A triterpenoid saponin possessing antileishmanial activity from the leaves of Careya arborea

Slowly Making Sense: A Review of the Two-Step Venom System within Slow (Nycticebus spp.) and Pygmy Lorises (Xanthonycticebus spp.)

Since the early 2000s, studies of the evolution of venom within animals have rapidly expanded, offering new revelations on the origins and development of venom within various species. The venomous mammals represent excellent opportunities to study venom evolution due to the varying functional usages, the unusual distribution of venom across unrelated mammals and the diverse variety of delivery systems. A group of mammals that excellently represents a combination of these traits are the slow (Nycticebus spp.) and pygmy lorises (Xanthonycticebus spp.) of south-east Asia, which possess the only confirmed two-step venom system. These taxa also present one of the most intriguing mixes of toxic symptoms (cytotoxicity and immunotoxicity) and functional usages (intraspecific competition and ectoparasitic defence) seen in extant animals. We still lack many pieces of the puzzle in understanding how this venom system works, why it evolved what is involved in the venom system and what triggers the toxic components to work. Here, we review available data building upon a decade of research on this topic, focusing especially on why and how this venom system may have evolved. We discuss that research now suggests that venom in slow lorises has a sophisticated set of multiple uses in both intraspecific competition and the potential to disrupt the immune system of targets; we suggest that an exudate diet reveals several toxic plants consumed by slow and pygmy lorises that could be sequestered into their venom and which may help heal venomous bite wounds; we provide the most up-to-date visual model of the brachial gland exudate secretion protein (BGEsp); and we discuss research on a complement component 1r (C1R) protein in saliva that may solve the mystery of what activates the toxicity of slow and pygmy loris venom. We conclude that the slow and pygmy lorises possess amongst the most complex venom system in extant animals, and while we have still a lot more to understand about their venom system, we are close to a breakthrough, particularly with current technological advances.

The Effects of a Combination of Quillaja saponaria and Yucca schidigera on Eimeria spp. in Broiler Chickens

A series of studies was carried out to determine the anticoccidial effects of a product derived from plant material sourced from Quillaja saponaria and Yucca schidigera. These plants are known to contain high concentrations of triterpenoid and steroidal saponins, substances that are known to display an array of biological effects. Battery tests involving individual Eimeria acervulina, Eimeria maxima, and Eimeria tenella infections and graded levels of a quillaja/yucca combination (QY) (0, 200, 250, and 300 ppm) were conducted. Body weight gain, coccidial lesion scores, and total oocysts per gram of feces (OPG) were used to evaluate anticoccidial effects. In addition, three floor pen trials evaluated the effects of 250 ppm QY in the control coccidial infections. The first pen trial measured the effects of 250 ppm QY, both alone and in combination with 66 ppm salinomycin (Sal), in a 2 3 2 factorial treatment arrangement. Two additional 42-day pen studies assessed the effects 250 ppm QY in birds vaccinated for coccidiosis. Data from the three battery trials indicated that at doses of 250 ppm QY or more, weight gain was improved, E. acervulina and E. tenella lesion scores were reduced, and OPG was lowered. In general, OPG was reduced by about 50% across all species by 250 and 300 ppm QY. Results of the pen study indicated that 250 ppm QY and Sal, when fed individually, reduced OPG and lesion scores and improved final performance. However, when QY and Sal were administered concurrently, further significant reductions in OPG occurred. The final performance of broilers vaccinated for coccidiosis was also improved at 250 ppm QY, as was OPG at both 21 and 28 days. Thus, at QY doses of 250 ppm or more, anticoccidial activity was evident but lacked the potency exhibited by many standard anticoccidials. When combined with either Sal or a live coccidiosis vaccine, QY improved the anticoccidial effects and performance of these anticoccidial methods.

Phytochemical profile and ethnopharmacological applications of Lecythidaceae: An overview

ETHNOPHARMACOLOGICAL RELEVANCE

The family Lecythidaceae has about 25 genera and 400 identified species, which are distributed especially in the pantropical region, mostly found in the tropics of Central and South America, Southeast Asia and Africa. The third most abundant family in Amazonian forests and the genus Eschweilera, with the large number of species in Lecythidaceae.

