Synergistic activity and heterogeneous acquired resistance of combined MDM2 and MEK inhibition in KRAS mutant cancers.

There are currently no effective targeted therapies for KRAS mutant cancers. Therapeutic strategies that combine MEK inhibitors with agents that target apoptotic pathways may be a promising therapeutic approach. We investigated combining MEK and MDM2 inhibitors as a potential treatment strategy for KRAS mutant non-small cell lung cancers (NSCLC) and colorectal carcinomas that harbor wild-type TP53. The combination of pimasertib (MEK inhibitor) and SAR405838 (MDM2 inhibitor) was synergistic and induced the expression of PUMA and BIM, led to apoptosis and growth inhibition in vitro, and tumor regression in vivo. Acquired resistance to the combination commonly resulted from the acquisition of TP53 mutations, conferring complete resistance to MDM2 inhibition. In contrast, resistant clones exhibited marked variability in sensitivity to MEK inhibition, which significantly impacted sensitivity to subsequent treatment with alternative MEK inhibitor-based combination therapies. These results highlight both the potential promise and limitations of combining MEK and MDM2 inhibitors for treatment of KRAS mutant NSCLC and colorectal cancers.

Triggering apoptosis in cancer cells with an analogue of cribrostatin 6 that elevates intracellular ROS.

Elevation of reactive oxygen species (ROS) is both a consequence and driver of the upregulated metabolism and proliferation of transformed cells. The resulting increase in oxidative stress is postulated to saturate the cellular antioxidant machinery, leaving cancer cells susceptible to agents that further elevate their intracellular oxidative stress. Several small molecules, including the marine natural product cribrostatin 6, have been demonstrated to trigger apoptosis in cancer cells by increasing intracellular ROS. Here, we report the modular synthesis of a series of cribrostatin 6 derivatives, and assessment of their activity in a number of cell lines. We establish that placing a phenyl ring on carbon 8 of cribrostatin 6 leads to increased potency, and observe a window of selectivity towards cancer cells. The mechanism of activity of this more potent analogue is assessed and demonstrated to induce apoptosis in cancer cells by increasing ROS. Our results demonstrate the potential for targeting tumors with molecules that enhance intracellular oxidative stress.

Supporting cystic fibrosis disease management during adolescence: the role of family and friends.

BACKGROUND: Successful management of a complex disease, such as cystic fibrosis (CF), requires support from family and friends; however, few studies have examined social support in adolescents with CF. METHODS: Twenty-four adolescents were interviewed about the support they receive from family and friends. Interviews were transcribed, coded and analysed to determine the types, frequency and perceived supportiveness of specific behaviours. RESULTS: Both family and friends provided treatment-related support to adolescents with CF. Family provided more tangible support and friends provided more relational support. Adolescents also reported that the manner, timing and context of support behaviours influenced their perceptions of the behaviours' supportiveness. A subset of adolescents (17%) chose not to disclose their diagnosis to their friends. CONCLUSIONS: The provision of support appears to be distinct from adolescent's perception of support and there may be some behaviours, such as treatment reminders, that are important to disease management but viewed as less supportive by adolescents. Facilitating increased social support holds the promise of improving disease management during adolescents, but more work is need to understand which aspects of support are related to management outcomes.

In vitro antimicrobial, anthelmintic and cyclooxygenase-inhibitory activities and phytochemical analysis of Leucosidea sericea.

ETHNOPHARMACOLOGICAL RELEVANCE: Leucosidea sericea is used as a vermifuge and in the treatment of ophthalmia by various tribes in southern African countries. AIM OF THE STUDY: The study aimed at screening leaves and stems of Leucosidea sericea for pharmacological activity and validating the plant's traditional use. A general phytochemical screening was also carried out. MATERIALS AND METHODS: Petroleum ether (PE), dichloromethane (DCM), ethanol (EtOH) and water extracts of the plant parts were investigated for antimicrobial, anthelmintic and cyclooxygenase (COX) inhibitory activities. Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and Candida albicans were used for the antimicrobial evaluation. Caenorhabditis elegans was used for the anthelmintic assay using the microdilution technique. Cyclooxygenase-1 and -2 (COX-1 and -2) were used to evaluate the anti-inflammatory potential of the plant extracts. Phytochemical analysis for phenolic compounds, including gallotannins, condensed tannins and flavonoids was done using 50% methanol extracts of the leaves and stems employing spectrophotometric methods. RESULTS: The leaf extracts exhibited broad spectrum antibacterial activity ranging from 0.025 to 6.25mg/ml. The most noteworthy minimum inhibitory concentration (MIC) of 0.025 mg/ml was exhibited by PE and DCM leaf extracts against Bacillus subtilis and Staphylococcus aureus, respectively. In the anthelmintic assay, the best minimum lethal concentration (MLC) value of 0.26 mg/ml was observed for the DCM and EtOH leaf extracts. Both leaf and stem organic solvent extracts exhibited high to moderate inhibition against COX-1 and -2 at a screening concentration of 250 microg/ml. At lower concentrations, the extracts displayed a dose-dependent inhibition, with the lowest IC(50) values of 0.06 microg/ml (COX-1) and 12.66 microg/ml (COX-2) exhibited by the PE extract of the leaves. Generally, the leaf extracts exhibited better pharmacological activities and contained higher amounts of phenolic compounds than the stem extracts. Alkaloids and saponins were only detected in the leaf and stem extracts, respectively. CONCLUSION: The reported results support the local use of Leucosidea sericea against eye infections and as a vermifuge. The pharmacological activities exhibited by the leaf extracts are probably due to their higher phenolic levels.

Anti-inflammatory, anticholinesterase, antioxidant and phytochemical properties of medicinal plants used for pain-related ailments in South Africa.

ETHNOPHARMACOLOGICAL RELEVANCE: Extracts of seven South African medicinal plants used traditionally for the treatment of pain-related ailments were evaluated. AIMS OF THE STUDY: The study was aimed at evaluating medicinal and therapeutic potentials of the investigated traditional medicinal plants. Plant extracts were evaluated for anti-inflammatory activity and other pharmacological properties such as anticholinesterase and antioxidant activities. Phytochemical analysis of total phenolic contents, condensed tannins, gallotannins and flavonoids in the aqueous methanol extracts of the medicinal plants were also carried out. MATERIALS AND METHODS: The evaluation of anti-inflammatory activity of 50% methanol (50% MeOH), petroleum ether (PE), dichloromethane (DCM) and ethanol (EtOH) plant extracts was done against cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes. 50% MeOH, PE, DCM and EtOH extracts were tested for acetylcholinesterase (AChE) inhibition, while 50% MeOH extracts were tested for 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and ferric-reducing power in the antioxidant assays. Total phenolic compounds, condensed tannins, gallotannins and flavonoids were quantitatively determined using spectrophotometric methods. RESULTS: At the screening assay concentration (0.25 microg/microl), 13 extracts showed good COX-1 inhibitory activity (>50%), while good activity was observed in 15 extracts against COX-2 enzyme. All the extracts of Crinum moorei (bulbs) showed good inhibition against both COX-1 and COX-2 enzymes. Though not significantly different (P=0.05), the highest COX-1 percentage inhibition (100%) was shown by Aloe ferox leaf PE and Colocasia antiquorum tuber DCM extracts, while Colocasia antiquorum tuber PE extract exhibited the highest (92.7%) percentage inhibition against COX-2. Crinum moorei bulb DCM extract showed the lowest EC(50) value (2.9 microg/ml) in the AChE assay. In addition, good to moderate bioactivities were observed in some extracts of Aloe ferox (leaves), Crinum moorei (bulbs) and Pycnostachys reticulata (leaves) in all the assays. The presence and/or amounts of phenolic compounds varied with plant species. CONCLUSION: The results obtained in this study validate the use of the investigated medicinal plants in South African traditional medicine for pain-related ailments.

Galantamine in frontotemporal dementia and primary progressive aphasia.

