Two new ellagic acid glycosides from leaves of Diplopanax stachyanthus

Novel chemical-structure TPOR agonist, TMEA, promotes megakaryocytes differentiation and thrombopoiesis via mTOR and ERK signalings

BACKGROUND

Non-peptide thrombopoietin receptor (TPOR) agonists are promising therapies for the mitigation and treatment of thrombocytopenia. However, only few agents are available as safe and effective for stimulating platelet production for thrombocytopenic patients in the clinic.

PURPOSE

This study aimed to develop a novel small molecule TPOR agonist and investigate its underlying regulation of function in megakaryocytes (MKs) differentiation and thrombopoiesis.

METHODS

A potential active compound that promotes MKs differentiation and thrombopoiesis was obtained by machine learning (ML). Meanwhile, the effect was verified in zebrafish model, HEL and Meg-01 cells. Next, the key regulatory target was identified by Drug Affinity Responsive Target Stabilization Assay (DARTS), Cellular Thermal Shift Assay (CETSA), and molecular simulation experiments. After that, RNA-sequencing (RNA-seq) was used to further confirm the associated pathways and evaluate the gene expression induced during MK differentiation. In vivo, irradiation (IR) mice, C57BL/6N-TPOR^em1cyagen (Tpor^-/-) mice were constructed by CRISPR/Cas9 technology to examine the therapeutic effect of TMEA on thrombocytopenia.

RESULTS

A natural chemical-structure small molecule TMEA was predicted to be a potential active compound based on ML. Obvious phenotypes of MKs differentiation were observed by TMEA induction in zebrafish model and TMEA could increase co-expression of CD41/CD42b, DNA content, and promote polyploidization and maturation of MKs in HEL and Meg-01 cells. Mechanically, TMEA could bind with TPOR protein and further regulate the PI3K/AKT/mTOR/P70S6K and MEK/ERK signal pathways. In vivo, TMEA evidently promoted platelet regeneration in mice with radiation-induced thrombocytopenia but had no effect on Tpor^-/- and C57BL/6 (WT) mice.

CONCLUSION

TMEA could serve as a novel TPOR agonist to promote MKs differentiation and thrombopoiesis via mTOR and ERK signaling and could potentially be created as a promising new drug to treat thrombocytopenia.

Analytical Profiling of Phenolic Compounds in Extracts of Three Cistus Species from Sardinia and Their Potential Antimicrobial and Antioxidant Activity

The Cistaceae family is well represented in Sardinia, and the Cistus genus is widely used in traditional medicine. Nowadays only few studies have been performed on this genus vegetating in Sardinia in spite of its ethnobotanical importance. Moreover, in the past there have been conflicting opinions among botanists for the exact assignment of the species growing in Sardinia. We started several years ago to carried out studies on this genus and in the present study was to evaluate the in vitro activity of several samples of Cistus salvifolius L., Cistus monspeliensis L., and Cistus albidus L. collected in Sardinia as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and four Candida species and their antioxidant activity using DPPH, ABTS, and FRAP assays. Furthermore, the phenolic content and composition of the extracts were first evaluated. Using statistical multivariate analysis on the complete metabolomics profile of all Cistus species growing wild in Sardinia, we confirmed the botanical classification, and we observed an interesting correlation between metabolomics profile and antioxidant activity.

Defatted Seeds of Oenothera biennis as a Potential Functional Food Ingredient for Diabetes

The defatted seeds of Oenothera biennis (DSOB) are a by-product of evening primrose oil production that are currently not effectively used. In this study, α-glucosidase inhibition, aldose reductase inhibition, antioxidant capacity, polyphenol composition, and nutritional value (carbohydrates, proteins, minerals, fat, organic acid, and tocopherols) of DSOB were evaluated using the seeds of Oenothera biennis (SOB) as a reference. DSOB was an excellent inhibitor of α-glucosidase (IC₅₀ = 3.31 μg/mL) and aldose reductase (IC₅₀ = 2.56 μg/mL). DSOB also showed considerable antioxidant capacities (scavenging of 2,2-diphenyl-1-picrylhydrazyl, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, nitric oxide, peroxynitrite, and hydroxyl radicals). DSOB was a reservoir of polyphenols, and 25 compounds in DSOB were temporarily identified by liquid chromatography coupled with electrospray ionization–quadrupole time of flight–mass spectrometry analysis. Moreover, the carbohydrate, protein, and mineral content of DSOB were increased compared to that of SOB. DSOB contained large amounts of fiber and low levels of sugars, and was rich in calcium and iron. These results imply that DSOB may be a potential functional food ingredient for diabetes, providing excellent economic and environmental benefits.

