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Viral-borne diseases are amongst the oldest diseases known to mankind. They are responsible for some of the most ravaging effects wrought on human health and well-being. The use of plants against these ailments is entrenched in both traditional and secular medicine around the globe. Their natural abundance and chemical diversity have also boosted their appeal in drug discovery.The plant family Amaryllidaceae is distinguished for its alkaloid principles, some of which are of considerable interest in the clinical arena. This account is the outcome of a literature review undertaken to establish the applicability of these substances as antiviral agents.The survey utilized the search engines Google Scholar, PubMed, SciFinder, Scopus and Web of Science engaging the word 'antiviral' in conjunction with 'Amaryllidaceae' and 'Amaryllidaceae alkaloid'. The search returned over five hundred hits, of which around eighty were of relevance to the theme of the text.Over eighty isoquinoline alkaloids have been screened against nearly fifty pathogens from fourteen viral families, the majority of which were RNA viruses. Potent activities were reported in some instances, such as that of trans-dihydronarciclasine against Yellow fever virus (ICThe Amaryllidaceae offers a viable platform for plant-based antiviral drug discovery. Its cause is strengthened not only by its wide proliferation and exploitation of its members in alternative forms of medicine, but also by its rich chemical diversity which has already spawned useful antiviral drug leads.

Protozoan-borne diseases are prominent amongst diseases caused by parasites. Given their alarming morbidity and mortality statistics, there is ever growing interest in new therapies against these diseases. Whilst synthetic drugs such as benznidazole and melarsoprol have had a profound influence on the clinical setup, there has been significant interest in the phytochemical platform to also deliver such drug candidates. The plant family Amaryllidaceae is recognizable for its isoquinoline alkaloids, which exhibit attractive molecular architectures and interesting biological properties. This survey focuses on the antiprotozoal activities of 73 of such substances described in 18 different species of the Amaryllidaceae. Of these, 2-O-acetyllycorine was identified as the most potent (IC50 0.15 μg/mL against Trypansoma brucei brucei). Also considered are structure-activity relationships which have served to modulate activities, as well as the plausible mechanisms that underpin these effects and afford insight to the Amaryllidaceae alkaloid antiprotozoal pharmacophore.

The spread of malaria is thought to have followed human expansion out of Africa some 60 – 80 thousand years ago. With its prevalence in pantropical countries of the world and epicenter localized in Africa, malaria is now considered an unnecessary burden to overworked and under-resourced healthcare structures. Plants have long afforded a fertile hunting ground for the search and identification of structurally diverse antimalarial agents, such as quinine and artemisinin. This survey examines the antiparasitic properties of the family Amaryllidaceae via the antiplasmodial activities demonstrated for its lycorane alkaloid principles. Of these, 24 were natural compounds identified in 20 species from 11 genera of the Amaryllidaceae family, whilst the remaining 28 were synthetically derived entities based on the lycorane skeleton. These were screened against ten different strains of the malarial parasite Plasmodium falciparum, wherein the parent compound lycorine was shown to be the most potent with an IC50 of 0.029 µg/mL in the FCR-3 strain seen to be the best. Structure-activity relationship studies revealed that good activities were detectable across both the natural compounds as well as the synthetically accessed derivatives. Such studies also highlighted that there are several inherent structural features that define the lycorane alkaloid antiplasmodial pharmacophore, such as the nature of its ring systems and properties of its substituents. Mechanistically, a limited number of studies confirmed that lycorane alkaloids manifest their action by targeting enzymes associated with the plasmodial FAS-II biosynthetic pathways. Overall, these alkaloids have provided useful, convenient, and accessible scaffolds for antimalarial-based drug discovery.

Globalization and multidrug resistance are amongst the factors implicated in the resurgence of infectious diseases in recent years. This has fostered a compelling need in drug discovery to replace (or supplement) existing schedules. The floral biodiversity has been identified as a viable resource platform due to its inimitable chemical characteristics as well as the presence of numerous of its members in traditional medicinal approaches towards these diseases. Whilst the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease therapies, this survey shows that it has a significant presence in the remediation of infections and infection-related ailments. This verifiable indigenous knowledge could amplify efforts towards the identification of the active chemical constituents.

The birth, growth, proliferation and death of cells involve a rigorous and continuous process in place to ensure the survival of living organisms. The cell cycle prevails at the core of this process to facilitate the division of a parent cell as well as the duplication of its genetic matter. Although checkpoints exist to steer the course of a cell from one phase to the other, malfunctions at any point of the four active phases of the cell cycle can have detrimental effects. Cancer is thought to be a consequence of such a malfunction in the cell cycle which endows a cell with enhanced replicative potential, immunity to anti-growth signals and the ability to evade apoptosis. This characteristic has been exploited in cancer chemotherapy since a significant number of anticancer drugs manifest their action via cell cycle modulatory effects. The plant family Amaryllidaceae is distinguished for its alkaloid principles which exhibit potent (at the sub-nanomolar level in some cases) and cell line specific antiproliferative activities, with apoptosis induction a key feature of these properties. As a consequence there has been sustained interest in these chemical entities as a source of new anticancer drugs. This has been matched by the large body of work that has emerged over the past two decades addressing their cytotoxic potential, establishing a structure-activity relationship basis as well as probing their mode of action. This review focuses on studies which highlight how Amaryllidaceae alkaloids modulate the cell cycle of cancer cells.

