Cardenolides from the methanolic extract of Nerium oleander leaves possessing central nervous system depressant activity in mice

Quantitative evaluation of cardiac glycosides and their seasonal variation analysis in Nerium oleander using UHPLC-ESI-MS/MS

INTRODUCTION

Nerium oleander is an eminent source of structurally diverse cardiac glycosides (CGs), plays a prominent role in the treatment of heart failure, and inhibits the proliferation of cancer cell lines. CGs exert their cardiotonic action by binding to the extracellularly exposed recognition sites on Na⁺ /K⁺ -ATPase, an integral membrane protein that establishes the electrochemical gradient of Na⁺ and K⁺ ions across the plasma membrane.

OBJECTIVE

We aimed to quantitatively determine CGs and their seasonal variation in leaf and stem samples of N. oleander utilizing UHPLC-ESI-MS/MS techniques.

METHODS

The UHPLC-ESI-MS/MS analytical method was developed utilizing multiple reaction monitoring (MRM) mode. The Waters BEH C18 (150 mm × 2.1 mm, 1.7 μm) column was used with a 22-min linear gradient consisting of acetonitrile and 5 mM ammonium acetate buffer.

RESULTS

In total 21 CGs were quantitatively determined in the seasonal leaf and stem samples of N. oleander along with the absolute quantitation of the three chemical markers odoroside H (244.8 μg/g), odoroside A (231.4 μg/g), and oleandrin (703.9 μg/g). The season-specific accumulation of chemical markers was observed in the order of predominance odoroside A (summer season, stem), odoroside H (winter season, stem), and oleandrin (rainy season, leaf). Besides this, the remaining 18 CGs were relatively quantified in the same samples.

CONCLUSION

The developed method is simple and reliable and can be used for the identification and quantification of multiple CGs in N. oleander.

Structural Analysis of Diastereomeric Cardiac Glycosides and Their Genins Using Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry

Ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) is an economical and indispensable tool in natural product research to investigate novel metabolites, biomarker discovery, chemical diversity exploration, and structure elucidation. In this study, the structural analysis of 38 naturally occurring cardiac glycosides (CGs) in various tissues of Nerium oleander was achieved by the extensive use of mass spectrometry. The chemical diversity of CGs was described on the basis of characteristic MS/MS fragmentation patterns, accurate mass measurement, and published scientific information on CGs from Nerium oleander. It was observed that only six genins, viz., Δ¹⁶anhydrogitoxigenin, Δ¹⁶adynerigenin, gitoxigenin, oleandrigenin, digitoxigenin, and adynerigenine, produce 38 diverse chemical structures of CGs. Among them, 20 were identified as diastereomers having a difference in a sugar (l-oleandrose, β-d-diginose, and β-d-sarmentose) unit. However, the differentiation of diastereomeric CGs was not possible by only MS/MS fragments. Thus, the diastereomer's chromatographic elution order was assigned on the basis of the relative retention time (RRt) of two reference standards (odoroside A and oleandrin) among their diastereomers. Besides this, the in-source fragmentation of CGs and the MS/MS of m/z 325 and 323 disaccharide daughter ions also exposed the intrinsic structure information on the sugar units. The daughter ions m/z 162, 145, 113, 95, and 85 in MS/MS spectra indicated the abundance of l-oleandrose, β-d-diginose, and β-d-sarmentose sugars. At the same time, m/z 161, 143, 129, and 87 product ions confirmed the presence of a β-d-digitalose unit. As a result, the UPLC-ESI/TQD system was successfully utilized for the structure characterization of CGs in Nerium oleander tissues.

Cardenolide and pregnatriene compounds from the roots of Nerium oleander

Cardenolide and pregnatriene compounds were isolated from the chloroform fraction of the 95% aqueous ethanolic extract of dried roots of Nerium oleander. The stereochemical structure of the cardenolide and pregnatriene compounds was determined to be 3β-O-(D-diginosyl)-14β-hydroxy card-20(22)-enolide and 12β-hydroxy pregna-4,6,16-triene-3,20-dione using spectroscopic methods including IR, HRMS and NMR spectroscopy.