Cytotoxic Property of Grias neuberthii Extract on Human Colon Cancer Cells: A Crucial Role of Autophagy

Traditional herbal medicine has become an important alternative in the treatment of various cancer types, including colon cancer, which represents one of the main health problems around the world. Therefore, the search for new therapies to counteract this disease is very active. Grias neuberthii is an endemic plant located in the Ecuadorian Amazon region, which has been used in traditional medicine for its pharmacological properties, including its ability to inhibit tumor cell growth, although scientific studies are limited. We have analyzed the effect of this plant on two colon carcinoma cell lines, that is, RKO (normal p53) and SW613-B3 (mutated p53) cells. Among several extracts obtained from various parts of G. neuberthii plant, we identified the extract with the greatest cytotoxic potential, derived from the stem bark. The cytotoxic effect was similar on both cell lines, thus indicating that it is independent of the status of p53. However, significant differences were observed after the analysis of colony formation, with RKO cells being more sensitive than SW613-B3. No evidence for apoptotic markers was recorded; nevertheless, both cell lines showed signs of autophagy after the treatment, including increased Beclin-1 and LC3-II and decreased p62. Finally, three chemical compounds, possibly responsible for the effect observed in both cell lines, were identified: lupeol (1), 3′-O-methyl ellagic acid 4-O-β-D-rhamnopyranoside (2), and 19-α-hydroxy-asiatic acid monoglucoside (3).

Cycloartane-type triterpenoid derivatives and a flavonoid glycoside from the burs of Castanea crenata

Five undescribed cycloartane-type triterpenoids, which were isolated for the first time from the genus, and a flavonoid glycoside together with 11 known compounds were isolated from the burs of Castanea crenata. The structures were elucidated based on the spectroscopic analysis of 1D and 2D NMR and MS data. All isolated compounds were evaluated for antiviral activities against HRV1B-, CVB3-, and PR8-infected cells. Most kaempferol derivatives showed statistically significant antiviral activities against HRV1B-infected cells. Among the tested compounds, kaempferol-3-O-[2″,6″-di-O-Z-p-coumaroyl]-β-d-glucopyranoside exhibited the most consistent and effective antiviral activities against all infections.

Antimicrobial and antioxidant activities of triterpenoid and phenolic derivatives from two Cameroonian Melastomataceae plants: Dissotis senegambiensis and Amphiblemma monticola

Background

Antimicrobial resistance is a serious threat against humankind and the search for new therapeutics is needed. This study aims to investigate the antimicrobial and antioxidant activities of ethanol extracts and compounds isolated from Dissotis senegambiensis and Amphiblemma monticola, two Cameroonian Melastomataceae species traditionally used for the treatment of fever, malaria and infectious diseases.

Methods

The plant extracts were prepared by maceration in ethanol. Standard chromatographic and spectroscopic methods were used to isolate and identify fourteen compounds from the two plant species [1–6 (from D. senegambiensis), 3, 4 and 7–14 (from A. monticola)]. A two-fold serial micro-dilution method was used to determine the minimum inhibitory concentration (MIC) against four bacterial strains including two resistant bacterial strains, methicillin resistant S. aureus (MRSA3) and methicillin resistant S. aureus (MRSA4) and three yeast strains.

Results

The fractionation of EtOH extracts afforded fourteen compounds belonging to triterpenoid and phenolic derivatives. The ethanol extracts, compounds 3, 5–8, 10 and the mixture of 10 + 12 were active against all the tested bacterial and fungal species. Compound 7 (MIC = 16–32 μg/mL) and 10 (MIC = 8–16 μg/mL) displayed the largest antibacterial and antifungal activities, respectively. Compounds 7, 10 and the mixture of 10 + 12 showed prominent antibacterial activity against methicillin- resistant S. aureus (MRSA) which is in some cases equal to that of ciprofloxacin used as reference antibacterial drug. Compound 8 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and butylated hydroxytoluene used as reference antioxidants. The tested samples were non-toxic to normal cells highlighting their good selectivity.

Conclusions

The result of this investigation reveals the potential of D. senegambiensis and A. monticola as well as the most active compounds in the search for new antimicrobial and antioxidant agents. So, further investigations are needed.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2229-2) contains supplementary material, which is available to authorized users.

