Background. Malaria is the leading cause of morbidity and mortality in African countries. We aimed this study at evaluating the in vitro antiplasmodial, antioxidant, and cytotoxicity activity of Lophira lanceolata extracts. Method. The aqueous and ethanol extracts were obtained by maceration. It tested in vitro the extracts against Plasmodium falciparum 3D7 and multiresistance Dd2. Macrophage cell lines (RAW 264.7 cells) and red blood cells were used for cytotoxicity tests. The antioxidant activity was assessed by 1,1-diphenyl-2-picrylhydrazine (DPPH), hydrogen peroxide (H2O2), nitric oxide (NO) reduction, and ferric reducing antioxidant power (FRAP) scavenging. Results. The in vitro antiplasmodial results showed that the ethanol extract was the most active, with IC50 of 24.51 ± 4.77 µg/mL and 31.86 ± 3.10 µg/mL, respectively, on the resistant Dd2 and sensitive 3D7 strains unlike the aqueous which indicated moderate activity with an IC50 of 51.36 ± 4.86 μg/mL and 56.36 ± 4.27 μg/mL, respectively, on the resistant Dd2 and sensitive (3D7) strains. However, the ethanol extract had the highest activity, with an IC50 of 8.153 g/mL, 1915 g/mL, 30.81 g/mL, and 54.66 g/mL, respectively, for DPPH, H2O2, NO, and FRAP, while the aqueous extract had an IC50 of 6.724, 2387681, 185.7, and 152.0 g/mL, respectively, for DPPH, H2O2, NO, and FRAP. The cytotoxicity test reveals that both extracts do not promote red blood cell haemolysis. They presented weak activity against RAW 264.7 cells and red blood cells. Conclusion. According to these findings, the aqueous and ethanol extracts have antiplasmodial and antioxidant activity but with no cytotoxic effects on red blood cells or RAW cells. However, it will be important to investigate the in vivo antiplasmodial and antioxidant activity of these extracts.

Background. Reduction of oxidative stress during malaria infection is considered as being of great benefit so long as treatment and drug development approaches are concerned. This study had the aim of evaluating the antimalarial and antioxidant activities of the ethanolic extract of Terminalia macroptera in Swiss albino mice infected with the Plasmodium berghei NK65 strain. Methods. In vivo, the antiplasmodial activity of the plant ethanolic extract was tested in a four-day suppressive and curative assay using P. berghei in Swiss albino mice. The extract was administered to the mice at doses of 125, 250, and 500 mg/kg per day. Then, parameters, such as parasite suppression and survival time of the mice, were evaluated. Furthermore, the effect of plant extract on liver damage, oxidative stress indicators, and lipid profile changes in P. berghei-infected mice were studied. Results. Administration of T. macroptera significantly suppressed P. berghei infection by 55.17%, 70.69%, and 71.10% at doses of 125, 250, and 500 mg/kg, respectively, whereas chloroquine had 84.64% suppression relative to the untreated group 1% Dimethyl sulfoxide (1% DMSO) at day 4 (post-infection) in the four-day suppressive test. This suppression activity rate was dose-dependent. The curative test also presented a significant reduction in parasitemia and an extension of the survival time of the treated groups. Treatment of infected parasitized mice with the extract of T. macroptera had a significant ( p < 0.05 ) reduction in parameters, such as total protein, aspartate aminotransferase, and alanine aminotransferase. Infection may also lead to a significant increase in the enzymatic activity of liver catalase and superoxide dismutase compared with the normal control group. The non-enzymatic antioxidant activity in parasitized mice was significantly reduced in malondialdehyde and increased in glutathione and nitric oxide when compared with the normal control group. Conclusions. These findings support the ethnobotanical use of T. macroptera stem bark as an antimalarial remedy coupled with antioxidant activity. However, further in vivo toxicity tests are required to ascertain its safety.