AIM OF THE REVIEW

The present review compiles information since the 1934s about of ethnopharmacology, and chemical constituents of species of Lecythidaceae, as well as a summary of the bioactivities shown by the extracts, fractions, and secondary metabolites.

MATERIALS AND METHODS

All relevant information on ethnopharmacology, and chemical constituents of species of Lecythidaceae were gathered from electronic databases including Web of Science, Science Direct, Elsevier, ResearchGate, and Google Scholar. Information was also obtained from local books, PhD. and MSc. Dissertations.

RESULTS

The phytochemical diversity of the family was demonstrated with 180 different metabolites that have been reported from 25 species, most of them being triterpenes or flavonoids. The pharmacological studies carried out with the extracts, fractions and compounds showed promising antibacterial, antifungal, anti-inflammatory, antinociceptive, cytotoxic and antioxidant activities.

CONCLUSION

The present review provides an insight into ethnopharmacology, phytochemistry and pharmacology of species of Lecythidaceae. Based on the pharmacological studies it has been found that different plant species of Lecythidaceae possess a wide range of bioactivities such as anti-arthritic, anti-inflammatory, antileishmanial, antibacterial and antifungal. These activities are due to the presence of bioactive compounds including triterpenoids and their glycosides derivatives, flavonoids, steroids, sesquiterpenoids, alkaloids, and other compounds. However, there are many plants, which have not been assessed pharmacologically and hence warrant further studies.

An investigation of the antileishmanial properties of semi-synthetic saponins

Leishmaniasis is a neglected tropical disease caused by insect-vector borne protozoan parasites of the, Leishmania species. Whilst infection threatens and affects millions of the global poor, vaccines are absent and drug therapy limited. Extensive efforts have recently been made to discover new leads from small molecule synthetic compound libraries held by industry; however, the number of new chemical entities identified and entering development as anti-leishmanials has been very low. This has led to increased interest in the possibility of discovering naturally derived compounds with potent antileishmanial activity which may be developed towards clinical applications. Plant-derived triterpenoid and steroidal saponins have long been considered as anti-microbials and here we describe an investigation of a library of 137 natural (9) and semi-synthetic saponins (128) for activity against Leishmania mexicana, a causative agent of cutaneous leishmaniasis. The triterpenoid sapogenin, hederagenin, readily obtained in large quantities from Hedera helix (common ivy), was converted into a range of 128 derivatives. These semi-synthetic compounds, as well as saponins isolated from ivy, were examined with a phenotypic screening approach to identify potent and selective anti-leishmanial hits. This led to the identification of 12 compounds, including the natural saponin gypsogenin, demonstrating high potency (ED50 < 10.5 μM) against axenic L. mexicana amastigotes, the mammalian pathogenic form. One of these, hederagenin disuccinate, was sufficiently non-toxic to the macrophage host cell to facilitate further analyses, selectivity index (SI) > 10. Whilst this was not active in an infected cell model, the anti-leishmanial properties of hederagenin-derivatives have been demonstrated, and the possibility of improving the selectivity of natural hederagenin through chemical modification has been established.

Antileishmanial activity and mechanism of action from a purified fraction of Zingiber officinalis Roscoe against Leishmania amazonensis

In recent years, considerable attention has been given to identify new antileishmanial products derived from medicinal plants, although, to date, no new effective compound has been recently applied to treat leishmaniasis. In the present study, the antileishmanial activity of a water extract from Zingiber officinalis Roscoe (ginger) was investigated and a purified fraction, named F10, was identified as responsible by this biological activity. The chemical characterization performed for this fraction showed that it is mainly composed by flavonoids and saponins. The water extract and the F10 fraction presented IC50 values of 125.5 and 49.8 μg/mL, respectively. Their selectivity indexes (SI) were calculated and values were seven and 40 times higher, respectively, in relation to the value found for amphotericin B, which was used as a control. Additional studies were performed to evaluate the toxicity of these compounds in human red blood cells, besides of the production of nitrite, as an indicator of nitric oxide (NO), in treated and infected macrophages. The results showed that both F10 fraction and water extract were not toxic to human cells, and they were able to stimulate the nitrite production, with values of 13.6 and 5.4 μM, respectively, suggesting that their biological activity could be due to macrophages activation via NO production. In conclusion, the present study shows that a purified fraction from ginger could be evaluated in future works as a therapeutic alternative, on its own or in association with other drugs, to treat disease caused by L. amazonensis.

