Rare fish species holds key to cure of heart diseases

A rare species of fish found in Lake Victoria could hold the ultimate key to curing heart diseases.

Zebra fish, also known as Pundamilia nyererei, have the ability to regenerate damaged heart tissue at an amazing rate. They can regrow 20 per cent of heart tissue within weeks.

Scientists hope this could lead to the development of new treatments that would make the human heart to heal itself.

In a study estimated to cost Sh6.3 billion, the British Medical Foundation hopes to learn the biological trick that gives this fish the extraordinary ability of heart tissue regeneration.

The fish, which is almost extinct in Lake Victoria because predation by Nile Perch, is a favourite pet for fish lovers and is found in homes and aquaria in many parts of the country.

In an interview with The Independent, Prof Peter Weissberg, medical director of the British Heart Foundation, says the fish’s unique biological capacity can be adopted and applied on human beings.

“Scientifically, mending human hearts is an achievable goal and we really could make recovering from a heart attack as simple as getting over a broken leg,” Prof Weissberg was quoted as saying early this week.

The fish has been at the centre of research in Kenya and other places in the world where it is found.

Two years ago, researchers from Tokyo’s Institute of Technology and the Swiss Federal Institute of Aquatic Science and Technology observed the fish, in the family of cichlid, evolve into a new species in Lake Victoria to better adapt to sighting its prey and predators.

Although the fish may not be able to stop people from getting heart ailments, it offers new hope that sufferers can fully recover from such diseases.

By making the heart tissue to regenerate, the technology could help do away with the much more difficult and risky business of heart transplants.

According to a study published in September in the journal European Urology, researchers at the Zebra fish Centre for Advanced Drug Discovery in Canada have already identified one drug, rosuvastanin, for cholesterol-lowering from the fish.

This drug has also been found to suppress the growth of transplanted human prostate cancer cells in mice.

The study could rekindle efforts to restock the species in Lake Victoria as a possible cash earner.

Zebra fish are classified by the International Union of Conservation of Nature and Natural Resources as a threatened species.

A fisherman, Mr Jasper Okech, told the Nation that the fish, which is also found in rivers and springs, has become rare in Lake Victoria.

Mr Okech said that for the 12 years he had been fishing on the lake, he had only caught two zebra fish, both of which were very young in 2005.

He sold one to a Kisumu businessman for Sh4,000.

A researcher at the Kenya Marine and Fisheries Research Institute, Mr Oweke Ojwang’, said the species, originally from Asia, had been domesticated because of its beauty.

“Those who have them at home believe that observing the fish as it moves and plays in the aquarium can reduce stress and depression,” he said.

Mr Okech also added a cultural angle: “Beautiful fish like these fish were mainly used in the Luo community as food for a son-in-law who came to pay dowry, since it was considered one of the most precious and rare types of fish.”

The fish, he says was valued because it was considered to improve fertility in men and women, besides other medicinal values.

Mr Alex Nyaoke, curator of the Kisumu Museum Aquarium, said the fish is found in small rivers in Nyanza and Tanzania, notably River Kanyaboli, Ndere Beach and a few springs in Ugenya.

The species started disappearing from its natural habitat with the introduction of the Nile Perch, which feeds on small fish.

The situation, Mr Nyaoke said, was made worse with the spread of the water hyacinth.

“The fish likes breeding in small springs before moving to bigger water bodies.”