Cephalostatin-1 is showing “exceptional promise in the fight against cancer”, including leukemia, by inhibiting cancer cell growth, the department of forestry, fisheries and the environment, has announced.
A cancer-fighting compound extracted from a rare deep-sea tube worm has been discovered in South Africa’s waters off the South Coast.
Cephalostatin-1 is showing “exceptional promise in the fight against cancer”, including leukemia, by inhibiting cancer cell growth, the department of forestry, fisheries and the environment, has announced.
It said the anti-cancer compound is found in Cephalodiscus gilchristi, a marine worm commonly known as the Agar animal or acorn worm.
The discovery of the compound was first detected and isolated in 1990 and the scientific breakthrough has been in the making for several years, the department said.
“This is a shining example of the treasures our oceans hold,” said the department’s minister, Dion George. “But these gifts are under threat. Protecting our oceans is not just about conserving nature, it’s about saving lives, creating jobs and securing our future.”
The United States National Cancer Institute has hailed Cephalostatin-1 as one of the most potent anti-cancer agents ever tested, given its potential to achieve the selective killing of cancer cells.
“This discovery underscores the untapped potential of South Africa’s marine biodiversity and the critical need to keep these waters clean, healthy, and sustainably managed,” said the department.
Beyond its health implications, the discovery of Cephalostatin-1 is opening doors for South African researchers, biotech innovators and marine scientists.
“It’s creating new opportunities in marine bioprospecting, pharmaceuticals, and sustainable development, while reinforcing South Africa’s role as a leader in global medical research,” the department said.
While cephalostatins have shown promise in preclinical studies, “clinical trials have been hampered by the difficulty in obtaining sufficient quantities of the natural compounds”, said Thobile Zulu-Molobi, a spokesperson in the office of the minister.
The compounds are characterised by a central pyrazine ring connecting two highly oxygenated steroidal subunits with spiroketal systems.
“The complex structure of cephalostatins has presented significant challenges for synthetic chemists, motivating numerous research efforts to develop efficient syntheses,” Zulu-Molobi said.
Because of the exceptionally small quantity of the natural chemical in the marine worm, the department is focused on its protection and responsible use of it.
“Therefore, South Africa would encourage the continued clinical synthesis of the compound rather than extraction of the rare worm,” Zulu-Molobi said.
According to the South African National Biodiversity Institute (Sanbi), the marine worm is endemic to South Africa and is found in shallow temperate waters, up to 1 000m depth. “They occur predominantly on the South Coast, although some specimens have been found on the West Coast” it said.
As adults, they are found on rocky surfaces on the seafloor, living in their tube network. They are also commonly found attached to lace animals or sponges. Details about the service these animals perform in the ecosystem is not yet known.
“With the growing global interest in alternative medicines, marine invertebrates such as the agar animal play an important role in bio-discovery, which means exploring biological resources for industrial or commercial use,” said Sanbi.
“Natural compounds extracted from the South African agar animal produces one the most powerful compounds ever tested against leukemia cancer cells, according to the National Cancer Institute. These compounds are called cephalostatins, and they prevent the growth of cancer cells.”
Sanbi noted that little is known about this unusual animal and its conservation status is not assessed.
“Research is being undertaken to harness the natural products of this animal for the benefit of the medical industry. As it shows great potential in the medical industry, it is important to assess the population abundance of this species so that it can be preserved for the future as the bio-medical research field grows,” it said.
About 100 species of hemichordate worms have been described globally and 11 of these have been recorded in South African waters, it added.
Biodiscovery is the process of screening animals and plants for the presence of compounds useful to humans, according to the Marine Protected Areas website, which includes the environment department, Sanbi, the department of science and technology, the National Research Foundation and the African Coelacanth Ecosystem Programme.
Several laboratories in South Africa are looking for such compounds and, once discovered, work on identifying its structure. They also investigate the enzyme pathways by which the compound has been made, and try to establish alternative ways by which the compound can be artificially produced. Drug discovery takes a long time, with clinical trials needed to test the effectiveness and safety of potential medicines.
South Africa’s waters are filled with such a large diversity of life and some of these have provided remarkable biomedical discoveries, the website said. “These include seaslugs and nudibranchs, seasquirts (ascidians) and sponges that have cancer-fighting compounds.
“The frilled or silver nudibranch Leminda millecra is found only on the South and East coast of South Africa and has produced compounds that fight oesophagal cancer. Sponges from Sodwana, the Tsitsikama area and Aliwal shoal have also produced amazing useful compounds with further work unde w ay.”
Of Cephalostatin-1, it said: “One of the most potent compounds ever tested against cancer comes from a very strange animal found only in South Africa’s ocean. This animal is known as a hemichordate (a small animal phylum that includes acorn worms and pterobranchs) and is a worm-like colonial animal that lives within a prickly network of jelly-like tubes.”
The marine worm is named after South Africa’s first government marine biologist, John Gilchrist.
South Africa’s oceans are a lifeline, George added. “Every job created through marine research, and every life saved through discoveries like Cephalostatin-1, starts with protecting our waters.”
The department said it continues to take strong action to defend the country’s marine ecosystems — from expanding marine protected areas to enforcing pollution control and sustainable fishing practices. “These efforts help preserve the biodiversity that fuels scientific breakthroughs and supports communities who depend on the sea.
“In partnership with academic and research institutions, as well as global research bodies, the department is committed to promoting responsible marine science and environmental stewardship. Discoveries like Cephalostatin-1 show that by protecting our oceans, we’re also protecting our people.”