Role of 7,8-dimethoxycoumarin in anti-secretary and anti-inflammatory action on pyloric ligation-induced gastritis in rats

The present study was designed to investigate the effect of 7,8-dimethoxycoumarin (DMC) isolated from ethyl acetate extract of Citrus decumana peels on gastritis in rats. Isolation of 7,8-DMC from ethyl acetate extract of C. decumana peels was done by column and preparative thin layer chromatography using different solvents on polarity basis. Furthermore, effect of 7,8-DMC (50, 75, and 100 mg/kg, i.p.) in pyloric ligation-induced gastritis was studied in rats. The highest dose of 7,8-DMC showed significant decrease in the gastric volume, total acidity, ulcerative index, thiobarbituric acid reactive species levels, and myeloperoxidase activity, whereas there was an increase in the glutathione level. However, the lowest and medium doses did not produce significant results as compared to omeprazole and N-acetyl cysteine-treated groups. Compound 7,8-DMC (100 mg/kg) showed ameliorative effect on gastric inflammation and may be used as a therapeutic agent in the treatment of gastritis.     

Vaccination with 73kDa recombinant heavy chain myosin generates high level of protection against Brugia malayi challenge in jird and mastomys models

We have earlier reported identification, expression and purification of a 2.0kb cDNA clone coding for Brugia malayi heavy chain myosin which exhibited strong immuno-reactivity with bancroftian sera from endemic normal (EN) human subjects which are considered to be putatively immune. In the present study, immunoprophylactic characterization of B. malayi recombinant myosin was carried out in rodent models and the protective efficacy was evaluated by assessing the microfilarial burden and adult worm counts in vaccinated host after an infective larval challenge. Data indicates that immunization resulted in to a significant reduction in microfilarial burden (approximately 76%) and adult worm establishment (54-58%), accompanied with embryostatic effect (70-75%) in both the animal models. The findings suggest that immune-protection by recombinant myosin was conferred through both humoral and cellular arms of immunity as indicated by an increased antibody titer with predominance of IgG2a and IgG2b isotypes along with elevated level of IgG1 apart from significant proliferation of lymphocytes, increased nitric oxide production and profound adherence of splenocytes causing cytotoxicity to microfilariae and infective larvae. The present study indicates that the recombinant B. malayi myosin is a promising vaccine candidate against human lymphatic filarial infection.     

Molecular cloning and characterization of a novel immunoreactive ATPase/RNA helicase in human filarial parasite <Emphasis Type="Italic">Brugia malayi</Emphasis>

DEAD box proteins are putative RNA unwinding proteins found in organisms ranging from mammals to bacteria. We have identified a novel immunodominant cDNA clone, BmL3-helicase, encoding DEAD box RNA helicase by immunoscreening of a larval stage cDNA library of Brugia malayi. The cDNA sequence exhibited strong sequence homology to Caenorhabditis elegans and C. briggsae RNA helicase, a prototypic member of the DEAD (Asp-Glu-Ala-Asp) box protein family. The clone also showed similarity with RNA helicase of Wolbachia, an endosymbiotic bacterium of filarial parasite. It was overexpressed as ∼50 kDa His-tag fusion protein, and ATP hydrolysis assay of recombinant enzyme showed that either ATP or dATP was required for the unwinding activity, indicating BmL3-helicase as an ATP/dATP-dependent RNA helicase. The recombinant protein also demonstrated cross-seroreactivity with human bancroftian sera. The presence of BmL3-helicase in various life stages of B. malayi was confirmed by immunoblotting of parasite-life-cycle extracts with polyclonal sera against the BmL3-helicase, which showed high levels of expression in microfilaria, L_3, and adult (both male and female) stages. In the absence of an effective macrofilaricidal agent and validated anti-filarial drug targets, RNA helicases could be utilized as a rational drug target for developing agents against the human filarial parasite. Nucleotide sequence reported in this paper is available in the GenBank™, EMBL, and DDBJ databases under the accession number EF409381.     

