Formulation development and characterization of lumefantrine nanosuspension for enhanced antimalarial activity.

Variable and low oral bioavailability (4-11%) of lumefantrine (LUF), an anti-malarial agent, is characterized by very low solubility in aqueous vehicle. Thus, the present study was intended to formulate lyophilized nanosuspensions of LUF to resolve its solubility issues for the improvement of oral bioavailability. A three level 32 factorial design was applied to analyze the influence of independent variables, concentration of polysorbate 80 (X1) and sonication time (X2) on the responses for dependent variables, particle size (Y1) and time to 90% release of LUF (t90) (Y2). Optimized formulation (F3) has shown to possess lowest particle size (95.34 nm) with minimum t90 value (⁓3 mins), which was lyophilized to obtain the dry powder form of the nanosuspension. The characterization parameters confirmed the amorphous form of LUF with good stability and no chemical interactions of the drug with the incorporated components. Further, saturation solubility study revealed increased solubility of the LUF nanosuspension (1670 µg/mL) when compared to the pure drug (212.33 µg/mL). Further, rate of dissolution of LUF from the nanosuspension formulations were found to be significantly (p < 0.05) higher when compared to the pure drug. Fabricated lyophilized nanosuspension was found to be stable at 25 ± 2 °C/60 ± 5% RH and 40 ± 2 °C/75 ± 5% RH for the duration of three months. In conclusion, lyophilized nanosuspension showed ∼8-folds increase in drug release, which indicated a better way to offer higher release of LUF in controlling malaria.

Synthesis, characterization, and evaluation of five coordinated copper(II) complexes as antibacterial, artificial nuclease, and SOD mimics.

The copper(II) complexes with ciprofloxacin (CFLH), levofloxacin (LFLH), norfloxacin (NFLH), and neutral bidentate ligands have been synthesized and characterized. The complexes have been evaluated for their antibacterial activity against selective species. Complexes have been also checked for their interacting behavior with DNA, and were found to have two different modes of interaction, classical and partial intercalation. Tested complexes were found to be better antioxidants with their IC(50) values ranging from 0.51 to 0.97 µM.

Ternary copper(II) complexes of levofloxacin and phenanthroline derivatives: in-vitro antibacterial, DNA interactions, and SOD-like activity.

A series of ternary copper(II) complexes have been derived using levofloxacin and five phenanthroline derivatives. Complexes were characterized using infrared spectroscopy, Thermogravimetric (TG)-analysis, fast atom bombardment mass spectroscopy and reflectance spectra. Synthesized complexes exhibit the only d-d band at ∼ 666 nm points toward a distorted square pyramidal geometry at metal centre with one unpaired electron responsible for paramagnetic behaviour of whole moiety. Binding behaviour of the complexes toward Herring Sperm DNA were determined using ultraviolet-Vis (UV-Vis) absorption titration and viscometric titration experiment, where as the cleavage efficacy of the complexes toward pUC19 DNA was determined by electrophoresis in presence of ethidium bromide. Complexes exhibit superoxide dismutase-like activity with their IC(50) values ranging from 0.7917 to 1.7432 µM.

DNA interactions and promotion in antibacterial activities of ciprofloxacin drug due to formation of mixed-ligand complexes of oxovanadium(IV).

Mixed-ligand complexes of oxovanadium(IV) of the type [VOAL]*2H(2)O [where A = ciprofloxacin and L = uninegative bidentate ligands] have been synthesized and characterized using infrared spectra, electronic spectra, magnetic measurements, elemental analyses, thermal investigation, and mass spectroscopy. Here, we tried to increase an antibacterial activity of ciprofloxacin drug due to formation of mixed-ligand complexes. The complexes were found to be more potent compare to some standard drugs, ligands and metal salt against selective gram(+ve) and gram(-ve) organisms. Binding of the complexes with DNA have been investigated by spectroscopic absorption titration and viscometric techniques. The mixed-ligand complexes show good binding ability. The cleavage efficacy has been determined using gel electrophoresis method and complexes were found to be more active compared to parental ligands and metal salt.

DNA-interaction and in vitro antimicrobial studies of some mixed-ligand complexes of cobalt(II) with fluoroquinolone antibacterial agent ciprofloxacin and some neutral bidentate ligands.

Six new mixed-ligand complexes of Co(II) with ciprofloxacin (Cip) and neutral bidentate ligands have been synthesized and characterized. Binding and cleavage of DNA with the complex were investigated using spectroscopic method, viscosity measurements and gel electrophoresis techniques. Antibacterial activity has been assayed against two Gram((-ve)) and three Gram((+ve)) microorganisms using the doubling dilution technique.