Profile on medicinal plants used by the people of North Eastern Morocco: Toxicity concerns

In the North Eastern region of Morocco, many people are interested in medicinal plants and their uses. However, the rationale for the utilization of medicinal plants has remained largely underestimated with little or no scientific data on plant safety. In this paper we attempt to describe and establish a detailed list of current knowledge in relation to the toxicity of these plants and to evaluate the scientific data concerning the harmful effects of the selected natural products. Our approach consists of collecting published data from literature in specialized journals, books and website related to the toxic plants. This research revealed that 89 plant species, retrieved from 287 plants used as medicine in the North-Eastern region of Morocco, are considered toxic or present some kind of toxicity. Our data determines 55 compounds isolated from the plants which are dominated by five groups of toxic compounds: alkaloids followed by glucosides, terpenoids, protides and phenolics. The present work discusses toxicity-related issues arising from the use of medicinal plants by local people. We conclude that the database considered in this study could serve as an important source of information on the toxicity of medicinal plants used by this society.

Cardenolides from the Apocynaceae family and their anticancer activity

Cardenolides, as a group of natural products that can bind to Na(+)/K(+)-ATPase with an inhibiting activity, are traditionally used to treat congestive heart failure. Recent studies have demonstrated that the strong tumor cytotoxicities of cardenolides are mainly due to inducing the tumor cells apoptosis through different expression and cellular location of Na(+)/K(+)-ATPase α-subunits. The leaves, flesh, seeds and juices of numerous plants from the genera of Nerium, Thevetia, Cerbera, Apocynum and Strophanthus in Apocynaceae family, are the major sources of natural cardenolides. So far, 109 cardenolides have been isolated and identified from this family, and about a quarter of them are reported to exhibit the capability to regulate cancer cell survival and death through multiple signaling pathways. In this review, we compile the phytochemical characteristics and anticancer activity of the cardenolides from this family.

Can Coffee Chemical Compounds and Insecticidal Plants Be Harnessed for Control of Major Coffee Pests?

Pests and pathogens threaten coffee production worldwide and are difficult to control using conventional methods, such as insecticides. We review the literature on the chemistry of coffee, concentrating on compounds most commonly reported from Coffea arabica and Coffea canephora. Differences in chemistry can distinguish coffee species and varieties, and plants grown under different biogeographic conditions exhibit different chemotypes. A number of chemical groups, such as alkaloids and caffeoylquinic acids, are known to be insecticidal, but most studies have investigated their effects on coffee quality and flavor. More research is required to bridge this gap in knowledge, so that coffee can be bred to be more resistant to pests. Furthermore, we report on some pesticidal plants that have been used for control of coffee pests. Locally sourced pesticidal plants have been underutilized and offer a sustainable alternative to conventional insecticides and could be used to augment breeding for resilience of coffee plants.

Nerium indicum leaf alleviates iron-induced oxidative stress and hepatic injury in mice

CONTEXT

Nerium indicum Mill. (Apocynaceae) was reported for its efficient in vitro antioxidant and iron-chelating properties.

OBJECTIVE

This study demonstrates the effect of 70% methanol extract of N. indicum leaf (NIME) towards in vitro DNA protection and ameliorating iron-overload-induced liver damage in mice.

MATERIALS AND METHODS

Phytochemical and HPLC analyses were carried out to standardize the extract and the effect of Fe(2+)-mediated pUC18 DNA cessation was studied. Thirty-six Swiss Albino mice were divided into six groups of blank, negative control (iron overload only), and iron-overloaded mice receiving 50, 100, and 200 mg/kg b.w. doses of NIME and desirox (20 mg/kg b.w.). The biochemical markers of hepatic damage, various liver and serum parameters, and reductive release of ferritin iron were studied.

