Sweroside: An iridoid glycoside of potential neuroprotective, antidiabetic, and antioxidant activities supported by molecular docking.

Oxidative stress can be a series burden on human health and may lead to many chronic diseases such as diabetes and neurological disorders. The use of natural products to scavenge the reactive oxygen species has attracted the attention of many researchers, to safely manage these conditions with fewer side effects, in available and cost-effective ways. The current study aimed at the isolation and structure elucidation of sweroside from Schenkia spicata (Gentianaceae) and the evaluation of its antioxidant, antidiabetic, neuroprotective, and enzyme inhibitory potential via in vitro and in silico studies. The antioxidant potential was evaluated by a variety of assays as ABTS, CUPRAC and FRAP, showing values of 0.34 ± 0.08, 21.14 ± 0.43, and 12.32 ± 0.20 mg TE/g, respectively, while demonstrating 0.75 ± 0.03 mmol TE/g for phosphomolybdenum (PBD) assay. Acetylcholinestrase (AChE), butyrylcholinesterase (BChE) and tyrosinase inhibitory activities were used to evaluate the neuroprotective effect, while the antidiabetic potential was evaluated by measuring α-amylase and glucosidase inhibitory activities. Results revealed that sweroside showed antioxidant and inhibitory effects on the enzymes tested with the exception of AChE. It demonstrated good tyrosinase inhibitory ability with 55.06 ± 1.85 mg Kojic acid equivalent /g. Regarding the antidiabetic ability, the compound displayed both amylase and glucosidase (0.10 ± 0.01 and 1.54 ± 0.01 mmol Acarbose equivalent/g, respectively) inhibitory activities. Molecular docking studies of sweroside on the active sites of the aforementioned enzymes in addition to NADPH oxidase were performed using Discovery Studio 4.1 software. Results revealed good binding affinities of sweroside to these enzymes mainly through hydrogen bonds and van der Waals interactions. Sweroside can be an important antioxidant and enzyme inhibitory supplement, yet further in vivo and clinical studies are required.

Antimicrobial metabolite of Cordyceps tenuipes targeting MurE ligase and histidine kinase via in silico study.

Cordyceps spp. are widely healthy foods around the world with several traditional uses and bio-functionalities. The chemical characterization of ethyl acetate-soluble extract of the entomopathogenic fungus Cordyceps tenuipes NBRC 111,630 afforded two new metabolites with 1,6-dioxaspiro[4.4]nonane motif, tenuipesone A (1) and tenuipesone B (2), along with four well-known metabolites (3-6). The elucidation of the chemical structures was carried out via extensive spectroscopic experiments including FTIR, HRMS, 1D-NMR, and 2D-NMR. The probable biosynthetic pathway of 1 and 2 was hypothesized. From the six isolates, beauvericin (6) exhibited antimicrobial activity against Bacillus subtilis and Staphylococcus aureus with respective MIC of 6.25 and 12.5 µM. Docking results exhibited that beauvericin (6) has significant binding affinities against MurE and HK proteins with ΔG = - 8.021 and - 8.585 kcal/mol, respectively. KEY POINTS: • Six compounds, including two new, were isolated from the entomopathogenic fungus Cordyceps tenuipes. • Plausible biosynthetic pathway of compounds 1, 2, 4, and 5 was hypothesized. • Beauvericin (6) exhibited significant antimicrobial activity against Bacillus subtilis and Staphylococcus aureus alongside binding affinities against MurE and HK proteins in MOE study.

Sweroside Ameliorated Memory Deficits in Scopolamine-Induced Zebrafish (Danio rerio) Model: Involvement of Cholinergic System and Brain Oxidative Stress.

Sweroside is a secoiridoid glycoside and belongs to a large group of naturally occurring monoterpenes with glucose sugar attached to C-1 in the pyran ring. Sweroside can promote different biological activities such as antifungal, antibacterial, hepatoprotective, gastroprotective, sedative and antitumor, antioxidant, and neuroprotective activities. Zebrafish were given sweroside (12.79, 8.35, and 13.95 nM) by immersion once daily for 8 days, along with scopolamine (Sco, 100 µM) 30 min before the initiation of the behavioral testing to cause anxiety and memory loss. Employing the novel tank diving test (NTT), the Y-maze, and the novel object recognition test (NOR), anxiety-like reactions and memory-related behaviors were assessed. The following seven groups (n = 10 animals per group) were used: control, Sco (100 µM), sweroside treatment (2.79, 8.35, and 13.95 nM), galantamine (GAL, 2.71 µM as the positive control in Y-maze and NOR tests), and imipramine (IMP, 63.11 µM as the positive control in NTT test). Acetylcholinesterase activity (AChE) and the antioxidant condition of the brains were also evaluated. The structure of sweroside isolated from Schenkia spicata was identified. Treatment with sweroside significantly improved the Sco-induced decrease of the cholinergic system activity and brain oxidative stress. These results suggest that sweroside exerts a significant effect on anxiety and cognitive impairment, driven in part by the modulation of the cholinergic system activity and brain antioxidant action.