Cytotoxic saponin poliusaposide from Teucrium polium

Three saponin glycosides have been isolated and characterized from Teucrium polium L. (Lamiaceae).

Natural product based leads to fight against leishmaniasis

The growing incidence of parasitic resistance against generic pentavalent antimonials, specifically for visceral disease in Indian subcontinent, is a serious issue in Leishmania control. Notwithstanding the two treatment alternatives, that is amphotericin B and miltefosine are being effectively used but their high cost and therapeutic complications limit their use in endemic areas. In the absence of a vaccine candidate, identification, and characterization of novel drugs and targets is a major requirement of leishmanial research. This review describes current drug regimens, putative drug targets, numerous natural products that have shown promising antileishmanial activity alongwith some key issues and strategies for future research to control leishmaniasis worldwide.

Anti-leukemic activity of Wattakaka volubilis leaf extract against human myeloid leukemia cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Wattakaka volubilis has been traditionally used in Ayurvedic medicine in India for treatment of several ailments such as bronchial asthma, inflammations, tumors, piles, leucoderma, application to boils, rat bite etc.

AIM OF THE STUDY

The present study was designed to investigate anti-leukemic activity of the crude aqueous methanolic extract and to identify active compounds from the leaves of Wattakaka volubilis.

MATERIALS AND METHODS

The leaves of Wattakaka volubilis were extracted with aqueous methanol. Liquid-liquid fractionation of the crude methanolic extract with different organic solvents was done and the fractions were screened for in vitro anti-leukemic activity using different leukemic cell lines. The active fractions were then subjected to chromatographic separation for isolation of bioactive compounds. Structure of isolated compound was elucidated by spectroscopic methods. The in vitro anti-leukemic activities of different extracts of the leaves and isolated compound WVP were studied in U-937, HL-60 and K-562 cell-lines by using cell count, MTT [(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] and DNA laddering assays, flow-cytometric and confocal microscopic techniques.

RESULTS

Kaempferol-3-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→6)-O]-β-d-glucopyranoside (WVP) was isolated from crude leaves extract of Wattakaka volubilis. Both the n-butanolic extract (WVB) of Wattakaka volubilis and its isolate WVP were found to be responsible for in vitro anti-leukemic activity. The IC(50) values of WVB were found be 120, 100 and 50(μg/ml) in U937, K562, and HL-60 cell lines, respectively. Whereas, the pure isolate WVP exhibited anti-leukemic activity with IC(50) values of 13.5, 10.8, and 13.2(μg/ml) in U937, K562, and HL-60 cell lines, respectively. The flow-cytometric analysis confirms that the cell cycle arrest occurs at G1 phase in case of U937 and K562 cell lines and G2/M phase in case of HL60 cell lines. Similarly both confocal microsocopic analysis and DNA laddering assay confirm the apoptosis and cell cycle arrests of leukemic cells.

CONCLUSION

The overall results provide evidence for the ethnopharmacological relevance for use of the plant Wattakaka volubilis in developing novel agents for the treatment of leukemia.

Intracellular drug delivery in Leishmania-infected macrophages: Evaluation of saponin-loaded PLGA nanoparticles

Drug delivery systems present an opportunity to potentiate the therapeutic effect of antileishmanial drugs. Colloidal carriers are rapidly cleared by the phagocytic cells of the reticuloendothelial system (RES), rendering them ideal vehicles for passive targeting of antileishmanials. This paper describes the development of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) for the antileishmanial saponin β-aescin. NPs were prepared using the combined emulsification solvent evaporation/salting-out technique. Confocal microscopy was used to visualise the internalisation and intracellular trafficking of fluorescein- and nile red-labelled PLGA NPs in J774A.1 macrophages infected with GFP-transfected Leishmania donovani. The in vitro activity of aescin and aescin-loaded NPs on L. infantum was determined in the axenic model as well as in the ex vivo model. The developed PLGA NPs were monodispersed with Z(ave)<300 nm, exhibited negative zeta potentials and had relatively high drug loadings ranging from 5.80 to 8.68% w/w PLGA. The fluorescent NPs were internalised by the macrophages and trafficked towards the lysosomes after 2 h in vitro incubation. Co-localisation of the NPs and the parasite was not shown. A two-fold increase in activity was observed in the ex vivo macrophage model by encapsulating β-aescin in PLGA NPs (IC(50), 0.48-0.76 µg/mL vs. 1.55 ± 0.32 µg/mL for the free drug).