Introduction. Resistance to common antimalarial drugs and persistence of the endemicity of malaria constitute a major public health problem in Cameroon. The aim of this study was to evaluate the in vitro antiplasmodial, antioxidant, and cytotoxic activities of aqueous and ethanol extracts of Bridelia micrantha used by Cameroonian traditional healers for the treatment of malaria. Methods. Aqueous and ethanolic stem bark extracts were prepared according to standard procedures. The SYBR Green method was used for antiplasmodial activity on strains of Plasmodium falciparum sensitive to chloroquine (3D7) and resistant (Dd2). In vitro antioxidant activities of B. micrantha were determined using the scavenging activity of 2,2 ′ -diphenyl-1-picrylhydrazyl, nitric oxide, ferric reducing power, and hydrogen peroxide as well as their cytotoxicity on RAW 264.7 macrophage cells and red blood cells (RBC). Results. The aqueous and ethanol extracts of Bridelia micrantha showed antiplasmodial activity on the 3D7 strain with I C 50 of 31.65 ± 0.79  μg/ml and 19.41 ± 2.93  μg/ml, respectively, as well as 37.64 ± 0.77  μg/ml and 36.22 ± 1.04  μg/ml for the Dd2 strain, respectively. The aqueous and ethanol extracts showed free radical scavenging properties. The IC 50 aqueous and ethanol extract was approximately 0.0001737 μg/ml, 42.92 μg/ml, 1197 μg/ml, 63.78 μg/ml and 4.617 μg/ml, 429.9 μg/ml, 511 μg/ml, and 69.32 μg/ml for DPPH, NO, H2O2, and FRAP, respectively, which were compared to ascorbic acid ( 8.610 e − 005  μg/ml, 2901 μg/ml, 3237 μg/ml, and 18.57 μg/ml). The aqueous and ethanol extracts of B. micrantha were found to be nontoxic with CC 50 values of 950 ± 6.6  μg/ml and 308.3 ± 45.4  μg/ml, respectively. Haemolysis test showed that the two extracts were not toxic. Conclusion. These results suggest that B. micrantha can serve as an antimalarial agent. However, further studies are needed to validate the use of B. micrantha as an antimalarial.

Background. Malaria is a serious public health problem, especially in sub-Saharan Africa. The aim of this study was to scientifically provide baseline information on the use of Khaya grandifoliola stem bark as an antimalaria drug by traditional healers. Method. The stem barks of K.grandifoliola were harvested and dried to obtain powder, and fifty grams of the powder were soaked in ethanol and hot distilled water respectively, for the preparation of ethanol and aqueous extracts, then dried in an oven at 40°C for the ethanol extract and 50°C for the aqueous extract. Plasmodium falciparum strains 3D7 sensitive and Dd2 resistant to chloroquine, were used to evaluate in vitro antiplasmodial activity using SYBR Green. The ability of the extracts to prevent oxidative stress was assessed by trapping 2, 2′-diphenyl-1-picrylhydrazyl (DPPH); nitric oxide, hydrogen peroxide and ferric reducing power. The cytotoxicity test of the extracts was carried out on RAW 264.7 cell lines and on erythrocytes. The data obtained were entered in the Excel software, then in Graph pad where the IC50 was calculated and the curves plotted. Results. The fifty percent inhibition (IC50) of the antiplasmodial activity of the chloroquine-resistant strain PfDd2 were 54.27 ± 2.41 μg/mL and 31.19 ± 4.06 μg/mL respectively, for the aqueous and ethanol extracts. As for the Chloroquino-sensitive Pf3D7, IC50 of 53.06 μg/mL was obtained for the aqueous extract and 28.03 ± 1.90 μg/mL for ethanol. The DPPH radical scavenging activity presented IC50 of 104 μg/mL for the aqueous and 2.617 μg/mL for the ethanol extract; for the Nitric oxide (NO) presented an IC50 of 301 ± 21 μg/mL for the aqueous extract 140.7 ± 21 μg/mL for the ethanol; for hydrogen peroxide the ethanol and aqueous presented IC50 of 845.1 ± 21 μg/mL and 509.4 ± 21 μg/mL respectively. The cytotoxicity on RAW 264.7 cells presented High CC50 in particular >1000 μg/mL and 467.4 μg/mL respectively for the aqueous and ethanol extract. Conclusion. Extracts of Khaya grandifoliola exhibited antiplasmodial activity. The ability to inhibit oxidative stress as well as lower cell toxicity on RAW 264.7 and erythrocytes, is a good indicator. However, in vivo tests remain important in order to confirm the use of this plant for the treatment of malaria.

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