BACKGROUND/AIMS: The treatment of frontotemporal dementia (FTD) has been mainly symptomatic. Small randomized or open-label case control studies of neurotransmitters have been inconclusive. We tried galantamine in the 2 most common varieties of FTD. METHOD: Thirty-six behavioral variety FTD and primary progressive aphasia (PPA) patients were treated in an open-label period of 18 weeks and a randomized, placebo-controlled phase for 8 weeks with galantamine. The primary efficacy measures were the Frontal Behavioral Inventory, the Aphasia Quotient of the Western Aphasia Battery, the Clinical Global Impression of Severity and the Clinical Global Impression of Improvement. RESULTS: No significant differences in behavior or language were found for the total group. A treatment effect (p = 0.009), in a subgroup of subjects with PPA in the global severity score, in favor of galantamine was detected in the placebo-controlled withdrawal phase but was not considered significant after correction for multiple comparisons. The language scores for the treated PPA group also remained stable compared to the placebo group, which showed deterioration. CONCLUSION: Galantamine is not effective in the behavioral variety of FTD, but a trend of efficacy is shown in the aphasic subgroup, which may be clinically significant. Galantamine appeared safe in FTD/PPA.

Riding the wave: South Africa's contribution to ethnopharmacological research over the last 25 years.

South Africa is a country with both rich floral biodiversity and cultural diversity. Traditional herbal medicines form an important part of the healthcare of most South Africans, and relies heavily on the use of indigenous plants. This article briefly describes the role South Africa has played in recent years, in contributing to the worldwide increase in research in the field of ethnopharmacology.

Improving seedling vigour of indigenous medicinal plants with smoke.

The application of smoke and aqueous smoke solutions stimulates seed germination in a number of plant species. This study highlights the effects of aerosol smoke and smoke solutions on the germination and seedling vigour of three South African indigenous medicinal plants Albuca pachychlamys, Merwilla natalensis and Tulbaghia violacea. The vigour index of one-week-old seedlings of all three species examined was increased with the application of dry smoke and smoke extract dilutions, as compared to control treatments. Seedlings of A. pachychlamys germinated with smoke solutions showed a significant (p0.05) gain in bulb and leaf mass (27.9 and 197.6 mg respectively) compared to untreated seedlings (9.9 and 124.7 mg respectively) when grown in vitro for 75 days. The leaf mass of smoke solution-treated seedlings of T. violacea was significantly (p0.05) higher (120.4 mg) than that of untreated seedlings (47.6 mg). Subsequently, the height of seedlings in both species was also significantly (p0.05) greater. Seedlings germinated in water and then transferred to smoke solutions (1:2000) showed enhancement of some of the growth parameters studied. Albuca pachychlamys and T. violacea seeds exposed to aerosol smoke exhibited higher seedling survival percentages than from non-smoked seeds, while no significant effect was observed for M. natalensis seedlings. This investigation shows that the application of smoke technology can be adopted to produce high vigour seedlings.

Phytochemical and pharmacological screening of Sterculiaceae species and isolation of antibacterial compounds.

Little previous phytochemical investigation has been conducted on South African Sterculiaceae species used in traditional medicine. In this study, five species, varying in growth type (small herbs, shrubs and large trees) and traditional usage were investigated. The species screened were Cola greenwayi Brenan, Cola natalensis Oliv., Dombeya burgessiae Gerr. ex Harv., Dombeya cymosa Harv. and Hermannia depressa N.E.Br. Extracts were screened for alkaloids, cardiac glycosides, cyanogenic glycosides, saponins and tannins. The probable presence of bufadienolides in the leaf material of Dombeya burgessiae and Dombeya cymosa was determined. Alkaloids, cyanogenic glycosides and saponins were absent in all the plant material investigated. Tannins were detected in the leaf extract of Cola greenwayi and in the leaves, stems and roots of Hermannia depressa. Extracts were screened for anti-inflammatory and antibacterial activity using the cyclooxygenase-1 (COX-1) inhibition assay and the microdilution antibacterial assay. The ethanol and dichloromethane extracts of Cola greenwayi, Dombeya burgessiae and Dombeya cymosa, and the dichloromethane extracts of Hermannia depressa showed the highest levels of COX-1 inhibition. It is possible that the high levels observed may be due to the presence of tannins in some of the extracts. Generally, all the aqueous extracts exhibited low activity. Similarly, no antibacterial activity was observed with the aqueous extracts, although some mild activity was exhibited with some of the ethanol and ethyl acetate extracts. Following the general phytochemical and pharmacological screening, extracts showing antibacterial activity were further purified using bioassay-guided fractionation. Dombeya rotundifolia (Hochst.) Planch., which was screened in a previous study, was also included in the isolation of active compounds. A bioautographic assay, using Staphylococcus aureus, was used to detect the presence of the antibacterial compounds. These were isolated and identified as fatty acids.