Globalization, the modern lifestyle, immuno-suppressive agents, invasive surgical procedures, the loss of efficacies of existing drugs, and multidrug resistance are some of the factors used to explain the rise in fungal infections in recent years. Significant advances have been made in attempts to replace existing antifungal schedules, especially with synthetic targets. The identification of other platforms for drug discovery is now entrenched in research programs across the globe. Plants offer significant benefits owing to their numerical superiority, exceedingly broad chemical basis and appealing sustainability characteristics. Furthermore, plants have a long and rich historical association with traditional approaches towards fungal diseases. These have in numerous instances served as markers in the bioassay-guided identification of the active constituents. Although the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease chemotherapies, around 30 of its species have been examined for antifungal activities with microgram per millilitre inhibitory activities detected in several instances. This review focuses on the nearly 40 constituents from the family, mainly isoquinoline alkaloids, which have been screened against around 50 fungal pathogens. Encouragingly, microgram per millilitre growth inhibitory activities were applicable for several of the compounds with a minimum inhibitory concentration of 4 μg/ml seen to be the lowest.

Ethnopharmacological relevance Boophone disticha is the most common member of the South African Amaryllidaceae used extensively in traditional medicine of the various indigenous population groups, including the Sotho, Xhosa and Zulu as well as the San. This survey was carried out to identify and highlight areas relevant to the traditional usage of Boophone disticha. Pharmacological aspects were examined with the purpose of reconciling these with the traditional usage of the plant. In relation to phytochemical make-up, particular attention was paid on how its alkaloid constitution might corroborate the various biological effects manifested by the plant. Materials and methods Information gathering involved the use of four different database platforms, including Google Scholar, ScienceDirect, SciFinder® and Scopus. Arrangement and detailing of this information is as reflected in the various sections of the paper. Results Sixteen categories were identified under which Boophone disticha finds use in traditional medicine. These were shown to include general usage purposes, such as ‘cultural and dietary’, ‘well-being’, ‘personal injury’, ‘divinatory purposes’, ‘psychoactive properties’ and ‘veterinary uses’. Furthermore, traditional usage was seen to involve six body systems, including functions pertaining to the circulatory, gastrointestinal, muscular, neurological, respiratory and urinary systems. The four remaining categories relate to use for inflammatory conditions, cancer, malaria and tuberculosis. Overall, three areas were discernible in which Boophone disticha finds most usage, which are (i) ailments pertaining to the CNS, (ii) wounds and infections, and (iii) inflammatory conditions. In addition, several aspects pertaining to the toxic properties of the plant are discussed, including genotoxicity, mutagenicity and neurotoxicity. Conclusion The widespread ethnic usage of Boophone disticha has justified its standing as a flagship for the Amaryllidaceae and its relevance to South African traditional medicine. Furthermore, its promising pharmacological and phytochemical profiles have stimulated significant interest in the clinical realm, especially in the areas of cancer and motor neuron disease chemotherapy. These collective properties should prove useful in steering the progress of the plant towards a wider audience.

Several of the Amaryllidaceae alkaloids are known for their cytotoxic properties, of which the lycorine group representatives are prominent for potent and cell line specific antiproliferative activities. As a distinct niche within the lycorine group, the phenanthridones, exemplified by narciclasine and pancratistatin, have shown much promise as remarkably selective cytotoxic agents and are presently at various stages of development, with a clinical candidate likely to appear on the market within the next decade. The crinane group of the Amaryllidaceae has also spawned several molecules, such as crinamine and haemanthamine, with promising cytotoxic activities. In the present study, the β-crinane distichamine as well as the phenanthridone narciprimine, both rare constituents of the Amaryllidaceae, are revealed as novel antiproliferative agents. Apoptosis-inducing effects are demonstrated for distichamine in human acute lymphoblastic leukemia (CEM) cells. These findings provide further insights to the structural details of the apoptosis-inducing pharmacophores resident within both series of alkaloids.

seco-Derivatives of the anticancer agent pancratistatin bearing the 2S,3S,4S,5S configuration were accessed via a novel, highly diastereoselective anti-aldol reaction. Structure–activity relationships reveal important insights into the seco-pancratistatin pharmacophore as a potent and selective inhibitor of human cytochrome P450 3A4 (CYP3A4), and highlight features of concern in advancing a potent, selective anticancer agent in the pancratistatin series.

A library of natural and semi-synthetic Amaryllidaceae alkaloids was screened for cytochrome P450 3A4 (CYP3A4) inhibitory activity. Of the crinane, lycorane and galanthamine representatives examined two semi-synthetic silylated lycorane analogues, accessed via a chemoselective silylation strategy from lycorine, and the natural compound narciclasine exhibited low micromolar activities. Important pharmacological features uncovered include the lack of CYP3A4 inhibitory activity seen for galanthamine and the selective activity that is seen with narciclasine over pancratistatin.

Graphical abstract The direct chemoselective differential functionalization of the ring-C hydroxyl groups present in the Amaryllidaceae alkaloid lycorine is described allowing for selective manipulation of the 1,2-hydroxyl groups. A mini-library comprised of synthetic and natural lycorane alkaloids was prepared and their apoptosis-inducing activity investigated in human leukemia (Jurkat) cells. Further insights into the nature of this interesting apoptosis-inducing pharmacophore are described, including the requirement of both free hydroxyl groups in ring-C., The direct chemoselective differential functionalization of the ring-C hydroxyl groups present in the Amaryllidaceae alkaloid lycorine is described allowing for selective manipulation of the 1,2-hydroxyl groups. A mini-library comprised of synthetic and natural lycorane alkaloids was prepared and their apoptosis-inducing activity investigated in human leukemia (Jurkat) cells. Further insights into the nature of this interesting apoptosis-inducing pharmacophore are described, including the requirement of both free hydroxyl groups in ring-C.