Design, synthesis, and molecular modeling of quinoline-based derivatives as anti-breast cancer agents targeting EGFR/AKT signaling pathway.

Two series of quinoline-thiazole and quinoline-thiazolidinone hybrids were designed, synthesized, and evaluated for their in vitro antitumor activity on MCF-7 breast cancer cell line. In comparison with lapatinib (IC50  = 4.69 µM), compounds 4b and 6b exhibited the best antiproliferative activity with IC50 values of 33.19 and 5.35 µM, respectively. Although compound 6b showed higher cytotoxicity, compound 4b exhibited better inhibitory activity toward the epidermal growth factor receptor (EGFR) pathway than compound 6b as represented by the significant reduction in the EGFR kinase activity and the levels of phosho-EGFR and phosho-AKT when compared to lapatinib as a reference standard. Moreover, compound 4b was capable of down-regulating the anti-apoptotic genes Bcl-2 and survivin and up-regulating the level of the pro-apoptotic gene BAX. Molecular modeling study was carried out to predict the binding interactions of both compounds into the target kinase. Finally, the physicochemical properties were investigated in silico as well.

Shoot aqueous extract of Manihot esculenta Crantz (cassava) acts as a protective agent against paracetamol-induced liver injury.

Manihot esculenta Crantz (Euphorbiaceae), known as cassava, is a widely cultivated plant, considered one of the main sources of food in the tropical and subtropical regions of Africa and Asia. The aim of the present study was the evaluation of the antioxidant and anti-inflammatory effects of cassava shoot aqueous extract (CSAE) on liver injury induced by paracetamol and investigation of its effect on hyperhomocysteinemia. CSAE was administered to male albino rats classified into seven groups: control, treated, and prophylactic groups. A significant reduction in liver enzymes, malondialdehyde, and homocysteine were observed when compared to the paracetamol group, together with an increase in paraoxonase-1. Histopathological and histochemical results indicated that CSAE effectively ameliorate these parameters. Two main flavonol glycosides, quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside, in addition to a minor myricetin 3-O-rutinoside, were identified in CSAE. CSAE showed a therapeutic potential against paracetamol-induced liver injury probably through antioxidant activity of its flavonol glycosides.

Topical Wound Healing Activity of Myricetin Isolated from Tecomaria capensis v. aurea.

Wounds and burn injury are major causes of death and disability worldwide. Myricetin is a common bioactive flavonoid isolated naturally from the plant kingdom. Herein, a topical application of naturally isolated myricetin from the shoots of Tecomaria capensis v. aurea on excisional wound healing that was performed in albino rats. The wounded rats were treated every day with 10 and 20% myricetin for 14 days. During the experiment, the wound closure percentage was estimated at days 0, 7, and 14. Effects of myricetin on the inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and cluster of differentiation 68 (CD68) in the serum were evaluated using immunosorbent assay kits. The percentage of wound closure and contraction was delayed in wounded rats (67.35%) and was remarkably increased after treatment of wounded rats with myricetin; the treatment with 20% myricetin was the most potent (98.76%). Histological findings exhibited that 10% myricetin caused the formation of a large area of scarring at the wound enclosure and stratified squamous epithelium without the formation of papillae as in the control group. Treatment with 20% myricetin exhibited less area of scarring at the wound enclosure as well as re-epithelialization with a high density of fibroblasts and blood capillaries in the wound. Level elevations of serum pro-inflammatory cytokines, IL-1ß, and TNF-α and macrophage CD68 were decreased in wounded rats treated with myricetin. Thus, it can be suggested that the enhancements in inflammatory cytokines as well as systemic reorganization after myricetin treatment may be recommended to play a crucial part in the promotion of wound healing. The findings suggest that treatment with a higher dose of myricetin was better in improving wound curing in rats. It could serve as a potent anti-inflammatory agent and can be used as an adjunctive or alternative agent in the future.

Albizia anthelmintica: HPLC-MS/MS profiling and in vivo anti-inflammatory, pain killing and antipyretic activities of its leaf extract.