DNA cleavage, binding and intercalation studies of drug-based oxovanadium(IV) complexes.

The complexes of oxovanadium(IV) with ciprofloxacin and various uni-negative bidentate ligands have been prepared and their structure investigated using spectral, physicochemical and elemental analyses. The viscosity measurement suggest that the complexes bind to DNA by intercalation. The DNA binding efficacy was determined using absorption titration to obtain the binding constant (K(b)). The DNA cleavage efficacy was determined using gel electrophoresis. The DNA binding and cleavage efficacy were increased in the complexes relative to the parental ligands and metal salts. Antibacterial activity has been assayed against two Gram((- ve)) i.e. Escherichia coli, Pseudomonas aeruginosa and three Gram((+ ve)) Staphylococcus aureus, Bacillus subtilis, Serratia marcescens microorganisms using the doubling dilution technique. The results show a significant increase in antibacterial activity in the complexes compared with parental ligands and metal salts.

Five-coordinated oxovanadium(IV) complexes derived from amino acids and ciprofloxacin: synthesis, spectral, antimicrobial, and DNA interaction approach.

Five-coordinated oxovanadium(IV) complexes with ciprofloxacin and various uninegative bidentate amino acids have been prepared. The structure of complexes has been investigated using spectral, physicochemical, mass spectroscopy, and elemental analyses. The antimicrobial activities (MIC) of the complexes, ligands, metal salt, and some standard drugs have been evaluated using the doubling dilution technique against Staphylococcus aureus, Bacillus subtilis, Serratia marcescens (gram-positive), and Pseudomonas aeruginosa, and Escherichia coli (gram-negative) bacteria. The result shows the significant increase in the antibacterial activity of the ligand, metal, and ciprofloxacin on complexation. The interaction of the complexes with pBR322 DNA has been investigated using spectroscopic, gel electrophoresis, and viscometric techniques. This shows that the complexes can bind to pBR322 DNA by the intercalative mode. The superoxide dismutase-like activity of the complexes has been determined.

Iron(III) complexes: preparation, characterization, antibacterial activity and DNA-binding.

Iron(III) have been combined to well known quinolones (ciprofloxacin) and some Schiff bases with the help of coordination approach. Characterization of these compounds have been done using elemental analysis, magnetic measurements, thermogravimetric analysis, IR, UV-VIS, (1)H NMR and (13)C NMR spectral investigation. Analytical studies suggest that the iron(III)-quinolone complexes assume a six-coordinated dimeric distorted octahedral geometry. All the compounds show a good antibacterial activity against broad range of bacteria like Bacillus cereus, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi and Serratia marcescens, whereas no significant inhibition towards growth of fungal strains like Aspergillus Niger, Aspergillus flavus and Lasiodiplodia theobromae. Analyses of all these compounds show effective sperm herring DNA inhibition.

In-vitro biological evaluation of some ONS and NS donor Schiff's bases and their metal complexes.

Complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with the Schiff bases salicylidene-o-aminothiophenol (H2L) and thiophene-o-carboxaldeneaniline (SB) have been synthesized and characterized by elemental analyses, magnetic measurements, thermogravimetric analyses as well as infrared spectra and reflectance spectra. The nature of the bonding has been discussed on the basis of IR spectral data. Magnetic susceptibility measurements and electronic spectral data suggest a six-coordinated octahedral structure for these complexes. The complexes of Mn(II), Co(II), Ni(II), Cu(II) are paramagnetic, while Zn(II) and Cd(II) are diamagnetic in nature. The complexes were tested for their antimicrobial activities against Salmonella typhi, Escherichia coli and Serratia marcescens using the "Disc Diffusion Method". The results are compared with the standard drug (tetracycline) and show moderate activity.

2-methoxyestradiol does not inhibit superoxide dismutase.

It has been reported in the literature that the endogenous estrogen metabolite 2-methoxyestradiol (2-ME) inhibits both manganese and copper,zinc superoxide dismutases (Mn and Cu,Zn SODs) and that this mechanism is responsible for 2-ME's ability to kill cancer cells. In fact, as demonstrated using several SOD assays including pulse radiolysis, 2-ME does not inhibit SOD but rather interferes with the SOD assay originally used. Nevertheless, as confirmed by aconitase inactivation measurements and lactate dehydrogenase release in human leukemia HL-60 cells, 2-ME does increase superoxide production in these cells and is more toxic than its non-O-methylated precursor 2-hydroxyestradiol. Other mechanisms previously suggested in the literature may explain 2-ME's ability to increase intracellular superoxide levels in tumor cells.