Recent advances in leishmaniasis treatment

About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for the period 2005-2006

This review is the fourth update of the original review, published in 1999, on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2006. The review covers fundamental studies, fragmentation of carbohydrate ions, method developments, and applications of the technique to the analysis of different types of carbohydrate. Specific compound classes that are covered include carbohydrate polymers from plants, N- and O-linked glycans from glycoproteins, glycated proteins, glycolipids from bacteria, glycosides, and various other natural products. There is a short section on the use of MALDI-TOF mass spectrometry for the study of enzymes involved in glycan processing, a section on industrial processes, particularly the development of biopharmaceuticals and a section on the use of MALDI-MS to monitor products of chemical synthesis of carbohydrates. Large carbohydrate-protein complexes and glycodendrimers are highlighted in this final section.

Identification of a sulfonoquinovosyldiacylglyceride from Azadirachta indica and studies on its cytotoxic activity and DNA binding properties

Chromatographic separation of the methanolic extract of the leaves of Azadirachta indica led to the isolation of a sulfonoglycolipid characterized as a sulfonoquinovosyldiacylglyceride (SQDG), by extensive 2D NMR and mass spectral analysis. SQDG induces apoptosis in a dose dependent manner with IC(50) 8.3 μM against acute lymphoblastic leukemia (ALL) MOLT-4 cell lines. The compound showed significant DNA binding properties as evidenced by the enhancement of melting temperature and perturbation of the characteristic B-form in CD evidence of calf thymus DNA. The DNA binding was also characterized by isothermal calorimetry where a predominantly enthalpy driven binding to CT DNA was revealed.

Leishmanicidal activity of Echinaster (Othilia) echinophorus crude extract

In this study, a methanolic extract from Echinaster (Othilia) echinophorus was evaluated for activity against Leishmania amazonensis. The extract showed activity against the promastigote and amastigote forms with IC50 values of 62.9 and 37.5 μg.mL-1 respectively. This extract showed a moderate toxicity on macrophages from BALB/c mice. A dose of 100 mg/kg/day was effective when administered during 15 days by intraperitoneal route to BALB/c mice infected experimentally.

Antimalarial activity of a cis-terpenone

Background

Malaria is the third most prevalent cause of infectious disease in the world. Resistance of the parasite to classical drugs makes the discovery of new and effective drugs more urgent. The oxidized derivative of hydroxy-cis terpenone (OHCT) is a synthetic molecule that is not toxic to cultured human liver cells at concentrations as high as 60 μM and inhibits activity of cytochrome P450s that metabolize many drugs.

Methods

OHCT activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum, and a P. falciparum clone that is partially resistant to artemisinin was assayed in vitro.

Results

OHCT at nanomolar concentrations was effective against all intraerythrocytic stages of P. falciparum and exhibited activity in vitro against both chloroquine-sensitive and -resistant strains of P. falciparum as well as a P. falciparum clone that is partially resistant to artemisinin. Moreover, OHCT exhibited potent activity against gametocytes, the form that is transmitted by mosquitoes and essential for the spread of malaria.

Conclusion

OHCT displays strong growth inhibitory activity against all stages of P. falciparum and no evidence of toxicity to human cells in culture. It is easily synthesized and has the potential for inhibiting metabolism of drugs used in combination therapies.

Glycosylation of sesamol by cultured plant cells

The glycosylation of sesamol was investigated using cultured cells of Nicotiana tabacum and Eucalyptus perriniana. The cultured suspension cells of N. tabacum converted sesamol into its beta-glucoside (7%) as well as the disaccharide, sesamyl 6-O-(beta-D-glucopyranosyl)-beta-D-glucopyranoside (beta-gentiobioside, 30%). On the other hand, sesamyl 6-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside (beta-rutinoside, 56%), together with the beta-glucoside (3%), was produced when sesamol was incubated with suspension cells of E. perriniana.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins. The literature from January 2005 to December 2006 is reviewed and 478 references are cited.