In the current work, the phytochemical composition of a leaf methanol extract from Albizia anthelmintica was thoroughly investigated. The antioxidant, anti-inflammatory, analgesic, and antipyretic activities of the extract were investigated. In the carrageenan induced hind paw edema bioassay; the extract significantly reduced the edema thickness in rats and diminished the leukocyte migration to the peritoneal cavity in mice. The extract exhibited central and peripheral anti-nociceptive effects; it significantly decreased the number of acetic acid induced writhes and prolonged the latency time in the hot plate test. The extract showed a substantial antipyretic activity as it decreased significantly the elevated rectal temperature in mice after intraperitoneal injection of Brewer's yeast. Molecular docking of some major compounds in the extract to COX-1, COX-2 and 5-LOX, enzymes involved in the inflammation cascade, revealed appreciable interactions with the conserved amino acid residues in these target proteins. These findings were confirmed with in vitro enzyme inhibitory assays in which the extract showed IC50 values of 4.11, 0.054, and 1.74 µg/mL towards COX-1, COX-2 and 5-LOX, respectively. The extract displayed solid antioxidant properties as well with a TAC value of 35.13 U/L and EC50of 5.36 µg/mL in DPPH assay. These findings suggested that Albizia anthelmintica is a good antioxidant with potential therapeutic efficacy for treating inflammation, pain and related oxidative stress disorders.

Phenolic metabolites, biological activities, and isolated compounds of Terminalia muelleri extract.

CONTEXT: Terminalia muelleri Benth. (Combretaceae), is rich with phenolics that have antioxidant and cytotoxic activities. No screening studies were published before on T. muelleri. OBJECTIVE: The study focused on isolation and identification of secondary metabolites from aqueous methanol leaf extract of T. muelleri and evaluation of its biological activities. MATERIALS AND METHODS: The n-butanol extract was chromatographed on polyamide 6, and eluted with H2O/MeOH mixtures of decreasing polarity, then separated by different chromatographic tools that yielded 10 phenolic compounds. The antioxidant activity of the extract was evaluated by investigating its total phenolic and flavonoid content and DPPH scavenging effectiveness. The extract and the two acylated flavones were evaluated for their anticancer activity towards MCF-7 and PC3 cancer cell lines. Molecular docking study of the acylated flavones was performed against topoisomerase enzyme. RESULTS AND DISCUSSION: Two acylated flavonoids, apigenin-8-C-(2″-O-galloyl) glucoside 1 and luteolin-8-C-(2″-O-galloyl) glucoside 2, were isolated and identified for the second time in nature, with eight tannins (3-10), from the leaves of T. muelleri. The extract and compound 10 showed the most significant antioxidant activity (IC50 = 3.55 and 6.34 µg/mL), respectively. The total extract and compound 2 demonstrated cytotoxic effect against MCF-7 with IC50 = 29.7 and 45.2 µg/mL respectively, while compound 1 showed cytotoxic effect against PC3 (IC50 = 40.8 µg/mL). The docking study of compounds 1 and 2 confirmed unique binding mode in the active site of human DNA topoisomerase enzyme. CONCLUSIONS: Terminalia muelleri is a promising medicinal plant as it possesses high antioxidant activity and moderate cytotoxic activity against MCF-7.

Rumpictuside A: Unusual 9,10-anthraquinone glucoside from Rumex pictus Forssk.

A new 8-ionized hydroxylated 9,10-anthraquinone namely, 1-hydroxy-3-methyl-9,10-anthraquinone-6-O-ß-D-glucopyranoside-8-olate (Rumpictuside A, 1) along with five known flavonoids, apigenin 7-O-ß-D-glucoside (2), vitexin (3), quercetin 3-O-ß-D-glucouronide (4), orientin (5), and isorientin (6) were isolated from Rumex pictus. The structures of isolated compounds were identified by the extensive spectroscopic techniques such as, UV, FT-IR, 1D, 2D NMR and HR-FAB-ESI-MS. The ionized hydroxyl group in the new anthraquinone (1) was rarely found for anthraquinone glycosides isolated from natural sources. All the isolated compounds were found inactive against influenza A virus infection. Compounds 2-6 exhibited significant antioxidant activity against DPPH and ABTS+. The alcoholic extract exhibited moderate activity while the new anthraquinone 1 showed the lowest activity against both assays.

Soft coral Cespitularia stolonifera: New cytotoxic ceramides and gastroprotective activity.

