Malaria is an infectious and parasitic disease that affects millions of people in the tropical and
subtropical regions of the world. In Brazil, most cases are in the Legal Amazon, especially due
to the favorable conditions for the existence of the vector. Malaria, a disease caused by protozoa
of the genus Plasmodium, is the protozoan that kills most human beings in the world. The
resistance described in Southeast Asia by Plasmodium falciparum, to artemisinin derivatives, a
drug classically used to treat the disease, threatens malaria control, highlighting the need for
the development of new drugs, especially natural products. Medicines from natural substances
are able to treat about 80% of the diseases that affect humanity. Libidibia ferrea Mart. ex Tul.
var. ferrea, is a tree that grows throughout Brazil, being found mainly in the North and Northeast
regions, being commonly known as jucá. Jucá has been extensively investigated for its various
biological properties (anti-inflammatory, analgesic, anticancer, antioxidant, antimicrobial and
healing) but there are no studies on its action against Plasmodium parasites. In this context, the
objective was to evaluate the in vitro anti-plasmodial activity of the hydroalcoholic extract of
Jucá (L. ferrea) (EHJ). The preparation of the hydroalcoholic extract of Jucá was carried out
using fruits, the fruits (1.5 kg) were sanitized with 70º Gl alcohol and dried at room temperature.
After 48 hours, the fruits were placed in a forced air circulation oven at 40ºC for 72 hours.
Subsequently, the fruits were crushed and placed for maceration in 96° Gl alcohol, in the
proportion of 5 liters to 1 kg of fruit, for 7 days. Then, the macerate was filtered and the tincture
was extracted using a rotary evaporator. For the cytotoxicity assay, the MTT method with WI-
26VA4 cells (ATCC CCL-75 lung fibroblast) was used. This test consists of the rapid
colorimetric evaluation of the growth of cell lines in vitro. To obtain the intraerythrocyte phases
of Plasmodium falciparum, parasites of the W2 strain (chloroquine-resistant) were cultured in
human red blood cells in vitro under ideal conditions for growth. For the anti-plasmodial test,
synchronized cultures of P. falciparum with 0.5% ring-stage parasitemia and 2% hematocrit
were distributed in a 96-well plate (180μL per well). The tested compound was added (20μL)
to the test plate, in triplicate, and in different serial concentrations from 50 to 0.20μg/mL. In the
tests performed, cytotoxicity was recorded as the percentage of reduction in absorbance. The
hydroalcoholic extract of Jucá did not show cytotoxic activity by MTT, with an IC50 value
greater than 100 µg/ml. In the determination of IC50 by anti-plasmodial test, the value was
11.10 µg/ml. In addition, the selectivity index (SI) 9 was obtained, which corresponds to the
relationship between the cytotoxic and anti-plasmodial activities of the hydroalcoholic extract
of Jucá. The extract showed low hemolytic activity at the highest concentrations and did not
show hemolytic activity at the lowest concentrations tested. Due to its anti-plasmodial activity
at the concentrations tested and low toxicity, the Jucá extract is presented as a candidate for
herbal medicine in the treatment of malaria, and may also potentiate its effect if associated with
other herbal medicines.
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