The Amaryllidaceae occupies a privileged status amongst medicinal plants in having delivered the Alzheimer's drug galanthamine to the clinical market. Following its resounding success, there have been several positive indicators for the emergence of an anticancer drug from the family due to the potent antiproliferative activities manifested by several of its alkaloid constituents. Of these, the phenanthridones such as pancratistatin hold most promise as potential chemotherapeutics having succumbed to various phases of clinical trials. Other cytotoxic targets of the Amaryllidaceae are to be found within the lycorane and crinane groups, as exemplified by crinine and lycorine. Although the molecular targets of these alkaloids still remain elusive, much effort has gone into understanding their mode of action in cancer cells. Recent findings have shown that the apoptotic pathway may be a key factor in cancer cell death instigated by Amaryllidaceae alkaloids. As such, this review seeks to: (a) examine the apoptotic effects of Amaryllidaceae alkaloids in cancer cells; (b) explore the molecular basis to these effects; and (c) provide a pharmacophoric rationale in support of these activities.

Cells cultured from Alzheimer disease leptomeninges or skin were grafted into the cortex of adult thymectomized rats. At 3 days post-implant, plaque-like aggregates were found in the cortex, corpus callosum, septum and caudate nucleus. These structures were immunopositive for human amyloid precursor protein (APP), human amyloid beta peptide (Aβ), cathepsin D, apolipoprotein E and ubiquitin. Aberrant tau + neurites, reactive astrocytes and microglia were associated with many aggregates. Although birefringent amyloid occupied the central area of most aggregates, these structures had disappeared by l month post-implant. Aβ and APP produced by grafted non-neural human cells can penetrate rat brain and form plaque-like structures, which can be effectively cleared by the rat.

The plant family Amaryllidaceae is renowned for its unique alkaloid constituents which possess a significant array of structural diversity. Several of these alkaloids are known for their interesting biological properties, of which galanthamine and pancratistatin have acquired a privileged status due to their relevance in the pharmaceutical arena. In particular, galanthamine represents the first prescription drug emanating from the Amaryllidaceae after its approval by the FDA in 2001 for the treatment of Alzheimer's disease. Following on this commercial success there have been sustained projections for the emergence of an anticancer agent related to pancratistatin due to the potency, selectivity, low toxicity and high tolerability typifying targets of this series of alkaloids. The lycorine series of alkaloids have also garnered widespread interest as cytotoxic agents and were amongst the earliest of the Amaryllidaceae constituents to exhibit such activity. To date over 100 of such naturally-occurring or synthetically-derived alkaloids have been screened for cytotoxic effects against a number of cancer cell lines. This survey examines the cytotoxic properties of lycorine alkaloids, highlights the outcomes of structure-activity relationship orientated studies and affords plausible insights to the mechanistic rationale behind these effects.

In this study, the South African Amaryllid Boophone haemanthoides was examined for its phytochemical composition and cytotoxicity. In the process eight alkaloid structures, including the new compound distichaminol, were identified in bulb ethanolic extracts. Of the isolates, lycorine and distichamine exhibited strong activities against human acute lymphoblastic leukemia (CEM), breast adenocarcinoma (MCF7) and cervical adenocarcinoma (HeLa) cells with IC50S ranging from 1.8 to 9.2 microM.

The cytochrome P45O activities of the naturally occurring Amaryllidaceae alkaloid narciclasine (3), isolated from Narcissus pseudonarcissus, and synthetic derivative trans-dihydronarciclasine (5) are reported. While narciclasine was found to possess potent inhibitory activity to human CYP3A4, its dihydro analogue was inactive. This study revealed that the C1-C10b double bond is required for inhibition of this crucial metabolizing enzyme. Compound 5 also demonstrated no inhibition of the related human cytochromes CYP19 and CYP1A1. This study elevates the status of trans-dihydronarciclasine (5) as a highly privileged, readily available molecule, with potent and selective anticancer activity.

The plant family Amaryllidaceae is known for its horticultural and ornamental appeal as well as its medicinal value. In relation to these characteristics, trade in Amaryllid flower varieties (especially daffodils) is a multi-million dollar revenue generator for the floriculture industry. Of greater significance are the medicinal attributes of the family, which has already spawned the Alzheimer's prescription drug galanthamine, a potent and selective inhibitor of the enzyme acetylcholinesterase, of significance in the progression of neurodegeneration associated with motor neuron diseases, with annual global sales of around $150 million. Furthermore, it is anticipated that an anticancer drug target related to the Amaryllidaceae alkaloid pancratistatin, presently under advanced clinical evaluation, will enter commercial circulation within the next decade. Members of the Amaryllidaceae are distributed through both tropical and subtropical regions of the globe, but are of prominence within three distinct geographical locations, including Andean South America, the Mediterranean basin, and southern Africa. The southern African zone is known to harbor at least a third of the worldwide complement of around 1000 species, many of which are widely utilized in the traditional medicinal practices of the indigenous people of the region. Given its therapeutic and economic value, its natural abundance in the southern African region, coupled to its widespread usage in ethnic medicine, the family Amaryllidaceae provides a diverse and accessible platform for phytochemical based drug discovery. A consolidation of its traditional usage as well as its chemical and pharmacological profiles will thus guide efforts aimed at maximizing this potential. In undertaking this survey of the Amaryllidaceae of southern African, we aimed to achieve these goals.

Beta-2-glycoprotein I (beta2GPI), a 50-kDA serum glycoprotein that binds negatively charged phospholipids plays a role in coagulation, thrombosis, and the clearance of phosphatidylserine expressing cells. Because of its recently recognized role in several autoimmune responses, we have developed a method that quantifies plasma beta2GPI levels by using a competitive ELISA assay. When combined with data from a standard ELISA, this method determines the concentration of free beta2GPI and the fraction of antibody-bound beta2GPI thereby facilitating quantification of total antigen in individuals with autoimmune antibodies. Standard competitive inhibition ELISA was compared with this method, which uses known amounts of standard beta2GPI added to the plasma as an internal standard. Identical results were obtained with both methods for plasma samples from normal individuals that did not contain blocking antibodies. Analysis of plasma from antiphospholipid syndrome patients (patients with autoantibodies to beta2GPI) by the internal standard method, however, resulted in significantly lower apparent beta2GPI levels indicating that a substantial fraction of the plasma beta2GPI was bound by antibody.