Fatty acid composition of Heterorhabditis sp. during storage.

The fatty acid composition of three North West European isolates of Heterorhabditis sp. from different geographical origins, UK211 (England), HF85 (The Netherlands) and EU17 (Estonia) was assessed directly after harvest and, for UK211 and HF85, after 5 weeks storage in water at 20 degrees C. Lipid represented 34-43% of the dry weight of fresh nematodes. Of this, neutral lipid (NL) comprised from 70% (HF85) to over 90% (UK211, EU17). The fatty acid patterns were similar between the three isolates. Oleic (C18:In-9), palmitic (C16:0), and linoleic (C18:2n-6) acid predominated with 51, 13 and 12%, respectively in the total lipid (TL) of fresh nematodes (average for the three isolates). Levels of unsaturation (U.I.) of fresh nematodes were on average 110, 112, 113 and 152 for the TL, NL, phospholipid and free fatty acid fractions, respectively. EU17 had a slightly lower U.I than the other two strains, despite its more northern origin. Changes in fatty acid composition due to storage were most significant in the NL fraction. The U.I. for the NL fraction increased during storage, suggesting a preferential use of saturated fatty acids.

The ultrastructure of the cuticle and sheath of infective juveniles of entomopathogenic steinernematid nematodes.

The ultrastructure of the cuticle of infective juveniles (IJs) of Steinernema carpocapsae (newly emerged and 80-day-old) and newly emerged IJs of S. riobravis, S. feltiae and S. glaseri was examined using transmission electron microscopy. The thickness of four distinctive layers of the cuticle was measured: epicuticle, cortical and median layer, striated layer and fibrous mat. The thickness of the cuticle was correlated with the size of the IJ. In the case of newly emerged IJs, the smallest species, S. carpocapsae, had a cuticle thickness of c. 270 nm compared with c. 460 nm for S. glaseri, the largest of the four species. The overall thickness of the cuticle or the thickness of the cuticle layers was not correlated with the ability of the IJs of the four species to survive desiccation per se. The major difference between newly emerged IJs of the four species was that S. carpocapsae had a proportionately thicker striated layer compared with the other three species. The significance of this is not known but it may be an adaptation involving the nictation behaviour of this species. A substantial change was observed in the cuticle of aged (80-day-old) IJs of S. carpocapsae, whereby the thickness of the cortical and median layer increased by more than 100% and the overall thickness of the cuticle increased by about 50%. Two possible explanations for this increase are: (i) new material was synthesized; or (ii) the fluid content of this layer increased due to an increase in the permeability of the outer layers of the cuticle. The ultrastructure of the sheaths of S. feltiae and S. glaseri was also examined and, apart from S. glaseri having a thicker sheath, the structure of the sheath in both species was similar, with the epicuticle and striated layer still visible.

Glycogen: its importance in the infectivity of aged juveniles of Steinernema carpocapsae.

Infective juveniles (IJs) of Steinernema carpocapsae (All) are able to remain relatively highly infective even when they have almost exhausted their neutral lipid reserves. This is not seen in other steinernematid species so we proposed that carbohydrate may be important for infectivity in aging IJs of S. carpocapsae. The present study investigated glycogen utilization in IJs of 4 entomopathogenic nematodes, S. carpocapsae, S. riobravis (Biosys 355), S. feltiae (UK76) and S. glaseri (NC), stored in distilled water at 25 degrees C. The 4 species had appreciable amounts of glycogen; from ca. 8% dry weight in S. riobravis to ca. 18% in S. glaseri. Infective juveniles of S. carpocapsae and S. riobravis survived for 120-135 days and utilized ca. 90% of their glycogen reserve at an almost constant rate during a 112-day storage period. Steinernema feltiae and S. glaseri lived for much longer (> 450 days) and during a 250-day storage period their glycogen content decreased by 27 and 40%, respectively. In contrast to the other 3 species, the rate of lipid decline preceded that of glycogen in S. carpocapsae. The rate of glycogen decline in S. carpocapsae IJs incubated with the glycolytic inhibitor, iodoacetamide (10(-4) M) was significantly reduced (P < 0.05) compared with untreated nematodes, and the infectivity of inhibitor-treated aged (> 80 days) IJs was reduced compared with controls. Incubating aged (80-day) IJs of S. carpocapsae (mean neutral lipid content ca. 10% of initial level) with 10(-4) M iodoacetamide for 24 h significantly reduced (P < 0.05) their infectivity compared with freshly harvested inhibitor-treated IJs and untreated controls. Following an 11-day recovery period, the infectivity of inhibitor-treated aged IJs recovered significantly (P < 0.05). The evidence suggests that glycogen is an important source of energy for maintaining infectivity in aged IJs of S. carpocapsae.

