Page 86 - University of Pretoria RESEARCH REVIEW 2018

Plant poisonings
of veterinary and economic importance
Christo Botha, Department of Paraclinical Sciences
Livestock mortalities as a result of ingesting poisonous plants are a major concern for farmers in South Africa, and of direct economic importance to the farming community.
South Africa is inherently rich in flora and the native plant life is the richest temperate flora in the world. There are more than 24 500 taxa of flowering plants indigenous to South Africa. With such diversity in plant
life, there are invariably numerous potentially poisonous plants as well. The problem is exacerbated by many exotic and invasive plant species that have become naturalised in South Africa.
Christo Botha, Professor and Head of Department of Paraclinical Sciences at UP, has focused his research on plant poisonings and mycotoxicoses affecting livestock. With his
Zehtu Mathe, Christo Botha and Michael Famuyide.
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postgraduate students and research collaborators, he has also investigated new or lesser-known plant poisonings in livestock and companion animals. In 2018, he co-authored articles published in Mycotoxin Research, and in the Journal of the South African Veterinary Association.
Although there are over 600 indigenous and exotic poisonous plants known, not all are equally important. While the scientific documentation of new and lesser known plant poisonings is still a key objective, Professor Botha’s research efforts have recently focussed on the prevention of poisoning caused by cardiac glycoside-containing plants, and the mechanisms of action of the poisonous chemical compounds.
In collaboration with doctoral student, Hamza Isa, the immunisation of
livestock to prevent yellow tulp poisoning was evaluated. These findings were accepted for publication in Toxicon and Toxins. While vaccination as a means of preventing cardiac glycoside-induced poisoning seems to be quite feasible, improved methods that would induce the generation of antibodies able to bind and inactivate the plant toxin deserves further investigation.
To reduce the use of sentient animals in experimentation, Master’s students, Danielle Henn and Zehtu Mathe, used established cell lines as in vitro models to investigate cytotoxicity and subcellular mechanisms of toxicity of compounds isolated from poisonous plants. Their projects focussed on ‘krimpsiekte’ (shrinking disease), a chronic form of cardiac glycoside poisoning, and on ‘vermeersiekte’ or Geigeria poisoning.