The cytotoxic activity of the total alkaloids isolated from different parts of Solanum pseudocapsicum

The total alkaloid fractions of the methanolic extracts of the leaves, ripe fruits, roots, seeds and stem of Solanum pseudocapsicum were subjected to in-vitro cytotoxicity, short-term toxicity and long-term survival studies. All the five fractions exhibited potent activity. The total alkaloid fraction of leaves was found to be the most potent. The HT-29 cell line was the most sensitive to the fractions. The cytotoxic concentration (CTC(50)) values for all these fractions ranged between 0.39-0.91, 0.68-2.8, 0.92-3.56, 4.05-8.2, 3.28-5.65 and 0.95-5.55 microg/ml, respectively for HT-29, RD-228, A-549, HEp-2, B(16)F(10) and Vero cell lines. In short-term toxicity studies, the fractions showed 50% viability at 93-128 microg/ml for DLA cells and 141-189 microg/ml for human lymphocytes. In the long-term survival studies on the cell lines RD-228, HEp-2 and Vero, cells retained their regenerative capacities at concentrations below 8 microg/ml. The total alkaloids of the plant, especially from the leaves merit further investigations to identify the active constituents in animal models.     

Cryopreservation of cardiac homografts

A homograft valve bank for cryopreservation of cardiac homografts was established at the Institute of Cardiovascular Diseases in July 1995. From July 1995 to February 1999, 169 donor hearts were processed. All except four hearts were procured post mortem. Aortic valves (149) and pulmonary valves (139) were the common homografts dissected out for use. The valves were immersed in a cocktail of five broad spectrum antibiotics and antifungals for an average of 48 to 72 hours before cryopreservation. Fifty-three (35.57%) aortic and 42 (30.21%) pulmonary valves had to be discarded for various reasons like fungal contamination, failure to sterilise, HBsAg positivity etc.; 153 homografts have been released for use so far. Analysing the usual methods of procurement, sterilisation protocol, culture and cryopreservation used for cardiac homografts at this centre, this paper recommends observance of timeliness, use of appropriate media for preservation of heart parts, administration of specific drugs and safeguards necessary for cryopreservation procedure.     

Disseminated histoplasmosis presenting as AIDS cholangiopathy

Histoplasma capsulatum is a common opportunistic pathogen that often causes disseminated infection among AIDS patients from endemic areas. Virtually any organ system can be affected, but biliary involvement has not been described. We report the first case of AIDS cholangiopathy associated with H. capsulatum.     

Impact of ivermectin drug combinations on Pediculus humanus capitis infestation in primary schoolchildren of south Indian rural villages

Background  Antifilarial drug combinations including ivermectin provide antifilarial activity with ancillary benefits on intestinal helminths and ectoparasites, such as chiggers and lice. The impact of single oral dose of antifilarial drugs, viz; (1) diethylcarbamazine (DEC) alone, (ii) DEC + albendazole (ALB), (iii) ivermectin (IVR) + DEC and (iv) IVR + ALB, was determined, on the head louse ( Pediculus humanus capitis ) in primary school children in a rural community in south India.
Methods  Primary school children ( n  = 534) of age 6–10 years from four villages of South India were examined for the presence of head lice before and after single dose of DEC + ivermectin drug combination. The effectiveness and the duration of cure sustained by these drugs were quantified. The head louse was examined by "combing method" during post-treatment periods at 15, 45, 60 and 75 days interval.
Results  The antifilarial drug consumption rate was similar (96–98%) in all treatment arms. In pre-treatment survey the prevalence of head lice in children administered with DEC, DEC + ALB, IVR + DEC and IVR + ALB arm was 86%, 80%, 87% and 80%, respectively, with the latter two arms demonstrating significant reduction in louse infestation ( P  < 0.05) for 60 days.
Conclusion  Single dose with IVR combination demonstrates a greater impact in reducing head louse infestation in the endemic rural communities for nearly 60 days. Therefore, in regions such as Africa where ivermectin is part of the antifilariasis campaign, this drug will have an additional benefit in reducing head lice infestation.     

