Genus Carissa L.: a newly explored sustainable source of virulence inhibitors: a mini review.

Misuse of antibiotics led to the world wide spread of antimicrobial resistance threatening human lives. The notable resistance of bacterial cells to antibiotics and immune system is the difficulty associated with biofilm-linked illnesses. Natural products from plant origin with antibiofilm activity could provide more therapeutic activity with fewer adverse effects. Carissa L. is a potential drug candidate that can be considered as an agro-food waste sustainable virulence inhibitor source. This mini-review sheds light on recent studies dealing with the anti-virulence potential of Carissa species and its different mechanisms of action. The traced articles revealed that Carissa species exhibited potent antibiofilm, anti-quorum sensing, hyaluronidase inhibitory and anti-adhesion potentials, in addition to violacein, and swimming motility inhibition activities. Ursolic acid, oleanolic acid, and methyl oleanate are the main phytoconstituents of Carissa with claimed virulence inhibitory potentials. Carissa species are safe, valuable, and effective anti-virulence drugs suppressing pathogenicity when compared to conventional antibiotics.

Neopetromin, a Cyclic Tripeptide with a C-N Cross-Link, from the Marine Sponge Neopetrosia sp., That Causes Vacuole Fragmentation in Tobacco BY-2 Cells.

HPLC-MS analysis revealed the presence of an unreported peptide in the extract of the marine sponge Neopetrosia sp. Its structure was determined as a tripeptide, named neopetromin (1), composed of two tyrosine and one tryptophan residues with a heteroaromatic C-N cross-link between side chains. The absolute configuration of amino acids was determined using Marfey's method after ozonolysis and hydrolysis of 1. Compound 1 promoted vacuole fragmentation in an actin-independent manner in tobacco BY-2 cells.

An unusual 2-O-glyceryl-glycosyl-γ-pyrone from Erigeron annuus (L.) with potential antifungal activity: in-vitro and in-silico study.

Phytochemical characterisation of the polar fraction of Erigeron annuus extract led to the isolation of glycerylerigeroside (1), a unique γ-pyrone derivative. Structure of 1 was decided by intensive study of NMR and mass spectra as 3-O-[4'-((1,3-dihydroxypropan-2-yl)oxy)-ß-D-glucopyranoside)]-4H-pyran-4-one, with uncommon glyceroxy side chain attached to 4' position of pyromeconic acid ß-D-glucopyranoside. Antimicrobial potential of 1 was tested against Staphylococcus aureus, Salmonella enterica, and Candida albicans. Compound 1 strongly inhibited growth of Candida albicans (MIC = 17.24 µM/disc), compared to fluconazole (MIC = 16.33 µM/disc). Meanwhile, it moderately inhibited the growth of Staphylococcus aureus (MIC = 71.84 µM/disc) and Salmonella enterica (MIC = 71.84 µM/disc), as compared with thiophenicol (MIC = 14.05 µM/disc) and (MIC = 14.05 µM/disc), respectively. The binding mode of 1 with the active site of sterol 14α-demethylase (CYP51) from Candida albicans (PDB ID: 5TZ1), in combination with fluconazole, was predicted by molecular docking study and supported the antifungal activity.

A new linear peptide, higapeptin, isolated from the mud flat-derived fungus Acremonium persicinum inhibits mitochondrial energy metabolism.

A combination of LC-MS/MS and feature-based molecular networking analyses led to the isolation of a new adenopeptin analog, higapeptin (1), and four known peptides, adenopeptin (2), adenopeptins B and C (3 and 4), and acremopeptin (5), from the rice culture of the fungus Acremonium persicinum (18F04103) isolated from a mud flat of the Ariake Sea in Kyushu, Japan. The structure of 1 was determined by NMR and MS/MS fragmentation analyses. The absolute configuration of the constituent amino acids was determined by Marfey's analysis after acid hydrolysis. The C-terminal residue was synthesized, and its absolute configuration was established by Marfey's analysis. Compounds 1 and 2 were found to inhibit mitochondrial energy metabolism, similar to efrapeptin D (6), a known mitochondrial ATPase inhibitor.

epi-Magnolin, a tetrahydrofurofuranoid lignan from the oleo-gum resin of Commiphora wightii, as inhibitor of pancreatic cancer cell proliferation, in-vitro and in-silico study.

