Synthesis of piperine–amino acid ester conjugates and study of their cytotoxic activities against human cancer cell lines

Abstract  

A series of piperine–amino acid ester conjugates (4a–4r) were synthesized under mild conditions and screened for their cytotoxic activities against a panel of human cancer cell lines (IMR-32, MCF-7, PC-3, DU-145, Colo-205, and Hep-2). The parent compound piperine lacked significant activity but the analogues were effective to in all tested human cancer cell lines. The introduction of d- and l-amino acid side chain to piperine through peptide linkage significantly increased cytotoxic activity. Among the tested conjugates, 4p showed significant cytotoxic activity against DU-145 cell lines with IC₅₀ of 21 μM. The synthetic protocol is suitable for generating piperine derivatives with various structural motifs for exploring the desired activity.     

Future of liver transplantation: non-human primates for patient-specific organs from induced pluripotent stem cells

Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripoten...     

Carnosic acid attenuates renal injury in an experimental model of rat cisplatin-induced nephrotoxicity

Nephrotoxicity is one of the serious dose limiting side effects of cisplatin when used in the treatment of various malignant conditions. Accumulating evidence suggests that oxidative stress caused by free radicals and apoptosis of renal cells contributes to the pathogenesis of cisplatin-induced nephrotoxicity. Present study was aimed to explore the effect of carnosic acid, a potent antioxidant, against cisplatin induced oxidative stress and nephrotoxicity in rats. A single dose of cisplatin (7.5 mg/kg) caused marked renal damage, characterized by a significant (P < 0.05) increase in serum creatinine, blood urea nitrogen (BUN) and relative weight of kidney with higher kidney MDA (malondialdehyde), tROS (total reactive oxygen species), caspase 3, GSH (reduced glutathione) levels and lowered tissue nitrite, SOD (superoxide dismutase), CAT (catalase), GSH-Px (glutathione peroxidase), GR (glutathione reductase) and GST (glutathione S-transferase) levels compared to normal control. Carnosic acid treatment significantly (P < 0.05) attenuated the increase in lipid peroxidation, caspase-3 and ROS generation and enhanced the levels of reduced glutathione, tissue nitrite level and activities of SOD, CAT, GSH-Px, GR and GST compared to cisplatin control. The present study demonstrates that carnosic acid has a protective effect on cisplatin induced experimental nephrotoxicity and is attributed to its potent antioxidant and antiapoptotic properties.     

Plant HDAC inhibitor chrysin arrest cell growth and induce p21 WAF1 by altering chromatin of STAT response element in A375 cells

Background

Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells.

Methods

Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27). The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays.

Results

Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21^WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis.

Conclusion

Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (?692 to ?684) region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21 ^WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating cell cycle progression negatively via the induction of the CDK inhibitor p21 ^WAF1 .     

Baseline plasma adiponectin levels as a predictor of left ventricular systolic dysfunction in patients referred for coronary angiography

The objective of the present study was to determine the association between plasma adiponectin and left ventricular (LV) systolic function. Baseline plasma adiponectin was measured in 389 patients undergoing coronary angiography for a variety of indications at a Veterans Affairs Medical Center. Detailed demographic, clinical, laboratory, and angiographic data were available for patients. LV systolic function was assessed using ventriculography, and patients were grouped into those with normal or mild dysfunction (ejection fraction > or =45%) versus those with moderate to severe systolic dysfunction (ejection fraction <45%). After adjusting for a variety of clinically relevant covariates known to affect LV systolic function, adiponectin was independently associated with LV systolic function in the entire cohort of patients (p = 0.0002) using multivariate linear regression analysis. In addition, using multivariate logistic regression analysis, adiponectin was an independent predictor of the presence of moderate to severe LV dysfunction (odds ratio 1.54, 95% confidence interval 1.21 to 1.97, p = 0.0005). Moreover, baseline adiponectin was also independently associated with LV function in both the myocardial infarction (MI) and non-MI subpopulations of patients (p = 0.0401 and p= 0.0023, respectively). Finally, in the non-MI subpopulation, baseline adiponectin was an independent predictor of moderate to severe LV systolic dysfunction (odds ratio 1.52, 95% confidence interval 1.15 to 2.02, p = 0.0034). In conclusion, baseline plasma adiponectin was an independent predictor of LV systolic dysfunction in a population of patients referred for coronary angiography.     

