Volume 4, Issue 1 (2017)
Research Paper
Identification of sibling species in field collected Anopheles minimus using ovarian nurse cell chromosome in two malaria endemic areas in Myanmar
Maung Maung Mya, Sein Thaung, Phyo Aung Naing, Ye Ye Myint, Thuza Nyein Mu, Yan Naung Maung Maung
Abstract: Malaria remains a major health problem in Myanmar. Anopheles dirus and Anopheles minimus are the principal vectors of malaria, but Anopheles maculatus, Anopheles vagus, Anopheles annularis, Anopheles philippnensis, Anopheles stiphensi and Anopheles culicifacies are secondary or suspected vectors of malaria in Myanmar. The aim of the present study was to know the prevalence of sibling species complex of Anopheles minimus using ovarian nurse cell polytene chromosome method and determine the potential vector using vector incrimination. Therefore the study was done in Pyin Oo Lwin Township Mandalay Region and Kamamaung Township Kayin State from October 2014 to September 2015. Anopheles mosquitoes were collected by animal bait K-net, human bait indoor and outdoor and light trap collection. A total of 1153 Anopheles mosquitoes comprising six mosquito species were collected from Pho Ne Dun Village, Pyin Oo Lwin Township. The highest number 553 of Anopheles minimus were collected. 953 Anopheles mosquitoes (524 from Katine Htit and 429 from Kine Taw) comprising nine species were collected from Kamamaung Township. Of these 93 and 92, Anopheles minimus was collected from Katine Htit and Kine Taw villages respectively. After identification blood fat Anopheles minimus was kept in paper cups with glucose. When ovary development reached to the semigravid stage (Christophe stage), ovary specimens were dissected and preserved in Cornoy’s fixative in screw type bottle and ovaries were tapered to vectors polytene chromosome. Head and thorax were homogenized tested for circumsporozoite antigen by ELISA method. Result found that all collected Anopheles minimus were observed sibling species A in both areas.
Circumsporozoite ELISA test found that only one Anopheles minimus A was found sporozoite positive in Kamamaung Township 0.54% (1/185) and not found any sporozoite positivity in Anopheles minimus A collected from Pyin Oo Lwin Township (0/553).
Research Paper
Identification of Withanolide-M and Stigmasterol as Potent neuroprotectant and Dual inhibitor of Inducible/Neuronal Nitric Oxide Synthase by Structure-Based Virtual Screening
Gaurav Kumar, Sumedha Mukherjee, Ranjana Patnaik
Abstract: Nitric oxide (NO) is an important intracellular signaling molecule, generated by catalysis from nitric oxide synthases (NOSs). In the face of NO playing beneficial roles, its overproduction by the neuronal nitric oxide synthase (nNOS) or inducible nitric oxide synthase (iNOS) is detrimental in neurological disorders, whereas that derived from the endothelial nitric oxide synthase (eNOS) is beneficial. Therefore, dual inhibition of iNOS and nNOS without inhibiting eNOS is a promising neuroprotective approach for combating stroke. Withania somnifera (WS) has been used for centuries as a nerve tonic and Nootropic agents in Ayurveda. Present structure-based molecular docking study was performed to identify novel, potent and dual iNOS/nNOS inhibitor by screening the Withania somnifera constituents. A ligand database containing 36 phytochemicals present in W. somnifera along with nNOS and iNOS selective inhibitor was molecularly docked onto catalytic heme domain of three NOS isoforms. This approach identified two phytosteroids withanolide-M and stigmasterol that have higher selectivity, bind with the lower binding energy and established a number of H -bonds or hydrophobic contacts with the catalytic oxygenase domain of iNOS and nNOS than their selective inhibitors (AT2 and S19). Their suitability for Lipinski’s Rule of Five, the ability to cross the Blood-Brain Barrier (BBB), high human intestinal absorption score make them a potent possible neurotherapeutic agent to combat neurological disorders mediated by nNOS and iNOS activation.
Research Paper
Detection and Analysis of Heart Rate during Arrhythmia
Chandra Mani, Munendra Singh
Abstract: In this work, an algorithm has been developed for the analysis of heart rhythm and detection of sinus tachycardia, sinus bradycardia and atrial fibrillation. The proposed algorithm analysis the heart rhythm and heart rate of ECG dataset using P wave. The rhythm is identified regular with very high heart rate for sinus tachycardia, whereas very low heart rate for sinus bradycardia. The proposed algorithm detected the R-R intervals present in ECG data are irregular, and P wave is abnormal for atrial fibrillation. The results show that in normal ECG sample, the R-R interval of consecutive R peaks is normally constant and the variation in the heart rate is 7.5%. In the case of abnormal ECG sample, R-R intervals of consecutive R peaks changes significantly, and variation in the heart rate exceeded to 7.5% once in the ECG sample. In the case of sinus bradycardia, the rhythm is regular, and heart rate is less than 60, whereas in the case of sinus tachycardia, the rhythm is regular and heart rate is greater than 100. In the case of atrial fibrillation, irregular rhythm is observed and correlation coefficients of P wave are not more than 74%.
