Oral administration of low doses of plant-based HBsAg induced antigen-specific IgAs and IgGs in mice,without increasing levels of regulatory T cells

Plant-based oral vaccines run the risk of activating regulatory T cells (Tregs) and suppressing the antigen-specific immune response via oral tolerance. Mice humanized for two HLA alleles (HLA-A2.1 and HLA-DR1) were used to measure changes in Tregs and antigen-specific immune responses induced by the oral administration of tobacco (Nicotiana tabacum), expressing the hepatitis B surface antigen (HBsAg). Antigen-specific CD8+ T cell activation was not detected, but the plant-based oral immunization, without adjuvant, resulted in humoral responses comparable to those obtained by adjuvanted DNA immunization. Treg titers did not increase with DNA immunization. In contrast, with plant immunization, Tregs increased linearly to reach a plateau at high antigen doses. The highest humoral IgA and IgG responses correlated with the lowest plant antigen dose (0.5 ng), while for DNA immunization the best antibody responses were obtained at higher antigen doses. These experiments suggest that plant-based oral vaccines could be adjusted to minimize tolerance, while still inducing an immune response. Oral tolerance and adjuvant engineering in plants are discussed.     

The polyphenol 3, 4, 5 - tri-hydroxy benzoic acid inhibits indian daboia russelli venom and its hemorrhagic complex induced local toxicity

Despite a long history on treatment and management of snakebite, as of now, no satisfactory cure exists to treat local toxicity, including anti-venom therapy. Several natural compounds from plants and their synthetic analogs have shown to be protective. In this study 3, 4, 5-tri-hydroxy benzoic acid, the gallic acid (GA) was tested against the local toxicity of Daboia russelli (DR) venom and its purified hemorrhagic complex (HC). GA inhibited in vitro proteolytic activity of both DR venom and HC but, it did not inhibit phospholipase activity of DR venom. GA inhibited hemorrhage, edema forming, dermo- and myonecrotic activities of both HC and DR venom in in vivo experiments. GA was particularly effective against hemorrhagic activity but, GA inhibition had a greater effect on HC when compared to DR venom. The inhibition was likely due to GA induced structural changes in HC as revealed by alterations in fluorescence emission and CD spectral properties. However, the inhibition was not due to chelating property of GA as suggested by UV-visible spectral studies. Inhibition of collagen type IV, laminin and fibronectin degradation essentially provided the biochemical basis for GA which inhibited local effects of HC as well as DR venom. Thus, the study appears highly promising to explore GA and its generics against ruthless local effects and perhaps systemic hemorrhage of DR and other snake bites as well. Further, these agents will possibly find an immense value in the regulation of matrix metalloproteases (MMPs) in processes such as wound healing, inflammation and in the treatment of cancer.     

Molecular cycloencapsulation augments solubility and improves therapeutic index of brominated noscapine in prostate cancer cells

We have previously shown that a novel microtubule-modulating noscapinoid, EM011 (9-Br-Nos), displays potent anticancer activity by inhibition of cellular proliferation and induction of apoptosis in prostate cancer cells and preclinical mice models. However, physicochemical and cellular barriers encumber the development of viable formulations for future clinical translation. To circumvent these limitations, we have synthesized EM011-cyclodextrin inclusion complexes to improve solubility and enhance therapeutic index of EM011. Phase solubility analysis indicated that EM011 formed a 1:1 stoichiometric complex with β-CD and methyl-β-CD, with a stability constant (K(c)) of 2.42 × 10(-3) M and 4.85 × 10(-3) M, respectively. Fourier transform infrared spectroscopy suggested the penetrance of either a O-CH(2) or OCH(3)-C(6)H(4)-OCH(3) moiety of EM011 in the β-CD or methyl-β-CD cavity. In addition, multifarious techniques, namely, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, NMR spectroscopy, and computational studies validated the cage complex of EM011 with β-CD and methyl-β-CD. Moreover, rotating frame overhauser enhancement spectroscopy showed that the H(a) proton of the OCH(3)-C(6)H(4)-OCH(3) moiety was in close proximity with H3 proton of the β-CD or methyl-β-CD cavity. Furthermore, we found that the solubility of EM011 in phosphate buffer saline (pH 7.4) was enhanced by ~11 fold and ~21 fold upon complexation with β-CD and methyl-β-CD, respectively. The enhanced dissolution of the drug CD-complexes in aqueous phase remarkably decreased their IC(50) to 28.5 μM (9-Br-Nos-β-CD) and 12.5 μM (9-Br-Nos-methyl-β-CD) in PC-3 cells compared to free EM011 (~200 μM). This is the first report to demonstrate the novel construction of cylcodextrin-based nanosupramolecular vehicles for enhanced delivery of EM011 that warrants in vivo evaluation for the superior management of prostate cancer.     

