Venomous snakebites affect thousands of people across Africa each year, but help can come too late if antivenom medication or expert assistance is unavailable. A team of researchers in the Faculty of Health Sciences at the North-West University (NWU) is investigating whether medicines already used to treat other conditions could help combat snakebite envenomation.
Led by Prof. Anél Petzer, the research focuses on identifying small molecule therapeutics (SMTs) capable of neutralising the toxic enzymes found in snake venoms. If successful, the approach could provide an alternative treatment option that is easier to store, transport and administer than conventional antivenoms.
The work comes at a time when many countries continue to face shortages of antivenom medicines. Conventional antivenoms are expensive to produce, require refrigeration and must be administered intravenously in healthcare facilities. Researchers believe medicines already available on the market could help address some of these challenges while expanding access to treatment, particularly in rural communities.
"Venoms consist of many enzymes that are responsible for the toxic effects observed after envenomation," says Prof. Petzer. "If we can eliminate the activity of those enzymes, we can halt or slow the progression of the toxicity and thus provide a valuable alternative to conventional antivenom."
How the new strategy works
SMTs are compounds commonly found in medicines such as aspirin and ibuprofen. According to Prof. Petzer, they work by binding to specific venom enzymes and preventing them from causing damage in the body.
The research team analyses the enzymes present in different snake venoms and uses computer modelling to identify medicines that may be able to inhibit them. Existing medicines are then tested to determine whether they can block venom activity.
Prof. Petzer says repurposing medicines already on the market offers several advantages.
"The drug already has the appropriate safety profile and is already in an acceptable dosage form. Furthermore, it saves a lot of time, money and resources associated with novel drug design," she says.
The team aims to address several challenges associated with current antivenom treatment. Oral medicines could potentially be distributed through clinics, pharmacies and emergency care services, while tablets and capsules can often be stored at room temperature. Oral preparations are generally more affordable than antivenoms.
Results are promising
The project has already produced several milestones. Researchers have analysed venoms from the green and black mamba, rinkhals, Cape cobra, Mozambique spitting cobra, puff adder, Gaboon adder and rhombic night adder. The team has also established laboratory assays for key venom enzymes and identified hundreds of potential drug candidates through database screening and molecular modelling.
"We have identified more than 500 drugs and categorised them according to availability, cost and route of administration to align with World Health Organization recommendations and goals," Prof. Petzer says.
The next phase of the project will involve testing the most promising candidates in animal models before progressing to preclinical studies and clinical trials. If successful, the research could help expand access to snakebite treatment in communities where antivenom medications remain difficult to obtain.
Prof. Anél Petzer