A New C-methyl Isoflavone and Other Compounds from the Roots of Amphiblemma monticola(Melastomataceae)

The phytochemical study of the EtOH extract of the roots of Amphiblemma monticola Jacq.-Fél. led to the isolation of a new C-methyl isoflavone, amphiblemmone A (1), along with ten known compounds, including 3,4’-di- O-methylellagic acid (2), dimethyl 4,4’,5,5’,6,6’- hexahydroxybiphenyl-2,2’-dicarboxylate (3), lupeol (4), ellagic acid (5), β-sitosterol (6), sitosterol 3- O-β-D-glucopyranoside (7), 3-hydroxy-4,5-dimethoxybenzoic acid (8), 3- O-methylellagic acid 4′- O-β-D-xylopyranoside (9), and a mixture of oleanolic acid (10) and ursolic acid (11). The structures were elucidated using spectroscopic analyses (IR, UV, NMR and MS) and comparison with literature data. Compounds 2-11 were isolated for the first time from the genus Amphiblemma. This is the first report of compounds 2-4, 8 and 9 from the Melastomataceae family.

Therapeutic potentials of Crataegus azarolus var. eu- azarolus Maire leaves and its isolated compounds

Background

Hyperglycemia is a complicated condition accompanied with high incidence of infection and dyslipidemia. This study aimed to explore the phyto-constituents of Crataegus azarolus var. eu- azarolus Maire leaves, and to evaluate the therapeutic potentials particularly antimicrobial, antihyperglycemic and antihyperlipidemic of the extract and the isolated compound (3β-O-acetyl ursolic acid).

Methods

Total phenolics and flavonoidal contents were measured by RP-HPLC analysis. Free radicals scavenging activity of different extraction solvents was tested in-vitro on DPPH free radicals. The antimicrobial activity of the ethanolic extract and its fractions as well as the isolated compounds were evaluated in-vitro on variable microorganisms. Animal models were used to evaluate the antihyperglycemic and antihyperlipidemic activities of the ethanolic extract along with the isolated compound (3β-O acetyl ursolic acid).

Results

RP- HPLC analysis of the phenolics revealed high content of rutin, salicylic and ellagic acids. Six compounds belonging to triterpenes and phenolics were isolated from chloroform and n-butanol fractions namely: ursolic acid, 3β-O-acetyl ursolic acid, ellagic acid, quercetin 3-O-β methyl ether, rutin and apigenin7-O-rutinoside. Ethanolic extract showed the highest DPPH radical scavenger activity compared to other solvents. Ethanolic extract, hexane fraction, ursolic acid, 3β-O acetyl ursolic acid and quercetin 3-O-methyl ether showed variable antimicrobial activity against E. coli, P. aeruginosa, S. aureus, and C. albicans. Administration of the ethanolic extract or 3β-O acetyl ursolic acid orally to the mice reduced blood glucose significantly in a time- and dose-dependent manner. Ethanolic extract significantly reduced LDL-C, VLDL-C, TC and TG and increased HDL-C in rats. Ethanolic extract and 3β-O acetyl ursolic acid reduced in-vitro activity of pancreatic lipase.

Conclusion

This study reveals that Crataegus azarolus var. eu- azarolus Maire has the efficiency to control hyperglycemia with its associated complications. This study is the first to evaluate antihyperglycemic and antihyperlipidemic potentials of 3β-O acetyl ursolic acid.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1729-9) contains supplementary material, which is available to authorized users.

Bioassay-guided In vitro Study of the Antimicrobial and Cytotoxic Properties of the Leaves from Excoecaria Lucida Sw

Background:

Excoecaria lucida Sw. (Euphorbiaceae) is a plant conventionally used throughout the Caribbean in the treatment of infectious diseases.

Objective:

To evaluate, using bioassay-guided fractionation, the in vitro cytotoxicity and antimicrobial activity of E. lucida leaves.

Materials and Methods:

A 95% ethanol crude extract was dried and fractionated by solid-liquid separation in four phases (hexane, dichloromethane, ethyl acetate, and butanol). Antimicrobial activity (3 bacteria, 6 yeasts, and 2 fungi) was evaluated by the dilution method with resazurin (2048, 512, 128, 32, and 8 μg/mL). The cytotoxicity assays were evaluated in two cell lines: MRC-5 and RAW 264.7; calculating the selectivity index. Assays were performed for the total extract, the isolated compound with the highest yield, and the ethyl acetate and butanol phases. Isolated compounds were characterized by nuclear magnetic resonance and mass spectrometry techniques.

