Journal of Biomedical Sciences https://www.nepjol.info/index.php/JBS <p>Official journal of the Nepal Health Research Society.</p> <p>JBS is currently accepting submissions by Email – <a href="mailto:jbs.editors@gmail.com">jbs.editors@gmail.com</a></p> <p>There is NO publication/processing fee for submissions to the journal.</p> <p>The first author of each original article accepted for publication will receive NPR 500 (Nepalese Citizens) from the journal after the article is published.</p> Nepal Health Research and Welfare Society en-US Journal of Biomedical Sciences 2676-1343 In vitro anti-bacterial activity of Tinospora cordifolia leaf extract and its phytochemical screening https://www.nepjol.info/index.php/JBS/article/view/23633 <p><strong>Background: </strong>Antimicrobial resistance is the main concern worldwide to combat infectious. Over the years studies on leaf extracts <em>Tinospora cordifolia</em> have demonstrated the potent role its antibacterial property. The current study is an attempt to test its antibacterial property against Escherichia coli cell division.</p> <p><strong>Material and methods: </strong>Phytochemical screening assay of <em>T. cordifolia </em>leaf extract was done using standard procedure and the results showed the presence of alkaloid, carbohydrate, terpenoid, steroid, tannin, amino acid, flavonoid and glycoside components.</p> <p><strong>Results: </strong>HPLC analysis revealed the presence of berberine in <em>T. cordifolia </em>leaf extract. Further <em>E. coli</em> cells were treated with berberine to study its efficacy in inhibiting cell division. Antibacterial assay was performed by using disc diffusion method.</p> <p><strong>Conclusion: </strong>Among aqueous, methanolic, ethanolic, chloroform, hexane and acetone extract only methanolic extract showed zone of inhibition.</p> B. Praiwala S. Priyanka N. Raghu N. Gopenath A. Gnanasekaran M. Karthikeyan R. Indumathi N.K. Ebrahim B. Pugazhandhi P. Pradeep M.S. Ranjith S. Balasubramanian Kanthesh M. Basalingappa ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2019-04-17 2019-04-17 5 2 10 17 10.3126/jbs.v5i2.23633 Cell signaling in yeast: A mini review https://www.nepjol.info/index.php/JBS/article/view/23634 <p><strong>Background: </strong>Understanding cellular mechanism of communication is the main goal of systems biology. Unicellular yeasts are effective model to understand the molecular interactions that generate cell polarity induced by external inputs. The mechanisms of many extracellular stimuli are induced by complexes of cell surface receptors, G proteins. The mechanisms of many extracellular stimuli are induced by complexes of cell surface receptors, G proteins and mitogen activated protein (MAP) kinase complexes. Many components, their interrelationships, and their regulators of these mechanisms were initially identified in yeast. A complex web of sensing mechanisms and cooperation among signaling networks such as a cyclic adenosine monophosphate dependent protein kinase, mitogen-activated protein kinase cascade and 5-adenosine monophosphate activated protein kinase induce various changes in physiology, cell polarity, cell cycle progression and gene expression to achieve differentiation. Ras-cAMP pathway explained in yeast model with signalling function of the oncogenic mammalian Ras protein. So studies on yeast cells may enlighten some underlying mechanism which will be beneficial to understand the mechanisms of disease.</p> N.N. Shipingana N. Raghu S. Veerana Gowda T.S. Gopenath M.S. Ranjith A. Gnanasekaran M. Karthikeyan B. Roy B. Pugazhandhi P. Pradeep S. Balasubramanian Kanthesh M. Basalingappa ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2019-04-17 2019-04-17 5 2 18 22 10.3126/jbs.v5i2.23634 Quorum sensing: A molecular cell communication in bacterial cells https://www.nepjol.info/index.php/JBS/article/view/23635 <p><strong>Background: </strong>Quorum sensing is a cell-to-cell communication, which is extensively observed in bacteria. This process allows the cell to detect, analyze, share and act upon various environmental stimuli based on cell density. The molecular aspect of this process is the secretion and detection of chemical signaling molecules called autoinducers (AIs), which act upon the gene expression. The quorum sensing signaling pathway is specifically observed only bulk population or in other words, the quorum sensing is effective only in high cell density. The quorum sensing circuit in the bacterial population is widely studied under the following heading; quorum sensing in Gram positive bacterium, Quorum sensing in Gram negative bacterium and the Quorum sensing with respect to Interkingdom communication. These models are studied using the widely studied models like <em>Vibrio fischeri</em> in Gram negative QS circuit, <em>Staphylococcus aureus</em> in Gram positive QS circuit and <em>Vibrio harveyi.</em> This review paper details the introduction of quorum sensing and their gene level explanation and how they effect on the virulence of a particular species of bacteria. This paper also throws light on the realization that the bacteria has the capable of performing coordinated activities that was so long contributed to the eukaryotic cell performance.</p> - Geethanjali V. Dinesh Kumar N. Raghu T.S. Gopenath S. Veerana Gowda K.W. Ong M.S. Ranjith A. Gnanasekaran M. Karthikeyan B. Roy B. Pugazhandhi P. Pradeep S. Balasubramanian Kanthesh M. Basalingappa ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2019-04-17 2019-04-17 5 2 23 34 10.3126/jbs.v5i2.23635