The little blue pill that gives men more oomph in the bedroom has an unexpected benefit – it can slow the spread of malaria.
Viagra doesn’t just have a stiffening effect on men’s anatomy, it also makes the one-celled parasite that causes malaria more rigid.
Pfizer makes Viagra, a popular treatment for erectile dysfunction.
A team of European researchers have found that this effect deforms the red blood cells that transport the parasite, encouraging the spleen to clear them from the system.
With fewer infected red blood cells circulating the body, it becomes harder for one of the most common malaria parasites, Plasmodium falciparum, to be transmitted to an uninfected mosquito when it feeds on an infected person or animal.
Illustration: michaelmucci.com
Lead researcher Catherine Lavasec, from the Pasteur Institute in France, said there was a desperate need for novel interventions to target the transmission of the malaria parasite from a human host to the mosquito.
“Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination,” she said.
Normally, infected blood cells slip by the spleen because they are as squishy as healthy red blood cells.
Using an artificial spleen, the team found that certain drugs such as Viagra, also known as sildenafil, could stiffen these cells by inhibiting an enzyme that would normally make them squishy. The stiff cells are then cleared by the spleen.
As well as treating erectile dysfunction, Viagra has been used to lower blood pressure and relieve altitude sickness.
The research team said their findings are “proof of principle” that certain drugs can target malaria-infected red blood cells and these may be used as a new class of antimalarial drugs.
More than 198 million people were infected with malaria and more than 500,000 people died from the disease in 2013, according to the latest global estimates collected by the World Health Organisation.
The malaria parasite can only be transmitted by the females of certain varieties of mosquitoes from the Anopheles genus. Females need nutrients from a blood meal to develop their eggs.
The study was partly funded by the Bill & Melinda Gates Foundation and the Wellcome Trust and has been published in the scientific journal PLOS Pathogens.