Results:

Fractionation process led to the isolation of ellagic acid (784.29 mg), 3,3',4'-tri-O-methyl ellagic 4-O-β-D-glucopyranoside acid (6.1 mg), and corilagin (6.91 mg). The most active were ethyl acetate phase and ellagic acid with IC₅₀= 128 μg/mL against seven and five different species of microorganisms, respectively. The total extract (IC₅₀=512 μg/mL) and the ethyl acetate phase (IC₅₀=128 μg/mL) were cytotoxic in both cell lines, while butanol phase and ellagic acid both with IC₅₀>2048 μg/mL seemed to be safer.

Conclusions:

The results obtained indicate that the Excoecaria leaves can be conventionally used as antimicrobial, but it should be present that some cytotoxicity could appear. In addition, the three identified compounds were reported for the first time in the species.

SUMMARY

Excoecaria lucida leaves (Euphorbiaceae) are used by the Cuban population due to their antimicrobial activity. This ethnopharmacological knowledge is confirmed by the integrated antibacterial and antifungal in vitro screening developed, using the bioassay-guided fractionation method.

Abbreviations Used: MRC-5-SV2: Diploid human lung fibroblasts cells, RAW 264.7: Murine macrophages cells, IC50: Inhibitory Concentration 50%, ATCC: American Type Culture Collection, CCEBI: Culture Collection of Industrial Biotechnology Center, CECT: Spanish Culture Collection Type, CFU: Colony forming units, CC50: 50% cytotoxic concentration, CO2: Carbon dioxide, SI: Selectivity index, IR: Infrared spectroscopy, ¹H NMR: Nuclear Magnetic Resonance of hydrogen, ¹³C NMR: Nuclear Magnetic Resonance of carbon, HMQC: Heteronuclear Multiple-Quantum Correlation, HMBC: Heteronuclear Multiple Bond Correlation, COSY: Correlation Spectroscopy, NOESY: Nuclear Overhauser Effect Spectroscopy, KBr: Potassium bromide, DMSO-D₆: Deuterated dimethyl sulfoxide, LC.MS: Liquid Chromatography-Mass Spectrometry, [α]_D: Optical rotation, EL1: ellagic acid, EL2: 3,3’,4’-tri-O-methyl ellagic 4-O-β-D-glucopyranoside acid, EL3: corilagin, Active (+), inactive (-).

A Novel Ellagic Acid Derivative from Desbordesia glaucescens

One novel ellagic acid derivative, desglauside (1), was isolated from the leaves of Desbordesia glaucescens together with three known compounds [3 ’,4′-di-O-methylellagic acid (2), oleanolic acid (3) and β-sitosterol-3-O-β-D-glucopyranoside (4)]. Their structures were elucidated on the basis of NMR spectroscopic and MS analysis, and by comparison with related published data. The crude extract, fractions and isolated compounds showed no activity against four yeast strains [Candida albicans (ATCC 9002), C. parapsilopsis (ATCC22019), C. tropicalis (ATCC750), Cryptococcus neoformans (IP95026) and one isolate of Candida guilliermondii].

Antibacterial, antioxidant, and topical anti-inflammatory activities of Bergia ammannioides: A wound-healing plant

CONTEXT

Despite the traditional use of Bergia ammannioides Henye ex Roth. (Elatinaceae) for the treatment of wounds in India, there is a scarcity of scientific data supporting this use.

OBJECTIVE

The objective of this study is to assess wound-healing potentiality of the plant, to study pharmacological activities that may contribute in eliminating wound complications, and to investigate the biologically active fractions.

MATERIAL AND METHODS

The ethanolic extract (EtOH) of the aerial parts was fractionated to obtain n-hexane (HxFr), chloroform (ClFr), ethyl acetate (EtFr), and n-butanol (BuOH) fractions. EtOH and its fractions were formulated in strength of 5 and 10% w/w ointment and tested for wound-healing activity using the excision model. The topical anti-inflammatory, in vitro antioxidant, and antibacterial activities were evaluated. HxFr and EtFr were chemically investigated to isolate their constituents.

