Localization of a 25 kDa Human Sperm Surface Protein: Its Role in In-Vitro Human Sperm Capacitation

A human endometrial sialic acid-binding glycoprotein (SABP) binds specifically to a 25 kDa protein on the plasma membranes of human non-capacitated sperm heads. In-vitro labelling of the sperm surface sialoglycoconjugates and subsequent incubation with SABP, suggests removal of some sialoglycoconjugate moieties from the sperm surface upon interaction with SABP. SABP also induces the exposure of mannose ligand receptors on the sperm surface and increases the production of superoxide anion (O2 .–). Key words:human sperm capacitation/mannose receptor/SABP/sialoglycoconjugates/superoxide anio

Reactive Oxygen Species, Redox Signaling and Neuroinflammation in Alzheimers Disease: The NF-kappa B Connection

Oxidative stress and inflammatory response are important elements of Alzheimers disease (AD) pathogenesis, but the role of redox signaling cascade and its cross-talk with inflammatory mediators have not been elucidated in details in this disorder. The review summarizes the facts about redox-signaling cascade in the cells operating through an array of kinases, phosphatases and transcription factors and their downstream components. The biology of NF-kappa B and its activation by reactive oxygen species (ROS) and proinflammatory cytokines in the pathogenesis of AD have been specially highlighted citing evidence both from post-mortem studies in AD brain and experimental research in animal or cell-based models of AD. The possibility of identifying new disease-modifying drugs for AD targeting NF-kappa B signaling cascade has been discussed in the end

Overcoming multidrug resistance (MDR) in cancer in vitro and in vivo by a quinoline derivative

Multidrug resistance (MDR) mediated by the over expression of drug efflux protein P-glycoprotein (P-gp) is one of the major impediments to successful treatment of cancer. P-gp acts as an energy-dependent drug efflux pump and reduces the intracellular concentration of structurally unrelated drugs inside the cells. Therefore, there is an urgent need for development of new compound that are less toxic and effective against drug resistance in cancer. Preclinical studies have shown that quinoline derivatives possess anticancer activities. Here, we report the antitumor potential of quinoline derivative, 2-(2-Methyl-quinolin-4ylamino)-N-phenyl acetamide (S4). To evaluate the cytotoxic potential of S4, we used four different cell lines (Hela, HCT-116, CCRF-CEM, and CEM/ADR 5000) in vitro, and showed that S4 kills doxorubicin resistant T lymphoblastic leukemia cell, CEM/ADR 5000 in a concentration dependent manner while others remains unaffected. Moreover, S4 induces apoptosis in CEM/ADR 5000 cells through generation reactive oxygen species (ROS). This is substantiated by the fact that the antioxidant N-acetyle-cysteine (NAC) completely blocks ROS generation and, subsequently, abrogates S4 induced apoptosis. Furthermore, in vivo treatment with S4 significantly increases the life span of swiss albino mice bearing sensitive and doxorubicin resistant subline of Ehrlich ascites carcinoma. In addition, intraperitoneal application of S4 in mice does not show any systemic toxicity at concentrations that in preliminary trials in a mice Ehrlich ascites carcinoma model. Therefore, present report provides evidence that S4, a quinoline derivative, may be a promising new therapeutic agent against drug resistant cancers