A plant long used in traditional medicine is now at the centre of research that could shape future cancer treatment options in South Africa and beyond.
Researchers at the North-West University(NWU) are investigating the anti-cancer potential of Lessertia frutescens, commonly known as cancer bush, after laboratory studies showed activity against several forms of cancer, including drug-resistant small cell lung cancer and colorectal cancer.
According to Prof. Chrisna Gouws, a research professor in the Centre of Excellence for Pharmaceutical Sciences in the Faculty of Health Sciences, the research team tested extracts from the indigenous plant on cultured human cancer cells and more advanced laboratory-grown “mini-tumours” known as spheroids.
“Lessertia frutescens has shown significant anticancer activity against several different cancer types in our research,” she says.
Targeting cancers considered incurable
She says the findings became more important when the team observed activity in cancers that no longer respond to conventional treatment.
“What is very interesting and exciting is the apparent activity in drug-resistant cancers such as resistant small cell lung cancer where known chemotherapies have limited to no activity,” Prof. Gouws says.
“This provides us with new avenues to investigate for treatment options to treat cancers currently considered incurable.”
The research team said another factor attracting attention is the plant’s longstanding use in traditional medicine and its safety profile.
“An important consideration is that this plant has a long history of use and is considered non-toxic and safe for use,” Prof. Gouws says.
“It’s anticancer activity comes without the significant side-effects known to occur with most standard chemotherapies.”
Other systems in the body may benefit
Researchers also found that the plant may support other systems in the body during treatment.
“Lessertia has known boosting effects for the digestive and immune systems, and it can have mood-enhancing activities as well,” she says.
“It may therefore not only target the cancer but positively impact the patient as a whole at the same time.”
The team is now studying the plant’s phytochemicals to identify the molecules responsible for the anticancer activity and understand how they work.
“Although many molecules have been identified and shown to contribute to the anticancer activity of the plant, the mechanism of action remains mostly unclear,” says Prof. Gouws.
“We are therefore delving deeper now to try and understand how and why this plant works.”
The next phase of the study will include animal model testing later this year to confirm safety and efficacy before future clinical trials can be considered.
At the same time, the researchers are developing a complementary medicine product that may be available in pharmacies by 2027.
Prof. Gouws says the project could also create economic opportunities.
“Chemotherapy can be very expensive and inaccessible in rural areas. A new plant-based treatment will be much more cost-effective and may be more accessible because it can be manufactured locally,” she says. “An increase in demand for the plant material will also create economic opportunities through farming.”
More about Prof. Chrisna Gouws
Prof. Gouws leads the strategic project for Human-Based New Approach Methodologies for Biomedical Research. She holds a PhD in biochemistry and has more than 15 years’ experience in utilising cell culture-based models for human health and disease research, including developing new complex in vitro models for applications in drug research, including traditional medicinal remedies and plant materials for cancer treatment.
She is the founder and executive committee chair for the Society for Advanced Cell Culture Modelling for Africa, a board member of International Microphysiological Systems Society, and co-editor of the NAM Journal.
Prof. Chrisna Gouws and her team have been researching cancer bush for five years.
Lessertia frutescens, commonly known as cancer bush
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