Evaluation of cytotoxic and anti-tumor activity of partially purified serine protease isolate from the Indian earthworm Pheretima posthuma

Objective

To isolate, partially purify and evaluate the cytotoxic and antitumor activity of a serine protease from the chosen Indian earthworm Pheretima posthuma.

Methods

Whole animal extract was prepared and purified its protein constituents by size and charge based chromatographic separation techniques using Sephadex G-50 and DEAE-Cellulose resin respectively. Average molecular weight of the protein isolate was determined and analyzed for its cytotoxic property against Vero cells in different dilutions (1: 20 and 1: 40) and anti-tumor activity by MTT assay (a colorimetric assay) using breast cancer cell line MCF-7, with tamoxifen as standard.

Results

One of the protein constituents after purification was characterized as serine protease by Caseinolytic plate diffusion assay. Average molecular weight of this purified isolate was determined, by SDS-PAGE analysis with standard protein ladder, as of 15 kDa. The performed tests suggested that the 15kDa fraction has potent cytotoxic activity and satisfactory antitumor activity as well in vitro.

Conclusions

Exact molecular mechanism of the cytotoxic and antitumor activities is yet to be explored and currently we are working on ultra-purification and biophysical characterization of this fraction. Further investigation into the mechanism(s) of cytotoxic and antitumor activities at molecular level would be useful in treatment of various classes of cancer and viral infections in future.     

Clitoria ternatea ameliorated the intracerebroventricularly injected streptozotocin induced cognitive impairment in rats: behavioral and biochemical evidence

Rationale

Clitoria ternatea, commonly known as Aparajita, is used as Medhya rasayana in Ayurveda. The role of C. ternatea in experimental models of cognitive impairment is yet to be explored.

Objectives

The present study was designed to study the effect of aqueous and hydroalcoholic extracts of C. ternatea on biochemical and behavioral parameters related to cognitive impairment in in vitro and in vivo studies.

Methods

In vitro free radical scavenging and enzyme-inhibitory (cholinesterase, glycogen synthase kinase-3-β, rho kinase, prolyl endopeptidase, catechol-O-methyl transferase, and lipoxygenase) activities of aqueous and hydroalcoholic extracts of C. ternatea plant were evaluated. Based on in vitro results, hydroalcoholic extract of C. ternatea (100, 300, and 500 mg/kg, p.o.) was selected for evaluation in intracerebroventricularly injected streptozotocin (STZ)-induced cognitive impairment in male Wistar rats. Behavioral assessment was performed at baseline and on the 14th, 21st, and 28th days after STZ injection using elevated plus maze, passive avoidance, Morris water maze, and photoactometer. Oxidative stress parameters (malondialdehyde, reduced glutathione, nitric oxide levels, and superoxide dismutase activity), cholinesterase activity, and rho kinase (ROCK II) expression were studied in cerebral cortex and hippocampus of rats' brain at the end of the study.

Results

The hydroalcoholic extract possessed significantly more in vitro antioxidant and enzyme-inhibitory activities as compared to aqueous extract. The hydroalcoholic extract of C. ternatea prevented STZ-induced cognitive impairment dose dependently by reducing oxidative stress, cholinesterase activity, and ROCK II expression.

Conclusion

In vitro and in vivo results suggest the potential of hydroalcoholic extract of C. ternatea for treatment of cognitive deficit in neurological disorders.     

Optimal control strategy–based AGC of electrical power systems: A comparative performance analysis

This study extensively addresses the application of optimal control approach to the automatic generation control (AGC) of electrical power systems. Proportional‐integral structured optimal controllers are designed using full‐state feedback control strategy employing performance index minimization criterion. Some traditional single/multiarea and restructured multiarea power system models from the literature are explored deliberately in the present study. The dynamic performance of optimal controllers is observed superior in comparison to integral/proportional‐integral controllers tuned using some recently published modern heuristic optimization techniques. It is observed that optimal controllers show better system results in terms of minimum value of settling time, peak overshoot/undershoot, various performance indices, and oscillations corresponding to change in area frequencies and tie‐line powers along with maximum value of minimum damping ratio in comparison to other controllers. The results are displayed in the form of tables for ease of comparison. Sensitivity analysis affirms the robustness of the optimal feedback controller gains to wide variations in some system parameters from their nominal values.     

Virostatic potential of micro-nano filopodia-like ZnO structures against herpes simplex virus-1

Herpes simplex virus type-1 (HSV-1) entry into target cell is initiated by the ionic interactions between positively charged viral envelop glycoproteins and a negatively charged cell surface heparan sulfate (HS). This first step involves the induction of HS-rich filopodia-like structures on the cell surface that facilitate viral transport during cell entry. Targeting this initial first step in HSV-1 pathogenesis, we generated different zinc oxide (ZnO) micro-nano structures (MNSs) that were capped with multiple nanoscopic spikes mimicking cell induced filopodia. These MNSs were predicted to target the virus to compete for its binding to cellular HS through their partially negatively charged oxygen vacancies on their nanoscopic spikes, to affect viral entry and subsequent spread. Our results demonstrate that the partially negatively charged ZnO-MNSs efficiently trap the virions via a novel virostatic mechanism rendering them unable to enter into human corneal fibroblasts - a natural target cell for HSV-1 infection. The anti-HSV-1 activity of ZnO MNSs was drastically enhanced after creating additional oxygen vacancies under UV-light illumination. Our results provide a novel insight into the significance of ZnO MNSs as the potent HSV-1 inhibitor and rationalize their development as a novel topical agent for the prevention of HSV-1 infection.     

