Ecotoxocology And Ecophysiology
Zoology and Environmental Biology
At the Zoology And Environmental Biology department office
Appointment on Visitation important
Topic: Toxicity And Endocrine Disrupting Potential Of Various Herbicide Formulations
Toxicity and endocrine disrupting potential of numerous pesticides have been established. But less is still known about the toxicity disruption potential within the herbicides groups despite the numerous exposure impacts and physiological effects lesson from Atrazine herbicide. My current work is focusing on the teratogenicity, thyroidal and reprotoxicity of many old and emerging herbicides. The other aspect is the occurrence of pesticide residues in various plant products,
|# ||Certificate ||School||Year |
||Ph.D (Ecotoxicology and Ecophysiology( Endocrine Disrupting Substances)
||Botany and Zoology Department, Stellenbosch University, South Africa.
Assessment of Teratogenicity, Thyroidal and Reproductive toxicity of Penoxsulam herbicide using Xenopus laevis
Several pesticides that finds their ways into the aquatic ecosystems have inherent capacities to disrupt the reproductive development of animals. They causes physiochemical disruption particularly through the hypothalamus-pituitary-gonadal axis that sometimes alter progression of spermatogenesis/oogenesis, disrupts sex hormones biosynthesis and functions, including alteration in circulation levels of sex hormone steroids, induction of hepatic biosynthesis of Vitellogenin and growth of oviducts in males as well as altering gonadal differentiation and sex ratios (Flament et al., 2011; Orton and Tyler, 2011).
The aquatic herbicide groups are particularly more worrisome, because they are directly applied into aquatic system. These include Imazapyr, Diquat dibromide, Glufosinate ammonium, Glyphosate and Penoxsulam.
Despite the recent negative evidence from some of these aquatic herbicides, not much is known about the exposure impacts of Penoxsulam, particularly in regards to its teratogenicity, thyroidal and gonadal potential.
Penoxsulam is a post-emergence, acetolactate synthase (ALS) inhibitor herbicide developed by Dow AgroSciences. It is expected to be very mobile, but not very persistent, in environments. It degrades by two different transformation mechanisms, producing thirteen different identified transformation products.
Materials and Methods
Using the following Protocols
a. The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a standardised 4-day flexible bioassay for assessment of potential developmental and teratogenic effects. FETAX protocol assesses mortality, malformation and growth inhibition during the embryonic developmental phase.
b. The Xenopus metamorphosis assay (XEMA) is an animal-based model that is intended to identify substances that may interfere with the normal functioning of the hypothalamic-pituitary thyroid (HPT) axis using Xenopus laevis (OECD 2007). The primary endpoints including hind-limb length, developmental stage and thyroid gland histology, while snout vent length, wet weight, and mortality.
c. Lutz et al (2004) Protocol on Gonadal development
Contribution to Knowledge
This study will further enhanced the human knowledge and understanding of exposure impacts of aquatic herbicide formulations on non-target organisms.
BABALOLA OLUWASEUN is a Lecturer I at the Department of Zoology and Environmental Biology
BABALOLA has a Ph.D in Ecotoxicology and Ecophysiology( Endocrine Disrupting Substances from Botany and Zoology Department, Stellenbosch University, South Africa.