Five known furofuran lignans, dia-sesamin (1), 5-methoxysesamin (2), epi-magnolin (3), kobusin (4) and yangambin (5) were isolated for the first-time from the oleo-gum resin of Commiphora wightii. This is the first report on the 13C NMR assignments for epi-magnolin (3). Each of the isolated compounds was evaluated for its ability to inhibit MIA PaCa-2 pancreatic cancer cell line. Among them, epi-magnolin (3) displayed potential activity (IC50 = 29 nM) compared to colchicine (IC50 = 56 nM). 3D-flexible alignment revealed that epi-magnolin (3) has great matching with the tubulin polymerization inhibitor, colchicine. Meanwhile, docking studies exhibited that compounds 1-5 displayed good binding free energies against colchicine binding site (CBS) of tubulin with binding modes that were highly comparable to that of colchicine. Compounds 2, 3, and 5 showed superior binding free energies than colchicine (-24.37 kcal/mol). epi-Magnolin (3) showed the highest binding score against CBS. MD simulation studies confirmed the stability of epi-magnolin (3) in the active site for 200 ns. Furthermore, four online servers (Swiss ADME, pkCSM pharmacokinetics, AdmetSAR, and ProTox-II) were utilized to predict the ADMET parameters. The in-silico pharmacokinetics predictions reveled that epi-magnolin (3) has significant oral bioavailability and drug-like capabilities.Communicated by Ramaswamy H. Sarma.

Aaptocarbamates A-G, chlorinated terpene carbamates with antiosteoclastogenic activities from the marine sponge Aaptos sp.

Six undescribed chlorinated sesquiterpene carbamates, aaptocarbamates A-F, and a chlorinated tris-norsesquiterpene carbamate, aaptocarbamate G, were isolated from the marine sponge Aaptos sp. collected in Indonesia. Aaptocarbamates D-F and G possess tetrahydrofurans and a tetrahydrofuranone, respectively. The relative configurations of the tetrahydrofuran units were determined by the NOE correlations and DFT-based calculation of the 13C chemical shifts. This is the first time that chlorinated terpene carbamates have been reported from natural sources. Various aaptamine derivatives have been reported from the Aaptos sponges so far, the isolation of chlorinated terpene carbamates is very rare. Aaptocarbamates A, B, and D showed 60% inhibition of the RANKL-induced formation of multinucleated osteoclasts in RAW264 macrophages at 20 µM.

The medicinal activity of lyophilized aqueous seed extract of Lepidium sativum L. in an androgenic alopecia model.

This study evaluated the topical effect of Lepidium sativum lyophilized seed extract (LSLE) towards Sustanon-induced alopecia in male adult Wistar albino rats in vivo, compared to minoxidil topical reference standard drug (MRD). LC-MS/MS together with molecular networking was used to profile the metabolites of LSLE. LSLE treated group revealed significant changes in alopecia related biomarkers, perturbation of androgenic markers; decline in testosterone level and elevation in 5α-reductase (5-AR); decline in the cholesterol level. On the other hand, LSLE treated group showed improvement in vascular markers; CTGF, FGF and VEGF. Groups treated topically with minoxidil and LSLE showed significant improvement in hair length. LC-MS/MS profile of LSLE tentatively identified 17 constituents: mainly glucosinolates, flavonoid glycosides, alkaloids and phenolic acids. The results point to the potential role of LSLE in the treatment of alopecia through decreasing 5(alpha)-dihydrotestosterone levels. Molecular docking was attempted to evaluate the probable binding mode of identified compounds to androgen receptor (PDB code: 4K7A).

Integration of LC/MS, NMR and Molecular Docking for Profiling of Bioactive Diterpenes from Euphorbia mauritanica L. with in Vitro Anti-SARS-CoV-2 Activity.

In spite of tremendous efforts exerted in the management of COVID-19, the absence of specific treatments and the prevalence of delayed and long-term complications termed post-COVID syndrome still urged all concerned researchers to develop a potent inhibitor of SARS-Cov-2. The hydromethanolic extracts of different parts of E. mauritanica were in vitro screened for anti-SARS-Cov-2 activity. Then, using an integrated strategy of LC/MS/MS, molecular networking and NMR, the chemical profile of the active extract was determined. To determine the optimum target for these compounds, docking experiments of the active extract's identified compounds were conducted at several viral targets. The leaves extract showed the best inhibitory effect with IC50 8.231±0.04 µg/ml. The jatrophane diterpenes were provisionally annotated as the primary metabolites of the bioactive leaves extract based on multiplex of LC/MS/MS, molecular network, and NMR. In silico studies revealed the potentiality of the compounds in the most active extract to 3CLpro, where compound 20 showed the best binding affinity. Further attention should be paid to the isolation of various jatrophane diterpenes from Euphorbia and evaluating their effects on SARS-Cov-2 and its molecular targets.

