Over the past several years there has been some success in lowering the global death toll provided by malaria infections. However, even with those efforts, there were still almost 500,000 deaths in 2017 and over 219 million cases of malaria worldwide. Moreover, with antimalarial drug resistance on the rise and climate change allowing tropical diseases to spread further than once thought possible, malaria infections are at a critical tipping point that could have mortality and morbidity rates soaring very soon if new drug interventions are not identified.
Thankfully, researchers at the University of Campinas (UNICAMP) in Brazil are actively searching for new treatment options and have stumbled upon some interesting new data that could prove extremely useful in the fight against this persistent parasitic infection.
Amazingly, the researchers found antimalarial in a seemingly unlikely candidate, the aҫaí berry. Findings from the new study—published recently in ACS Omega through an article titled “Chemical Genomic Profiling Unveils the in vitro and in vivo Antiplasmodial Mechanism of Açaı́ (Euterpe oleracea Mart.) Polyphenols”—showed that berry extracts can reduce parasites in the blood and prolong the survival of infected mice.
“Widespread drug-resistant parasite strains push for the development of novel antimalarial drugs,” the authors wrote. “Plant-derived natural products are key sources of antimalarial molecules. Euterpe oleracea Martius (“açaı́”) originates from Brazil and has anti-inflammatory and antineoplastic properties.”
Aҫaí is native to Brazil, where some traditional healers use the berries to treat malaria symptoms. In recent years, the high antioxidant content of the grape-like fruit has boosted its popularity outside of Brazil and has caused some to consider it a “superfood.” This antioxidant activity arises mainly from polyphenols—compounds that have been linked to health benefits such as weight loss, cardiovascular disease prevention, and decreased cancer risk. The UNICAMP team wanted to determine if aҫaí extracts could treat malaria in mice, and if so, whether polyphenols in the berries were responsible for the therapeutic effect.
“We evaluated the antimalarial efficacy of three phenolic fractions of açaı́; total phenolics (1), nonanthocyanin phenolics (2), and total anthocyanins (3). In vitro, fraction 2 moderately inhibited parasite growth in chloroquine-sensitive (HB3) and multiresistant (Dd2) Plasmodium falciparum strains, while none of the fractions was toxic to noncancer cells,” the authors penned. “Despite the limited activity in vitro, the oral treatment with 20 mg/kg of fraction 1 reduced parasitemia by 89.4% in Plasmodium chabaudi-infected mice and prolonged survival. Contrasting in vitro and in vivo activities of 1 suggest key antiplasmodial roles for polyphenol metabolites rather than the fraction itself.”
The team extracted polyphenols from aҫaí berries and then treated malaria parasite cultures growing in a Petri dish with the extracts. They found that a class of polyphenols called nonanthocyanin phenolics inhibited the growth of both chloroquine-resistant and -sensitive parasites. Then, the researchers orally administered aҫaí polyphenols to malaria-infected mice.
Remarkably, the treatment reduced the parasitic load in the mice’s blood by 89.4% compared with untreated mice. All of the mice given polyphenols survived for more than 15 days, whereas none of the untreated mice lived. The aҫaí extracts appeared to interfere with the parasites’ protein homeostasis, or the balance between protein production and degradation, the researchers said.
“We performed haploinsufficiency chemical genomic profiling (HIP) utilizing heterozygous Saccharomyces cerevisiae deletion mutants to identify molecular mechanisms of açaı́ fractions. HIP results indicate proteostasis as the main cellular pathway affected by fraction 2. These results open avenues to develop açaı́ polyphenols as potential new antimalarial candidates,” the authors concluded.