RESULTS

Application of EtOH, HxFr, and EtFr (10% w/w ointments) leads to 71.77, 85.62, and 81.29% healing of the wounds with an increase in the collagen content. HxFr had the strongest anti-inflammatory (64.5% potency relative to Voltaren®) and antibacterial activity (MIC = 104 μg/ml against Staphylococcus aureus), while EtFr showed the strongest antioxidant activity against DPPH, ABTS(•+), and super oxide radical with an IC50 value of 10.25 ± 0.01, 66.09 ± 0.76, and 167.33 ± 0.91 µg/ml, respectively. β-Sitosterol, lupeol, cyclolaudenol, and cycloartenol were isolated from HxFr. Quercetin, ellagic acid, kaempferol-3-O-α-l-rhamnoside, and quercetin-3-O-α-l-rhamnoside were isolated from EtFr.

DISCUSSION AND CONCLUSION

Our study presents scientific evidence for the efficacy of B. ammannioides in enhancing wound healing, and the first isolation of cyclolaudenol and cycloartenol from Bergia.

Fatty acid synthase inhibitors separated from oiltea camellia by high-speed counter-current chromatography

The inhibitory effects of oiltea camellia extracts (OCEs) and its active components on fatty acid synthase (FAS) were investigated. OCE potently inhibited the activity of FAS with an half-maximal inhibitory concentration (IC₅₀) value of 2.30 μg/mL. The inhibition kinetic results showed that OCE and acetyl-CoA competitively inhibited FAS but these compounds exhibited mixed inhibition against malonyl-CoA and NADPH. Further study uncovered that the active components of OCE, ellagic acid (EA) and 3-O-methylellagic acid 4'-O-β-D-glucopyranoside (MEAG), which were isolated and purified by high-speed counter-current chromatography (HSCCC) using a 2-phase solvent system of chloroform-ethanol-water-acetic acid (4:3:2:0.01, v/v/v/v), inhibited FAS with IC₅₀ of 2.50 and 37.73 μg/mL, respectively. Their inhibition kinetics were different from that of OCE. Both of them exhibited uncompetitive inhibition for nicotinamide adenine dinucleotide phosphate (NADPH) and decreased the FAS activity through inactivation of acetyl/malonyl transferase on FAS. These results suggest that OCE could be a valuable resource for bioactive substances.

PRACTICAL APPLICATION

With the gradual increase in tea oil production, it was in urgent need of dealing with Camellia fruit hull, which was always discarded because of low economic benefits. Camellia fruit hull has been shown to have significant antioxidant effects including 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability and ferric-reducing antioxidant power. This study found that the ethanolic extract of Camellia fruit hull at low concentration efficiently inhibited FAS activity, which is a potential therapy target of both obesity and cancer. These results suggest that OCE could be a valuable resource for bioactive substances.

Ellagic Acid Derivatives from Syzygium cumini Stem Bark: Investigation of their Antiplasmodial Activity

Bioguided fractionation of Syzygium cumini (Myrtaceae) bark decoction for antiplasmodial activity was performed, leading to the isolation of three known ellagic acid derivatives (ellagic acid, ellagic acid 4-O-α-L-2″-acetylrhamnopyranoside, 3-O-methylellagic acid 3′-O-α-L-rhamnopyranoside), as well as the new derivative 3-O-methylellagic acid 3′-O-β-D-glucopyranoside. Activity investigation was based on the reduction of P. falciparum (PfK1) parasitaemia in vitro and the inhibition of β-hematin formation, a known mechanism of action of some antimalarial drugs. Among the investigated ellagic acid derivatives, only ellagic acid was able to reduce P. falciparum parasitaemia in vitro and inhibit β-hematin formation, suggesting that free hydroxyl groups are necessary for activity within this class of compounds.

Ellagic acid glycosides fromTurpinia ternata

Bioassay-guided fractionation of the methanolic extract of Turpinia ternata stems, has led to the isolation of the new ellagic acid derivative 3,4'-di-O-methylellagic acid-4-O-alpha-L-arabinofuranoside (1), and the known compounds ellagic acid (2), 3-O-methyl ellagic acid (3), 3-O-methylellagic acid-3'-O-alpha-L-rhamnopyranoside (4), and 3,3'-di-O-methylellagic acid-4'-O-alpha-D-glucopyranoside (5). Their structures were elucidated by extensive spectroscopic methods. Compounds 1, 3, and 4 showed moderate antioxidant activity against DPPH free radical, whereas compound 1 was found to be moderately cytotoxic against Artemia salina larvae.