Assessing African medicinal plants for efficacy and safety: agricultural and storage practices.

The paper reviews an important but little researched area of ethnopharmacology, namely, the effect of cultivation and post-harvest storage practices on levels of biological activity in traditionally used medicinal plants. Changes in COX-1 inhibition and antibacterial activity, for example, occur at the onset of senescence and, in some species, are influenced by plant age. Plants in cultivation were also shown to have reduced anthelmintic and antibacterial activity while hypoxoside production was affected by nitrogen and phosphorous. Irrigation treatments, however, increased anthelmintic activity and, therefore, could be applied to medicinal plants cultivated in low rainfall areas. Pesticides have also been implicated in the regulation of plant growth and secondary metabolite production in cultivated medicinal plants, but residue levels have, so far, not been monitored. Post harvest storage of medicinal plants has been poorly researched in southern Africa. Available data indicates that antibacterial and anti-inflammatory activity changes following storage and is both species and temperature dependent. Similar trends were noted for materials that had been rapidly aged. Fatty acids with antibacterial activity are stable in dry specimens and, as such, may account for the fact that activity is unaffected by storage in certain instances.

Biological activities and distribution of plant saponins.

Plant saponins are widely distributed amongst plants and have a wide range of biological properties. The more recent investigations and findings into their biological activities were summarized. Isolation studies of saponins were examined to determine which are the more commonly studied plant families and in which families saponins have been identified.

Linear distortion of octahedral metal centres by multiple hydrogen bonds in modular ML(4) systems.

A series of compounds of the type [M(1)(4)(H(2)O)(2)]SO(4)[middle dot]2H(2)O containing a simple urea-based pyridyl ligand have been synthesised and characterised by X-ray crystallography. The enclathrated water exists within discrete linearly stacked cavities and causes significant distortions in the M-OH(2) bonds due to the presence of a strongly hydrogen bonded water square.

2-amidopyrroles and 2,5-diamidopyrroles as simple anion binding agents.

Four new 2-amidopyrroles and 2,5-diamidopyrroles have been synthesized and their anion complexation properties investigated. The crystal structures of these receptors have been elucidated and reveal hydrogen bonding in the solid state leading to dimer and network formation. Selectivity for oxo-anions has been demonstrated by (1)H NMR titration techniques.

Three- and four-membered rings from cycloadditions of 1,3-thiazolium-4-olates and aldehydes.

2-Aminothioisomünchnones, a well-known family of masked dipoles, react with aromatic aldehydes in a domino cascade reaction that produces episulfides (thiiranes) or beta-lactams (2-azetidinones). This sequence is initiated by a [3+2] dipolar cycloaddition followed by ring opening of cycloadducts and intramolecular rearrangement to afford these unusual ring contractions. The nature of the reaction products depends on the structural characteristics of the starting dipole and the experimental conditions. Episulfides are obtained selectively as cis isomers with respect to both aryl groups, whereas beta-lactams are produced as cis/trans mixtures. These structural features were determined unequivocally by X-ray crystallographic analysis. The beta-lactams still possessed a flexible acyclic chain containing sulfur, a salient lead modification of the bioactive cyclic penems and cephems. The preferential production of exo transition structures was rationalized with the aid of computational calculations at the B3LYP/6-31G* level.

