Substances isolated from marine sponges show potential for treating malária

Brazilian researchers have discovered chemical compounds in marine sponges that have the potential to eliminate the malaria parasite, including strains that are resistant to conventional antimalarial drugs. The research results were published in the journal ACS Infectious Diseases.

Caused by protozoa and transmitted by the bites of Anopheles mosquitoes, malaria is one of the world’s most deadly infectious diseases. According to the World Health Organization (WHO), there were around 600,000 malaria-related deaths in 2023 alone, 75% of which were children under the age of five.

Two newly discovered compounds, batzelladins F and L, were found to rapidly eliminate the parasites that cause malaria, including Plasmodium falciparum, which is predominant in Africa and more lethal, and Plasmodium vivax, which is predominant in South America. The efficacy of the substances was proven through tests on blood samples from patients and infected mice.

“These are robust results that give us hope for a new treatment. Although the compounds did not completely eliminate the protozoa, they can serve as inspiration for the synthesis of new chemical structures with enhanced action,” says Rafael Guido, a professor at the University of São Paulo’s São Carlos Institute of Physics (IFSC-USP) and co-author of the study.

The study involved a multidisciplinary team from USP, the National Museum, the Federal University of São Carlos (UFSCar), and the Roraima Tropical Medicine Research Center. It was supported by FAPESP through ten projects (13/07600-3, 24/04805-8, 15/01017-0, 19/17721-9, 22/01063-5, 21/03977-1, 22/01066-4, 23/09209-1, 22/15947-2, 20/01229-5), as well as funding from the National Council for Scientific and Technological Development (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES).

Roberto Berlinck, a professor at the São Carlos Institute of Chemistry (IQSC-USP) who also signed the paper, said that the finding highlights the importance of Brazilian biodiversity, which is at risk.

“We don’t usually associate the negative impact of climate change with the discovery of new drugs or, more specifically, with curing diseases. The Monanchora arbuscula sponges live in an environment that’s threatened by ocean warming. Therefore, a natural product that we’re just beginning to investigate could disappear,” the researcher warns.

Berlinck also points out that climate change has led to an increase in malaria cases worldwide.

Methodology

To investigate the mechanisms of action of batzelladins, the group of researchers isolated them from the other compounds found in the marine sponge and characterized their chemical structure. This work was carried out by Anderson L. Noronha, from IQSC-USP.

The researchers noted that batzelladins act quickly and effectively on young parasites, inhibiting their ability to multiply inside the host’s red blood cells. According to Guido, this rapid action means that the parasites are less likely to develop resistance to treatment.

“We observed that the parasite dies as soon as it comes into contact with the chemical compounds. This is important because molecules that kill the parasite slowly allow it to adapt and generate resistance,” explains Giovana Rossi Mendes, from IFSC-USP, who was responsible for carrying out the tests with the blood samples and mice.

In addition to fighting malaria, substances derived from marine sponges have demonstrated anti-parasitic activity against other diseases, including leishmaniasis and Chagas disease.

“At first glance, it may seem unusual that a substance with the potential to cure malaria, a disease related to tropical forests, is present in a marine microorganism, which wouldn’t need to protect itself from this pathogen. But the apparent disconnection is actually commonplace in prospecting studies for natural products with biological activity,” says Guido.

These substances are what scientists call secondary metabolites: organic compounds that perform adaptive functions for the organisms that produce or accumulate them. These functions include defense against enemies, attraction between sexes, repulsion of predators, and occupation of physical space, among others.

“Just like the agents that cause malaria, marine sponges are very ancient organisms that have accumulated these secondary metabolites over years of evolution to ensure their success in the environment in which they find themselves, the oceans,” explains Guido.

About São Paulo Research Foundation (FAPESP)
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