In vitro and in vivo antifilarial potential of marine sponge, Haliclona exigua (Kirkpatrick), against human lymphatic filarial parasite Brugia malayi

The present study reports on the antifilarial activity of a marine sponge Haliclona exigua (phylum Porifera). The crude methanol extract and n-butanol-soluble fraction killed adult Brugia malayi at 31.25-μg/ml concentration (both in motility and 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay) while the chloroform fraction was lethal at a lower concentration of 15.6 μg/ml. The activity could be located in a single molecule araguspongin C which brought about mortality of worm at 15.6 μg/ml. In vivo evaluation of the crude extract (5?×?500 mg/kg, orally) and the chloroform fraction (5?×?250 mg/kg, orally) in B. malayi-infected rodent host, Mastomys coucha, did not show any significant microfilaricidal actions; however, microfilarial densities in both the treated groups were significantly much lower than those of untreated group in contrast to standard filaricide diethylcarbamazine which exerted 79% microfilaricidal action on day 8 of treatment. Both these extracts also demonstrated adulticidal (macrofilaricidal) activity which was more pronounced in the chloroform fraction (50.2%). In addition, there was moderate adverse effect on the reproductive potential of female worms (crude extract 46.5%; chloroform 58.6%). The findings suggest that the marine sponge H. exigua possesses adulticidal and embryostatic action against human lymphatic filarial parasite B. malayi in experimental rodent model and this activity could be attributed to the presence of araguspongin C.     

Molecular basis of the mucosal immune system: from fundamental concepts to advances in liposome-based vaccines

The mucosal immune system, the primary portal for entry of most prevalent and devastating pathogens, is guarded by the special lymphoid tissues (mucosally associated lymphoid tissues) for immunity. Mucosal immune infection results in induction of IgA-manifested humoral immunity. Cell-mediated immunity may also be generated, marked by the presence of CD4(+) Th1 and CD8(+) cells. Furthermore, the immunity generated at the mucosal site is transported to the distal mucosal site as well as to systemic tissues. An understanding of the molecular basis of the mucosal immune system provides a unique platform for designing a mucosal vaccine. Coadministration of immunostimulatory molecules further accelerates functioning of the immune system. Mimicking receptor-mediated binding of the pathogen may be achieved by direct conjugation of antigen with an immunostimulatory molecule or encapsulation in a carrier followed by anchoring of a ligand having affinity to the cells of the mucosal immune system. Nanotechnology has played a significant role in mucosal vaccine development and among the available options liposomes are the most promising. Liposomes are phospholipid bilayered vesicles that can encapsulate protein as well as DNA-based vaccines and offer coencapsulation of adjuvant along with the antigen. At the same, time ligand-conjugated liposomes augment interaction of antigen with the cells of the mucosal immune system and thereby serve as suitable candidates for the mucosal delivery of vaccines. This article exhaustively explores strategies involved in the generation of mucosal immunity and also provides an insight to the progress that has been made in the development of liposome-based mucosal vaccine.     

Prior killing of intracellular bacteria Wolbachia reduces inflammatory reactions and improves antifilarial efficacy of diethylcarbamazine in rodent model of Brugia malayi

