the top scoring ligand with a possible mechanism of action involving the modulation of the voltage-gated sodium channel.

Metabolomic profiling and biological investigation of Tabebuia Aurea (Silva Manso) leaves, family Bignoniaceae.

Both ethyl acetate and aqueous fractions of Tabebuia aurea leaves exhibited noteworthy antioxidant and nephroprotective activities against carbon tetrachloride (CCl4)-induced nephrotoxicity in rats, as evidenced by the remarkable improvements of renal serum biomarkers and histopathological features. Additionally, the ethyl acetate fraction displayed a prominent in vitro antitrypanosomal activity against Trypanosoma brucei; consequently, the leaves were subjected to LC-HR-ESI-MS metabolomic profiling to discover the constituents that possibly underlie their bioactivities. Therefore, ten metabolites were characterized, mostly dominated by flavonoids. Interestingly, two identified constituents viz., 3,9,12,15-octadecatetraenoic acid (9) and 9,11,13-octadecatrienoic acid (10) are reported firstly herein from the genus Tabebuia. Furthermore, among the dereplicated constituents, rutin (5) and kaempferol 3-O-rutinoside (6) exhibited the highest docking scores as effective antitrypanosomal compounds.

Marine natural products from sponges (Porifera) of the order Dictyoceratida (2013 to 2019); a promising source for drug discovery.

Marine organisms have been considered an interesting target for the discovery of different classes of secondary natural products with wide-ranging biological activities. Sponges which belong to the order Dictyoceratida are distinctly classified into 5 families: Dysideidae, Irciniidae, Spongiidae, Thorectidae, and Verticilliitidae. In this review, compounds isolated from Dictyoceratida sponges were discussed with their biological potential within the period 2013 to December 2019. Moreover, analysis of the physicochemical properties of these marine natural products was investigated and the results showed that 78% of the compounds have oral bioavailability potential. This review highlights sponges of the order Dictyoceratida as exciting source for discovery of new drug leads.

Anti-Inflammatory Potential of Green Synthesized Silver Nanoparticles of the Soft Coral Nephthea Sp. Supported by Metabolomics Analysis and Docking Studies.

BACKGROUND: Soft corals have been endorsed as a plentiful source of bioactive compounds with promising anti-inflammatory activities; therefore, exploring their potential as source of anti-inflammatory metabolites has stimulated a growing research interest. PURPOSE: To investigate the anti-inflammatory potential of the soft coral, Nephthea sp., in its bulk and silver nanostructure. Metabolomics analysis of Nephthea sp., followed by molecular docking studies, was also conducted in order to explore and predict the secondary metabolites that might provide its inhibitory actions on inflammation. MATERIALS AND METHODS: The petroleum ether and ethyl acetate fractions were used to synthesize silver nanoparticles. The prepared silver nanoparticles were characterized through UV-vis spectrophotometric, transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Testing for the anti-inflammatory activity was performed against COX-1 and COX-2. Furthermore, liquid chromatography-mass spectrometry (LC-MS) based metabolomics analysis and molecular docking were also applied. RESULTS: A variety of secondary metabolites were identified, among them, sesquiterpenes were found to prevail. The petroleum ether and acetone fractions of Nephthea sp. showed the highest COX-2 inhibitory activities, possibly attributable to their substantial contents of terpenoids. Additionally, the green synthesized silver nanoparticles of both the petroleum ether and ethyl acetate fractions of Nephthea sp. demonstrated higher anti-COX-2 properties. CONCLUSION: The obtained results showed the effectiveness of non-targeted metabolomics technique in metabolic profiling of Nephthea sp., helping the search for new bioactive metabolites in future chemical studies on this soft coral. The interesting anti-inflammatory potential of the tested extracts and their nanoparticles could also be relevant to the development of new, effective anti-inflammatory agents.

Metabolomic profiling and anti-infective potential of Zinnia elegans and Gazania rigens (Family Asteraceae).

The present study evaluates the chemical composition of Zinnia elegans and Gazania rigens based on their metabolomic profiles using liquid chromatography coupled with high-resolution mass spectrometry (LC-HR-MS), alongside with the anti-infective activities of their ethanol extracts, as well as, different fractions. A significant difference was observed between the LC-MS profiles of the two plants such as, coumarins, sesquiterpene lactones and phenylethanoids which were characteristic for Z. elegans, while amides and phenolic acid derivatives were characteristic for G. rigens. These results highlight the chemical potential of Z. elegans and G. rigens. Furthermore, the ethyl acetate fraction of Z. elegans showed a significant antimalarial activity with IC50 values of 21.03 and 13.72 µg/mL against Plasmodium falciparum D6 and P. falciparum W2, respectively.

New bioactive metabolites from the elicited marine sponge-derived bacterium Actinokineospora spheciospongiae sp. nov.

Several approaches have been dedicated to activate the cryptic gene clusters in the genomes of actinomycetes for the targeted discovery of new fascinating biomedical lead structures. In the current study, N-acetylglucosamine was used to maximize the chemical diversity of sponge-derived actinomycete Actinokineospora spheciospongiae sp. nov. HR-ESI-MS was employed for dereplication study and orthogonal partial least square-discriminant analysis was applied to evaluate the HR-ESI-MS data of the different fractions. As a result, two new fridamycins H (1) and I (2), along with three known compounds actinosporin C (3), D (4), and G (5) were isolated from the solid culture of sponge-associated actinomycete Actinokineospora spheciospongiae sp. nov., elicited with N-acetylglucosamine. Characterization of the isolated compounds was pursued using mass spectrometry and NMR spectral data. Fridamycin H (1) exhibited significant growth inhibitory activity towards Trypanosoma brucei strain TC221. These results highlight the potential of elicitation in sponge-associated actinomycetes as an effective strategy for the discovery of new anti-infective natural products.

Hepatoprotective potential of Malvaviscus arboreus against carbon tetrachloride-induced liver injury in rats.

Malvaviscus arboreus Cav. is a medicinal plant belonging to family Malvaceae with both ethnomedical and culinary value; however, its phytochemical and biological profiles have been scarcely studied. Accordingly, this work was designed to explore the chemical composition and the hepatoprotective potential of M. arboreus against carbon tetrachloride (CCl4)-induced hepatotoxicity. The total extract of the aerial parts and its derived fractions (petroleum ether, dichloromethane, ethyl acetate, and aqueous) were orally administered to rats for six consecutive days, followed by injection of CCl4 (1:1 v/v, in olive oil, 1.5 ml/kg, i.p.) on the next day. Results showed that the ethyl acetate and dichloromethane fractions significantly alleviated liver injury in rats as indicated by the reduced levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TB), and malondialdehyde (MDA), along with enhancement of the total antioxidant capacities of their livers, with the maximum effects were recorded by the ethyl acetate fraction. Moreover, the protective actions of both fractions were comparable to those of silymarin (100 mg/kg), and have been also substantiated by histopathological evaluations. On the other hand, liquid chromatography-high resolution electrospray ionization mass spectrometry (LC‒HR‒ESI‒MS) metabolomic profiling of the crude extract of M. arboreus aerial parts showed the presence of a variety of phytochemicals, mostly phenolics, whereas the detailed chemical analysis of the most active fraction (i.e. ethyl acetate) resulted in the isolation and identification of six compounds for the first time in the genus, comprising four phenolic acids; ß-resorcylic, caffeic, protocatechuic, and 4-hydroxyphenylacetic acids, in addition to two flavonoids; trifolin and astragalin. Such phenolic principles, together with their probable synergistic antioxidant and liver-protecting properties, seem to contribute to the observed hepatoprotective potential of M. arboreus.