Susinjan Bhattacharya

Cardioprotective Role of Syzygium cumini Against Glucose-Induced Oxidative Stress in H9C2 Cardiac Myocytes

Diabetic patients are known to have an independent risk of cardiomyopathy. Hyperglycemia leads to upregulation of reactive oxygen species (ROS) that may contribute to diabetic cardiomyopathy. Thus, agents that suppress glucose-induced intracellular ROS levels can have therapeutic potential against diabetic cardiomyopathy. Syzygium cumini is well known for its anti-diabetic potential, but its cardioprotective properties have not been evaluated yet. The aim of the present study is to analyze cardioprotective properties of methanolic seed extract (MSE) of S. cumini in diabetic in vitro conditions. ROS scavenging activity of MSE was studied in glucose-stressed H9C2 cardiac myoblasts after optimizing the safe dose of glucose and MSE by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide. 2′,7′-dichlorfluorescein diacetate staining and Fluorescence-activated cell sorting analysis confirmed the suppression of ROS production by MSE in glucose-induced cells. The intracellular NO and H2O2 radical–scavenging activity of MSE was found to be significantly high in glucose-induced cells. Exposure of glucose-stressed H9C2 cells to MSE showed decline in the activity of catalase and superoxide dismutase enzymes and collagen content. 4′,6-diamidino-2-phenylindole, propidium iodide and 10-N-nonyl-3,6-bis (dimethylamino) acridine staining revealed that MSE protects myocardial cells from glucose-induced stress. Taken together, our findings revealed that the well-known anti-diabetic S. cumini can also protect the cardiac cells from glucose-induced stress.

Reactive Oxygen Species and Cellular Defense System

Reactive oxygen species (ROS) is a collective term used for oxygen-derived free radicals (superoxide, hydroxyl radical, nitric oxide) and non-radical oxygen derivatives of high reactivity (singlet oxygen, hydrogen peroxide, peroxynitrite, hypochlorite). ROS can be either harmful or beneficial to the body. An imbalance between formation and removal of free radicals can lead to a pathological condition called as oxidative stress. However, the human body employs molecules known as antioxidants to counteract these free radicals. But late several studies have indicated that antioxidants can also have deleterious effects on human health depending on dosage and bioavailability. This makes it essential to analyze the extent of utility of antioxidants in the improvement of human health. It is noteworthy that if the generation of free radicals exceeds the protective effects of antioxidants, this can cause oxidative damage which accumulates during the life cycle, and this has been implicated in aging and age-dependent diseases such as cardiovascular disease, cancer, neurodegenerative disorders, and other chronic conditions. This chapter highlights the main themes from studies on free radicals, antioxidants, and oxidative stress and effect of oxidative stress in diseases.

An assessment of norepinephrine mediated hypertrophy to apoptosis transition in cardiac cells: A signal for cell death

OBJECTIVES Heart is an organ which is under a constant work load that generates numerous stress responses. Heart failure is associated with increased plasma norepinephrine (NE) and hypertrophic cell death. Within the current study we try to understand the concentration dependent molecular switch from hypertrophy to apoptosis under stress. METHODS The effect of increasing concentration of NE on cell death was studied using MTT assay based on which further experimental conditions were decided. Trypan Blue staining and TUNEL assay were done at selected concentrations of NE. Cellular and nuclear morphology at these concentrations was studied using Haematoxylin-Eosin, DAPI and PI stains. The molecular switch between hypertrophy and cell death was studied by expression analysis of β-MyHC and TNF-α. Rhodamine and DCFH-DA staining were done to evaluate the role of mitochondria and ROS under these conditions. Role of caspases under these transitions was also evaluated. RESULT NE shows steep falls in cell viability at 50 μM and 100 μM concentrations. The cellular and nuclear morphology is altered at these concentrations along with alterations at molecular level showing a shift from hypertrophy towards cell death. Altered mitochondrial membrane potential and increase in ROS support this which leads to caspase dependent activation of cell death. CONCLUSION We show that at 50 μM NE, there occurs a transition from cellular hypertrophy towards death. This could be beneficial to prevent hypertrophy induced cardiac cell death and evaluating cardio protective therapeutic targets in vitro.

Effectiveness of Arbuscular Mycorrhizal Fungal Isolates on Arabica Coffee (Coffea arabica L.)

ABSTRACT A glasshouse investigation was conducted to study the effectiveness of eight arbuscular mycorrhizal (AM) fungal isolates on Coffea arabica, Sln. 5. Coffee seedlings raised in the presence of AM fungi in polythene bags generally showed an increase in plant growth (height, number of leaves, leaf area and biomass) and plant nutritional status (P and Zn) over those grown in the absence of soil inoculation with AM fungi. The extent of growth and nutritional status enhanced by AM fungi varied with the isolates of AM fungi inhabiting the roots of coffee seedlings. Of the eight isolates, Gigaspora margarita and Acaulospora laevis were the best AM symbionts for arabica coffee compared with the others used under this experiment.

Events of Molecular Changes in Epithelial-Mesenchymal Transition

EMT is the process by which epithelial cells, characterized by well-developed intercellular contacts, transdifferentiate into motile and invasive mesenchymal cells. This process is associated with the loss of transmembrane intercellular adhesion molecule E-cadherin and disruption of cell-cell junctions along with acquisition of migratory properties. EMT is integral in embryonic development, wound healing, and stem cell behavior; however, its aberrant activation by micro-environmental alterations and abnormal stimuli can lead to cancer progression. Here, we review the different molecular changes associated with EMT that are responsible for downregulation of epithelial genes. Increased knowledge of the EMT process is essential for therapeutic targeting of cancer cells.

Evaluation of Antibacterial Activity of Lactobacillus Spp. on Selected Food Spoilage Bacteria.

This study was done to isolate Lactobacillus species from curd, amla/Indian gooseberry and orange and to assess their antagonistic ability against selected food spoilage bacteria, Escherichia coli, Pseudomonas spp. and Bacillus spp. isolated from natural food sources. In the approaches used, native Lactobacillus spp. were isolated from amla, orange and curd and identified by standard microbiological methods. Their antagonistic affect was tested by disc diffusion tests against three selected test isolates, Escherichia coli, Pseudomonas and Bacillus spp. isolated from tomato, pumpkin, cauliflower, ladys finger, carrot, and milk. There are recent patents also suggesting use of novel strains of Lactobacillus for microbial antagonism. In our present work, the lactobacilli isolated from different food sources showed varied ability to inhibit the growth of test isolates. The growth of test isolates was inhibited by Lactobacillus isolates with one of the Lactobacillus isolate from amla being the most potent inhibitor.