Chemopreventive effect of bacoside A on N-nitrosodiethylamine-induced hepatocarcinogenesis in rats

Purpose

Chemoprevention is an effective approach to control hepatocarcinogenesis. Bacoside A, the active constituent of Bacopa monniera Linn., is anticipated to play a role in chemoprevention of liver cancer.

Methods

In the present study, we investigated the chemopreventive effect of bacoside A against N-nitrosodiethylamine-induced hepatocarcinogenesis in an animal model.

Results

Administration of carcinogen showed a significant elevation in the levels of lipid peroxidation, serum tumor marker enzymes and liver injury marker enzymes with subsequent decrease in the levels of both hemolysate and liver antioxidant status. Bacoside A co-treatment maintained the N-nitrosodiethylamine-induced alterations at near normal level. Histopathological and electron microscopic study of the liver tissue also supports the above biochemical observations.

Conclusions

From our findings we conclude that bacoside A is effective to prevent DEN-induced hepatocellular carcinoma by quenching lipid peroxidation and enhancing antioxidant status through free radical scavenging mechanism and having potential of protecting endogenous enzymatic and non-enzymatic antioxidant activity.     

The Na–K–Cl Co-transporter in astrocyte swelling

Ion channels, exchangers and transporters are known to be involved in cell volume regulation. A disturbance in one or more of these systems may result in loss of ion homeostasis and cell swelling. In particular, activation of the Na⁺–K⁺–Cl⁻ cotransporters has been shown to regulate cell volume in many conditions. The Na⁺–K⁺–Cl− cotransporters (NKCC) are a class of membrane proteins that transport Na, K, and Cl ions into and out of a wide variety of epithelial and nonepithelial cells. Studies have established the role of NKCC1 in astrocyte swelling/brain edema in ischemia and trauma. Our recent studies suggest that NKCC1 activation is also involved in astrocyte swelling induced by ammonia and in the brain edema in the thioacetamide model of acute liver failure. This review will focus on mechanisms of NKCC1 activation and its contribution to astrocyte swelling/brain edema in neurological disorders, with particular emphasis on ammonia neurotoxicity and acute liver failure.     

Cell type and gender-dependent differential regulation of the p202 and Aim2 proteins: implications for the regulation of innate immune responses in SLE

Upon sensing cytosolic double-stranded DNA (dsDNA), the murine Aim2 (encoded by the Aim2 gene) protein forms an inflammasome and promotes the secretion of proinflammatory cytokines, such as IL-1β and IL-18. In contrast, the p202 protein (encoded by the Ifi202 gene) does not form an inflammasome. Previously, we have reported that the interferon (IFN) and female sex hormone-induced increased nuclear levels of p202 protein in immune cells are associated with increased susceptibility to develop a lupus-like disease. However, signaling pathways that regulate the expression of Aim2 protein remain unknown. Here we report that the expression of Aim2 gene is induced in bone marrow-derived macrophages (BMDMs) by IFN-α treatment and the expression is, in part, STAT1-dependent. However, treatment of splenic T or B cells with IFN-α or their stimulation, which induced the expression of Ifi202 gene, did not induce the expression of Aim2 gene. Furthermore, treatment of cells with the male hormone androgen increased levels of Aim2 mRNA and protein. Moreover, treatment of murine macrophage cell lines (RAW264.7 and J774A.1) with IFN-α differentially induced the expression of Aim2 and p202 proteins and regulated their sub-cellular localization. Additionally, activation of Toll-like receptors (TLR3, 4, and 9) in BMDMs and cell lines also differentially regulated the expression of Aim2 and Ifi202 genes. Our observations demonstrate that cell type and gender-dependent factors differentially regulate the expression of the Aim2 and p202 proteins, thus, suggesting opposing roles for these two proteins in innate immune responses in lupus disease.     