Research Paper
Phytoconstituents obtained from Tanzanian medicinal plants display a high potential to inhibit Glucosamine-6-phosphate synthase as an antimicrobial target
Tomisin Happy Ogunwa
Abstract: Recent pharmacological research has focused attention on biological properties of bioactive compounds derived from medicinal plants. With the aid of in silico modeling and computational studies, the possible antimicrobial activity of phytoconstituents isolated from various Tanzanian medicinal plants was investigated. Out of the eighteen compounds selected and docked against a critical antimicrobial target, Glucosamine-6-phosphate synthase from Escherichia coli (E. Coli), eight (8) compounds including baphikinone, annonaine, rheediaxanthone B, isorheediaxanthone, forbexanthone, amaniensine, 12-hydroxy-des-D-garcigerrin A and baphikixanthone showed high binding affinity towards the enzyme. The molecular interaction, in comparison with the reference compounds, fructose-6-phosphate and fluconazole revealed that the compounds favorably docked on the binding site and the enzyme-ligand complex possessed low binding energy value, implying that the compounds may be potent inhibitors of the enzyme. The binding energy values obtained ranged from -7.0 kcal/mol to -9.3 kcal/mol compared to -7.6 kcal/mol and -6.0 kcal/mol obtained for fluconazole and fructose-6-phosphate respectively. The compounds penetrated and appeared to completely blocked the active site and, engaged amino acid residues at the active site in strong hydrogen bonds. These residues include Val-399, Thre-352, Glu-488, Ser-349, Gln-348, Thre-302, Ala-602, Lys-603, and Ser-303 most of which are required for catalytic activity. Hydrophobic interaction also seemed to participate in stabilizing the enzyme-ligand complex. Overall, the binding affinity and configuration for the selected phytoconstituents were comparable to the control ligands. Hence, the compounds may competitively hinder the synthesis of glucosamine-6-phosphate that is required for bacterial and fungal cell wall production. The results obtained in this study validate the antimicrobial potential of the medicinal plant sources of the compounds and show that they possess the ability to inhibit glucosamine-6-phosphate synthase as a target while providing insights into the possible molecular interaction involved in the antimicrobial effects observed in earlier reported wet experiments.
Research Paper
Larvicidal, Ovicidal and repellent effect of Citrus hystrix DC (Kaffir lime) fruit, peel and internal materials extracts on Aedes aegypti mosquitoes
Maung Maung Mya, Zar Zar Aung, Chit That Nwe, Aye Win Oo, Than Myat Htay, Sein Thaung and Yan Naung Maung Maung
Abstract: The present study aimed to evaluate the larvicidal, ovicidal and repellent activity of ethanol extracts of dry fruit, peels and internal fruit materials of Citrus hystrix DC against Aedes aegypti. Aedes aegypti larvae were collected from Than Byu Zayat Township Mon State and 50 each 3 rd and 4th instar larvae were exposed for 24 hours in various concentrations of ethanol extracts of different parts of the Citrus hystrix fruit, done 5 replicates. The dry fruit and peels extracts resulted in significantly higher 100% mortality (P<0.05) when compared to the mortality (86.8%) caused by internal material of Citrus hystrix fruit at the concentration of 0.1gm/100ml against Aedes larvae. The dose 0.0125g/100 ml of Citrus hystrix fruit extract was found to be 100% protection from oviposition of gravid Aedes aegypti mosquitoes in laboratory. The LC50 and LC90 values were 0.0138, 0.0142 and 0.0276, and 0.0515, 0.0522 and 0.1045 g for fruit extract, peel and internal material. The highest repellency activity of complete protection time of Citrus hystrix DC dose 0.0002g/cm2 was found dry fruit extract followed by peel extract and lowest activity was found internal fruit materials extracts. These three extracts provided 100%, 97.52% and 92.15% protection from bite for 30min and 96.72%, 86.25% and 80.25% protection for 60 min and 88.52%, 80.1% and 73.52% protection for 90min, against adult Aedes aegypti. These extracts did not cause dermal irritation when applied to animal skins. The findings of the present study revealed that the ethanol extract of the fruit of Citrus hystrix DC has strong larvicidal, ovicidal and repellent properties on Aedes mosquitoes as a good source of preparations for mosquito control.