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; β-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.

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.

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.

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.

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 characterized compounds were screened and compared for their inhibitory potential against SARS-CoV-2 main protease (M pro ) using Autodock Vina and MOE software.Interestingly, most compounds were able to bind effectively to the active site of M pro , 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.

Abstract. Malvaviscus arboreus Cav., commonly known as Sleeping Hibiscus, is a plant species that belongs to the family Malvaceae with ornamental, culinary, and ethnomedical importance. This medicinal herb was reported to exhibit noteworthy antioxidant, cytotoxic, hepatoprotective, and anti-infective activities attributed to the presence of a variety of phytochemicals. In this work, the volatile compositions of the leaves and flowers of M. arboreus were studied and compared for the first time using the headspace gas chromatography-mass spectrometry (GC–MS) technique. Overall, 39 components were identified, comprising 36 from the leaves and 11 from the flowers, with an evident greater contribution of oxygenated compounds (89.54% in leaves and 89.35% in flowers) to their total volatiles. Phenolic ethers (41.64%) and ketones (21.57%) were the major chemical groups emitted by the flowers, while ketones (27.40%) and carboxylic acids (18.16%) dominated the volatile blends of the leaves. Anethole (32.32%), methyl isobutenyl ketone (19.18%), and methyl chavicol (9.32%) were the most abundant floral volatiles, whereas acetic acid (18.16%) was the major constituent given off by the leaves, followed by 2-cyclohexenone (9.60%) and anethole (7.39%). Additionally, from a biosynthetic point of view, the floral volatiles of M. arboreus showed the prevalence of phenylpropanoids/benzenoids (41.64%); however, fatty acid derivatives (54.30%) predominated among those produced by the leaves. The obtained results revealed noteworthy qualitative and quantitative variations in M. arboreus leaves and flowers' headspace volatiles that would help complement our phytochemical knowledge on this limitedly studied plant.   Resumen. Malvaviscus arboreus Cav., comúnmente conocida como “Sleeping Hibiscus”, es una especie vegetal que pertenece a la familia Malvaceae con importancia ornamental, culinaria y etnomédica. Se ha reportado que esta hierba medicinal exhibe actividades antioxidantes, citotóxicas, hepatoprotectoras y antiinfecciosas notables que se atribuyen a la presencia de una variedad de fitoquímicos. En este trabajo se estudiaron las composiciones volátiles de las hojas y flores de M. arboreus y fueron comparadas utilizando la técnica de cromatografía de gases-espectrometría de masas (GC-MS). En total, se identificaron 39 componentes comprendiendo 36 de las hojas y 11 de las flores, con un evidente mayor aporte de compuestos oxigenados (89,54% en hojas y 89,35% en flores). Los éteres fenólicos (41,64%) y cetonas (21,57%) fueron los principales grupos químicos emitidos por las flores, mientras que las cetonas (27,40%) y los ácidos carboxílicos (18,16%) dominaron las mezclas volátiles de las hojas. Anetol (32,32%), metil isobutenil cetona (19,18%) y metil chavicol (9,32%) fueron los volátiles florales más abundantes, mientras que el ácido acético (18,16%) fue el principal componente desprendido por las hojas, seguido de la 2-ciclohexenona. (9,60%) y el anetol (7,39%). Adicionalmente, desde el punto de vista biosintético, los volátiles florales de M. arboreus mostraron la prevalencia de fenil propanoides/benzenoides (41,64%); sin embargo, los derivados de ácidos grasos (54,30%) predominaron entre los producidos por las hojas. Los resultados obtenidos revelaron variaciones cualitativas y cuantitativas notables en los volátiles de las hojas y flores de M. arboreus que ayudarán a complementar nuestro conocimiento fitoquímico en esta planta estudiada hasta ahora de forma limitada.

The cytotoxic potential of the crude extract, different fractions, and green synthesized nanoparticles of the soft coral Nephthea sp. was studied, supported by LC-HR-ESI-MS metabolomics analysis and molecular docking of the dereplicated compounds.

Abelmoschus esculentus Linn. (okra, F. Malvaceae) is a fruit widely consumed all over the world. In our study, the anti-Alzheimer’s potential of A. esculentus was evaluated. An in vitro DPPH free radical assay on A. esculentus seed’s total extract and AChE inhibition potential screening indicated a significant anti-Alzheimer’s activity of the extract, which was confirmed through an in vivo study in an aluminum-intoxicated rat model. Additionally, in vivo results demonstrated significant improvement in Alzheimer’s rats, which was confirmed by improving T-maze, beam balance tests, lower serum levels of AChE, norepinephrine, glycated end products, IL-6, and MDA. The levels of dopamine, BDNF, GSH, and TAC returned to normal values during the study. Moreover, histological investigations of brain tissue revealed that the destruction in collagen fiber nearly returns back to the normal pattern. Metabolomic analysis of the ethanolic extract of A. esculentus seeds via LC–HR-ESI-MS dereplicated ten compounds. A network pharmacology study displayed the relation between identified compounds and 136 genes, among which 84 genes related to Alzheimer’s disorders, and focused on AChE, APP, BACE1, MAPT and TNF genes with interactions to all Alzheimer’s disorders. Consequently, the results revealed in our study grant potential dietary elements for the management of Alzheimer’s disorders.