Risperidone treatment of outpatients with schizophrenia: no evidence of sex differences in treatment response.

OBJECTIVE: Given the renewed interest in the role of sex differences in schizophrenia, we undertook a post hoc analysis to determine whether sex differences in treatment response were present among outpatients with schizophrenia who received risperidone in an 8-week, open-label, Phase IV clinical study. METHOD: We evaluated 330 adult patients (232 men, 98 women) with a DSM-III-R diagnosis of schizophrenia for safety and 292 (206 men, 86 women) for efficacy. Antipsychotic and antiparkinsonian medications were discontinued at study entry. Treatment with risperidone was initiated at a dosage of 2 mg daily, increased to the target dosage of 6 mg daily by day 3, and maintained at 6 mg daily until day 14. The dosage was then maintained at 6 mg daily, increased or decreased by 2 mg daily each week, based on the patient's response. Risperidone treatment was given for 8 weeks; the permitted dosage range was 4 mg to 10 mg daily. RESULTS: Both male and female participants responded well to risperidone treatment; by the final assessment day, they had experienced decreases from baseline in their total Positive and Negative Syndrome Scale (PANSS) scores of 41.0% and 36.5%, respectively. Most male (77%) and female (78%) participants were considered to be PANSS responders: risperidone was effective against both the positive and negative symptoms of schizophrenia. Both sexes showed improvements over baseline in the incidence and severity of parkinsonism, dystonia, and dyskinesia. No significant (P > 0.05) sex differences in treatment response were observed for any of the efficacy outcomes or in the incidence and severity of extrapyramidal symptoms (EPS). CONCLUSIONS: In this population of outpatients with chronic schizophrenia, both men and women responded well to flexible doses of risperidone. No significant sex differences were evident either in treatment response or in neurological side effects. The absence of sex differences in response to risperidone treatment may obviate the need for a sex-based differential dosing in schizophrenia management.

Crystal chemistry and physical properties of superconducting and semiconducting charge transfer salts of the type (BEDT-TTF)(4)[A(I)M(III)(C2O4)3]*PhCN (A(I) = H30,NH4,K; M(III) = Cr, Fe, Co, Al; BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene.

Synthesis, structure determination by single-crystal X-ray diffraction, and physical properties are reported and compared for superconducting and semiconducting molecular charge-transfer salts with stoichiometry (BEDT-TTF)(4)[A(I)M(III)(C(2)O(4))(3)].PhCN, where A(I) = H(3)O, NH(4), K; M(III) = Cr, Fe, Co, Al; BEDT-TTF = bis(ethylenedithio) tetrathiafulvalene. Attempts to substitute M(III) with Ti, Ru, Rh, or Gd are also described. New compounds with M = Co and Al are prepared and detailed structural comparisons are made across the whole series. Compounds with A = H(3)O(+) and M = Cr, Fe are monoclinic (space group C2/c), at 150, 120 K a = 10.240(1) A, 10.232(12) A; b = 19.965(1) A, 20.04(3) A; c = 34.905(1) A, 34.97(2) A; beta = 93.69(1) degrees, 93.25(11) degrees, respectively, both with Z = 4. These salts are metallic at room temperature, becoming superconducting at 5.5(5) or 8.5(5) K, respectively. A polymorph with A = H(3)O(+) and M = Cr is orthorhombic (Pbcn) with a = 10.371(2) A, b = 19.518(3) A, c = 35.646(3) A, and Z = 4 at 150 K. When A = NH(4)(+), M = Fe, Co, Al, the compounds are also orthorhombic (Pbcn), with a = 10.370(5) A, 10.340(1) A, 10.318(7) A; b = 19.588(12) A, 19.502(1) A, 19.460(4) A; c = 35.790(8) A, 35.768(1) A, 35.808(8) A at 150 K, respectively, with Z = 4. All of the Pbcn phases are semiconducting with activation energies between 0.15 and 0.22 eV. For those compounds which are thought to contain H(3)O(+), Raman spectroscopy or C=C and C-S bond lengths of the BEDT-TTF molecules confirm the presence of H(3)O(+) rather than H(2)O. In the monoclinic compounds the BEDT-TTF molecules adopt a beta' ' packing motif while in the orthorhombic phases (BEDT-TTF)(2) dimers are surrounded by monomers. Raman spectra and bond length analysis for the latter confirm that each molecule of the dimer has a charge of +1 while the remaining donors are neutral. All of the compounds contain approximately hexagonal honeycomb layers of [AM(C(2)O(4))(3)] and PhCN, with the solvent occupying a cavity bounded by [M(C(2)O(4))(3)](3-) and A. In the monoclinic series each layer contains one enantiomeric conformation of the chiral [M(C(2)O(4))(3)](3-) anions with alternate layers having opposite chirality, whereas in the orthorhombic series the enantiomers form chains within each layer. Analysis of the supramolecular organization at the interface between the cation and anion layers shows that this difference is responsible for the two different BEDT-TTF packing motifs, as a consequence of weak H-bonding interactions between the terminal ethylene groups in the donor and the [M(C(2)O(4))(3)](3-) oxygen atoms.