RESULTS AND DISCUSSION

The presence of different phytocomponents was revealed from phytochemical and HPLC analyses. A substantial supercoiled DNA protection, with [P]50 of 70.33 ± 0.32 µg, was observed. NIME (200 mg/kg b.w.) significantly normalized the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and bilirubin by 126.27, 125.25, 188.48, and 45.47%, respectively. NIME (200 mg/kg b.w.) was shown to alleviate the reduced levels of superoxide dismutase, catalase, glutathione-S-transferase, and non-enzymatic-reduced glutathione, by 48.95, 35.9, 35.42, and 13.22%, respectively. NIME also lowered raised levels of lipid peroxidation, protein carbonyl, hydroxyproline, and liver iron by 32.28, 64.58, 136.81, and 83.55%, respectively.

CONCLUSION

These findings suggest that the active substances present in NIME may be capable of lessening iron overload-induced toxicity, and possibly be a useful drug for iron-overloaded diseases.

Proceraside A, a new cardiac glycoside from the root barks of Calotropis procera with in vitro anticancer effects

We have studied the ethyl acetate fraction of the methanolic extract of the root barks of Calotropis procera (Asclepiadaceae) from Egypt. Bioassay-directed fractionation and final purification of the extract resulted in the identification of a new cardenolide glycoside named proceraside A (1) together with two known compounds, frugoside (2) and calotropin (3). Their structures were elucidated by extensive NMR studies and mass spectrometric data. The in vitro cytotoxicity of the isolated compounds was evaluated against A549 non-small cell lung cancer, U373 glioblastoma and PC-3 prostate cancer cell lines. They showed potent activity against the tested cancer cell lines with IC50 ranging from 0.005 to 0.3 μg/mL. Cisplatin was used as positive control.

Oleander toxicosis in equids: 30 cases (1995-2010)

OBJECTIVE

To determine clinical, laboratory analysis, and necropsy findings for equids with oleander toxicosis and to identify factors associated with outcome.

DESIGN

Retrospective case series.

ANIMALS

30 equids.

PROCEDURES

Medical records of equids with detectable concentrations of oleandrin in serum, plasma, urine, or gastrointestinal fluid samples and equids that had not received cardiac glycoside drugs but had detectable concentrations of digoxin in serum were identified via a medical records database search. Descriptive statistics were calculated for medical history, physical examination, laboratory analysis, and necropsy variables. Logistic regression analysis was used to identify physical examination and laboratory analysis factors significantly associated with outcome.

RESULTS

3 of 30 (10.0%) equids died before or immediately after arrival at the hospital. Of the other 27 equids, 23 (85.2%) had gastrointestinal tract abnormalities, azotemia was detected for 19 (70.4%), and a cardiac arrhythmia was ausculted for 18 (66.7%). Mortality rate for all equids was 50.0%; mortality rate for hospitalized equids was 44.4%. The most common cause of death was cardiac dysfunction. Odds of survival to discharge from the hospital were lower for equids with cardiac arrhythmias versus those without arrhythmias and decreased with increasing Hct and serum glucose concentrations. Odds of survival increased with increasing serum chloride concentration and duration of hospitalization.

CONCLUSIONS AND CLINICAL RELEVANCE

Equids with oleander toxicosis frequently had simultaneous gastrointestinal tract, cardiac, and renal problems. Oleander intoxication should be a differential diagnosis for equids with colic in geographic areas where oleander is found, especially when azotemia or cardiac arrhythmias are detected concurrently.

Flavonoid and cardenolide glycosides and a pentacyclic triterpene from the leaves of Nerium oleander and evaluation of cytotoxicity

A pentacyclic triterpene, oleanderocioic acid, two flavonoidal glycosides, quercetin-5-O-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside and kaempferol-5-O-[α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside, and a cardenolide, oleandigoside, together with 11 known compounds, were isolated from the leaves of Nerium oleander. Their structures were elucidated on the basis of spectroscopic analysis. The growth inhibitory and cytotoxic activities of eight compounds were evaluated against the MCF-7 human breast cancer cell line using a sulforhodamine B assay. Three compounds, oleandrin, odoroside A and B were further assayed using a panel of 57 human cancer cell lines.

