Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
20 September 2024 | Story André Damons | Photo Supplied
zebrafish-blue-in-aquarium
Zebrafish blue in an aquarium.

A researcher from the University of the Free State (UFS) hopes to make living with epilepsy and other diseases of the central nervous system (CNS) easier by using South African plants extracts which may have anti-epileptic properties and testing them on zebrafish larvae.

Prof Anke Wilhelm, Associate Professor and Divisional Head of Organic Chemistry in the UFS Department of Chemistry, focuses her research on the isolation of active GABAergic compounds (substances that affect the brain’s GABA system, which helps control nervous system activity) by using a test that measures the movement of zebrafish larvae.

Even though obtaining regulatory approval for use as a treatment for epilepsy is a long and complex process, Prof Wilhelm hopes to contribute to the better pain management of people suffering from epilepsy and diseases of the CNS through an affordable alternative drug with less side effects.

The tests are done in a zebrafish bioassay (an analytical method to determine the potency of a substance by its effect on living animals) housed at the UFS’ Chemistry Department.

Why zebrafish larvae?

Prof Wilhelm, who is a National Research Foundation Y2-rated synthetic organic chemist, says zebrafish share about 70% of their genes with humans, and about 84% of human genes known to be associated with diseases have a counterpart in zebrafish. This makes them a valuable model for studying human biology and disease.

“Zebrafish are powerful tools for modelling a wide range of CNS diseases, contributing significantly to the understanding of disease mechanisms and the development of potential treatments,” she says. “Mood disorders, anxiety, insomnia, and attention deficit hyperactivity disorder (ADHD) are all diseases which may be studied through this bioassay.”

She explains that the zebrafish larvae are studied seven days after fertilisation in their bioassay. The larvae are incubated with the specific plant extract at a certain (non-toxic) concentration for three hours. Pentylenetetrazol (PTZ), a GABAA receptor antagonist that has been extensively used in rodent models for acute seizure and anxiety, is then administered to induce concentration-dependent seizures in the zebrafish larvae.

“GABA receptor antagonists are drugs that inhibit the action of gamma-aminobutyric acid, the chief inhibitory neurotransmitter in the mammalian central nervous system,” Prof Wilhelm says. “A specialised infrared camera is then used to track the movement of the larvae inside a chamber. The data is then converted into a graph which shows the movement of each larva over 30 minutes.

“If lowering of movement is observed at a specific concentration it means that the plant extract may have the potential to be used as an epileptic drug, since it has the ability to counteract the induced seizure in the larvae. This bioassay is extremely useful in drug discovery and toxicity screening of plant extracts.”

Zebrafish embryos, she says, develop quickly, with major organs forming within 36 hours of fertilisation. This rapid development allows researchers to observe the effects of experiments in a short period. The maintenance of a zebrafish model is less costly and labour-intensive than using a rodent model. “The use of zebrafish larvae allows for high-throughput screening due to their small size and transparency, which facilitates observation of CNS-related effects. Their genetic and physiological similarities to humans make them a valuable model for early-stage drug discovery.”

Potential uses

The next step in the research, according to Prof Wilhelm, is to identify a single compound from a natural source which may have potential anti-epileptic activity while causing less side effects than current drugs on the market. Researchers would then investigate the possibility of synthesising such a compound on a large scale, to eliminate the use of a natural resource and promote sustainability.

“Many plant extracts which I have screened show a synergistic effect in the zebrafish bioassay, meaning that the extract or the combination of compounds shows potential, but the isolated compounds are inactive. Even if a plant extract shows promise in preclinical and early clinical studies, obtaining regulatory approval for use as a treatment for epilepsy is a long and complex process.

“This includes demonstrating consistent efficacy, safety, and quality in large-scale clinical trials. One of the major challenges in using plant extracts is the lack of standardisation. The concentration of active compounds in plant extracts can vary depending on factors like the plant's growing conditions, harvest time, and extraction methods. This variability makes it difficult to ensure consistent efficacy and safety, therefore this is a time-consuming process.”

Green chemistry

After being approached by Dr Glen Taylor, Senior Director of the UFS Directorate Research Development (DRD), in 2017, regarding funding for Noldus Daniovision equipment, Prof Wilhelm received training from Prof Matthias Hamburger of the University of Basel in Switzerland on how to use such equipment. The larval zebrafish locomotive bioassay was established at the UFS Chemistry Department during 2017 and 2018 and now provides a third-stream income for the department, in conjunction with the Department of Genetics, where the adult zebrafish are housed.

Prof Wilhelm’s other research interests include green chemistry, food sustainability, and recycling. She is looking into green extraction techniques using non-conventional extraction methods to recover valuable bioactive compounds from agricultural and food residues. “Techniques like ultrasound, microwave-assisted extraction, and the use of deep eutectic solvents are becoming popular for their efficiency and alignment with circular economy principles.”

News Archive

Researcher takes home gold at international Famelab competition
2017-06-26

Description: Famelab competition Tags: Famelab competition

UFS researcher nabbed a top international award for
her ground-breaking metallurgical research in the UK.
Photo: Supplied

Recently, University of the Free State (UFS) Centre for Environmental Management master’s student, Tshiamo Legoale, was announced the FameLab International champion at the Cheltenham Science Festival in the United Kingdom. She is probing methods to use wheat as a gold hyper-accumulator – or, as she puts it, “grow gold from wheat”. The young researcher made South Africa proud by winning both the audience’s and the judges’ vote.

Coming back home a hero
“Winning was a surprise to me, because all 31 contestants had wonderful research. They all had really good presentations. I’m very grateful for all the support that I received from home. Social media showed me a lot of love and support. When I felt unconfident, they gave me ‘likes’ and that boosted my confidence a bit,” said Legoale about her win.

As South Africa celebrates Youth Month in June, Tshiamo represents hope for thousands of young South Africans to overcome difficult circumstances and follow careers in science.

The human impact is crucial, because Legoale’s win is not only scientific. It is also social and political. As a young female scientist in South Africa, she represented one of three African countries making it to the finals of FameLab, which has grown to one of the largest science communication competitions internationally.

With this in mind, Legoale says it may, in the end, be necessary to balance the needs of communities with the desire to increase yield. “Are we looking to make a fortune or are we looking to put food on the table?” she asks. “These are all things we consider when we conduct such research.”

World-class research from Africa
In South Africa, an estimated 17.7 million tons of gold is wasted. “All this gold was mined out previously, but tiny amounts remain in the dumps,” Legoale explains.

Her research focuses on the uses of wheat as a gold hyper-accumulator, which essentially means wheat plants are used to harvest gold from mine dumps. Simply put, the wheat is planted in the dumps, where enzymes found in the roots react with the gold and the plant absorbs it. The gold is then absorbed by every part of the plant, except the seeds, which means the next harvest can be used for food if need be.

“South Africa's world-champion young scientist, Tshiamo, represents all that is good about this country – brilliant, bright, and set for a fine future. I'm so proud that British Council SA, together with our partners SAASTA and Jive Media Africa, can help her along the way. Huge congratulations to her from all of us – it is a big win for Africa on the world stage,” said Colm McGivern, British Council South Africa Country Director.

The research represents a win on multiple levels. First, there are the obvious potential socio-economic benefits: food production, job creation, and phytomining is more economical than other contemporary mining methods.

Then there is safety. It is a more environmentally friendly practice than methods like heap leaching, carbon-in-leach or carbon-in-pulp. It is also safer for miners themselves, who will not be exposed to dangerous chemicals like mercury, which has been responsible for a great deal of toxicity in mine dumps. And it is safer for those living in the surrounds.

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept