Lasioglossins LLIII affect the morphogenesis of Candida albicans and reduces the duration of experimental vaginal candidiasis in mice

Lasioglossins are a group of peptides with identified antimicrobial activity. The inhibitory effects of two synthetic lasioglossin derivatives, LLIII and D‐isomeric variant LLIII‐D, on morphological changes in Candida albicans in vitro and the effect of local administration of LLIII during experimental murine candidiasis were investigated. C. albicans blastoconidia were grown in the presence of lasioglossin LLIII or LLIII‐D at concentrations of 11.5 μM and 21 μM, respectively, for 1, 2 and 3 days and their viability determined by flow cytometry using eosin Y staining. Morphological changes were examined by light and fluorescent microscopy. The Candida‐inhibitory effect of daily intravaginal administration of 0.7 or 1.4 μg of LLIII was assessed in mice with experimentally‐induced vaginal candidiasis. LLIII and LLIII‐D lasioglossins exhibited candidacidal activity in vitro (>76% after 24 hr and >84% after 48 hr of incubation). After 72 hr incubation of Candida with low concentration of lasioglossins, an increase in viability was detected, probably due to a Candida antimicrobial peptides evasion strategy. Furthermore, lasioglossins inhibited temperature‐induced morphotype changes toward hyphae and pseudohyphae with sporadic occurrence of atypical cells with two or enlarged nuclei, suggesting interference with mitosis or cytokinesis. Local application of LLIII reduced the duration of experimental candidiasis with no evidence of adverse effects. Lasioglossin LLIII is a promising candidate for development as an antimicrobial drug for treating the vaginal candidiasis.

     

Platinum(II) complexes with steroidal esters of L-methionine and L-histidine: synthesis, characterization and cytotoxic activity

Twelve steroidal platinum(II) complexes were synthesized by reaction of potassium tetrachloroplatinate with steroidal esters of L-methionine and L-histidine. The steroidal esters coordinated as bidentate ligands via S and N donor atoms of L-methionine and via two N donor atoms of L-histidine. Cholesterol, cholestanol, diosgenine, pregnenolone, dehydroepiandrosterone, testosterone, estrone, and estradiol were used as the steroidal compounds. The esters and complexes prepared were characterized by infrared, mass, and (1)H NMR spectroscopy and elemental analysis. Platinum complexes were tested for in vitro cytotoxicity against several cancer cell lines: T-lymphoblastic leukemia CEM, breast carcinoma MCF-7, lung carcinoma A-549, multiple myeloma RPMI 8226, and one normal cell line human fibroblast BJ.     

Additional minor ecdysteroid components of Leuzea carthamoides

Seventeen additional minor ecdysteroid compounds were isolated and identified from the roots of Leuzea carthamoides (Wild.) DC. Eight of them are new phytoecdysteroids: carthamoleusterone (13) is a new side-chain cyclo-ether with five-membered ring; 14-epi-ponasterone A 22-glucoside (12) is a rare and unusual natural 14 beta-OH epimer; 15-hydroxyponasterone A (11) is also new and rare with its C-15 substituted position, as well as 22-deoxy-28-hydroxymakisterone C (18) possessing secondary hydroxyl in position C-28 and 26-hydroxymakisterone C (20) with hydroxy groups in positions 25 and 26. New are also 1 beta-hydroxymakisterone C (21) and 20,22-acetonides of inokosterone (8) and integristerone A (10). Series of already known ecdysteroids: ecdysone (1), 20-hydroxyecdysone 2- and 3-acetates (3 and 4), turkesterone (6), inokosterone (7), 24-epi-makisterone A (14), and amarasterone A (22) are reported here as new constituents of L. carthamoides. Seven earlier reported Leuzea ecdysteroids: 20-hydroxyecdysone (2), ajugasterone C (5), integristerone A (9), 24(28)-dehydromakisterone A (15), 24(28)-dehydroamarasterone B (16), (24Z)-29-hydroxy-24(28)-dehydromakisterone C (17) and makisterone C (19) are also included because they are now better characterized.     

Relevance of the capacity of phosphorylated fructose to scavenge the hydroxyl radical

The hydroxyl radical (OH) has detrimental biological activity due to its very high reactivity. Our experiments were designed to determine the effects of equimolar concentrations of glucose, fructose and mannitol and three phosphorylated forms of fructose (fructose-1-phosphate (F1P); fructose-6-phosphate (F6P); and fructose-1,6-bis(phosphate) (F16BP)) on OH radical production via the Fenton reaction. EPR spectroscopy using spin-trap DEPMPO was applied to detect radical production. We found that the percentage inhibition of OH radical formation decreased in the order F16BP > F1P > F6P > fructose > mannitol = glucose. As ketoses can sequester redox-active iron thus preventing the Fenton reaction, the Haber-Weiss-like system was also employed to generate OH, so that the effect of iron sequestration could be distinguished from direct OH radical scavenging. In the latter system, the rank order of OH scavenging activity was F16BP > F1P > F6P > fructose = mannitol = glucose. Our results clearly demonstrate that intracellular phosphorylated forms of fructose have more scavenging properties than fructose or glucose, leading us to conclude that the acute administration of fructose could overcome the body’s reaction to exogenous antioxidants during appropriate therapy in certain pathophysiological conditions related to oxidative stress, such as sepsis, neurodegenerative diseases, atherosclerosis, malignancy, and some complications of pregnancy.     

Norsesquiterpene hydrocarbon, chemical composition and antimicrobial activity of Rhaponticum carthamoides root essential oil

A detailed analysis of Rhaponticum carthamoides (Willd.) Iljin root essential oil was carried out by GC, GC-MS and GC-FTIR techniques. In total, 30 components were identified, accounting for 98.0% of total volatiles. A norsesquiterpene 13-norcypera-1(5),11(12)-diene (22.6%), followed by aplotaxene (21.2%) and cyperene (17.9%), were isolated and their structures confirmed by 1D and 2D-NMR spectra (COSY, ROESY, HSQC, HMBC and INADEQUATE). Selinene type sesquiterpenes and aliphatic hydrocarbons were among minor constituents of the essential oil. The oil exhibited antimicrobial activity against 5 of 9 strains of bacteria and yeast, when tested using broth micro-dilution method. Minimum inhibitory concentrations ranged between 32 and 256 μg/ml.     

Hazard function for cancer patients and cancer cell dynamics

The aim of the paper is to develop a procedure for an estimate of an analytical form of a hazard function for cancer patients. Although a deterministic approach based on cancer cell population dynamics yields the analytical expression, it depends on several parameters which should be estimated. On the other hand, a kernel estimate is an effective nonparametric method for estimating hazard functions. This method provides the pointwise estimate of the hazard function. Our procedure consists of two steps: in the first step we find the kernel estimate of the hazard function and in the second step the parameters in the deterministic model are obtained by the least squares method. A simulation study with different types of censorship is carried out and the developed procedure is applied to real data.     

2-(3-Amino-3-deoxy-beta-D-xylofuranosyl)thiazole-4-carboxamide: a new tiazofurin analogue with potent antitumour activity

A new tiazofurin analogue, 2-(3-amino-3-deoxy-beta-d-xylofuranosyl)thiazole-4-carboxamide (3), was synthesized starting from d-glucose and evaluated for its in vitro antiproliferative activity against a panel of human tumour cell lines. Compound 3 exhibited the most powerful cytotoxicity against K562 cells, being approximately 100-fold more potent than tiazofurin. This analogue was also active against Jurkat, HT-29 and HeLa malignant cells, with respective IC(50) values being ca. 2-, 27- and 17-fold lower than those observed for tiazofurin. Remarkably, compound 3 did not exhibit any significant cytotoxicity towards normal foetal lung MRC-5 cell line.     

Attenuation of Reactive Gliosis Does Not Affect Infarct Volume in Neonatal Hypoxic-Ischemic Brain Injury in Mice

Background

Astroglial cells are activated following injury and up-regulate the expression of the intermediate filament proteins glial fibrillary acidic protein (GFAP) and vimentin. Adult mice lacking the intermediate filament proteins GFAP and vimentin (GFAP^−/−Vim^−/−) show attenuated reactive gliosis, reduced glial scar formation and improved regeneration of neuronal synapses after neurotrauma. GFAP^−/−Vim^−/− mice exhibit larger brain infarcts after middle cerebral artery occlusion suggesting protective role of reactive gliosis after adult focal brain ischemia. However, the role of astrocyte activation and reactive gliosis in the injured developing brain is unknown.

Methodology/Principal Findings

We subjected GFAP^−/−Vim^−/− and wild-type mice to unilateral hypoxia-ischemia (HI) at postnatal day 9 (P9). Bromodeoxyuridine (BrdU; 25 mg/kg) was injected intraperitoneally twice daily from P9 to P12. On P12 and P31, the animals were perfused intracardially. Immunohistochemistry with MAP-2, BrdU, NeuN, and S100 antibodies was performed on coronal sections. We found no difference in the hemisphere or infarct volume between GFAP^−/−Vim^−/− and wild-type mice at P12 and P31, i.e. 3 and 22 days after HI. At P31, the number of NeuN⁺ neurons in the ischemic and contralateral hemisphere was comparable between GFAP^−/−Vim^−/− and wild-type mice. In wild-type mice, the number of S100⁺ astrocytes was lower in the ipsilateral compared to contralateral hemisphere (65.0±50.1 vs. 85.6±34.0, p<0.05). In the GFAP^−/−Vim^−/− mice, the number of S100⁺ astrocytes did not differ between the ischemic and contralateral hemisphere at P31. At P31, GFAP^−/−Vim^−/− mice showed an increase in NeuN⁺BrdU⁺ (surviving newly born) neurons in the ischemic cortex compared to wild-type mice (6.7±7.7; n = 29 versus 2.9±3.6; n = 28, respectively, p<0.05), but a comparable number of S100⁺BrdU⁺ (surviving newly born) astrocytes.

Conclusions/Significance

Our results suggest that attenuation of reactive gliosis in the developing brain does not affect the hemisphere or infarct volume after HI, but increases the number of surviving newborn neurons.