Copper nanoparticles synthesized by polyol process used to control hematophagous parasites

The present study was based on assessments of the anti-parasitic activities of the hematophagous (blood feeding) larvae of malaria vector, Anopheles subpictus Grassi, filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae), and the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae). The metallic copper nanoparticles (Cu NPs) synthesized by polyol process from copper acetate as precursor and Tween 80 were used as both the medium and the stabilizing reagent. The efficacy of synthesized Cu NPs was tested against the larvae of blood-sucking parasites. UV-vis spectra characterization was performed, and peak was observed at 575 nm, which is the characteristic to the surface plasmon bond of Cu NPs. The strong surface plasmon absorption band observed at 575 nm may be due to the formation of non-oxidized Cu NPs. X-ray diffraction (XRD) spectral data showed concentric rings corresponding to the 26.79 (111), 34.52 (200), and 70.40 (220) reflections. XRD spectrum of the copper nanoparticles exhibited 2θ values corresponding to the copper nanocrystal. No peaks of impurities are observed in XRD data. The scanning electron micrograph (SEM) showed structures of irregular polygonal, cylindrical shape, and the size range was found to be 35–80 nm. The size of the Cu NPs was measured by atomic force microscope (AFM) in non-contact mode. For imaging by AFM, the sample was suspended in acetone and spins coated on a silicon wafer. The line profile image was drawn by the XEI software and the horizontal line at 6 μm on a 2D AFM image. Research has demonstrated that metallic nanoparticles produce toxicity in aquatic organisms that is due largely to effects of particulates as opposed to release of dissolved ions. Copper acetate solution tested against the parasite larvae exposed to varying concentrations and the larval mortality was observed for 24 h. The larval percent mortality observed in synthesized Cu NPs were 36, 49, 75, 93,100; 32, 53, 63, 73, and 100 and 36, 47, 69, 88, 100 at 0.5, 1.0, 2.0, 4.0, and 8.0 mg/L against A. subpictus, C. quinquefasciatus and R. microplus, respectively. The larval percent mortality shown in copper acetate solution were 16, 45, 57, 66 and 100, 37, 58, 83, 87, and 100 and 41, 59, 79, 100, and 100 at 10, 20, 30, 40, and 50 mg/L against A. subpictus, C. quinquefasciatus, and R. microplus, respectively. The maximum efficacy was observed in Cu NPs and copper acetate solution against the larvae of A. subpictus, C. quinquefasciatus, and R. microplus with LC₅₀ and r ² values of 0.95 and 23.47, 1.01 and 15.24, and 1.06 and 14.14 mg/L with r ² = 0.766; 0.957 and 0.908; 0.946; and 0.816 and 0.945, respectively. The control (distilled water) showed nil mortality in the concurrent assay. The chi-square value was significant at p ≤ 0.05 level. This is the first report on anti-parasitic activity of the synthesized Cu NPs and copper acetate solution.     

Discovery of GAMA, a Plasmodium falciparum merozoite micronemal protein, as a novel blood-stage vaccine candidate antigen

One of the solutions for reducing the global mortality and morbidity due to malaria is multivalent vaccines comprising antigens of several life cycle stages of the malarial parasite. Hence, there is a need for supplementing the current set of malaria vaccine candidate antigens. Here, we aimed to characterize glycosylphosphatidylinositol (GPI)-anchored micronemal antigen (GAMA) encoded by the PF08_0008 gene in Plasmodium falciparum. Antibodies were raised against recombinant GAMA synthesized by using a wheat germ cell-free system. Immunoelectron microscopy demonstrated for the first time that GAMA is a microneme protein of the merozoite. Erythrocyte binding assays revealed that GAMA possesses an erythrocyte binding epitope in the C-terminal region and it binds a nonsialylated protein receptor on human erythrocytes. Growth inhibition assays revealed that anti-GAMA antibodies can inhibit P. falciparum invasion in a dose-dependent manner and GAMA plays a role in the sialic acid (SA)-independent invasion pathway. Anti-GAMA antibodies in combination with anti-erythrocyte binding antigen 175 exhibited a significantly higher level of invasion inhibition, supporting the rationale that targeting of both SA-dependent and SA-independent ligands/pathways is better than targeting either of them alone. Human sera collected from areas of malaria endemicity in Mali and Thailand recognized GAMA. Since GAMA in P. falciparum is refractory to gene knockout attempts, it is essential to parasite invasion. Overall, our study indicates that GAMA is a novel blood-stage vaccine candidate antigen.