Rapamycin protects against middle cerebral artery occlusion induced focal cerebral ischemia in rats

Stroke is a major cause of mortality and disability. The management with thrombolytic therapy has to be initiated within 3-4 h and is associated with limitations like increased risk of intracranial hemorrhage and progression of cerebral injury. Immunophilin inhibitors such as cyclosporine A and tacrolimus have been shown to afford neuroprotection by improving neurological functions and infarct volume in models of ischemic stroke. In the present study, the effect of rapamycin in middle cerebral artery occlusion (MCAo) model of ischemic stroke was evaluated.Ischemic stroke was induced in rats by occluding the MCA using the intraluminal thread. After 1 h of MCAo, animals were administered rapamycin (50, 150, 250 μg/kg, i.p.). After 2 h of occlusion, reperfusion was done. Thirty minutes after reperfusion, animals were subjected to diffusion-weighted magnetic resonance imaging for assessment of protective effect of rapamycin. Twenty-four hours after MCAo, motor performance was assessed, the animals were euthanized and the brains were removed for estimation of malondialdehyde, glutathione, nitric oxide and myeloperoxidase.Significant improvement was observed with rapamycin 150 and 250 μg/kg in percent infarct area, apparent diffusion coefficient and signal intensity as compared to vehicle treated group. Rapamycin treatment ameliorated motor impairment associated with MCAo and significantly reversed the changes in levels of malondialdehyde, glutathione, nitric oxide and myeloperoxidase.The results of the present study indicate neuroprotective effect of rapamycin in MCAo model of stroke. Therefore, rapamycin might be considered as a therapeutic strategy for stroke management.     

Hydroalcoholic extract of Zizyphus jujuba ameliorates seizures, oxidative stress, and cognitive impairment in experimental models of epilepsy in rats

The anticonvulsant effect of the hydroalcoholic extract of Zizyphus jujuba (HEZJ) fruit (100, 250, 500, and 1000 mg/kg, orally) was evaluated in experimental seizure models in rats. The effect of HEZJ on seizure-induced cognitive impairment, oxidative stress, and cholinesterase activity was also investigated. HEZJ (1000 mg/kg) exhibited maximum protection (100%) against generalized tonic-clonic seizures in the pentylenetetrazole (PTZ) seizure model and and 66.7% protection against tonic hindlimb extension in the maximal electroshock (MES) seizure model. Significant impairment in cognitive functions was observed in both PTZ- and MES-challenged rats. Pretreatment with HEZJ resulted in significant improvement in learning and memory. HEZJ also reversed the oxidative stress induced by both PTZ and MES. The significant decrease in cholinesterase activity observed in the PTZ and MES models was significantly reversed by pretreatment with HEZJ. Thus, the present study demonstrates the anticonvulsant effect of HEZJ as well as amelioration of cognitive impairment induced by seizures in rats.     

Successful combined use of Impella Recover 2.5 device and intra-aortic balloon pump support in cardiogenic shock from acute myocardial infarction

Ventricular assist devices (VADs) and intra-aortic balloon pumps (IABPs) are important tools that provide hemodynamic support to patients in cardiogenic shock. The Impella Recover 2.5 is a percutaneous VAD that provides temporary circulatory support. We report the case of a patient who required the combined support of both an IABP and the Impella device.     

Pathways between under/unemployment and health among racialized immigrant women in Toronto

Objective. We sought to document pathways between under/unemployment and health among racialized immigrant women in Toronto while exploring the ways in which gender, class, migration and racialization, as interlocking systems of social relations, structure these relationships.

Design. We conducted 30 interviews with racialized immigrant women who were struggling to get stable employment that matched their education and/or experience. Participants were recruited through flyers, partner agencies and peer researcher networks. Most interviews (21) were conducted in a language other than English. Interviews were transcribed, translated as appropriate and analyzed using NVivo software. The project followed a community-based participatory action research model.

Results. Under/unemployment negatively impacted the physical and mental health of participants and their families. It did so directly, for example through social isolation, as well as indirectly through representation in poor quality jobs. Under/unemployment additionally led to the intensification of job search strategies and of the household/caregiving workload which also negatively impacted health. Health problems, in turn, contributed to pushing participants into long-term substandard employment trajectories. Participants’ experiences were heavily structured by their social location as low income racialized immigrant women.

Conclusions. Our study provides needed qualitative evidence on the gendered and racialized dimensions of under/unemployment, and adverse health impacts resulting from this. Drawing on intersectional analysis, we unpack the role that social location plays in creating highly uneven patterns of under/unemployment and negative health pathways for racialized immigrant women. We discuss equity informed strategies to help racialized immigrant women overcome barriers to stable work that match their education and/or experience.