Red propolis could be used to treat schistosomiasis - Medical Xpress

Posted: 07 Dec 2020 01:31 PM PST

Well-known for its bactericidal and anti-fungal properties, Brazilian red propolis has now been found to act powerfully against the parasite that causes schistosomiasis, reducing the number of eggs and killing the helminths (worms).

In experiments performed at Universidade Guarulhos (UnG) in the state of São Paulo, Brazil, with FAPESP's support, 400 milligrams per kilogram of body weight was a sufficient dose of red propolis to reduce the parasite load by more than 60% in mice infected with the flatworm Schistosoma mansoni. It was equally effective against the immature and adult stages of the parasite. In vitro tests also showed that red propolis blocked reproduction and oviposition (egg-laying).

"Propolis, especially the red variety, is well-known for its action against bacteria and fungi. It protects the beehive from intruders, and we expected that some of its more than 20 substances would act against parasitic infectious agents. What surprised us was that it disrupted the worm's integument and killed adult as well as immature worms, which the conventional treatment for schistosomiasis doesn't do," said Josué de Moraes, a professor at UnG and last author of the article on the study published in the Journal of Ethnopharmacology.

The results of all the tests suggest red propolis may be more effective to treat schistosomiasis than the only pharmaceutical product available for this purpose. Before red propolis can be prescribed for patients, of course, it must be tested in clinical trials on humans with the disease.

Super-helminths

Schistosomiasis is the most common disease caused by helminths and affects some 300 million people worldwide. Despite its high prevalence in tropical and subtropical areas, it has been treated with a single drug for about 40 years.

"Praziquantel is effective but has major limitations," Moraes said. "In contrast with what we found in the study with red propolis, the drug doesn't combat infections caused by the immature stage of the parasite. It kills only adult worms, so patients have to wait until the growth cycle reaches the adult stage to start the treatment, by which time the infection has become chronic."

Another limitation of praziquantel is that some species have become drug-resistant after 40 years with no alternative treatment. Schistosome strains with low susceptibility to the drug have been isolated by researchers.

The research project led by Moraes at UnG's Center for Research on Neglected Diseases (NPDN) aims at drug repurposing to tackle schistosomiasis. "Because it's a neglected disease linked to poverty and lack of basic sanitation, this is basically the only way to find novel therapies. Repurposing is cheaper and quicker than developing new drugs from scratch," Moraes said.

The research group tested 73 nonsteroidal anti-inflammatory drugs sold in Brazil and elsewhere. They found five to be effective against the disease, with mefenamic acid (widely used for menstrual period pain relief) exhibiting the most promising results to date.

In an article published in mid-2020 in Trends in Parasitology, Moraes and a co-author note that the United States' Food and Drug Administration (FDA) has approved very few drugs for the treatment of parasitic diseases.

"Since the start of the century, the FDA has approved a total of 604 medications, some of which are novel drugs and others repurposed," Moraes said. "Only nine are antiparasitics, and of these only two are anthelmintics. In my view, helminthiases are the most neglected of neglected diseases."

Why red propolis?

Moraes explained that the decision to study the effects of red propolis in this project was made because the natural product had been fully characterized in studies by Severino M. Alencar, a researcher at the University of São Paulo's Luiz de Queiroz College of Agriculture (ESALQ-USP), and Bruno Bueno-Silva at UnG's Dentistry Department. Both are collaborators with NPDN.

"Brazilian red propolis has attracted attention in recent years owing to its pharmacological potential as well as its anti-microbial and anti-inflammatory action," he said. "Our study didn't investigate the mechanism of red propolis in the schistosome but analyzed the action of red propolis extract indirectly using scanning electron microscopy. For example, we set out to see if this natural product, which is made up of several substances, could get through the parasite's integument. This would increase its power to reach one or more targets and kill the worms, but we didn't identify any targets."

Green and brown propolis are likely to have some effect on schistosomiasis, Moraes added, but specific studies will be needed to analyze the other two natural products.

The discovery could also be applicable to other verminoses. "The schistosome is a model for the study of infections in humans and animals caused by other flatworms, or platyhelminths, such as tapeworms of the genus Taenia," he said. "The discovery, therefore, creates an opportunity for research relating to the treatment of other diseases that affect humans, cats, and dogs, and are also treated with praziquantel."

Explore further

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More information: Marcos P. Silva et al, Brazilian red propolis exhibits antiparasitic properties in vitro and reduces worm burden and egg production in an mouse model harboring either early or chronic Schistosoma mansoni infection, Journal of Ethnopharmacology (2020). DOI: 10.1016/j.jep.2020.113387

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Treatment Introduced by Researchers to Prevent Parasites in Sheep - Southeast AgNet

Posted: 09 Dec 2020 06:42 AM PST

(USDA/ARS) — The U.S. Department of Agriculture's Agriculture Research Service (ARS) announced a groundbreaking treatment that prevents anemia, weight loss, poor wool and meat production, and even death in sheep.

ARS researchers partnered with Virginia Tech and the University of Massachusetts' Medical School to solve H. contortus parasite infection, which also happens to be the number one health problem in the U.S. sheep industry. The parasite infects the stomach of ruminant mammals, feeding and interfering with digestion, before ultimately affecting the animal's overall health and stability.

"The H. contortus parasite has developed resistance to virtually all known classes of anti-parasitic drugs," said ARS Researcher Dr. Joseph Urban, who lead the research team in testing and implementation of a para-probiotic treatment to kill the parasite that causes H.contortus.

The worm parasite mates within the animal and its fertilized eggs pass through the animal's waste into the soil. The larvae then develop to re-infect other unsuspecting animals, spreading the infection throughout a pasture and creating a cycle of infection that hinders animal growth, development and production.

"This is a major problem and the newly-developed treatment is derived from bacteria normally found in the soil that can produce a protein that binds to receptors in the intestine of the parasite," said Dr. Urban. "The treatment will then kill the parasites and reduce debilitating infection in adult sheep."

"When the treatment was given to infected sheep at Virginia Tech there was a rapid and dramatic reduction of parasite reproduction and survival, without any negative effect observed in the sheep." said Dr. Anne Zajac, professor of parasitology at Virginia Tech's Virginia-Maryland College of Veterinary Medicine.

Para-probiotics are "inactive probiotics," or good bacteria that can still provide health benefits. Despite the growing interest in para-probiotic use, these types of treatments are not commercially available. The treatments are currently under review by the U.S. Food and Drug Administration and will likely be commercially produced in large amounts once approved. This will help to protect an even larger population of animals across the country.

"Para-probiotics represent a new evolution and hope in dealing with a malignant and pervasive parasite," said Dr. Raffi Aroian, a professor in the Molecular Medicine program at the University of Massachusetts' Medical School. "The development of new therapeutics for this issue has been extremely difficult to come by and I look forward to watching this new advancement unfold in the global and domestic industry."

This project was supported by the National Institutes of Health/National Institute of Allergy and Infectious Diseases; and the Agriculture and Food Research Initiative Competitive Grant from the USDA's National Institute of Food and Agriculture.

Source: Agricultural Research Service

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