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Davanagere, India

Sandhya B.,Karnatak University | Hegde A.H.,Karnatak University | Ramesh K.C.,Davanagere University | Seetharamappa J.,Karnatak University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein. © 2011 Elsevier B.V. All rights reserved. Source


Sowmya H.V.,Davanagere University | Krishnappa M.,Kuvempu University | Thippeswamy B.,Davanagere University
Environment, Development and Sustainability | Year: 2014

Penicillium simplicissimum was isolated from a local dumpsite of Shivamogga district for use in the biodegradation of polyethylene. Degradation was carried out using autoclaved, UV-treated and surface-sterilized polyethylene. Degradation was monitored by observing weight loss and changes in physical structure by scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. P. simplicissimum was able to degrade treated polyethylene (38 %) more efficiently than autoclaved (16 %) and surface-sterilized polyethylene (7.7 %). Enzymes responsible for polyethylene degradation were screened from P. simplicissimum. Enzymes were identified as laccase and manganese peroxidase. These enzymes were produced in large amount, enzyme activity was calculated using spectrophotometric method, and crude extraction of enzymes was carried out. Molecular weight of laccase was determined as 66 kDa and that of manganese peroxidase was 60 kDa. Capacity of crude enzymes to degrade polyethylene was also determined. By observing these results, we can conclude that P. simplicissimum may act as solution for the problem caused by polyethylene in nature. © 2014 Springer Science+Business Media Dordrecht. Source


Ravikumara N.R.,Kuvempu University | Ravikumara N.R.,Davanagere University | Madhusudhan B.,Davanagere University
Pure and Applied Chemistry | Year: 2011

In this study, tamoxifen citrate-loaded chitosan nanoparticles (tamoxcL-ChtNPs) and tamoxifen citrate-free chitosan nanoparticles (tamoxcF-ChtNPs) were prepared by an ionic gelation (IG) method. The physicochemical properties of the nanoparticles were analyzed for particle size, zeta (ζ) potential, and other characteristics using photon correlation spectroscopy (PCS), zeta phase analysis light scattering (PALS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC). The variation in particle size was assessed by changing the concentration of chitosan, pentasodium tripolyphosphate (TPP), and the pH of the solution. The optimized tamoxcL-ChtNPs showed mean diameter of 187 nm, polydispersity of 0.125, and ζ-potential of +19.1 mV. The encapsulation efficiency (EE) of tamoxifen citrate (tamoxc) increased at higher concentrations, and release of tamoxc from the chitosan matrix displayed controlled biphasic behavior. Those tamoxcL-ChtNPs tested for chemosensitivity showed dose- and time-dependent antiproliferative activity of tamoxc. Further, tamoxcL-ChtNPs were found to be hemocompatible with human red blood cells (RBCs) and safe by in vitro cytotoxicity tests, suggesting that they offer promise as drug delivery systems in therapy. © 2011 IUPAC. Source


Ravikumara N.R.,Kuvempu University | Ravikumara N.R.,Davanagere University | Tiyaboonchai W.,Naresuan University | Madhusudhan B.,Davanagere University
Current Nanoscience | Year: 2013

Phytoestrogens are the most important therapeutic molecules that are richly present in soya based foods. Genistein (GEN) is one among the prominent constituent of soybean. Isolated form of Genistein has poor bioavailability because of its low aqueous solubility, absorption and limited clinical efficacy. Encapsulated GEN could be used for colloidal drug delivery for the treatment of diseases including breast cancer. In the present study we have prepared poly lactic acid based nanoparticles with Genistein by emulsion diffusion method. The obtained genistein-loaded nanoparticles (GEN-PLA-NPs) were characterized for their size (PCS/ Zetasizer), shape (SEM) and other physical properties using FTIR and DSC. Encapsulation efficiency, release characteristics The sizes of the particles were ranged between 100 nm and 380 nm due to different solvents that were used during the preparation of nanoparticles. Under optimal conditions, different sizes of the particles (259.7 nm, 122.3 nm and 105.7 nm) were formed with encapsulation efficiency (73.9%, 57.9% and 61.4%, respectively). The drug and polymer interaction studies were performed by FTIR and DSC. When percent release of encapsulated drug was studies in PBS (pH 7.4), it was found to be biphasic pattern (Korsmeyer-Peppas model) with 21.27% release at 37°C in 24 h. In hemolysis experiment, Genistein loaded poly (lactic acid) nanoparticles exhibited non-toxic nature. These results demonstrated the feasibility of encapsulation of GEN and its non-toxic in vitro studies. © 2013 Bentham Science Publishers. Source


Joshi C.G.,Mangalore University | Gopal M.,Davanagere University | Kumari N.S.,NITTE University
International Journal of Cancer Research | Year: 2011

The practice of traditional medicines in treatment of cancer is based on the knowledge and use of plant based medicine since ancient time. The study of folk medicinal practices revealed the use of Tragia involucrata (Euphorbiaceae) along with other medicinal plants to treat certain tumours in some parts of Kerala, India. The aim of the present study was to evaluate the antitumor potential of hexane and ethyl acetate extracts (HE and EAE) and to asses the antioxidant activity of EAE of T. involucrata. The mice were injected with 106 Ehrlich's Ascites Carcinoma (EAC) cells subcutaneously and the extracts were administered intra-peritoneal (i.p.). In vitro antioxidant property of EAE was tested by 2, 2'-azinobis (3 -ethylbenzo{cyrillic}-thiozoline-6-sulphonic acid (ABTS)) and 1,1 -diphenyl-2-picrylhydrazyl (DPPH) methods. In vivo antioxidant potential of EAE was determined by nitric-oxide by Griess-reagent method, total antioxidant in serum by phosphomolybdenum method and super oxide dismutase by nitroblue tetrazolium (NBT) method. Administration of the extracts to mice challenged with EAC showed significant antitumour activity. The observed antitumor activity of the extracts was dose dependant. There was a significant increase in the percentage life span (ILS %) in extract treated mice. HE was not toxic to mice even at the dose of 2000 mg kg-1 body weight. EAE was toxic to animals when the dosage was increased beyond 150 mg kg-1. EAE was showing even a significant in vitro as well as in vivo antioxidant activity. In vivo antioxidant activity was showing the reciprocal dose response. From the results it may be concluded that the plant posses antitumor activity as claimed in traditional practices. © 2011 Academic Journals Inc. Source

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