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Asha Jaja-Chimedza, Postdoctoral Associate

Education

Ph. D. August 2014 Chemistry, Florida International University, Miami, Florida.

  • Dissertation: ‘Contribution of Lipophilic Bioactive Metabolites to the Toxicity of Strains of Freshwater Cyanobacterial Harmful Algal Blooms, Identified Using the Zebrafish (Danio rerio) Embryo as a Model for Vertebrate Development’.
M. Sc. August 2009 Chemistry, Florida International University, Miami, Florida.

  • Thesis: ‘Effects of Cyanobacterial Lipopolysaccharides on Various Detoxifying Enzymes and Metal Toxicity in Zebrafish (Danio rerio) Embryos’.
B. Sc. August 2005 Chemistry (Magna Cum Laude), Florida Agricultural and Mechanical University, Tallahassee, Florida.

Research & Teaching Experience

2015-Present NIH T-32 Postdoctoral Fellow: Botanical approaches to combat metabolic syndrome. SEBS, Rutgers University, New Brunswick, NJ.

  • Isolation and characterization of phytoactives with potential health benefits associated with metabolic syndrome.
  • Optimization of extraction methods towards the commercialization of bioactive products.
  • Use of in vitro and in vivo models for the analysis of phytochemicals associated with metabolic syndrome.
2009-2014 Graduate Research Assistant: Natural Products Chemistry. Florida International University, Miami, Florida.

  • Isolation of bioactive compounds in freshwater cyanobacteria using various chromatographic methods including column chromatography, flash chromatography, preparative thin-layer chromatography, and high-performance liquid chromatography.
  • Implementation of zebrafish embryos as a model for vertebrate development in the bioassay-guided purification of the bioactive compounds from the freshwater cyanobacteria.
  • Chemical characterization of bioactive compounds from freshwater cyanobacteria, using mass spectrometric analysis (HRESIMS, LCMS) and nuclear magnetic resonance spectroscopic analysis (1H, 13C, DEPT-135, COSY, HMQC, HMBC).
  • Development of analytical methods for the identification and quantitation of known phycotoxins and mycotoxins as well as the new isolated bioactive compounds using LC-MS.
  • Training students in the use of laboratory instruments and maintenance of the laboratory instruments.
  • Toxicological analysis of the bioactive compounds from the freshwater cyanobacteria in the zebrafish embryos.
  • Maintenance and breeding of adult zebrafish for bioassays as well as raising zebrafish embryos.
2007-2009 Graduate Research Assistant: Biochemistry and Toxicology. Florida International University, Miami, Florida.

  • Evaluation of the effects of lipopolysaccharides on the detoxifying enzymes in zebrafish embryos using various enzyme-based assays (GST, GR, GSH, SOD, CAT).
  • Use of enzyme-linked immunosorbent assay (ELISA) for the analysis of microcystin, cylindrospermopsin, and saxitoxin in cyanobacterial extracts, fish extracts, and water samples.
  • Evaluation of the effects of lipopolysaccharides on metal toxicity in zebrafish embryos.
  • Maintenance and breeding of zebrafish for bioassays.
2007-2014 Teaching Assistant. Florida International University, Miami, Florida.

  • Chemistry & Society Lab.
  • General Chemistry I and II Labs.
  • Organic Chemistry I and II Labs.
  • Introduction to Analytical Chemistry Lab.
  • Substituted for General Chemistry I and II and Analytical Chemistry Lectures.

Publications

  1. Kim, Y., Jaja-Chimedza, A., Merrill, D., Mendes, O., Raskin, I. A 14-day repeated-dose oral toxicological evaluation of an isothiocyanate-enriched hydro-alcoholic extract from Moringa oleifera Lam. seeds in rats. Toxicology Reports, Vol. 5., pp. 418-426, 2018.

  2. Jaja-Chimedza, A., Zhang, L., Wolff, K., Graf, B. L., Kuhn, P., Moskal, K., Carmouche, R., Newman, S., Salbaum, J. M., Raskin, I. A dietary isothiocyanate-enriched moringa (Moringa oleifera) seed extract improves glucose tolerance in a high-fat-diet mouse model and modulates the gut microbiome. J. Functional Foods, Vol. 47, pp. 376-385, 2018.

  3. Kuhn, P., Kalariya, H., Poulev, A., Ribnicky, D. M., Jaja-Chimedza, A., Roopchand, D. E., and Raskin, I. Grape polyphenols reduce gut-localized reactive oxygen species associated with the development of metabolic syndrome in mice. PLoS|ONE, Vol. 13, No. 10, article e0198716, 2018.

  4. Kim, Y., Wu, A. G., Jaja-Chimedza, A., Graf, B. L., Waterman, C., Verzi, M. P., Raskin, I. Isothiocyanate-enriched moringa seed extract alleviates ulcerative colitis symptoms in mice. PLoS ONE, Vol. 12, No. 9, article e0184709, 2017.

