Search

Objective: Phenotype based small molecule discovery is a category of chemical genetic study. The aim of this study was to observe the phytochemical based genetic effects of Sargassum wightii during organogenesis in embryonic zebrafish. Materials and Methods: The phytomolecules from S. wightii were extracted using organic solvents and treated with the 24 hold developing zebrafish embryos. The active extract was partially purified by column chromatography, C18 Sep-Pak column and reversed-phase high-performance liquid chromatography. Results: Initially, cardiac bulging was found in 2 dpf to 3 dpf (days post fertilization), then bradycardia and tubular heart were observed in the next 8 h, which also showed the reduction in the heart beat rates. The phenotypic mutation effects of bre, has, dou yan, heg and you were observed in the 3 dpf and 4 dpf of the extract treated zebrafish embryos. Conclusions: This study demonstrated that the phytomolecules from S. wightii exhibited potential molecular switches on the developmental process, which might have significant role in understanding the development based chemical genetic studies in zebrafish. [ABSTRACT FROM AUTHOR]

Background: Zebrafish is an important model organism for human neurobehavioural studies and compound screening for neurodegenerative disorders like Alzheimer's disease and dementia. Purpose: We wanted to analyse the rapid neurobehavioural effects based on acetylcholinesterase inhibitors from Tephrosia purpurea in zebrafish. Methods: Tephrosia purpurea (a herbal neuroactive molecule) extract was analyzed for its rapid neurobehavioural effects and the corresponding psychotic twitches were quantified. The inhibitory activity of acetylcholinesterase was analysed in Zebrafish. The activity of the molecule was confirmed after column chromatography and RP-HPLC purifications. The toxicity of the molecule was also studied in developing zebrafish embryos. Results: The psychotic body twitches were calculated as crude 484.67 ± 18.01 at 10 μg/ mL, column purified 616 ± 9.64 at 8 μg/mL, Sep-Pak C18 712.67 ± 19.5 at 6 μg/mL, and HPLC elution showed 815 ± 14.93. The minimum inhibitory concentration of acetylcholinesterase in crude and column purified was 100 ng/mL and 5 ng/mL. The IC50 value of acetylcholinesterase inhibitor was calculated as 626ng/mL for crude (P<0.000l), 28.92 ng/mL for Sep-Pak column elution and 64 ng/mL for Donepezil. The HPLC fifth elation showed inhibition percentage as 96.97 ± 0.12. The organogenesis effects were seen in the drug concentration of 10 ag/mL. Pericardial bulging, trunk and tail flexure with heart edema and head edema were observed in the embryos at higher dose of 30-40 μg The LC50 value was 34.87μg/mL. The studies showed that the inhibitory concentration of acetylcholinesterasn is comparatively higher than Donepezil. Conclusions. Rapid behaviour based screening us an unexpesive assay to identify neuroactive small molecules. This herbal can be further used for the development of drugs for Alzheimers disease. [ABSTRACT FROM AUTHOR]

Background & Objectives: Antibiotic resistance in pathogens has become a serious problem worldwide. Therefore, the search for new antibiotics for drug resistanct pathogens is an important endeavor. The present study deals with the production of anti-methicillin resistant Staphylococcus aureus (MRSA) potential of Streptomyces rubrolavendulae ICN3 and evaluation of anti-MRSA compound in zebrafish embryos., Methods: The antibiotic production from S. rubrolavendulae ICN3 was optimized in solid state fermentation and extracted. The antagonistic activity was confirmed against MRSA and purified in silica gel column and reverse phase--HPLC with an absorption maximum at 215 nm. Minimal inhibitory concentration of the compound was determined by broth microdilution method. Zebrafish embryos were used to evaluate the extract/compound for its minimal inhibition studies, influences on heart beat rates, haematopoietic blood cell count and lethal dose values., Results: Streptomyces rubrolavendulae ICN3 showed potent antagonistic activity against MRSA with a zone of 42 mm. The minimum inhibitory concentration was calculated as 500 μg/ml of the crude extract and the purified C23 exhibited 2.5 μg/ml in in vitro assay. The LC 50 value of the anti MRSA compound C23 was calculated as 60.49 μg/ml and the MRSA treated embryos survived in the presence of purified compound C23 at a dose of 10 μg/ml., Interpretation & Conclusions: Our results suggested that the compound was potent with less toxic effects in zebrafish embryonic model system for MRSA infection. Further structural evaluation and analysis in higher mammalian model system may lead to a novel drug candidate for drug resistant Staphylococcus aureus.