The structure of a new cardenolide diglycoside and the biological activities of eleven cardenolide diglycosides from Nerium oleander

A new cardenolide diglycoside (1) was isolated from Nerium oleander together with ten known cardenolide diglycosides 2-11. The structure of compound 1 was established on the basis of their spectroscopic data. The in vitro anti-inflammatory activity of compounds 1-11 was examined on the basis of inhibitory activity against the induction of the intercellular adhesion molecule-1 (ICAM-1). Compounds 2-5 were active at an IC(50) value of less than 0.8 µM. The cytotoxicity of compounds 1-11 was evaluated against three human cell lines normal human fibroblast cells (WI-38), malignant tumor cells induced from WI-38 (VA-13), and human liver tumor cells (HepG2). Compound 3 was active toward VA-13 cells, and compounds 2-5 were active toward HepG2 cells at IC(50) values of less than 1.3 µM. The multidrug resistance (MDR)-reversal activity of compounds 1-11 was evaluated on the basis of the amount of calcein in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compounds 1 and 8 showed moderate effects on calcein accumulation.

Characterization of the anticancer properties of monoglycosidic cardenolides isolated from Nerium oleander and Streptocaulon tomentosum

AIM OF THE STUDY

For identification of the active constituents we investigated the anticancer activity of cardenolides from Streptocaulon tomentosum Wight & Arn. (Asclepiadaceae) and from Nerium oleander L. (Apocynaceae) which are both used against cancer in the traditional medicine in their region of origin.

MATERIAL, METHODS AND RESULTS

The antiproliferative activity of cardenolides isolated from roots of Streptocaulon tomentosum (IC(50)<1-15.3 μM after 2 days in MCF7) and of cardenolide containing fractions from the cold aqueous extract of Nerium oleander leaves ("Breastin", mean IC(50) 0.85 μg/ml in a panel of 36 human tumor cell lines), their influence on the cellular viability and on the cell cycle (block at the G2/M-phase or at the S-phase in tumor cells, respectively) were determined using different cell lines. The murine cell line L929 and normal non-tumor cells were not affected. Bioactivity guided fractionation of Breastin resulted in the isolation of the monoglycosidic cardenolides oleandrine, oleandrigeninsarmentoside, neritaloside, odoroside H, and odoroside A (IC(50)-values between 0.010 and 0.071 μg/ml).

CONCLUSIONS

The observed anticancer activities of extracts and isolated cardenolides are in agreement with the ethnomedicinal use of Streptocaulon tomentosum and Nerium oleander. The most active anticancer compounds from both species are monoglycosidic cardenolides possessing the 3β,14β-dihydroxy-5β-card-20(22)-enolide structure with or without an acetoxy group at C-16. The results indicate that the cytotoxic effects are induced by the inhibition of the plasma membrane bound Na(+)/K(+)-ATPase.

A novel phytochemical, digoxigenin-3-O-rutin in the amelioration of isoproterenol-induced myocardial infarction in rat: a comparison with digoxin

INTRODUCTION

The commonly used cardiac glycoside, digoxin (DIG), has a narrow therapeutic window. Although some investigations were made to counteract its toxic effects, no alternate phytochemical is available till date that is more potent and safer than DIG.

AIMS

Our main aim was to isolate a novel cardenolide from the seeds of Trigonella foenum graceium and to evaluate its relative potential in comparison to that of DIG.

EXPERIMENTAL DESIGN

In one experiment effects of the isolated compound at 2.5, 5.0, and 10 mg/kg (p.o.) were evaluated in isoproterenol (ISO)-induced cardiovascular problems in rats. As the test drug (TDR) reversed most of the ISO-induced changes, it was subjected to the phytochemical analyses and was identified as digoxigenin-3-O-rutin. In another experiment effects of DIG and rutin (Rtn) were compared with those of TDR or DIG alone. The hydroxyl radical scavenging activity was also measured by electron spin resonance (EPR).

