Euterpe oleracea fruit (Açai)-enriched diet suppresses the development of experimental cerebral malaria induced by Plasmodium berghei (ANKA) infection.

BACKGROUND: Cerebral malaria is one of the most severe complications attributed to protozoal infection by Plasmodium falciparum, gaining prominence in children mortality rates in endemic areas. This condition has a complex pathogenesis associated with behavioral, cognitive and motor sequels in humans and current antimalarial therapies have shown little effect in those aspects. Natural products with antioxidant and anti-inflammatory properties have become a valuable alternative therapeutic option in the treatment of distinct conditions. In this context, this study investigated the neuroprotective effect of Euterpe oleracea (açai) enriched diet during the development of experimental cerebral malaria induced by the inoculation of Swiss albino mice with Plasmodium berghei ANKA strain. METHODS: After Plasmodium infection, animals were maintained on a feeding with Euterpe oleracea enriched ration and parameters such as survival curve, parasitemia and body weight were routinely monitored. The present study has also evaluated the effect of açai-enriched diet on the blood-brain barrier leakage, histological alterations and neurocognitive impairments in mice developing cerebral malaria. RESULTS: Our results demonstrate that between 7th-19th day post infection the survival rate of the group treated with açai enriched ration was higher when compared with Plasmodium-infected mice in which 100% of mice died until the 11th days post-infection, demonstrating that açai diet has a protective effect on the survival of infected treated animals. The same was observed in the brain vascular extravasation, where Evans blue dye assays showed significantly less dye extravasation in the brains of Plasmodium-infected mice treated with açai enriched ration, demonstrating more preserved blood-brain barrier integrity. Açai-enriched diet also attenuate the histopathological alterations elicited by Plasmodium berghei infection. We also showed a decrease of the neurological impairments arising from the exposure of cerebral parenchyma in the group treated with açai diet, ameliorating motor and neuropsychiatric changes, analyzed through the SHIRPA protocol. CONCLUSION: With these results, we conclude that the treatment with açai enriched ration decreased the mortality of infected animals, as well as protected the blood-brain barrier and the neurocognitive deficits in Plasmodium-infected animals.

Protection against murine cerebral malaria by dietary-induced oxidative stress.

Feeding 20% (w/w) menhaden-fish oil in a standard laboratory chow diet for 4 wk partially protected CBA/CaJ mice from the central nervous system consequences of infection with Plasmodium berghei (ANKA). Full protection (complete survival for 14 days postinfection) could be obtained by feeding a purified pro-oxidant vitamin E-deficient diet containing 4% (w/w) menhaden oil (MO - VE diet). The purified pro-oxidant MO - VE diet also exerted a pronounced suppressive effect against the parasite (depressed 6-day parasitemias). The anitmalarial effect of the MO - VE diet could be prevented by supplementing the diet with vitamin E or with either of 2 synthetic antioxidants, N,N'-diphenyl-p-phenylenediamine or probucol. These results suggest that the fish oil exerts its antimalarial effect by imposing a dietary-induced oxidative stress on the infected host erythrocyte, the parasite, or both. Nutritional manipulation of host oxidative stress status may be a useful adjunct therapy in patients undergoing treatment with pro-oxidant antimalarials such as drugs of the qinghaosu family.

Amelioration of murine cerebral malaria by dietary restriction.

CBA/T6 strain mice infected with Plasmodium berghei ANKA develop cerebral symptoms and die, with mononuclear cell attachment to the cerebral microvascular endothelium, petechial haemorrhages and breakdown of the blood-brain barrier, some 6-7 days post-inoculation. The effects of dietary restriction on this process were examined. Mice were fed ab libitum (Group 1) or their food was restricted to produce body weight loss of 1.0-2.0% (Group 2), 2.5-3.5% (Group 3), 4.0-6.5% (Group 4) or 7.0-9.5% (Group 5) relative to Group 1. Dietary restriction reduced deaths caused by cerebral malaria from 100% in Group 1 to 47% (Group 2), 43% (Group 3), 10% (Group 4) and 53% (Group 5). Restriction of food intake had no effect on (1) the progression of parasitaemia in infected mice (2) changes in haematocrit, spleen weight, total lymph node cell number or (3) peritoneal exudate cell number in either malaria-infected or uninfected mice. P. berghei ANKA infection did not significantly affect the proportion of lymph node leucocytes that were Thy-1+ T cells or CD8+ T cells, but did lead to significant increases in the CD4+ and B cell populations. Dietary restriction alone increased the lymph node CD4+ cell population but did not affect the increase in B cells in malaria-infected mice. P. berghei ANKA infection and dietary restriction together did not lead to increased CD4+ cell numbers in lymph node leucocytes. The in vitro proliferative response to isolated lymph node cells to concanavalin A or phorbol myristate acetate plus ionomycin was measured and found to be identical in all treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)