Little-known fruits contain powerful anti-inflammatory and anti-oxidant agents

Research shows that five fruit species native to Brazil’s Atlantic Rainforest biome have bioactive properties as outstanding as those of blueberries, cranberries, blackberries and strawberries.

By Maria Fernanda Ziegler  |  Agência FAPESP – Five native Brazilian berries, four of which belong to the genus Eugenia, are just starting to become well-known among scientists but are not yet familiar to the wider public, let alone shoppers. Their bioactive properties are so outstanding that they may soon be on display in supermarkets and highly ranked as fashionable foods. 

In addition to their nutritional value, the five fruit trees native to the Atlantic Rainforest have powerful anti-oxidant and anti-inflammatory properties, according to a study conducted at the University of São Paulo’s Luiz de Queiroz Agricultural College (ESALQ-USP) in partnership with the University of Campinas’s Piracicaba Dentistry School (FOP-UNICAMP) – both in Piracicaba, São Paulo State, Brazil – and at the University of the Frontier (UFRO) in Temuco, Chile.

“There wasn’t much scientific knowledge about the properties of these native fruits. The idea now, with the results of our study, is for them to be grown by family farmers, increase production scale and be taken up by retailers. Who knows, they could be the next açaí,” said Severino Matias Alencar, a researcher in ESALQ-USP’s Department of Agroindustry, Food & Nutrition, referring to the commercial success of the Amazonian berry Euterpe oleracea with large amounts of anti-oxidants. Brazil exports açaí puree to several countries. 

The study was supported by FAPESP, and some of its findings were published in the journal PLOS ONE.

The study evaluated phenolic compounds – chemicals that can have preventive or curative effects – and the anti-inflammatory and anti-oxidant mechanisms of material extracted from the leaves, seeds and pulp of araçá-piranga (Eugenia leitonii), cereja-do-rio-grande (E. involucrata, cherry of Rio Grande), grumichama (E. brasiliensis), ubajaí (E. myrcianthes) and bacupari-mirim (Garcinia brasiliensis), all typical of Brazil’s Atlantic Rainforest biome.

These species are increasingly rare, and some are classified as endangered. The samples for the study were supplied by two small farms in the interior of São Paulo State. Both sell plants with conservational aims. One of the farmers owns Brazil’s largest native fruit collection, with over 1,300 species under cultivation.

“We began our study by exploring the fruits’ bioactive properties, since we knew they could contain a large number of anti-oxidants, just like the well-known berries of the US and Europe, such as the blueberry, blackberry and strawberry, with which scientists are so familiar. Our native berries proved [to be] even better,” Alencar said.

According to the study, species of the genus Eugenia have huge economic and pharmacological potential, evidenced not only by many scientific publications but also by trade of their edible fruits, wood and essential oils and their use as ornamental plants.

They are examples of functional foods, which besides vitamins and nutritional values, have bioactive properties, such as the capacity to combat free radicals – unstable, highly reactive atoms that bind to other atoms in the organism and cause damage, such as cellular aging or disease.

“Our organisms naturally contain substances that neutralize and eliminate free radicals from the body without causing damage. However, factors like age, stress and diet can bring about an imbalance in this natural neutralization. If so, exogenous elements are required, particularly the intake of foods with anti-oxidant agents, such as flavonoids or anthocyanins from araçá-piranga, E. leitonii, and other fruits of the Eugenias,” said Pedro Rosalen, a researcher at FOP-UNICAMP.

Brazil has some 400 Eugenias, he added, including several endemic species. “We have an enormous number of native fruit trees with bioactive compounds that could benefit people’s health. They should be studied,” he said.

Alencar is a member of the research group for the project “Bioprospection of novel anti-inflammatory molecules from natural Brazilian native products”, and Rosalen, first author of the article in PLOS ONE, is the principal investigator.

Anti-inflammatory champion

The project studied fruits with strong anti-oxidant activity – for use by the food and pharmaceutical industries – and with anti-inflammatory properties. The standout was E. leitonii, as the researchers demonstrated in an article published in the Journal of Functional Foods.

“E. leitonii is an endangered species,” Rosalen said. “Its anti-inflammatory activity far exceeded that of other Eugenias. The action mechanism is also extremely interesting. It occurs spontaneously and right at the start of the inflammation, blocking a specific pathway in the inflammatory process. It also acts on the endothelium of blood vessels, preventing leukocytes from transmigrating to the damaged tissue and reducing exacerbation of the inflammatory process.”

Rosalen noted that anti-oxidants not only combat cellular aging and death but also help prevent diseases mediated by chronic inflammation. “The oxidative action of free radicals leads to the appearance of dependent inflammatory diseases, such as diabetes, cancer, arthritis, obesity and Alzheimer’s,” he said.

“We don’t notice many of the lesions caused by free radicals. They’re silent inflammations. Hence the importance of anti-oxidants, which can neutralize free radicals.”

The collaborative research project supported by FAPESP and UFRO also extended knowledge of a Chilean native species. In one study, the researchers demonstrated the anti-oxidant and vasodilatory action of Chilean guava (Ugni molinae).

Published in Oxidative Medicine and Cellular Longevity, the study concluded that food supplements obtained from the fruit and leaves of Chilean guava can have beneficial effects on the prevention and possibly treatment of cardiovascular diseases.

According to Alencar, if knowledge of these properties is disseminated, the production of native fruit species could be stimulated.

“Even before the project with UFRO, Rosalen and I already studied native fruit species because we believed they could be a source of excellent food solutions for society,” he said.

The article “Anti-oxidant and anti-inflammatory activities of unexplored Brazilian native fruits” by Juliana Infante, Pedro Luiz Rosalen, Josy Goldoni Lazarini, Marcelo Franchin and Severino Matias de Alencar (https://doi.org/10.1371/journal.pone.0152974) can be read at journals.plos.org/plosone/article?id=10.1371/journal.pone.0152974.