Arteperoxides A-C, tris-normonoterpene-sesquiterpene conjugates with peroxide-bridges from Artemisia judaica exhibiting antiosteoclastogenic activity.

Antiosteoclastogenic-guided screening was conducted with 120 extracts of the medicinal plants collected in Egypt that led to the selection of Artemisia judaica L. (Asteraceae). Three undescribed davanone-related terpenoids, arteperoxides A-C, were isolated from the extract with two known derivatives, hydroxydavanone and davana acid. Structural analysis revealed that arteperoxides A-C were tris-normonoterpene-sesquiterpene conjugates with peroxide bridges. Although davanone derivatives with peroxides, such as a hydroperoxyl and peroxyhemiketal groups, have been isolated from Artemisia species, arteperoxides A-C are the first variations observed to contain peroxide bridges between two terpene-derived units. The absolute configurations of arteperoxides A and B were studied based on their spectroscopic data compared with those of the semisynthetic analogs that have ether linkages. The natural and synthetic compounds were tested for the antiosteoclastogenic activity, and arteperoxide C and hydroxydavanone were more potent than other compounds at 20 µM.

Crataegus sinaica defatted methanolic extract ameliorated monosodium iodoacetate-induced oxidative stress andinhibited inflammation in a rat model of osteoarthritis.

Background and purpose: Osteoarthritis is a degenerative joint disease without definite treatment. It is characterized by intra-articular inflammation, cartilage degeneration, subchondral bone remodeling, and joint pain. The objective of the current study was to assess the anti-osteoarthritic effect and the possible underlying mechanism of action of Crataegus sinaica extract (CSE). Experimental approach: Intra-articular injection of monosodium iodoacetate in the right knee joint of all rats was done except for the sham group. One week later, the anti-inflammatory efficacy of CSE (100, 200, 300 mg/kg, daily p.o) for 4 successive weeks versus ibuprofen (40 mg/kg, p.o) was assessed. Serum inflammatory cytokines; as well as weekly assessment of knee joint swelling, joint mobility, and motor coordination were done. At the end of the experiment, a histopathological investigation of the affected knee joints and an x-ray investigation were also executed. Findings / Results: CSE significantly decreased joint swelling, pain behaviors, and serum levels of TNF-α, IL6, hyaluronic acid, and CTX-II. The radiographic findings revealed almost normal joint space with normal radiodensity and diameter in CSE-treated rats. As well, the histopathological and immunohistochemical investigations of the knee joints in CSE-treated groups retained the cartilage structure of knee joints. A significant reduction in the percentage of caspase-3-stained chondrocytes and a decrease in TGF-ß1 immuno-positive areas in the synovial lining and sub lining were recorded in CSE-treated rats, compared to the osteoarthritis control group. Conclusion and implications: This study approved the chondroprotective effects of CSE, and its ability to inhibit the pain associated with osteoarthritis.

Cyclopsammocinamides A and B, Enantiomeric Cyclic Peptides of Cyclocinamide A, from the Marine Sponge Psammocinia sp.

LC-MS and molecular networking analyses of the extract of the marine sponge Psammocinia sp. indicated the presence of two new compounds with multiple halogens. LC-MS-guided isolation yielded cyclic peptides, cyclopsammocinamides A (1) and B (2), in an enantiomeric relationship to cyclocinamide A (3). Planar structures of 1 and 2 were elucidated by NMR and mass spectroscopic analyses and the absolute configurations of the amino acid residues were determined using Marfey's method with their acid hydrolysates. The sponge extract exhibited cytotoxicity and the bioassay-guided isolation afforded a dimeric dilactone macrolide, swinholide A, as the cytotoxic compound.

Marine natural products that inhibit osteoclastogenesis and promote osteoblast differentiation.