Neutral lipids and the assessment of infectivity in entomopathogenic nematodes: observations on four Steinernema species.

An 8-point visual index was developed for Oil Red O staining of neutral lipids in infective juveniles (IJs) of Steinernema carpocapsae (A11), S. riobravis (Biosys 355), S. feltiae (UK76) and S. glaseri (NC). The visual index was found to be a reliable and rapid method for determining the relative neutral lipid content of individual IJs and was validated quantitatively by gas chromatography. The relationship between neutral lipid utilization and infectivity of IJs stored in distilled water at 25 degrees C was also investigated and the first quantitative results on neutral lipid utilization in entomopathogenic nematodes are reported. Neutral lipid contents of freshly harvested IJs of S. carpocapsae, S. riobravis. S. feltiae and S. glaseri were 31, 31, 24 and 26% dry wt, respectively. Steinernema carpocapsae showed a sigmoidal pattern for neutral lipid utilization while S. riobravis used neutral lipids at an almost constant rate. Survivorship of these two species ranged between 120 and 135 days, whereas S. feltiae and S. glaseri lived > 450 days and had a slower rate of lipid utilization during a 260 day storage period. Oil Red O staining showed that individual IJs in each population utilized lipids at different rates, even though they had the same initial lipid index. The infectivity of S. riobravis, S. feltiae and S. glaseri declined with lipid utilization. In contrast, S. carpocapsae maintained a high level of infectivity even at relatively low lipid levels. Therefore, neutral lipid content was found to be a suitable indicator of infectivity for S. riobravis, S. feltiae and S. glaseri but not for S. carpocapsae.

Mapping one form of autosomal dominant postaxial polydactyly type A to chromosome 7p15-q11.23 by linkage analysis.

Postaxial polydactyly type-A (PAP-A) in humans is an autosomal dominant trait characterized by an extra digit in the ulnar and/or fibular side of the upper and/or lower extremities. The extra digit is well formed and articulates with the fifth, or extra, metacarpal/metatarsal, and thus it is usually functional. In order to map the gene responsible for PAP-A, we studied a five-generation Indian family of 37 individuals (15 of whom were affected). A genomewide search with highly informative polymorphic markers on part of the pedigree showed linkage between the PAP-A phenotype and markers on chromosome 7p15-q11.23 (no crossovers were found with D7S526, D7S795, D7S528, D7S521, D7S691, D7S667, D7S478, D7S1830, D7S803, D7S801, or ELN). The highest LOD score was obtained with marker D7S801 (zeta max = 4.21; theta = 0). Haplotype analysis enabled the mapping of the PAP-A phenotype in this family between markers D7S2848 and D7S669. Analysis of additional families with PAP-A will narrow down the critical genomic region, facilitate positional cloning of the PAP-A gene, and/or uncover potential genetic heterogeneity.

Serum levels of unbound free fatty acids. I: Normative data in term newborn infants.

BACKGROUND: Free fatty acids (FFA) play essential roles in maintaining physiologic homeostasis in the newborn infant. Most of the FFA in serum is carried in complex with albumin, but a small fraction remains unbound in the aqueous phase. OBJECTIVE: This study's goal is to report the values of serum levels of unbound free fatty acids (FFAu) in pregnant women and their newborn infants at term gestation. METHODS: The measurements were made possible by the availability of the fluorescent probe for unbound FFA, acrylodated intestinal fatty acid binding protein (ADIFAB). Twenty-two mother-infant pairs were enrolled in the study. Maternal levels were obtained immediately before delivery, cord levels at the time of delivery, and infant levels after 24 hours of age. RESULTS: The level of FFAu measured in maternal samples was 11.8 +/- 4 nM, in cord samples 9.2 +/- 4 nM, and in infants 13.9 +/- 3 nM. These population averages are considerably greater than those observed in healthy adults (7.5 +/- 2.5 nM). No correlation was found between cord levels and birthweight, gestational age, labor duration, mode of deliver, and infant or maternal temperature. CONCLUSIONS: This investigation is the first to measure FFAu in a group of mothers and their infants and provides the technique for future investigations of the biologic activity of free fatty acids.