Partitioning and diversity of nuclear and organelle markers in native and introduced populations of Epipactis helleborine (Orchidaceae).

Variability of allozymes (1170 individuals, 47 populations) and chloroplast DNA (692 individuals, 29 populations) was examined in native European and introduced North American populations of Epipactis helleborine (Orchidaceae). At the species level, the percentage of allozyme loci that were polymorphic (P(99)) was 67%, with a mean of 2.11 alleles (A) per locus, and an expected heterozygosity (H(exp)) of 0.294. At the population level, mean P(99) = 56%, mean A = 1.81, and mean H(exp) = 0.231. Although field observations suggest that self-pollination occurs frequently, populations had a genetic structure consistent with Hardy-Weinberg expectations and random mating (mean F(IS) = 0.002). There was significant deviation from panmixia associated with population differentiation (mean F(ST) = 0.206). The distribution of two chloroplast haplotypes showed that 15 of the 29 populations were polymorphic. Using both nuclear and organelle F(ST) estimates, a pollen to seed flow ratio of 1.43 : 1 was calculated. This is very low compared with published estimates for other plant groups, consistent with the high dispersability of orchid seeds. Finally, there was no evidence for a genetic bottleneck associated with the introduction of E. helleborine to North America.

Perfluoroaryl boryl complexes: synthesis, spectroscopic and structural characterisation of a complex containing the bis(pentafluorophenyl)boryl ligand.

The synthesis, spectroscopic and structural characterisation of the bis(pentafluorophenyl)boryl derivative CpFe-(CO)2B(C6F5)2 are reported.

Structure of uranium(VI) oxide dihydrate, UO3.2H2O; synthetic meta-schoepite (UO2)4O(OH)6.5H2O.

Structure of uranium(VI) oxide dihydrate, P03.2H20; synthetic meta-schoepite (UO2)40(OH)6.5H20 f The structure of uranium oxide dihydrate, also known as meta-schoepite (UO2)4O(OH)6.5H2O, has been determined from a synthetic single crystal. The structure, at 150 K, space group Pbcn, lattice constants a = 14.6861 (4), b = 13.9799 (3) and c = 16.7063 (5) A, consists of layers of stoichiometry (UO2)4O(OH)6, formed from edge-sharing UO7 pentagonal bipyramids, interleaved with hydrogen-bonded water molecules. Three of the layer hydroxyl groups are linked through hydrogen bonding to single water molecules and the three remaining OH units form interactions with water molecules that each act as acceptors in two hydrogen bonds. One of the water molecules in the inter-layer region is disordered over two symmetry-related sites and forms hydrogen-bonded interactions only within the layer and with the uranyl O atoms. The relationship of the structure of meta-schoepite to that of schoepite is discussed in detail.