RESULTS

digoxigenin-3-O-rutin at 10 mg/kg markedly reduced the ISO-induced increase in cardiac lipid peroxidation and in the levels of serum creatinine phosphokinase-MB, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, and creatinine. It also reversed the ISO-induced changes in the cardiac histomorphology. Interestingly TDR appeared to be more effective than DIG alone or DIG and Rtn in combination.

CONCLUSION

The newly isolated digoxigenin-3-O-rutin appears to be more potent and safe than digoxin. Its higher efficacy could be due to its structural specificity and might have been mediated through its better free radical scavenging action.

Nematicidal cardenolides from Nerium indicum Mill

Three nematicidal cardenolides were obtained from the AcOEt extract of Nerium indicum Mill. by bioassay-guided fractionation. They include a new compound, 3beta-O-(beta-D-diginosyl)-14,15alpha-dihydroxy-5alpha-card-20(22)-enolide (1), and two known compounds, uzarigenin (2) and cardenolide N-1 (3). The median lethal concentrations (LC(50)) of compounds 1-3 against the nematodes Bursaphelenchus xylophilus, Panagrellus redivivus, and Caenorhabditis elegans at 72 h were 103.3, 49.0, and 45.4 mg l(-1), 257.0, 62.7, and 177.8 mg l(-1), and 242.9, 29.1, and 41.7 mg l(-1), respectively. This is the first report about the nematicidal activity of cardenolides.

New cytotoxic cardenolide glycoside from the seeds of Cerbera manghas

A new cytotoxic cardenolide glycoside, 3beta-O-(2'-O-acetyl-alpha-L-thevetosyl)-14beta-hydroxy-7-en-5beta-card-20(22)-enolide, (7,8-dehydrocerberin), together with five known cardenolides, 17beta-neriifolin, deacetyltanghinin, tanghinin, cerberin and 2'-O-acetyl-cerleaside A were isolated from the seeds of Cerbera manghas L. Their structures were elucidated by 1D- and 2D-NMR techniques as well as UV, IR and mass spectral data. 7,8-Dehydrocerberin, deacetyltanghinin and tanghinin exhibited cytotoxic activities against oral human epidermoid carcinoma (KB), human breast cancer cell (BC) and human small cells lung cancer (NCI-H187).

Therapeutic effects of herbal extracts and constituents in animal models of psychiatric disorders

A search for novel pharmacotherapy from medicinal plants for psychiatric illnesses has progressed significantly in the past decade. This is reflected in the large number of herbal preparations for which psychotherapeutic potential has been evaluated in a variety of animal models. The objective of this review is to provide an overview of herbal extracts and constituents that have significant therapeutic effects in animal models of psychiatric illnesses. Eighty five individual herbs reviewed were classified as anxiolytic, antidepressant, neuroleptic, antidementia, or anti-substance abuse herbs. The full scientific name of each herb, herbal part used, active constituent, extract, dose range and route, animal model, possible mechanisms of action, and pertinent references are presented via synoptic tables. The herbal mixtures were also mentioned. A considerable number of herbal constituents whose behavioral effects and pharmacological actions have been well characterized may be good candidates for further investigations that may ultimately result in clinical use. The investigation of a large portion of the herbal extracts and herbal mixtures is in its infancy. Herbal remedies that have demonstrable psychotherapeutic activities have provided a potential to psychiatric pharmaceuticals and deserve increased attention in future studies.

