1.Cleft analysis of Zika virus non-structural protein 1
Wiwanitkit SOMSRI ; Wiwanitkit VIROJ
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):763-764
The non-structural protein 1 is an important molecule of the viruses in flavivirus group including to Zika virus. Recently, the NS1 of Zika virus was discovered. There is still no complete information of the molecular interaction of NS1 of Zika virus which can be the clue for explanation for its pathogenesis and further drug search. Here the authors report the cleft analysis of NS1 of Zika virus and the result can be useful for future development of good diagnostic tool and antiviral drug finding for management of Zika virus.
2.Antioxidant antileishmanial cytotoxic and antimicrobial activities of a local plant Myrtus nivellei from Algeria Sahara
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):702-707
Objective: To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents. Methods: Phytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin–Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests. Results: Preliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxi-dant, antimicrobial and had a moderate antileishmanial activity. Conclusions: These observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.
3.Direct detection of rpoB and katG gene mutations of Mycobacterium tuberculosis in clinical samples
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):698-701
Objectives: To study the rpoB and katG gene mutation rate and its markers. Methods: Cross-sectional study methods were used to study Tuberculosis. A total of 45 sputum samples were collected from Annapurna Neurological Institute and Allied sci-ences. Then, acid fast bacilli staining were performed. Positive and negative samples were carried for conventional polymerase chain reaction identification and electrophoresis. Results: Out of 45 samples, 3 were acid fast bacilli positive and the rest were negative. Male participants were more as compare to female participants and the mutation in rpoB and katG gene was found similar i.e. 6.66%among the total samples. Conclusions: We can conclude that genetic mutation in Mycobacterium tuberculosis can be identified directly from the clinical samples. However, we have carried this study in less sample size and to validate research on large number of sample is recommended.
4.Assessment of pesticide contaminated sediment using biological response of tropical chironomid, Chironomus javanus Kiffer as biomarker
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):719-724
Objective: To investigate the use of a biomarker for assessment of the effects on the tropical chironomid, Chironomus javanus (C. javanus), Kiffer of sediment contaminated with an insecticide (chlorpyrifos). Methods: A wide range of biological responses to the tropical chironomid exposed were measured, including survival, growth rate and Acetylcholinesterase (AChE) activity. Results: The measured median lethal concentration (96 h LC50) of chlorpyrifos to C. javanus was 0.056 (95% CI 0.024–0.124) μg/kg. For sub-chronic levels of chlor-pyrifos between 0.001 and 0.25μg/kg administered for 10 days, the effects on the growth of C. javanus were reduced (larva size, head structure width and dry weight) at the significance level (P < 0.01) and the effects were concentration dependent. Following exposure to chlorpyrifos at the level of 0.001μg/kg for 48 and 96 h, the AChE activity in C. javanus was inhibited compared with control samples (P<0.05). Conclusions: This study demonstrated that C. javanus was sensitive when exposed to chlorpyrifos. This species could serve as a potential biomarker for assessing pesticide contamination at low environmental persistence and provides limited effects data on the sensitivity of tropical biota to contaminants for ecological risk assessment of organo-phosphate pesticides in the tropical aquatic ecosystem.
5.Construction and expression of a synthetic gene encoding nonstructural glycoprotein NS1 of dengue 2 virus in Pichia pastoris
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):689-693
Objectives: To express and characterize NS1 of Indonesian-specific DENV2 virus in Pichia pastoris (P. pastoris). Methods: A codon optimized synthetic gene derived from the DENV-2 NS1 amino acid sequences was synthesized commercially and inserted into the P. pastoris pPICZαA expression vector. The recombinant DENV-2 NS1 protein was purified by Ni-NTA af-finity chromatography, and its antigenicity was tested. Results: The recombinant DENV-2 NS1 protein was secreted as a protein with a mo-lecular weight of ~45 kDa, and the optimal expression condition was achieved by in-duction with 2%(v/v) methanol for 72 h. The purified recombinant DENV-2 NS1 protein was able to interact with a monoclonal antibody of NS1 in a commercial rapid test. Conclusions: The resulting recombinant DENV-2 NS1 protein produced in P. pastoris KM71 is a potential candidate for use in the development of a dengue diagnostic kit and vaccine.
