Antimalarial Efficacy of Ethanol Extract of Bridelia micrantha Stem Bark against Plasmodium berghei-Infected Mice.

Background: The spread of drug resistance is a significant issue, particularly in endemic countries with limited resources. The aim of this study was to evaluate antimalarial and antioxidant activity of B. micrantha in order to justify its use in traditional medicine. Methods: Evaluation of the in vivo antimalarial activity of B. micrantha was carried out according to the model of the suppressive and curative test of Peters' over 4 days in infected Swiss albino mice. Antioxidant parameters and stress were measured after intraperitoneal administration of 1 × 107 infected red blood cells. Results: At doses of 150 mg/kg, 300 mg/kg, and 600 mg/kg, administration of B. micrantha substantially produced suppression of P. berghei infection by 67.75%, 73.46%, and 78.99%, respectively, while 84.64% of the untreated group (1% DMSO) had suppression from chloroquine. The curative test significantly decreased the levels of parasitaemia and death in the treated groups. Furthermore, after B. micrantha extract was given to infected mice, a noteworthy increase in total protein, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) was observed. On the other hand, hepatic catalase (CAT) and superoxide dismutase (SOD) productions were considerably greater than that of the healthy control. Mice had considerably lower levels of nonenzymatic antioxidant markers such as glutathione, NO, and MDA showing that the liver was protected. Conclusion: The infected groups responded favorably to the ethanol extract of B. micrantha. This result justifies investigation for its use in Cameroon.

Efficacy of Khaya grandifoliola Stem Bark Ethanol Extract in the Treatment of Cerebral Malaria in Swiss albino Mice Using Plasmodium berghei NK65 Strain.

Background: Cerebral malaria is one of the most severe and dangerous forms of malaria and is potentially fatal. This study was aimed at evaluating the anticerebral malaria efficacy of Khaya grandifoliola used by traditional healers. Method: Fifty grams of Khaya grandifoliola stem bark was macerated in 1 L ethanol (95%) for 72 h. The filtrate was dried at 40°C until the obtention of a dry extract. The antimalarial test was evaluated using the Peter 4-day suppressive test and the Rane curative test. Mice were group into 6 groups of 6 mice each. For the antioxidant test, parameters such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), and nitric oxide (NO) were assessed. The livers of mice were crushed and centrifuged in order to be measured. Aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) using the Dutch Diagnostics Kit and blood were collected for haematological parameters. Results: The ethanol extract showed a suppressive activity of 78.12%, 75.30%, and 68.69% at 500 mg/kg, 250 mg/kg, and 125 mg/kg, respectively. Similarly, the curative activity showed a statistically significant reduction in parasitemia (p < 0.05). Antioxidant parameter assays showed a low value of MDA and a high value of SOD, CAT, NO, and GSH in the negative control group. A statistically significant higher values of ASAT and ALAT were observed in the negative control compared to the other test groups (p < 0.05). Haematological parameters showed a statistically significant decrease in white blood cells, red blood cells, haemoglobin, and platelets in the negative control group (p < 0.05). Conclusion: The results of this study justify the traditional usage of Khaya grandifoliola in the treatment of cerebral malaria. However, in vivo toxicity assessment is still necessary to verify its safeness.

Nematocidal Activity of Ethanol and Aqueous Extracts of Persea americana Seeds against Heligmosomoides polygyrus using the Worm Microtracker Method.