Osteoporosis is a disease that affects the quality of life of elderly people. The balance between bone formation mediated by osteoblasts and bone resorption by osteoclasts is important to maintain the normal bone condition. Therefore, the promotion of osteoblast differentiation and the suppression of osteoclastogenesis are effective strategies for osteoporosis treatment. Marine organisms are a promising source of biologically active and structurally diverse secondary metabolites, and have been providing drug leads for the treatment of numerous diseases. We describe the marine-derived secondary metabolites that can inhibit receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and promote osteoblast differentiation.

Isolation, Synthesis, and Structure-Activity Relationship Study on Daphnane and Tigliane Diterpenes as HIV Latency-Reversing Agents.

Three new diterpenes, stellejasmins A (1) and B (2) and 12-O-benzoylphorbol-13-heptanoate (3), were isolated from the roots of Stellera chamaejasme L. The structures of 1-3 were elucidated by extensive NMR and mass spectroscopic analyses. Compounds 1 and 2 are the first derivatives containing a hydroxy group at C-2 in the family of daphnane and tigliane diterpenes. The presence of a chlorine atom in 1 is unique in the plant metabolite. Compound 3 has an odd-number acyl group, which is biosynthetically notable. Human immunodeficiency virus (HIV) LTR-driven transcription activity was tested with 1-3 and 17 known diterpenes isolated from S. chamaejasme L. and Wikstroemia retusa A.Gray. Among these, gnidimacrin (4), stelleralide A (5), and wikstroelide A (20) were highly potent, with EC50 values of 0.14, 0.33, and 0.39 nM, respectively. The structure-activity relationship (SAR) was investigated using 20 natural and eight synthetic diterpenes. This is the first SAR study on natural daphnane and tigliane diterpenes.

Glabratephrin reverses doxorubicin resistance in triple negative breast cancer by inhibiting P-glycoprotein.

Triple-negative breast cancer is one of the most aggressive breast cancer. The first therapeutic option is chemotherapy, often based on anthracycline as doxorubicin. However, chemotherapy efficacy is limited in by the presence of P-glycoprotein (Pgp), a membrane transporter protein that effluxes doxorubicin, reducing its cellular accumulation and toxicity. Inhibiting Pgp activity with effective and non-toxic products is still an open challenge. In this work, we demonstrated that the natural product Glabratephrin (Glab), a prenylated flavonoid from Tephrosia purpurea with a unique chemical structure, increased doxorubicin accumulation and cytotoxicity in triple negative breast cancer cells with high levels of Pgp, characterized by both acquired or intrinsic resistance to doxorubicin. Glab also reduced the growth of Pgp-expressing tumors, without adding significant extra-toxicities to doxorubicin treatment. Interestingly, Glab did not change the expression of Pgp, but it reduced the affinity for Pgp and the efflux of doxorubicin, as suggested by the increased Km and the reduced Vmax. In silico molecular docking predicted that Glab binds two residues (phenylalanine 322, glutamine 721) localized in the transmembrane domains of Pgp, facing the extracellular environment. Moreover, site-directed mutagenesis identified glycine 185 as a critical residue mediating the reduced catalytic efficacy of Pgp elicited by Glab. We propose Glab as an effective and safe compound able to reverse doxorubicin resistance mediated by Pgp in triple negative breast cancers, opening the way to a new combinatorial approach that may improve chemotherapy efficacy in the most refractory and aggressive breast cancer.

Halichonic Acid B, a Rearranged Nitrogenous Bisabolene-Type Sesquiterpene from a Marine Sponge Axinyssa sp.

A new rearranged nitrogenous bisabolone-type sesquiterpene, halichonic acid B (1), was isolated from a marine sponge Axinyssa sp. together with halichonic acid (2) and (6R,7S)-7-amino-7,8-dihydro-α-bisabolene (3). The structure of 1 was determined by extensive NMR and MS analyses, revealing an unprecedented carbon framework, and its absolute configuration was elucidated by time-dependent density-functional theory (TDDFT)-based electronic circular dichroism (ECD) spectrum calculation. We propose that 1 and 2 may be biosynthesized in the same pathway, involving the reaction between farnesyl pyrophosphate and glycine, followed by cyclization.

Taichunins E-T, Isopimarane Diterpenes and a 20-nor-Isopimarane, from Aspergillus taichungensis (IBT 19404): Structures and Inhibitory Effects on RANKL-Induced Formation of Multinuclear Osteoclasts.