Bioisosteric replacement of cyclic ketone functionality with aryl halides was investigated on a centrally-flexible, five-component 1,2,3-triazole-containing pharmacophore, resulting in enhanced inhibition of aromatase (CYP450 19A1). Structure-activity data generated from both syn- and anti-aldol precursors provides significant insights into the requirements for enhanced potency, validating this novel ketone-to-aryl halide bioisostere hypothesis.

The plant family Amaryllidaceae is of provenance in the South African region which is known to harbor about a third of the global complement of around 1000 species. It has widespread usage in the traditional medicinal practices of the indigenous peoples of the region. As a consequence and given its unique alkaloid principles, its members have provided a viable platform for phytochemical based drug discovery. The medicinal potential of the family has been realized through the commercialization of galanthamine as an Alzheimer's drug due to its potent and selective inhibitory activity against the enzyme acetylcholinesterase. Further promising chemotherapeutic candidates of the family reside with the phenanthridone class of alkaloids such as pancratistatin which exhibit potent and cell line specific antiproliferative properties with significant potential for clinical development. Despite these interesting medicinal attributes, plants of the Amaryllidaceae are known to be poisonous and several of them have been classified as such. This survey taking into consideration Amaryllidaceae plants native to South Africa aims to strike a balance between the medicinal potential of the family on one hand and its adverse and toxic effects on the other.

The following series of experiments explores the post-xenografting differentiation of a naturally occurring, non-neuronal cell cultured from the leptomeninges of an 84-year-old woman. In culture, flat process-bearing human cells from the leptomeninges were positive for GFAP and 200 kDa neurofilament protein (negative for 68, 160 kDa neurofilament protein). The C3 spinal cord was exposed in 30 adult athymic rats. The hindlimb dorsal columns were transected at C3 and the nerve fibers aspirated to form a pocket, into which 10(6) fast blue-labeled, human leptomeningeal-derived cells were placed. The C3 spinal cord was studied immunohistochemically over 60 days. Three days later the dorsal horn contained fast blue-GFAP-positive astrocyte-like cells that were negative for neurofilament protein. By 7 days, large, process-bearing, fast blue-GFAP-positive (neurofilament protein-negative), astrocyte-like cells joined the native astrocytes of the pia-glia membrane and were in the gray matter of the spinal cord. Some of these astrocyte-like cells were also positive for the human specific histocompatibility complex, HLADR. These data extend the age, species and tissue of origin for pluripotential cells for CNS transplantation.

The plant family Amaryllidaceae occupies a privileged status within the botanical hierarchy due to its horticultural and ornamental appeal, as well as its widespread usage in the traditional medicinal practices of indigenous peoples across the globe. Of greater significance are the unique, structurally-diverse alkaloid constituents produced by members of the family, which has spawned several biologically significant molecules. In this regard, the Alzheimer's drug galanthamine has gained much prominence due to its selective and reversible inhibitory interaction with the enzyme acetylcholinesterase (AChE), of significance in the progression of neurodegeneration associated with Alzheimer's disease (AD). The lycorine series of compounds within the family have recently emerged as novel inhibitors of AChE, in some instances with higher levels of activity compared with the commercial drug galanthamine, making them attractive targets for natural product and synthetically-driven structure-activity relationship studies. This brief survey traces the emergence of lycorine compounds over the past decade as promising leads in the therapeutic approach towards AD and their possible future advancement onto the clinical stage.

The antiproliferative effect of interferon alpha (IFN-alpha) against cultured 253J human bladder tumour cells was enhanced when IFN-alpha was encapsulated into multilamellar phospholipid liposomes (MLV). Moreover, significant cytostasis of a variant 253J subline (253J alpha R, resistant to the antiproliferative effect of IFN-alpha), could be achieved by delivery of IFN-alpha contained in liposomes. Although the two cell lines have the same number and affinity of cell receptors for IFN-alpha, the 253J alpha R cells did not down-regulate receptors as observed for the IFN-sensitive 253J cells. The IFN-response genes, 2'-5' oligosynthetase and gene 6-16 were equally induced in both cell lines following incubation of the cells with either free IFN-alpha or liposome-encapsulated IFN-alpha. Incorporation of radiolabelled IFN-alpha into cells by liposomes was independent of the status of IFN-receptors (the receptors being either occupied or down-regulated). These observations are consistent with the hypothesis that the antiproliferative effects of IFN-alpha against 253J and 253J alpha R cells may be mediated by internalization of IFN-alpha.

The therapy of cancer is, in reality, the design of therapeutic strategies for therapy of metastatic disease. Metastases consist of unique subpopulations of tumor cells that are derived from the primary tumor, colonize distant target organs, and are able to subvert host immune responses, establish necessary angiogenesis, and obtain a sufficient nutrient supply while evolving to become autonomous from homeostatic mechanisms that function within normal, differentiated tissues. Attempts at eradication of metastases by conventional therapies have generally been unsuccessful due to genetic instability and heterogeneity of metastatic tumors; these properties lead to the emergence of tumor cells that are resistant to most conventional treatments. It may be possible to circumvent this heterogeneity by the activation of tissue macrophages to the tumoricidal state. Activated macrophages are able to kill tumor cells while sparing normal tissues, and efficient activation can be achieved by encapsulation of synthetic muramyl tripeptide analogues into multilamellar vesicles composed of phospholipids. Systemic administration of these liposome-encapsulated compounds leads to tumoricidal activation of alveolar and peritoneal macrophages and eradication of established tumor metastasis in numerous animal tumor models, and this form of therapy is enhanced by combination with parenteral administration of cytokines. Phase III clinical trials of recurrent osteosarcoma are currently in progress. Modulation of the tumor microenvironment by activated macrophages may prove to be an additional modality in treatment strategies that combine the use of biological response modifiers with conventional therapies.