In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol (1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3ß-ol (2), 24-methylcholesta-5, 24(28)-diene-3ß-acetate (3), 4-methyl-24-methylcholesta-22-ene-3-ol (4), and cholesterol, was isolated and characterized from CH2Cl2/MeOH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate (1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods. (-)-Alloaromadendren, ledane, (1)-alloaromadendren oxide, isoaromadendrene epoxide and (-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides (1) and (1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids (2) and (3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CH2Cl2/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.

New Isorhamnetin Derivatives from Salsola imbricata Forssk. Leaves with Distinct Anti-inflammatory Activity.

BACKGROUND: Salsola imbricata Forssk. is a shrub widely growing in Egypt, used as a camel food, traditionally, used as anti-inflammatory agent. Literature survey showed no report about the anti-inflammatory activity of S. imbricata. AIM OF THE STUDY: This work was designed to study the phenolic constituents and to provide evidence for the traditional use of S. imbricata as an anti-inflammatory agent. MATERIALS AND METHODS: The in vitro anti-inflammatory activity of the total aqueous methanol extract and some isolated compounds were investigated in RAW 264.7 macrophage cells using nitric oxide assay. All chemical structures were identified on the basis of electrospray ionization-mass spectrometry, one- and two-dimension nuclear magnetic resonance. RESULTS: Nine phenolic compounds, among them two new natural products; isorhamnetin-3-O-ß-D-glucuronyl (1'''→4'') glucuronide (1) and its dimethyl ester; isorhamnetin-3-O-ß-D-di glucuronate dimethyl ester (2), two isorhamnetin glycosides: Isorhamnetin-3-O-ß-D-galactopyranoside (3), isorhamnetin-3-O-ß-D-glucopyranoside (4), and isorhamnetin (5). In addition, an alkaloidal phenolic; trans N-feruloyl tyramine (6), three phenolic acids: Isovanillic acid (7), ferulic acid (8), and p-hydroxy benzoic acid (9) were isolated from salsola imbricata leaves. All compounds were isolated and identified for the first time from this plant except compound (6). The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells. CONCLUSION: The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells. SUMMARY: Investigation of the chemical constituents of the leaves of Salsola imbricata led to isolation of two new isorhamnetin derivatives: isorhamnetin.3-O-ß-D.glucuronyl (1'"→") glucuronide (1) and its dimethyl ester (2), together with seven known phenolic compounds. The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells. Abbreviations used: PC: Paper chromatography, MPLC : Medium Pressure Liquid Chromatography, HMBC: Heteronuclear multiple bond correlation, HMQC: Heteronuclear single quantum correlation, NMR: Nuclear magnetic resonance.

Secondary metabolites and bioactivities of Albizia anthelmintica.

BACKGROUND: Albizia species are rich in phenolics and terpenes in the different plant organs. They are widely used in traditional Chinese medicine. So this study investigated the phytochemical and biological activities of Albizia Anthelmintica. MATERIALS AND METHODS: Column chromatography has been performed for the isolation of compounds. Bioactivity studies of A. anthelmintica leaves were carried out on aqueous ethanol extract and some pure compounds were tested for their antioxidant activities. RESULTS: Eight compounds have been isolated for the first time from A. anthelmintica. The aqueous ethanol extract of A. anthelmintica showed moderate anti-inflammatory activity and significant for both analgesic and antioxidant activities. Quercetin-3-O-ß-D-glucopyranoside, kaempferol-3-O-ß-D-glucopyranoside, kaempferol-3-O-(6ß-O-galloyl-ß-D-glucopyranoside and quercetin-3-O-(6ß-O-galloyl-ß-D-glucopyranoside) exhibited potent antioxidant scavenging activity towards diphenyl-picrylhydrazine.

Phenolic metabolites from Pyruscalleryana and evaluation of its free radical scavenging activity.

Investigation of the aqueous alcoholic extract of Pyruscalleryana Decne. leaves led to the isolation of two new phenolic acids glycosides, namely protocatechuoylcalleryanin-3-O-ß-glucopyranoside (1) and 3'-hydroxybenzyl-4-hydroxybenzoate-4'-O-ß-glucopyranoside (2), together with nine known compounds among them lanceoloside A and methylgallate, which have been isolated for the first time from the genus Pyrus. Structures of the isolated compounds were established by spectroscopic analysis, including UV, IR, HRESI-MS, and 1D/2D NMR. The total extract and some isolated compounds were determined against DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl radical, for their free radical scavenging activity, the total alcoholic extract showed strong antioxidant activity while the two new compounds showed weak antioxidant activity.