  5. Jaja-Chimedza, A., Graf, B. L., Simmler, Ch., Kim, Y., Kuhn, P., Pauli, G. F., Raskin, I. Biochemical characterization and anti-inflammatory properties of an isothiocyanate-enriched moringa (Moringa oleifera) seed extract. PLOS | ONE, Vol. 12, No. 8, article e0182658, 2017.

  6. Jaja-Chimedza, A., Sanchez, K., Gantar, M., Gibbs, P., Schmale, M., Berry, J. P. Carotenoid glycosides from cyanobacteria are teratogenic in the zebrafish (Danio rerio) embryo model. Chemosphere, Vol. 174, pp. 478-489, 2017.

  7. Berry, J. P., Roy, U., Jaja-Chimedza, A., Sanchez, K., Matysik, J., Alia, A. High-resolution magic angle spinning nuclear magnetic resonance of intact Zebrafish embryos detects metabolic changes following exposure to teratogenic polymethoxyalkenes from Algae. Zebrafish, Vol. 13, No. 5, pp. 456-465, 2016.

  8. Haq, M., Gonzalez, N., Mintz, K., Jaja-Chimedza, A., De Jesus, C. L., Lydon, C., Welch, A., Berry, J. P. Teratogenicity of Ochratoxin A and the degradation product, Ochratoxin α, in the Zebrafish (Danio rerio) embryo model of vertebrate development. Toxins, Vol. 8, No. 2, article 40, 2016.

  9. Jaja-Chimedza, A., Saez, C., Gantar, M., Gibbs, P., Schmale, M., Berry, J. Identification of teratogenic polymethoxy-1-alkenes from Cylindrospermopsis raciborskii, and taxonomically diverse freshwater cyanobacteria and green algae. Harmful Algae, Vol. 49, pp. 156-161, 2015.

  10. Jaja-Chimedza, A., Gantar, M., Gibbs, P., Schmale, M., Berry, J. Polymethoxy-1-alkenes from Aphanizomenon ovalisporum inhibit vertebrate development in the zebrafish (Danio rerio) embryo model. Marine Drugs, Vol. 10, No. 10, pp. 2322-2336, 2012.

  11. Jaja-Chimedza, A., Gantar, M., Mayer, G. D., Gibbs, P., Berry, J. P. Effects of cyanobacterial lipopolysaccharides from Microcystis on Glutathione-based detoxification pathways in the Zebrafish (Danio rerio) Embryo. Toxins, Vol. 4, No. 6, pp. 390-404, 2012.

  12. Berry, J., Jaja-Chimedza, A., Dávalos-Lind, L., Lind, O. Apparent bioaccumulation of cylindrospermopsin and paralytic shellfish toxins by finfish in Lake Catemaco (Veracruz, Mexico). Food Addit Contam Part A Chem Anal Control Expo Risk Assess., Vol. 29, No. 2, pp. 314-321, 2012.

Presentations

  1. Asha Jaja-Chimedza, Patrick Gibbs, Miroslav Gantar, John Berry. Inhibition of Vertebrate Development in Zebrafish (Danio rerio) Embryos Exposed to Polymethoxy-1-alkenes Isolated from Freshwater Cyanobacteria. 7th Symposium on Harmful Algae in the US. Sarasota, FL, October 27-31, 2013. (Oral presentation)

  2. Asha Jaja-Chimedza, Patrick Gibbs, Miroslav Gantar, John Berry. Contribution of Lipophilic Toxins to the Toxicity of Toxigenic Strains of Freshwater Cyanobacteria. 16th Gordon Research Conference on Mycotoxins and Phycotoxins. Easton, MA, June 16-21, 2013. (Poster and Oral presentation)

  3. Asha Jaja-Chimedza, Patrick Gibbs, Miroslav Gantar, John Berry. Inhibition of Vertebrate Development in Zebrafish (Danio rerio) Embryos Exposed to Polymethoxy-1-alkenes Isolated from Freshwater Cyanobacteria. 15th International Conference on Harmful Algae. Changwon Gyeongnam, Korea, October 29 – Novermber 2, 2012. (Oral presentation)

  4. Asha Jaja-Chimedza. Purification and Characterization of Isotactic Polymethoxy Alkenes from Known Toxigenic Strains of Cyanobacteria. 33rd Annual Southeastern Phycological Colloquy. Miami, FL, October 14, 2011. (Oral presentation)

  5. Asha Jaja-Chimedza, Patrick Gibbs, John Berry. Cyanobacterial Developmental Toxins: Identification, Isolation, and Characterization. Joint Annual Meeting of the American Society of Pharmacognosy & the Phytochemical Society of North America. St. Petersburg, FL, July 10-14, 2010. (Poster)