Fifteen new isopimarane-type diterpenes, taichunins E-S (1-15), and a new 20-nor-isopimarane, taichunin T (16), together with four known compounds were isolated from Aspergillus taichungensis (IBT 19404). The structures of these new compounds were determined by NMR and mass spectroscopy, and their absolute configurations were analyzed by NOESY and TDDFT calculations of ECD spectra. Taichunins G, K, and N (3, 7, and 10) completely inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinuclear osteoclasts in RAW264 cells at 5 µM, with 3 showing 92% inhibition at a concentration of 0.2 µM.

Enhanced Activity and Sustained Release of Protocatechuic Acid, a Natural Antibacterial Agent, from Hybrid Nanoformulations with Zinc Oxide Nanoparticles.

Hybrid nanostructures can be developed with inorganic nanoparticles (NPs) such as zinc oxide (ZnO) and natural antibacterials. ZnO NPs can also exert antibacterial effects, and we used them here to examine their dual action in combination with a natural antibacterial agent, protocatechuic acid (PCA). To produce hybrid nanoformulations, we functionalized ZnO NPs with four types of silane organic molecules and successfully linked them to PCA. Physicochemical assessment confirmed PCA content up to ~18% in hybrid nanoformulations, with a PCA entrapment efficiency of ~72%, indicating successful connection. We then investigated the in vitro release kinetics and antibacterial effects of the hybrid against Staphylococcus aureus. PCA release from hybrid nanoformulations varied with silane surface modification. Within 98 h, only 8% of the total encapsulated PCA was released, suggesting sustained long-term release. We used nanoformulation solutions collected at days 3, 5, and 7 by disc diffusion or log reduction to evaluate their antibacterial effect against S. aureus. The hybrid nanoformulation showed efficient antibacterial and bactericidal effects that also depended on the surface modification and at a lower minimum inhibition concentration compared with the separate components. A hybrid nanoformulation of the PCA prodrug and ZnO NPs offers effective sustained-release inhibition of S. aureus growth.

Inhibition of cell-intrinsic NF-κB activity and metastatic abilities of breast cancer by aloe-emodin and emodic-acid isolated from Asphodelus microcarpus.

Anthraquinones are a major class of compounds naturally occurring in Asphodelus microcarpus. The pharmacological actions of anthraquinones in cancer cells are known to induce apoptosis or autophagy, and revert multidrug resistance. In this study, five anthraquinone-type analogs were isolated from the methanol extract of A. microcarpus leaves and identified as, emodin, rhein, physcion, aloe-emodin, and emodic acid. Among them, aloe-emodin and emodic-acid strongly inhibited the proliferation, cells-intrinsic NF-κB activity and metastatic ability of breast cancer. Although aloe-emodin inhibited p38 and ERK phosphorylation, emodic-acid more markedly inhibited JNK, in addition to p38 and ERK phosphorylation. Both aloe-emodin and emodic-acid inhibited the secretion of the pro-tumorigenic cytokines IL-1ß and IL-6, and VEGF and MMP expression, and subsequently inhibited the invasive and migratory potential of 4T1 cells. Thus, our study demonstrated the effects of aloe-emodin and emodin-acid in controlling the migratory and invasive ability of 4T1 breast cancer cells, in addition to inhibiting NF-κB activity and the expression of its downstream target molecules.

Anti-Vpr activities of homodrimane sesquiterpenoids and labdane diterpenoids from Globba sherwoodiana rhizomes.

Two new homodrimane sesquiterpenoids, globbatones A and B (1 and 2), and one 16-norlabdane diterpenoid, globbatone C (3), together with two new naturally occurring, (E)-labda-8(17),12-diene-15,16-olide (4) and γ-bicyclohomofarnesen-12-ol (5), and one known homodrimane sesquiterpenoid (6), nine known labdane diterpenoids (7-15), and one isospongian diterpenoid (16), were isolated from the chloroform extract of Globba sherwoodiana rhizomes. The structures of the new compounds 1-3 were elucidated based on 1D and 2D NMR and HRESIMS spectroscopic analyses. The chloroform extract of G. sherwoodiana rhizomes and 10 µM concentrations of some of its constituents 1, 3, 4, 8, 9, 12, and 14 showed the moderate anti-Vpr activities, without cytotoxic effects on the TREx-HeLa-Vpr cell line.