6.Serological survey of avian influenza virus infection of unvaccinated backyard chickens in Mandlhakazi, Southern Mozambique
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):686-688
Objective: To investigate serologically the presence of avian influenza virus (AIV) in backyard chickens from Mandlhakazi district, Southern Mozambique. Methods: A total of 439 sera samples from unvaccinated and apparently healthy backyard chickens from 4 villages (Chidenguele, Macuacua, Chizavane, and Nwadja-hane) were tested for the presence of AIV antibodies through commercial enzyme-linked immunoabsorbent assay (ELISA) kit used according to manufacturer instructions. Results: Anti-AIV antibodies were detected in all villages surveyed. The overall sero-prevalence obtained was 32.6% (95% CI 28.2%–37.0%). The highest prevalence of 51.3% (95% CI 42.3%–60.2%) was recorded in Macuacua village, while the lowest prevalence of 13.0%(95%CI 6.2%–19.9%) was found in Chizavane village. The results of logistic regression analyses suggested that chicken being located in Chizavane and Macuacua villages were more unlikely for getting the virus exposure (P<0.05). Conclusions: Our findings suggested that AIV is widespread within backyard chickens in the studied villages. Further research is needed to identify the circulating virus ge-notypes and determine the potential role of backyard chickens in the zoonotic trans-mission of AIV in Mozambique.
7.Chalcone analogue as potent anti-malarial compounds against Plasmodium falciparum:Synthesis, biological evaluation, and docking simulation study
Asian Pacific Journal of Tropical Biomedicine 2017;7(8):675-679
Objective: To investigate in vitro antimalarial activity of chalcone derivative compounds against Plasmodium falciparum 3D7 (Pf3D7) strain and in silico antimalarial activity. Methods: Synthesis of the chalcone derivatives was conducted via Claisen-Schmidt method using NaOH 60% base as catalyst. An in vitro antimalarial activity assay was carried out according to the Rieckmann method against the chloroquine-sensitive Pf3D7 strain. Molecular docking studies of the prepared compounds were performed using Discovery Studio 3.1 (Accelrys, Inc., San Diego, USA) software to dihydrofolate re-ductases–thymidylate synthase (PfDHFR-TS) protein with Protein Data Bank ID of 1J3I.pdb (sensitive-protein) and ID:4DP3.pdb (resistance-protein). Results: This work has successfully synthesized seven chalcone derivatives with a great antimalarial activity. It has been revealed that allyloxy, hydroxy and alkoxy functional groups could increase the antimalarial activity of the chalcone derivatives. The best antimalarial activity of the prepared compounds was possessed by 3b with an IC50 value of 0.59μM and categorized as an excellent antiplasmodial. Molecular docking studies of 3b showed binding interaction with the amino acid residues such as Ala16, Ile164, Phe58, Tyr170 of the 1J3I.pdb protein and also Ala16, Phe58, Ile112, Met55 of the 4DP3.pdb protein. Conclusions: An in vitro antimalarial assay of the prepared chalcone derivative (3a–g) showed an excellent and good antiplasmodial activity against the chloroquine-sensitive Pf3D7 strain. In silico antimalarial studies revealed that 3a–g made binding interaction with both sensitive-protein (1J3I.pdb) and resistance-protein (4DP3.pdb), which means that they were both active against chloroquine-sensitive and resistant plasmodium strain.