Towards developing standard operating procedures for pre-clinical testing in the mdx mouse model of Duchenne muscular dystrophy

This review discusses various issues to consider when developing standard operating procedures for pre-clinical studies in the mdx mouse model of Duchenne muscular dystrophy (DMD). The review describes and evaluates a wide range of techniques used to measure parameters of muscle pathology in mdx mice and identifies some basic techniques that might comprise standardised approaches for evaluation. While the central aim is to provide a basis for the development of standardised procedures to evaluate efficacy of a drug or a therapeutic strategy, a further aim is to gain insight into pathophysiological mechanisms in order to identify other therapeutic targets. The desired outcome is to enable easier and more rigorous comparison of pre-clinical data from different laboratories around the world, in order to accelerate identification of the best pre-clinical therapies in the mdx mouse that will fast-track translation into effective clinical treatments for DMD.     

Inhibition of HSP90 overcomes resistance to chemotherapy and radiotherapy in pancreatic cancer

Resistance of pancreatic ductal adenocarcinoma (PDAC) to radiotherapy and chemotherapy represents a significant clinical issue. Although the mechanisms of resistance are multi-faceted, client proteins of heat shock protein 90 (HSP90) such as hypoxia induced factor-1α (HIF-1α) have a central role in this process. The purpose of this investigation was to evaluate inhibition of HSP90 as a therapeutic strategy for radiosensitization in pancreatic cancer. Ganetespib, a selective inhibitor of HSP90, was evaluated as a radio-sensitizer in setting of PDAC. Inhibition of HSP90 by ganetespib potentiated the ability of radiation therapy to limit cell proliferation and colony formation in vitro. HIF-1α expression was upregulated by irradiation and HIF-1α-overexpressing stable cell lines were resistant to radiation. Inhibition of HSP90 with ganetespib reversed the effects of HIF-1α overexpression, by reducing signaling via proliferative, angiogenic and anti-apoptotic pathways. The potentiation of the antitumor effects of chemoradiotherapy by ganetespib and modulation of key pathways (e.g. HIF-1α, STAT3, and AKT) was confirmed in vivo in nude mice bearing HPAC xenograft tumors. These novel data highlight HIF-1α-mediated mechanisms of HSP90 inhibition that sensitize PDAC cells to chemoradiotherapy. This pathway and its pleiotropic effects warrant further evaluation in concert with conventional therapy in pancreatic cancer clinical trials.     

Chronic kidney disease of unknown aetiology: A comprehensive review of a global public health problem

The term chronic kidney disease of unknown aetiology (CKDu) refers to chronic kidney disease (CKD) in the absence of diabetes, long-standing hypertension, glomerulonephritis, obstructive uropathy or other apparent causes. An increasing number of CKDu cases have been reported from Latin America, Sri Lanka, India and others over the last two decades. These regional nephropathies share the following common attributes: (a) they affect low-to-middle income countries with tropical climates, (b) involve predominantly rural agricultural communities, (c) male predilection, (d) absence of significant proteinuria and hypertension, and (e) chronic tubulointerstitial nephritis on kidney biopsy. The current body of literature suggests that CKDu may be caused by heat stress, agrochemicals, contaminated drinking water or heavy metals; however, considerable regional disparities in CKDu research make it difficult to establish a common causal link. In the absence of a definite aetiology, specific preventive and therapeutic interventions are lacking. Improvement of working conditions of farmers and labourers, provision of safe drinking water and changes in agricultural practices are some of the measures that have been implemented; however, there is lack of data to assess their impact on the incidence and progression of CKDu. There is a need for a concerted global effort to address the current knowledge gaps, and to develop effective and sustainable strategies to tackle this devastating disease.