Murine pharmacokinetics and metabolism of oleandrin, a cytotoxic component of Nerium oleander

Pharmacokinetic studies of [3H]oleandrin, a cardiac glycoside component of Anvirzel, were conducted in mice after either an i.v. dose (40 micrograms/kg) or a p.o. dose (80 micrograms/kg). Oleandrin was rapidly absorbed after oral dosing (Cmax at 20 min) although the elimination half-life was longer (2.3 +/- 0.5 h) than that after i.v. dosing (0.4 +/- 0.1 h). The AUC0-infinity values obtained after i.v. and p.o. dosing were 24.6 +/- 11.1 and 14.4 +/- 4.3 (ng.h/ml), respectively, resulting in an oral bioavailability of approximately 30%. After i.v. administration, oleandrin concentration in liver was approximately twice that measured in heart or kidney tissue. Oleandrigenin, the aglycone of oleandrin, was also found in these tissues. At 5 min, > 60% of the total radioactivity in liver was due to oleandrin while 28% of the given dose was present as oleandrigenin. Twenty-four hours following injection, 8% of total radioactivity was excreted in urine and contained both oleandrigenin (4.4% of the injected dose) and oleandrin (1.9%). Sixty-six percent of injected radioactivity was found in feces and consisted of oleandrin and oleandrigenin in equal amounts. Uptake of oleandrin in brain after i.p. injection of oleandrin (3 mg/kg) or oleander extract (700 mg/kg) was examined. Measured by LC/MS/MS, oleandrin content in brain was higher following injection of extract than it was with an equivalent dose of oleandrin. The data suggest that components within oleander extract may enhance transport of oleandrin across the blood brain barrier.

A new cardenolide from the roots of Terminalia arjuna

A new cardenolide, 16,17-dihydroneridienone 3-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-galactopyranoside (1), was isolated from the roots of Terminalia arjuna.

LC/MS/MS analyses of an oleander extract for cancer treatment

An HPLC/MS/MS method has been developed for the characterization and quantification of the cardiac glycosides oleandrin, odoroside, neritaloside and the aglycone oleandrigenin, all contained in a patented-hot-water extract of Nerium oleander L (Anvirzel). Qualitative analysis of such extracts was achieved using a hybrid tandem quadrupole time-of-flight (QqTOF) mass spectrometer. Collision-induced dissociation (CID) mass spectra of oleandrin, oleandrigenin, odoroside, and neritaloside were obtained with greater than 5 ppm mass accuracy and resolution routinely in excess of 8000 (fwhm). The detection limit for oleandrin of 20 pg (injected) was realized when the precursor-to-product ion transition, m/z 577 --> 373, was monitored. We have also applied the analytical method to the determination of oleandrin, oleandrigenin, neritaloside, and odoroside in human plasma following an intramuscular injection of Anvirzel.

Steroids from the roots of Nerium oleander

Two new cardenolides, 3beta-hydroxy-5alpha-carda-14(15), 20(22)-dienolide (beta-anhydroepidigitoxigenin) (1) and 3beta-O-(D-digitalosyl)-21-hydroxy-5beta-carda-8,14,16 , 20(22)-tetraenolide (neriumogenin-A-3beta-D-digitaloside) (2), and two known compounds, proceragenin and neridienone A (3), have been isolated from the roots of Nerium oleander. The structures of 1 and 2 were elucidated on the basis of spectral data interpretation.

Bio-active cardenolides from the leaves of Nerium oleander

A bioactivity directed isolation of the methanolic extract of the fresh, uncrushed leaves of Nerium oleander showing a central nervous system (CNS) depressant effect in mice has been undertaken. As a result, four CNS depressant cardenolides including a new cardenolide, neridiginoside and three known constituents, nerizoside, neritaloside and odoroside-H, have been isolated which exhibited CNS depressant activity in mice at a dose of 25 mg/kg. The structure of neridiginoside was elucidated as 3 beta-O-(D-diginosyl)-5 beta, 14 beta-dihydroxy-card-20(22)-enolide, using spectroscopic methods including one-dimensional and two-dimensional NMR (COSY-45, NOESY, J-resolved, HMQC and HMBC). The known compounds have been indentified through spectral studies and comparison of data with those reported in the literature.