Background: Infections with gastrointestinal helminths constitute a serious obstacle to the good health of the local population in most African Countries. The aim of this study was to evaluate the anthelminthic activity of Persea americana ethanol and aqueous extracts against Heligmosomoides polygyrus using the worm microtracker. Method: Aqueous and ethanolic extracts of P. americana were prepared. Different concentrations of the extracts were tested against the egg and larvae stages of H. polygyrus using an automated high-throughput method. Briefly, embryonated eggs and larvae of this parasite were obtained after the incubation of fresh eggs at 25°C for 24, 48, and 96 hours for embryonated eggs, L1 and L2 larvae, respectively. One hundred microliters of the plant extracts at various concentrations were put in contact in a 96-well microplate with a suspension of 100 embryonated eggs in a total volume of 200 µL and incubated in a worm microtracker where the motility of the worms was recorded every 30 minutes for the ovicidal activity. The final tested extract concentration was 5, 2.5, 1.25, 0.625, and 0.3125 mg/mL, whereas ringer solution (0.95%) and 1.5% Dimethyl sulfoxide (DMSO) were used as negative controls and levamisole as positive control. The same method was used for larvicidal activities. The anthelmintic activity was determined using the average movement of the worms in the tested product compared with the negative control (1.5% DMSO and ringer solution). Results: The egg hatching rates of H. polygyrus had IC50 of 0.49 mg/mL (95% confidence interval: 71.70-92.03) and 0.22 mg/mL (95% confidence interval: 74.28-86.18) for the ethanol and aqueous extract, respectively. These IC50 indicate that the aqueous extract is more active for the inhibition of hatching at a 95% confidence interval. The aqueous and ethanol extracts presented mean inhibitory hatching rates of 78.33 ± 1.67% and 75.67 ± 1.15% at 5 mg/mL, respectively, with no significant differences. The highest percentage of inhibition of L1 larva was observed at 5 mg/mL with 89 ± 2.3%and 85 ± 2.7% for the ethanol and aqueous extracts, respectively. The lowest percentage of inhibition was observed at 0.3125 mg/mL, with 54.67 ± 3.38% and 49 ± 2.64% for the ethanol and aqueous extract, respectively. No significant differences were observed between the two extracts at 5 mg/mL with an inhibitory percentage of 90.67 ± 3.05% (ethanol) and 89.33 ± 2.08% (aqueous). Conclusion: Extracts of P. americana seeds possess nematocidal activity, however, further in silico and in vivo investigations are necessary to confirm their anthelminthic activity.

Antimalarial Efficacy and Antioxidant Activity of Lophira lanceolata Stem Bark Ethanol Extract Using Plasmodium berghei Induced-Malaria in Swiss Albino's Mice.

Background: Malaria remains a major public health problem in the tropical and subtropical regions. This study aimed of investigating the antimalarial and antioxidant activities of ethanol extract of Lophira lanceolata stem bark. Methodology. The antimalarial activity was determined using the Peter 4-days' suppressive and Rane's curative tests on Swiss albino: these mice were infected with 1 × 107 parasitized red blood cells. The percentage reduction of parasitemia was related to each test, and the liver homogenate was used to assay malondialdehyde, superoxide dismutase, nitrogen monoxide, catalase, and glutathione for the evaluation of oxidative stress. During the curative test, blood was collected for hematological parameters, alanine aminotransferase and aspartate aminotransferase to evaluate liver function. Result: The ethanol extract of L. lanceolata showed a dose-dependent suppressive activity with the highest suppression of 88.22% at 500 mg/kg. Suppression produced by the extract was not significantly higher than that of the reference drug with 96.1%. Similarly, the extract at doses 125, 250, and 500 mg/kg showed significant decreases (P < 0.05) in a dose-dependent manner during the curative test. The ethanol extract of L. lanceolata caused a reduction of tissue markers, such as hepatic oxidative stress, as it increased the enzymatic activity of antioxidant enzymes. Conclusion: The ethanol extract of L. lanceolata possesses both antimalarial and antioxidant activities. However, further in vivo toxicity tests are required to guarantee their safety.

Antimalarial and Antioxidant Activities of Ethanolic Stem Bark Extract of Terminalia macroptera in Swiss Albino Mice Infected with Plasmodium berghei.

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.

Antiplasmodial, Antioxidant, and Cytotoxic Activity of Bridelia micrantha a Cameroonian Medicinal Plant Used for the Treatment of Malaria.

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 IC50 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 IC50 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 (8.610e - 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 CC50 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.