Effect of chordal preservation on left ventricular function

Chordopapillary apparatus preservation was compared with valve-excising mitral valve replacement in a retrospective analysis of 360 patients, of whom 98 had total or partial chordal preservation and 262 had the conventional operation. No significant differences were seen in age, sex, pathology, crossclamp or cardiopulmonary bypass times between the 3 groups. Left ventricular fractional shortening decreased significantly in patients whose valves had been excised completely, whereas it remained unchanged in patients with either partial or total chordal conservation. There was a survival benefit for patients undergoing leaflet preservation (92% vs. 80% for conventional excision at 5 years; p=0.001). Chordal preservation during valve replacement for mitral valve disease improves survival, enhances functional status, preserves left ventricular geometry and function, and improves overall cardiac performance. Preservation of the posterior leaflet alone offers excellent results that are comparable to those of patients with total chordal preservation.     

Pulmonary resections in a tertiary care center—a prospective observational study of outcome

Introduction

In order to assess short term outcomes of pulmonary resections in one year, a prospective observational study was made. To assess the predictive factors for postoperative complications.

Subject and methods

Twenty eight patients who underwent pulmonary resections were included in the study prospectively from January 2011 to December 2011 in a single unit in a tertiary care cancer hospital and short term outcomes were analysed.

Results

Twenty patients underwent pulmonary resection for malignant conditions and 8 for benign conditions. Surgeries performed were lobectomy in 9, bilobectomy in 5, pneumonectomy in 3, lobectomy with chest wall excision in 3 and wedge resection in 8 patients. Of 8 patients who underwent wedge resection; 7 were for benign conditions and one for metastatic gestational trophoblastic neoplasia. Six patients developed postoperative complications. Two had air leak, one patient had prolonged ICU stay (>1 week), one had pneumonia and 2 had surgical site infection. Pulmonary complications occurred in 2 patients, both had Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) <80 %; one had pneumonia and the other was on mechanical ventilation for 48 hours and ICU for 9 days. Four of the patients who developed complication had Eastern Cooperative Oncology Group (ECOG) performance status of 3 and two of them who developed complication had ECOG performance status of two.

Conclusion

DLCO is an important predictor for postoperative complication apart from performance status, pulmonary function tests, smoking and diabetes mellitus.     

Development and evaluation of a competitive ELISA for estimation of rabies neutralizing antibodies after post-exposure rabies vaccination in humans.

OBJECTIVES: Currently three tests are approved for the estimation of neutralizing antibodies after rabies vaccination: the mouse neutralization test (MNT), the rapid fluorescent focus inhibition test (RFFIT), and the fluorescent antibody virus neutralization (FAVN) test. Performance of these tests requires a lot of expertise and is generally carried out in reference laboratories and, hence, they are not available to many people. The aim of the present study was to develop and evaluate a competitive ELISA (C-ELISA) for estimation of neutralizing antibodies in order to make this testing more widely available. METHODS: The C-ELISA was designed based on competition between a murine neutralizing monoclonal antibody (Mab) and the antibodies in serum of vaccinated people. The test was initially standardized using known negative and known positive serum samples for determining the optimal dilution of the Mab as well as the cut-off value (%) for ascertaining the level of inhibition. Nine hundred and ninety serum samples were tested from 250 people who had been administered purified chick embryo cell vaccine (PCECV). Serum samples were collected on days 0, 14, 30 and 90 post-vaccination, and were tested by C-ELISA. RESULTS: All the serum samples that were positive by RFFIT were also positive by C-ELISA. The titers obtained with C-ELISA were marginally higher than the RFFIT titers, but a significant correlation was noted between the two tests (r=0.897). None of the negative controls were detected to be positive for rabies antibodies by either of these tests. Therefore the C-ELISA was found to be 100% specific and sensitive in comparison to RFFIT. Further, the initial rise and fall of antibody titers on different days post-vaccination was comparable for both tests. CONCLUSIONS: The C-ELISA described herein can be used to quantify rabies neutralizing antibody levels after vaccination. This test is simple and can be conveniently used under field conditions for monitoring seroconversion after post-exposure rabies vaccination. Moreover it does not require handling of infectious virus by the end user.