The discovery of a novel five-component 1,2,3-triazole-containing pharmacophore that exhibits potent and selective inhibition of aromatase (CYP 450 19A1) is described. All compounds are derived from an initial aldol reaction of a phenylacetate derivative with an aromatic aldehyde. Structure–activity data generated from both syn- and anti-aldol adducts provides initial insights into the requirements for both potency and selectivity.

A series of saccharin derivatives I has been synthesized and evaluated for their inhibitory activity toward human leukocyte elastase and cathepsin G. Most of the compounds were found to be efficient and time-dependent inhibitors of elastase. Inactivated elastase was found to regain its activity almost fully after 24 h (80-90% activity) and the half-lives of reactivation ranged between 12-15 h. Addition of hydroxylamine to fully-inactivated enzyme led to rapid and complete recovery of enzymatic activity. A tentative mechanism of action is proposed on the basis of biochemical and model studies.

Neutrophil-derived mediators such as, for example, the serine proteinase elastase, cathepsin G and proteinase 3, play a critical role in inflammatory lung disease. This report describes the design, synthesis and in vitro inhibitory activity of some novel mechanism-based inhibitors of human leukocyte elastase and cathepsin G. The design of the inhibitors is based on the Gabriel-Colman rearrangement. The behavior of the synthesized compounds toward elastase and cathepsin G with respect to inhibitory prowess, mode of interaction, specificity, etc., has been found to be dependent on the recognition and reactivity elements present in each inhibitor.

The apoptosis-inducing ability of α-ethano bridged crinane alkaloids was investigated using natural and semi-synthetic derivatives uncovering novel structural requirements of this cytotoxic pharmacophore. An α-ethano bridge is required; an α- or ß-methoxy or hydroxyl H-bond acceptor are all tolerated at C-3; a small substituent (H, or OH) alone is tolerated at C-11; and a C-1 to C-2 double bond is shown to modulate, but is not a requirement for, apoptosis-inducing activity.

The total synthesis of fully functionalized polyhydroxyamide B,C- seco-analogues of the anticancer compound pancratistatin (PST) ( 1) is reported. Key steps include an Evans' MgCl 2-promoted anti-aldol reaction between a functionalized l-threose derivative and ( R)-(+)-oxazolidinone to stereoselectively form the C-1/C-10b bond and a regiospecific radical-mediated oxidative fragmentation of a 1,3-benzylidene. The B,C- seco compounds 25 and 26 exhibited low activity (ED 5030 microg/mL) for inducing apoptosis in human cancer cells.

Current therapy of human superficial bladder cancer includes the intravesical administration of antitumor drugs and immunomodulators. The purpose of these studies was to determine whether phospholipid liposomes that bind to human bladder cancer cells can improve the delivery of interferon alpha (IFN-alpha) to neoplastic urothelium. The antiproliferative activity of free IFN-alpha and IFN-alpha encapsulated in liposomes was assessed in vitro against the human transitional cell carcinoma line 253J. The cells were exposed to free and liposome-encapsulated IFN-alpha for short periods ranging from 30 minutes to four hours, and inhibition of cell growth was determined three days later. The production of greater than 25 percent cytostasis of 253J cells by free IFN-alpha required four hours of continuous exposure. In contrast, IFN-alpha encapsulated in liposomes produced 35 percent and 60 percent cytostasis after a 30-minute and four-hour exposure, respectively. Liposome-encapsulated IFN-alpha was also effective (50 percent cytostasis) against a subline of 253J cells selected for resistance against free IFN-alpha. Liposomes containing IFN-alpha were stable in the presence of human urine. In vivo studies in mice showed that intravesical administration of radiolabeled IFN-alpha or radiolabeled liposomes did not yield significant systemic absorption and deposition in distant organs. Collectively, these results suggest that the encapsulation of IFN-alpha within multilamellar liposomes may augment its antiproliferative activity, overcome some forms of tumor cell resistance to IFN-alpha, and prove useful for intravesical therapy of superficial bladder cancer.

The selective apoptosis-inducing activity of Amaryllidaceae alkaloids belonging to the crinane-type is reported. A mini-library of natural and synthetic crinane alkaloids was assembled. Biological screening indicated crinamine 4 and haemanthamine 9 to be potent inducers of apoptosis in tumour cells at micromolar concentrations. Structure-activity relationships demonstrated the requirement for both an alpha-C2 bridge and a free hydroxyl at the C-11 position as pharmacophoric requirements for this activity.

Human leptomeningeal (arachnoid and pia mater) cells in culture have been demonstrated in replicated studies to express typical neuronal proteins such as neurofilament protein and neuron-specific enolase. In addition, they can express glial fibrillary acidic protein. The present study examines the possibility that neuronal and glial proteins might be present in rat and human leptomeningeal cells in situ. The neuronal proteins 160 kDa and 200 kDa neurofilaments, neuron-specific enolase and microtubule-associated protein 2 were, however, not immunolocalized in either the pia mater or arachnoid. Glial fibrillary acidic protein and galactocerebroside were also not detected, while fibronectin and vimentin immunoreactivities were robust in all layers of the leptomeninges. Together with the previously reported expression of some neuronal and astroglial markers in cultured human leptomeninges, these observations suggest that culture alters the properties of leptomeningeal cells.

