R. K. Dey

Isolation of Triterpenoid Glycoside from Bark of Terminalia arjuna using Chromatographic Technique and Investigation of Pharmacological Behavior upon Muscle Tissues

This study reports the isolation and characterization of a new triterpenoid glycoside extracted from the bark of Terminalia arjuna. The isolation of the organic compounds was done using simple chromatographic technique. Compound characterization using various spectroscopic technique identify the final isolated compound as Olean-3β,22β-diol-12-en-28β-D- glucopyranoside-oic acid. The method of isolation is simple, cost effective and efficient. The preliminary bioactivity of the compound was also evaluated.

Reversion-inducing cysteine-rich protein with Kazal motifs and its regulation by glycogen synthase kinase 3 signaling in oral cancer

The reversion-inducing cysteine-rich protein with Kazal motifs (RECK) and glycogen synthase kinase (GSK3) are novel tumor suppressors, and emerging evidence has suggested their active role in oral cancer pathogenesis. In the present study, 112 human samples, including 55 fresh samples of 14 adjacent normal tissues, 25 noninvasive oral tumors, and 18 invasive tumors, were included. The messenger RNA (mRNA) expression, protein expression, and promoter methylation of the RECK gene, as well as the expression of GSK3β, phospho/total β-catenin, and c-myc, were measured by RT-PCR, bisulphate modification-PCR, immunohistochemistry, and Western blot analysis. Additionally, ectopic expression of in/active GSK3β was performed in cell culture experiments. This study provided information on the progressive silencing of RECK gene expression at the protein and mRNA levels paralleled with promoter hypermethylation at various stages of oral tumor invasion. RECK expression and the hypermethylation of the RECK gene promoter were negatively and positively correlated with pS9GSK3β/c-myc expression, respectively. Further, a negative trend of RECK protein expression with nuclear β-catenin expression was observed. Induced expression of active GSK3β reversed the RECK silencing in SCC9 cells. Collectively, our results demonstrated that the silencing of the RECK gene, possibly regulated by the GSK3β pathway, is an important event in oral cancer invasion and this pathway could be exploited for therapeutic interventions.

Co-delivery of docetaxel and doxorubicin using biodegradable PEG-PLA micelles for treatment of breast cancer with synergistic anti-tumour effects

ABSTRACT Poly(ethylene glycol)-poly(lactic acid) copolymer, prepared by ring opening polymerization, was used as a single platform to co-deliver both hydrophilic doxorubicin and hydrophobic docetaxel (DTX) in a simulated physiological environment. The average size of the negatively charged drug loaded polymeric micelles were found to be 293 nm. The drug loading (%) and encapsulation efficiency (%) were calculated to be 1.21 and 59.0, respectively. The in vitro cytotoxicity test using MCF7 breast cancer cells was conducted using 1 × 104 cells in 10% FBS and 1% antibiotic, and the absorbance of formazan was evaluated at 570 nm. Cell growth inhibition by MTT assay showed viability of 33% of the MCF7 cells after treatment with drug-loaded micelles for 48 h. Controlled release of drugs from the polymeric micelles indicated a burst release effect initially; whereas, 98% of drug could be released at pH 7.4 within a time period of 96 h. Time period for drug release shorten to 48 h only in simulated mild acidic pH (5.4) condition. The in vitro drug release study from micelles indicated synergistic cytotoxicity effect in human metastatic breast cancer MCF7 cell.

Development of docetaxel-loaded PEG–PLA nanoparticles using surfactant-free method for controlled release studies

ABSTRACT Docetaxel (DTX)-loaded poly(ethylene glycol)–poly(D,L-lactide) is prepared by nanoprecipitation method in the absence of any surfactants. The average particle size of the copolymer was found to be 101u2009nm. The drug entrapment efficiency (%) and drug loading (%) of polymer were found to be 9.471u2009±u20090.047 and 94.71u2009±u20090.466, respectively. The in vitro drug release characteristics show the controlled release of 98% of docetaxel in 72u2009h. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis measured in terms of cleaved Poly(ADP-ribose) Polymerase (PARP) and cleaved caspase-3 protein expression shows that the copolymer has better cytotoxicity effect and apoptosis in comparison to free DTX in HeLa cells. GRAPHICAL ABSTRACT

Synthesis and characterization of new shellac–hydroxypropylmethylcellulose composite for pharmaceutical applications

A new pH-responsive carrier matrix was designed from combination of shellac (Sh), hydroxpropylmethylcellulose (HPMC) and acrylic acid (AA). Characterization of materials was done using various advanced instrumentation techniques. The kinetics of thermal decomposition of materials were studied and compared using Coats–Redfern (CR) and Kissinger–Akahira–Sunose (KAS) mathematical models. The Arrhenius equations for thermal decomposition of shellac and chemically modified shellac (Sh–HPMC–AA) were computed to be kxa0=xa0(3.4xa0×xa01021) e−159.9/RT and kxa0=xa0(141.8) e−19.6/RTxa0s−1, respectively. The pH-responsive characteristics of Sh–HPMC–AA shows 288% swelling ratio. Further, the controlled release of 5-amino salicylic acid (5-ASA) was studied in buffer medium and Fick’s diffusion equation was applied for calculation of transport phenomenon. The enzymatic degradation study of Sh–HPMC–AA is also reported.