Desiccation survival and water contents of entomopathogenic nematodes, Steinernema spp. (Rhabditida:Steinernematidae).

The survival of exsheathed infective juveniles (IJs) of 4 Steinernema species, S. glaseri (NC), S. feltiae (UK76), S. carpocapsae (All) and S. riobravis (Biosys355), was assessed following fast and slow drying on glass slides and 1% (w/v) agarose, respectively. Freshly harvested and aged (75-day-old) IJs were desiccated on glass slides after removal of superficial water, at 0, 20, 40, 60 and 80% relative humidity (r.h.). Survival was assessed after rehydration with water, and movement was used as the criterion for survival. Evidence for an intrinsic mechanism to control water loss and survive desiccation was found in freshly harvested S. carpocapsae IJs. At all r.h.s tested, S. carpocapsae had the greatest survival and the slowest rate of water loss. For example, at 80% r.h. the survival time for 50% (S50) of S. carpocapsae IJs was ca. 45 min compared with 5-20 min for the other species. Survival of aged IJs was markedly reduced in the case of S. carpocapsae and S. riobravis, and to a lesser extent in S. feltiae and S. glaseri. The 2nd stage juvenile cuticle (sheath) was not important in aiding desiccation survival of S. carpocapsae and S. glaseri. Drying IJs slowly on 1% agarose at 80% r.h. greatly improved the survival of all 4 species, particularly S. glaseri and S. feltiae. The work is discussed in relation to possible mechanisms for survival of IJs during fast and slow drying.

Phospholipids and their fatty acids in infective juveniles of entomopathogenic steinernematid nematodes.

The composition of phospholipids and their fatty acids was investigated in the infective juveniles (IJs) of four species of entomopathogenic nematodes: Steinernema carpocapsae (strain All), S. riobravis (strain Biosys 355), S. feltiae (strain UK76) and S. glaseri (strain NC). In newly emerged IJs of the four species, phospholipids comprised 15-18% dry weight of the total lipids (or 5-6% dry weight of the nematode), and phosphatidylethanolamine and phosphatidylcholine constituted about 40 and 30%, respectively, of the total phospholipids, with phosphatidylserine (PS) and phosphatidylinositol (PI) collectively accounting for about 25%. Qualitatively, the four species had identical total phospholipid (combined non-acidic and acidic fractions) fatty acid profiles, although there were some differences in the relative proportions (mol%) of specific fatty acids. The fatty acid composition of the total phospholipids in newly emerged IJs was dominated by C16 fatty acids, specifically C16:0 (14-18%), C16:1n-7 (up to 20%) and C16:4 (up to 26%), whereas the major C18 fatty acid was C18:1n-9 (20-23%). Polyunsaturated C20 fatty acids collectively made up 8-13% of the total composition. When newly emerged IJs were stored in distilled water at 25 degrees C, the proportions of C16:0 and C16:4 decreased with storage time, whereas C16:3n-3 increased (by 30-fold in S. glaseri). These changes were mostly observed in the acidic phospholipid fraction (mainly PI and PS). No evidence was found for a correlation between the fatty acid composition of the phospholipids and the relative ability of the IJs of the four Steinernema species to survive desiccation stress.

Fatty acid composition of neutral lipid energy reserves in infective juveniles of entomopathogenic nematodes.

The fatty acid composition of neutral lipids from infective juveniles (IJs) of Steinernema carpocapsae strain All, S. riobravis strain Biosys 355, S. feltiae strain UK76, and S. glaseri strain NC stored in distilled water at 25 degrees C was determined. Newly emerged IJs of all four species had similar neutral lipid fatty acid profiles and of the 18 fatty acids identified, C18:1n-9 (43-49 mol %), C16:0 (18-23%), C18:2n-6 (8-14%) and C18:0 (4-8%) were the most abundant. Unsaturated fatty acids predominated, with about 50% being monoene and 14-22% polyene; the unsaturation index ranged from 91.6 in S. glaseri to 111.6 in S. carpocapsae. The fatty acid composition of the total lipid and the free fatty acid fraction mirrored that of the neutral lipids. During storage, the relative levels (%) of C16:0, C18:0, and C18:ln-9 in the neutral lipids declined significantly, suggesting they were preferentially utilised.