Once prostate cancer metastasizes to bone, conventional chemotherapy is largely ineffective. We hypothesized that inhibition of phosphorylation of the epidermal growth factor receptor (EGF-R) and platelet-derived growth factor receptor (PDGF-R) expressed on tumor cells and tumor-associated endothelial cells, which is associated with tumor progression, in combination with paclitaxel would inhibit experimental prostate cancer bone metastasis and preserve bone structure. We tested this hypothesis in nude mice, using human PC-3MM2 prostate cancer cells. PC-3MM2 cells growing adjacent to bone tissue and endothelial cells within these lesions expressed phosphorylated EGF-R and PDGF-Rα and -β on their surfaces. The percentage of positive endothelial cells and the intensity of receptor expression directly correlated with proximity to bone tissue. Oral administration of PKI166 inhibited the phosphorylation of EGF-R but not PDGF-R, whereas oral administration of STI571 inhibited the phosphorylation of PDGF-R but not EGF-R. Combination therapy using oral PKI166 and STI571 with i.p. injections of paclitaxel induced a high level of apoptosis in tumor vascular endothelial cells and tumor cells in parallel with inhibition of tumor growth in the bone, preservation of bone structure, and reduction of lymph node metastasis. Collectively, these data demonstrate that blockade of phosphorylation of EGF-R and PDGF-R coupled with administration of paclitaxel significantly suppresses experimental human prostate cancer bone metastasis.

Purpose: We sought to determine whether blockade of platelet-derived growth factor receptor (PDGF-R) activation by oral administration of a PDGF-R tyrosine kinase inhibitor (STI571) alone or in combination with i.p. paclitaxel can inhibit the progression of tumors caused by human ovarian carcinoma cells growing in the peritoneal cavity of female nude mice. Experimental Design: In several different experiments, paclitaxel-sensitive and paclitaxel-resistant metastatic human ovarian carcinoma cells were injected into the peritoneal cavity of nude mice. Seven days later, groups (n = 10) of mice began receiving a control treatment, STI571 alone, paclitaxel alone, or a combination of STI571 and paclitaxel. The mice were necropsied after 45 days of treatment. Results: Treatment with combination therapy significantly reduced tumor weight (relative to control or single-agent therapy) in all three human ovarian cancer cell lines. Immunohistochemical analyses revealed that PDGF-R activation was blocked by STI571 administered alone or in combination with paclitaxel. Tumor-associated endothelial cells expressed both PDGF-R and phosphorylated PDGF-R. In mice receiving combination therapy, tumor-associated endothelial cells underwent apoptosis, leading to decreases in microvessel density and tumor cell proliferation relative to control and single-agent therapy. Conclusions: These results show that administration of a PDGF-R tyrosine kinase inhibitor in combination with paclitaxel impairs the progression of ovarian cancer in the peritoneal cavity of nude mice, in part, by blockade of PDGF, an endothelial cell survival factor, which results in the increased apoptosis of tumor-associated endothelial cells.

We evaluated the expression of platelet-derived growth factor (PDGF) ligands and receptors in clinical specimens of human pancreatic adenocarcinomas and determined the therapeutic effect of STI571 (Gleevec), a protein tyrosine kinase inhibitor of PDGF receptor (PDGFR), on human pancreatic carcinoma cells growing in the pancreas and liver of nude mice.Immunohistochemical staining for PDGF-AA and -BB ligands, PDGFR-alpha and -beta, and phosphorylated PDGFR-alpha and -beta was performed on 31 specimens of human pancreatic cancer and L3.6pl human pancreatic adenocarcinoma cell line. To determine the in vivo effects of STI571, nude mice with L3.6pl cells injected into the pancreas were randomized 7 days later to receive one of the following treatments: sterile water p.o. (control), STI571, gemcitabine, or a combination of STI571 and gemcitabine.In 29 of 31 clinical specimens of human pancreatic adenocarcinoma, both tumor cells and tumor-associated endothelial cells expressed phosphorylated PDGFR-alpha and -beta. L3.6pl cells growing in culture expressed moderate amounts of PDGF-AA and little to no PDGFR-alpha or -beta, whereas L3.6pl cells growing in the pancreas of nude mice expressed a high level of PDGF and receptors. Colocalization immunohistochemical analysis demonstrated expression of activated PDGFR-beta by tumor-associated endothelial cells in both the pancreas and in liver metastases. Tumors of mice treated for 4 weeks with STI571 (50 mg/kg or 100 mg/kg p.o. daily) were slightly smaller than controls. Tumors treated with gemcitabine and STI571 (50 mg/kg) were70% smaller than tumors in control mice and 36% smaller than those in mice treated with gemcitabine only (P0.0002 and P0.04, respectively). Combination therapy also inhibited spontaneous metastasis to the liver. Tumors from mice treated with both STI571 and gemcitabine had decreased expression of activated (phosphorylated) PDGFR-alpha and -beta, decreased mean vessel density, decreased cell proliferation, and increased apoptosis of tumor cells.Collectively, these data show that activated PDGFR on tumor cells and tumor-endothelial cells can be a novel target for therapy of pancreatic carcinoma.

Objectives . We determined the expression of platelet-derived growth factor (PDGF), PDGF-receptor (PDGF-R), and phosphorylated PDGF-R (p-PDGF-R) on tumor cells and tumor-associated endothelial cells in clinical specimens of human ovarian carcinoma and human ovarian cancer cells growing in culture and in the peritoneal cavity of nude mice. Methods . Ten specimens of high-grade serous ovarian carcinoma were analyzed using immunohistochemistry (IHC). IHC was used to detect ligand and receptor expression in the human ovarian cancer cells from Hey A8 and SKOV3ip1 growing in culture. Cells from these lines were also implanted orthotopically into the peritoneal cavity of nude mice. IHC was used to determine ligand and receptor expression in tumors that formed in the peritoneal cavity. Results . All 10 evaluable samples expressed both PDGF AA and BB on tumor cells. Tumor cells were positive for PDGF-Rα in 10/10 samples, PDGF-Rβ in 8/10 samples, p-PDGF-Rα in 6/10 samples, and p-PDGF-Rβ in 4/10 samples. p-PDGF-Rα was positive in 4/10 tumor-associated endothelial cell samples and p-PDGF-Rβ was positive in 3/10 samples. Human ovarian cancer cells expressed PDGF, PDGF-R, and p-PDGF-R when growing in culture or in the peritoneal cavity of nude mice. PDGF-R and p-PDGF-R were also present on tumor-associated endothelial cells as demonstrated by simultaneous staining with CD31 antibody. Conclusions . PDGF and the corresponding receptors were expressed in autochthonous human ovarian cancer lesions on both tumor cells and tumor-associated endothelial cells. The ligand and receptor were also present on Hey A8 and SKOV3ip1 human ovarian cancer cells growing in vitro and in the peritoneal cavity of nude mice.