8.Antibiotic susceptibility and molecular characterization of resistance genes among Escherichia coli and among Salmonella subsp. in chicken food chains
Asian Pacific Journal of Tropical Biomedicine 2017;7(7):670-674
Objective: To investigate the occurrence of resistance genes among Escherichia coli (E. coli) and Salmonella subsp. isolated in chicken food chains in Phnom Penh, 2012–2013. Methods: Six hundred eighty two E. coli and 181 Salmonella Albany, Corvallis, and Kentucky strains were examined for susceptibilities to eight antimicrobials and following resistance genes were identified by PCR:blaTem, StrA, aadA, sul1, sul2, gyrA, Tet (A), and Tet (B). Results: E. coli presented high resistances to tetracycline, amoxicillin, and sulfameth-oxazole (63.1%–76.1%). Salmonella Albany and Salmonella Kentucky traduced high resistance percentages to amoxicillin, tetracycline, sulfamethoxazole, and nalidixic acid (84.6%–100%). Among amoxicillin-resistant isolates, blaTem genes were observed for 62%of E. coli isolates and 20%of 65 Salmonella Kentucky. The StrA gene was prevalent in 36%of 331 aminoglycoside-resistant E. coli and 90%of 40 aminoglycoside-resistant Salmonella Corvallis. The sul2 gene was predominant among sulfamethoxazole-resistant isolates, for 56%of 431 E. coli and 53%of 66 Salmonella Corvallis;the sul1 gene was observed in 54%of Salmonella Albany. The Tet (A) resistance gene was prevalent in E. coli (86%), Salmonella Corvallis (82%), Salmonella Kentucky (84%). High percentages of gyrA genes observed among nalidixic-acid resistant E. coli (91%), Salmonella Albany (92%), Salmonella Corvallis (75%) and Salmonella Kentucky (85%). Conclusions: Important occurrences of resistance gene were observed among E. coli and Salmonella in chicken food chains in Cambodia.
9.Antihypertensive and antioxidant activity of Cassytha filiformis L.:A correlative study
Yuliandra YORI ; Armenia A. ; Arifin HELMI
Asian Pacific Journal of Tropical Biomedicine 2017;7(7):614-618
Objective: To study the blood pressure lowering effect of Cassytha filiformis extract in animal models of hypertension and its correlation with the antioxidant activity. Methods: Male Sprague–Dawley rats were divided into two groups: endocrine hyper-tension (HTN group) that received a combination of prednisone and salt for two weeks and oxidative stress-associated hypertension (HTN-OS group) that received additional induction of L-Nitro Arginine Methyl Esther (L-NAME) for two days. Each group was subdivided into 4 and treated intravenously with the extract 5; 10; and 20 mg/kg, and vehicle control. The systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded. The blood was taken before and at the end of recording for the measurement of serum concentration of nitric oxide (NO). The changes of blood pressure were analyzed by two-way ANOVA while its correlation with NO concentration was analyzed by Pearson's Correlation. Results: The study showed a significant antihypertensive effect of the extract as compared with control group (P<0.05) in both hypertensive models. Extract in the dose of 5 mg/kg showed the best blood pressure lowering effect. However, the correlation analysis did not show an association between NO increase and blood pressure lowering effect (P>0.05). Conclusions: The study concludes that C. filiformis extract in the dose of 5 mg/kg ex-hibits the best blood pressure lowering effect in both animal models. Antihypertensive activity of the extract is not correlated with its antioxidant effect.
10.Dysregulation of Notch signaling related genes in oral lichen planus
Nowwarote NUNTHAWAN ; Osathanon THANAPHUM
Asian Pacific Journal of Tropical Biomedicine 2017;7(7):666-669
Objective: To investigate a dysregulation of Notch signaling in oral lichen planus (OLP) using public available microarray dataset. Methods: A mRNA expression profiling dataset from Gene Expression Omnibus was downloaded. Differential gene expression between OLP and normal oral epithelium was examined using NetworkAnalyst. The dysregulated genes related to Notch signaling were identified. Results: Thirteen genes in Notch signaling pathway were significantly differential expressed between OLP and normal epithelium. OLP samples significantly increased the mRNA levels of HEYL, APH1B, CNTN1 and PSEN2. Whilst, ITCH, HES1, TLE2, DLK2, DTX2, NOTCH3, JAG2, RFNG, and SPEN were downregulated in OLP groups. Conclusions: Notch signaling was dysregulated and may participate in pathophysiologic process in OLP.