Racemoside A, an anti-leishmanial, water-soluble, natural steroidal saponin, induces programmed cell death in Leishmania donovani

Leishmaniasis remains a major health problem of the tropical and subtropical world. The visceral form causes the most fatalities if left untreated. Dramatic increases in the rates of infection and drug resistance and the non-availability of safe vaccines have highlighted the need for identification of novel and inexpensive anti-leishmanial agents. This study reports that racemoside A, a water-soluble steroidal saponin purified from the fruits of Asparagus racemosus, is a potent anti-leishmanial molecule effective against antimonial-sensitive (strain AG83) and -unresponsive (strain GE1F8R) Leishmania donovani promastigotes, with IC(50) values of 1.15 and 1.31 microg ml(-1), respectively. Incubation of promastigotes with racemoside A caused morphological alterations including cell shrinkage, an aflagellated ovoid shape and chromatin condensation. This compound exerts its leishmanicidal effect through the induction of programmed cell death mediated by the loss of plasma membrane integrity as detected by binding of annexin V and propidium iodide, loss of mitochondrial membrane potential culminating in cell-cycle arrest at the sub-G(0)/G(1) phase, and DNA nicking shown by deoxynucleotidyltransferase-mediated dUTP end labelling (TUNEL). Racemoside A also showed significant activity against intracellular amastigotes of AG83 and GE1F8R at a 7-8-fold lower dose, with IC(50) values of 0.17 and 0.16 microg ml(-1), respectively, and was non-toxic to murine peritoneal macrophages up to a concentration of 10 microg ml(-1). Hence, racemoside A is a potent anti-leishmanial agent that merits further pharmacological investigation.

Two new triterpenoids and a steroidal glycoside from the aerial parts of Ocimum basilicum

Studies on the chemical constituents of the aerial parts of Ocimum basilicum have led to the isolation of three new compounds, basilol (1), ocimol (2), and basilimoside (3), along with two known constituents betulinic acid and oleanolic acid. The structures of the new constituents have been elucidated through spectral studies including 2D-NMR experiments (HMQC, HMBC, COSY, NOESY, and J-resolved) and chemical transformation, as p-formylphenyl 3beta-hydroxyolean-12-en-28-oate (1), 2-methoxy-4-carbomethoxyphenyl 3beta-hydroxy-lup-20(29)-en-28-oate (2), and (22E)-24xi-ethyl-25-methylcholesta-5,22-diene-3beta-ol-3-O-D-glucopyranoside (3).

Antiplasmodial activity of novel stilbene derivatives isolated from Parthenocissus tricuspidata from South Korea

New stilbene glycoside, piceid-(1-->6)-beta-D -glucopyranoside (compound 2, Fig. 1), was isolated from the MeOH extract of the leaves of Parthenocissus tricuspidata (Vitaceae) together with four known compounds, piceid (compound 1, Fig. 1), resveratrol (compound 3, Fig. 1), longistylin A (compound 4, Fig. 1), and longistylin C (compound 5, Fig. 1). Their structures were determined spectroscopically, particularly by 2D nuclear magnetic resonance (NMR) spectroscopic and chemical analysis. The antiplasmodial activity of isolated compounds were determined in vitro against a chloroquine-sensitive strain of Plasmodium falciparum (D10). Among the compounds isolated, piceid-(1-->6)-beta-D-glucopyranoside (2) had the most potential inhibition, with inhibitory concentration (IC(50)) values of 5.3 microM. To our knowledge, antiplasmodial activity of functional group position of stilbene is now being reported for the first time in this study. The result shows that the 3, 4'-position in stilbenes might play an essential role in antiplasmodial activity.

Steroidal saponins from the fruits of Asparagus racemosus

Three steroidal saponins, racemosides A (1), B (2) and C (3), were isolated from the methanolic extract of the fruits of Asparagus racemosus, and characterized as (25S)-5beta-spirostan-3beta-ol-3-O-{beta-D- glucopyranosyl (1-->6)-[alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranoside}, (25S)-5beta-spirostan-3beta-ol-3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside and (25S)-5beta-spirostan-3beta-ol-3-O-{alpha-L-rhamnopyranosyl-(1-->6)-[alpha-L-rhamnopyranosyl (1-->4)]-beta-D-glucopyranoside}, respectively, by spectrometric analysis and some chemical strategies.