We determined whether chronic administration of IFN-alpha at optimal biological dose inhibits angiogenesis of human pancreatic carcinoma growing in the pancreas of nude mice.Cells of the human pancreatic cancer cell line L3.6pl were implanted into the pancreas of nude mice. Seven days later, groups of mice received s.c. injection with IFN-alpha alone (50,000 units biweekly or 10,000 units daily), i.p. injection with gemcitabine alone (125 mg/kg biweekly), or injection with both daily IFN-alpha and biweekly gemcitabine for 35 days. In a survival study, the mice were treated until they became moribund.Biweekly treatments with 50,000 units of IFN-alpha alone were ineffective. In contrast, daily injections of IFN-alpha (10,000 units/day) alone, biweekly injections of gemcitabine alone, or the combination of IFN-alpha and gemcitabine reduced tumor volume by 53%, 70%, and 87%, respectively. Immunohistochemical analysis revealed that treatment with IFN-alpha alone or with IFN-alpha plus gemcitabine inhibited expression of the proangiogenic molecules basic fibroblast growth factor and matrix metalloproteinase 9 more than did treatment with gemcitabine alone. These treatments also decreased the staining of proliferating cell nuclear antigen within the tumor and induced apoptosis in tumor-associated mouse endothelial cells (staining with CD31/terminal deoxynucleotidyl transferase-mediated nick end labeling), leading to a decrease in microvessel density.These data show that administration of IFN-alpha at optimal biological dose and schedule in combination with gemcitabine induced apoptosis in tumor-associated endothelial cells and decreased growth of human pancreatic cancer cells in the pancreas, leading to a significant increase in survival.

BACKGROUND Expression of platelet-derived growth factor (PDGF) and activation (by autophosphorylation) of its receptor (PDGF-R), a tyrosine kinase, are associated with the growth of metastatic prostate tumor cells in the bone parenchyma. The tyrosine kinase inhibitor STI571 blocks the PDGF signaling pathway by inhibiting PDGF-R autophosphorylation. We examined the effects of STI571, given alone or with paclitaxel (Taxol), on tumor growth in a mouse model of prostate cancer metastasis. METHODS Human prostate cancer PC-3MM2 cells were injected into the tibias of male nude mice. Three days later the mice (20 per group) were randomly assigned to 5 weeks of treatment with oral and injected water (control), daily oral STI571, weekly injected paclitaxel, or STI571 plus paclitaxel. Lesions in bone and the surrounding muscles were then harvested and analyzed by histology, western blotting (for PDGF-R phosphorylation), immunohistochemistry (for expression of proangiogenic molecules), and double immunofluorescence (to identify endothelial cells and apoptotic tumor cells). Growth of bone lesions was monitored by digital radiography. Bone lesions from control mice were used to establish short-term cell cultures for analysis of PDGF-R phosphorylation. All statistical tests were two-sided. RESULTS PC-3MM2 cells cultured from bone lesions and treated in vitro with STI571 had less phosphorylated PDGF-R than untreated cells. In control mice, bone lesions expressed high levels of PDGF and activated (i.e., phosphorylated) PDGF-R, whereas lesions in the adjacent musculature did not. Activated PDGF-R was present on the surface of endothelial cells within the bone lesions but not in endothelial cells of uninjected bone. Mice treated with STI571 or STI571 plus paclitaxel had a lower tumor incidence, smaller tumors, and less bone lysis and lymph node metastasis than mice treated with water or paclitaxel alone (P

We evaluated whether treatment of orthotopic human prostate cancer in nude mice with pegylated IFN-alpha-2b (PEG-IFN-alpha-2b) and docetaxel could represent a two-compartment targeting of primary tumor (tumor cells and tumor-associated endothelial cells) and inhibition of regional lymph node metastasis. The antiangiogenic properties of IFN were combined with the cytotoxic properties of docetaxel, resulting in apoptosis of both tumor cells and endothelium and hence significant inhibition of primary tumor growth. We first determined the optimal biological dose of PEG-IFN-alpha-2b (70,000 IU/week) necessary to down-regulate the expression of basic fibroblast growth factor, matrix metalloprotease-9, and matrix metalloprotease-2. The therapeutic dose of docetaxel (10 mg/kg/week) was determined by efficacy and minimal body weight loss. Therapy beginning 3 days after orthotopic implantation of PC3-MM2 prostate cancer cells reduced tumor weight by 37% in mice treated with PEG-IFN-alpha-2b, by 60% in mice treated with docetaxel, and by 83% in those given both drugs. PEG-IFN-alpha-2b also induced apoptosis of tumor-associated endothelial cells and hence a significant decrease in microvessel density. Our data indicate that the combination of PEG-IFN-alpha and docetaxel inhibits neoplastic angiogenesis by inducing a decrease in the local production of proangiogenic molecules by tumor cells, resulting in increased apoptosis of tumor-associated endothelial cells.

