Antimalarial effect of flamboyant (Delonix regia) bark and papaya (Carica papaya L) leaf ethanolic extracts against Plasmodium berghei in mice

Plasmodium resistance of antimalarial drugs has been a major public health threat worldwide. New treatments are urgently required to harness and eradicate malaria in developing countries. One of the ways to overcome this issue is to develop new therapy from medicinal plants. The purpose of this study is to determine antiplasmodium activities from bark extract of Delonix regia and leaf extract of Carica papaya L., also to compare each ratio combination to find the most effective bioactivity. The experimental design was examined in eleven groups of mice, consisted of the positive control, negative control, Delonix regia bark extract with three different doses (4.80, 9.75, and 15.5 mg/g body weight/body weight of mice), Carica papaya leaves extract with three different doses (4.80, 9.75 mg/g, 15.5 mg/g body weight/BW of mice), and three combinations of Delonix regia and Carica papaya L., with ratio of 1:1, 1:3, and 3:1, respectively. The extract treatments were given daily for five days and on each day the parasite density were evaluated. Parasitemia examination was performed on before and after the treatment by performing blood smear preparation stained with Giemsa stain. The results showed that the plant extracts increased a drastically inhibition in combination of Delonix regia and Carica papaya L with ratio of 1:1 by showing its efficacy in rectifying immune conditions in Plasmodium berghei-infected mice. Meanwhile, each single dose of Delonix regia and Carica papaya L in 9.75 mg/g showed the highest inhibition rate compared in 4.80 and 15.5 mg/g, respectively. Histological examination of liver tissues of treated and untreated mice further supports the potential antimalaria of this plant. This examination validates the traditional use of this plant for the treatment of malaria.