The discovery of the endosymbiont Wolbachia, which has a mutualistic relationship with filarial nematodes, and its importance in filarial parasite biology has provided a lead for developing novel chemotherapeutic agents against human filariasis. Wolbachia also appears to be involved in immunopathological responses as well as adverse reactions after antifilarial therapy. The aim of the present study was to explore the potential of administering anti-Wolbachial therapy before antifilarial treatment to improve the filaricidal efficacy of the present-day filaricide diethylcarbamazine. An additional objective was to minimize host inflammatory reactions using a rodent model Mastomys coucha and Meriones unguiculatus infected with human lymphatic filariid Brugia malayi. We observed: (1) a 40-day treatment schedule of tetracycline alone resulted in delayed reduction in microfilaraemia and a low degree of macrofilaricidal efficacy; (2) tetracycline therapy followed by 100 mg/kg diethylcarbamazine (DEC) ×5 days led to marked reduction in microfilaraemia from day 48 onward after initiation of treatment. The combination treatment also brought about ∼70% death of adult B. malayi and sterilization of 82.3% of the surviving female worms, thus exhibiting remarkable enhancement in the antifilarial activity of DEC; (3) tissue inflammatory reactions and pathogenesis were significantly reduced as observed by histopathology, and peritoneal macrophage mediated oxidative burst shown by florescence-activated cell sorting (FACS) analysis using dichlorofluorescein diacetate (DCF-DA); and (4) the characteristic filarial antigen-specific and mitogen-specific cellular unresponsiveness was significantly reversed, possibly due to marked clearance of microfilaraemia. It is therefore advisable to give an anti-Wolbachial antibiotic trial before starting antifilarial therapy to achieve maximum benefits.     

Fine needle aspiration in the diagnosis of subcutaneous cysticercosis

Human cysticercosis commonly manifests as subcutaneous and intramuscular nodules. The current study highlights the role of fine needle aspiration cytology (FNAC) in the diagnosis of subcutaneous cysticercosis. One hundred and twenty two patients with subcutaneous swellings, diagnosed as cysticercus or suspicious of parasitic inflammation on FNAC, were included in the present study. The relevant clinical data, cytomorphological findings, and histopathological findings, wherever available were evaluated. In 57 cases, a definite evidence of cysticercus was obtained in the form of fragments of parasite bladder wall, hooklets, or intact larva. Out of these, biopsy correlation was available in 10 cases, eight of which failed to reveal any parasite. In 65 cases, larval fragments could not be identified on aspirates, and the diagnosis of parasitic inflammation was suggested on the basis of other cytomorphological findings, which are discussed. In 22 of these cases, a biopsy correlation was available, which revealed definite parasitic elements in six cases and the remaining 16 cases were reported as suggestive of parasitic cysts. Thus, to conclude, FNAC is a reliable and cost effective procedure for the diagnosis of subcutaneous parasitic nodules. It obviates the need for a subsequent histopathological examination, as the parasite may not be demonstrated even on biopsy specimens.     

Association of raised blood lead levels in pregnant women with preeclampsia: A study at tertiary centre

Objective

This study aims to find the blood lead levels in pregnant women and its association with pre-eclampsia.

Exploitation of Walnut (Juglans regia L.) Expressed Sequence Tags for Development of SSR Markers After In Silico Analysis

The walnut (Juglans regia) has been extensively characterized for expressed sequence tags (EST) sequences and currently 6169492 ESTs are available in National Center for Biotechnology Information. Although this is a valuable resource for marker development, the redundancy in sequences makes the mining out of unique candidates for designing markers cumbersome. Keeping this in view, the present study was undertaken with the aim to remove the data redundancy in walnut ESTs and then to develop simple sequence repeats (SSRs) markers. The EST sequences were assembled into a non-redundant set of 85 contigs and 1584 singletons (total sequences 1699), indicating 16.55% reduction in data redundancy. These 1699 sequences were then used to mine out SSR motifs. 132 EST-SSRs were detected, with dinucleotide repeats being predominant (70.45%), followed by trinucleotide repeats (27.27%) and very less frequent hexanucleotides (2.27%). These markers were validated by designing primer pairs. 15 of these designed primers were tested on a group of 37 walnut genotypes. Out of which 7 markers gave robust amplification, generating polymorphism. These findings indicate the usefulness of EST-SSRs in genome analysis. This study further emphasizes the importance of assembly of the vast amounts of data submitted in public databases. Our results have generated a set of non redundant walnut ESTs which is of prime importance for development of marker systems without any repetition or overlapping.