The purpose of this study was to optimize the antitumor andantiangiogenic activities of pegylated IFN-alpha (PEG-IFN-alpha)alone or in combination with paclitaxel against SKOV3ip1 human ovarian cancer cells growing orthotopically in female nude mice. Seven days after the i.p. implantation of tumor cells, groups of mice (n = 10) were injected s.c. once per week (for 4 weeks) with different doses of PEG-IFN-alpha (3,500, 7,000, 35,000, and 350,000 units). PEG-IFN-alpha at 7,000 units significantly decreased tumor incidence and volume. At doses exceeding 7,000 units, PEG-IFN-alpha was less efficacious. In another set of studies conducted 7 days after the i.p. implantation of SKOV3ip1 cells, groups of mice (n = 10) received (once per week for 4 weeks) either s.c. administrations of PEG-IFN-alpha (7,000 units), i.p. injections of paclitaxel (100 microg/wk), or a combination of PEG-IFN-alpha and paclitaxel. The mice were killed 7 days after the last treatment, and tumor burden was assessed. Administration of PEG-IFN-alpha at the optimal biological dose (7,000 units) in combination with paclitaxel significantly decreased angiogenesis and progressive growth of human ovarian carcinoma cells in a synergistic fashion. The combination therapy produced the most significant inhibition in expression of the proangiogenic molecules basic fibroblast growth factor and matrix metalloproteinase-9. Decreased microvessel density, decreased proliferating cell nuclear antigen staining, and increased endothelial cell apoptosis also correlated with therapeutic success. Collectively, the data suggest that combining the optimal biological dose of PEG-IFN-alpha with paclitaxel may provide a novel and effective approach to the treatment of human ovarian carcinoma.

Since vascular endothelial growth factor (VEGF) plays a major role in tumor angiogenesis, we determined whether blockage of VEGF receptor signaling using a novel tyrosine kinase inhibitor (PTK 787) decreases the growth and metastasis of human pancreatic carcinoma growing orthotopically in nude mice. Human pancreatic L3.6pl cells were injected into the pancreas of nude mice. Seven days later, groups of mice were given daily oral administrations of PTK 787 alone, twice weekly i.p. injections of gemcitabine, or combination therapy. The mice were necropsied when control mice became moribund (day 35). Therapy with PTK 787 alone, gemcitabine alone, or the combination of both agents produced respectively 60%, 70%, and 81% inhibition in the volume of pancreatic cancers. The combination therapy significantly decreased the incidence of lymph node and liver metastasis, leading to a significant increase in survival. Microvessel density (MVD) was significantly decreased in tumors treated with either PTK 787 alone or PTK 787 plus gemcitabine. MVD directly correlated with tumor cell proliferation and inversely correlated with apoptosis of tumor cells and associated endothelial cells. Collectively, our results demonstrate that blockade of VEGF-R signaling may provide an additional approach to the therapy of pancreatic cancer.

The family Amaryllidaceae has a long history of usage in the traditional medicinal practices of the indigenous peoples of South Africa, with three of its species known to be used for cancer treatment. Furthermore, the Amaryllidaceae is widely recognized for its unique alkaloid constituents, several of which exhibit potent and selective cytotoxic activities. In this study, several crinane alkaloids derived from local Amaryllidaceae species were examined for cytotoxic effects against the human cervical adenocarcinoma cell line, of which distichamine was the most potent (IC50 2.2 μM).

The alcoholic extract of the fresh bulbs of Cyrtanthus elatus yielded zephyranthine (1) and 1,2-O-diacetylzephyranthine (2), together with three other known alkaloids. Complete assignment of 1H and 13C NMR spectra of compounds 1 and 2 was done by employment of two-dimensional NMR techniques.

Astrocytoma vasculature patterns differ according to histological grade of malignancy with glioblastoma multiforme (WHO grade IV) showing most extensive endothelial proliferation. Here, we determined whether the vascular patterns of medulloblastoma and supratentorial primitive neuroectodermal tumors (PNETs), which can be hardly distinguished histopathologically, differ. We evaluated the spatial organization of vessels in medulloblastomas and PNETs using antibodies to von Willebrand factor (vWF) and CD34. Medulloblastoma capillaries showed slight endothelial cell hyperplasia. Microvessels sprouted from the capillaries and formed glomeruloid clusters. There were areas with chains of unopposed endothelial cells (3-10 cells). Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. Therefore, medulloblastomas and supratentorial PNETs showed different spatial organization of tumor vessels which can be used for differentiation of each tumor entity. These vascular patterns may reflect different tumor derived angiogenic stimuli.

Astrocytic tumours of the central nervous system express cell adhesion receptors of the integrin superfamily, CD44 and adhesion receptors of the immunoglobulin superfamily. Glioma cells utilize these receptors to adhere to and migrate along components of the extracellular matrix (ECM), which is uniquely distributed and regulated within the brain and the spinal cord. For penetration into healthy brain tissue a number of proteases are expressed, which degrade proteins of the extracellular matrix. Thus, glioma cell invasion into the adjacent brain tissue is dependent on the interaction of glioma cells with the extracellular matrix and the subsequent destruction of matrix barriers. There is a critical balance between expression of various adhesion receptors and proteases. The tight regulation of critical levels of proteases and receptors expressed by glioma cells or other cells is necessary for the "physiological" behaviour of glioma cells. Shifts in the balance of protein expression determine glioma cell behaviour in their micro-environment and can initiate or influence the complex process of glioma cell invasion. The complex receptor-ECM interaction in glioma cell invasion is discussed focussing upon the role of integrin receptors and matrix-metalloproteinases. Influencing these molecules or their regulation may lead to novel therapeutic approaches in the treatment of malignant glioma.

Comments on an article by Bushman and Anderson. We are concerned that Bushman and Anderson's article on media violence contains data that are incorrect or irreproducible. This is a serious issue; the article has already been referenced by numerous other formal papers according to a Google scholarly article search as well as in a statement to the U.S. Senate, in legal proceedings, and in California State law (Assembly Bill 1179 in 2005). Language: en