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Background: Malaria eradication has been complicated by the repeated emergence of antimalarial drug resistances. We aimed to determine whether a metabolite extract of Streptomyces hygrocopicus subsp. hygroscopicus could decrease the viability of Plasmodium falciparum 3D7 in vitro. Methods: S. hygroscopicus subsp. hygroscopicus isolates were inoculated and fermented on the ISP4 medium. The fermented S. hygroscopicus was mixed with ethylacetate 1:5 (v/v), and the solvent phase was evaporated. Several concentrations of isolated extract was added to the P. falciparum 3D7 culture containing trophozoite and schizont stages in 24 wells plates when the degree of parasite-infected erythrocytes reached 5%, then incubated for 8 hours. DNA parasite density was measured using flow cytometry, parasite degree and morphology were observed under microscopic by Giemsa-stained smears. Results: The metabolite extract affected the morphology of almost all of parasite asexual stages. Schizonts and trophozoites failed to grow and appeared damaged with pycnotic cores and loss of cytoplasmic content. At 8 hours there was a significant decrease in DNA parasite density in culture exposed to 2.6 mg/ml and 13 mg/ml (P = 0.002; P = 0.024) of the extract. The degree of parasite-infected erythrocytes was decreased from the beginning of exposure (0.02 mg/ml of the extract). There was a significant inverse correlation between the concentration of extract and the degree of parasite-infected erythrocytes as well as the density of DNA parasite (r = −0.772, P = 0.000; r =−0.753; P =0.000). Conclusion: Metabolite extract of S. hygroscopicus subsp. hygroscopicus causes morphological damage, decreases the degree of parasite-infected erythrocytes and the DNA density of P. falciparum 3D7 in vitro. [ABSTRACT FROM AUTHOR]

Background: We aimed to reveal the role of CD11b and hypoxia-inducible factors- 1alpha (HIF-1α) expressions on monocytes and alveolar macrophages of lung tissue, and the levels of serum surfactant protein-D (SP-D) in severe malaria-associated acute lung injury (ALI). Methods: The C57BL/6 mice were divided into control group, renal malaria group (inoculated with 106 Plasmodium berghei ANKA), and cerebral malaria group (inoculated with 107 P. berghei ANKA). The expressions of CD11b and HIF-1α in lung tissue were observed by immunohistochemistry, and serum SP-D levels were measured by ELISA. This study was conducted from June 2014 to February 2015 in the Laboratory of Parasitology, Faculty of Medicine, Universitas Brawijaya, Malang. Results: The CD11b expression on pulmonary tissue of renal and cerebral malaria mice were significantly higher than control mice (P=0.002; P=0.002), as well as the HIF-1α expression on pulmonary tissue (P=0.002; P=0.002). The level of serum SP-D in renal malaria and cerebral malaria mice were significantly higher than control mice (P=0.002; P=0.002). We found a strong correlation between the expression of CD11b and HIF-1α in lung tissue (r=0.937, P=0.000), as well as between CD11b expression and serum SP-D levels (r=0.907, P=0.000) and between HIF-1α expression and serum SP-D levels (r=0.913, P=0.000). Conclusion: Severe malaria-associated ALI increased the expression of CD11b and HIF-1α in the lung tissue and increased serum SP-D levels of C57BL/6 mice significantly. [ABSTRACT FROM AUTHOR]