Four-day Suppressive Test Research Articles

Efficacy of Albizia malacophylla (A.Rich.) Walp. (Leguminosae) methanol (80%) leaf extract and solvent fractions against Plasmodium berghei-induced malaria in mice model

Ethnopharmacological relevanceNovel drugs are needed to address the issue of malarial infection resistance; natural items can be a different source of these medications. Albizia malacophylla (A. Rich.) Walp. (Leguminosae) is listed as one of the antimalarial medicinal plants in Ethiopian folk medicine. However, there are no reports regarding the biological activity or phytochemistry of the plant. Aim of the studyThus, this study aimed to evaluate the A. malacophylla crude extract and solvent fractions' in vivo antimalarial activity utilizing 4-day suppressive, preventative, and curative tests in mice infected with P. berghei. Materials and methodsThe parasite Plasmodium berghei, which causes rodent malaria, was used to infect healthy male Swiss Albino mice, weighing 23–28 g and aged 6–8 weeks. Solvent fractions such as methanol, water, and chloroform were given in addition to an 80% methanolic extract at 100, 200, and 400 mg/kg doses. A Conventional test such as parasitemia, survival time, body weight, temperature, and packed cell capacity were employed to ascertain factors such as the suppressive, curative, and preventive tests. ResultsEvery test substance dramatically reduced the number of parasites in every experiment. Crude extract (with the highest percentage suppression of 67.78%) performs better antimalarial effect than the methanol fraction, which is the most efficient solvent fraction with a percentage suppression of 55.74%. With a suppression value of 64.83% parasitemia level, the therapeutic effects of 80% methanolic crude extract were greater than its curative and preventative effects in a four-day suppressive test. The survival period (17 days) was longer with the hydroalcoholic crude extract dose of 400 mg/kg than with other doses of the materials under investigation. ConclusionsThe results of this investigation validate the antimalarial characteristics of A. malacophylla leaf extract. The crude extract prevented weight loss, a decline in temperature, and a reduction in PCV. The results demonstrate that the plant has a promising antimalarial effect against P. berghei, hence supporting the traditional use of the plant. Therefore, it could serve as a foundation for the development of new antimalarial drugs.

Antimalarial and toxicological assessment of the tablet (AS201-01) ethyl acetate fraction of Andrographis paniculata Nees in animal models

Context: Andrographis paniculata has been used as a traditional medicine to treat malaria. The ethyl acetate fraction of A. paniculata containing diterpene lactone compounds was developed into a tablet dosage form, AS201-01. Aims: To determine the antimalarial activity and toxicity of AS201-01 to guarantee its efficacy and safety. Methods: Antimalarial assay in male Balb/c mice based on Peter’s four-day suppressive test at a dose of 6.25, 12.5, 25, and 50 mg/kg BW and 10 mg/kg BW of chloroquine as a positive control. In acute toxicity, AS201-01 was administered orally at a dose of 5, 50, 200, and 2,000 mg/kg BW in male rats (Wistar rats) and observed for 14 days to identify signs of toxicity and mortality. Meanwhile, AS201-01 was administered at 50, 327, and 1,000 mg/kg BW per day for 28 days in male and female rats to assess subchronic toxicity. Results: AS201-01 has antimalarial activity and exhibited the highest suppressive effect at 50 mg/kg BW dose with inhibition of 73.48%. Meanwhile, chloroquine at 10 mg/kg BW has an inhibition of 97.94%. AS201-01 was highly active as an antimalarial with an ED50 value of 5.95 mg/kg BW and increased survival time. Administration of AS201-01 is relatively safe in acute and subchronic toxicity studies. No clinical signs and mortality were observed in either study. The 50% lethal dose (LD50) was above 2,000 mg/kg BW. Conclusions: AS201-01 is effective as an antimalarial and non-toxic when administered orally at an equivalent therapeutic dose in an animal model.

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

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. 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. 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. 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.

Antimalarial activity of the 80%methanol extract and solvent fractions of Cucumis ficifolius A. rich roots against Plasmodium berghei in mice

Ethnopharmacological relevanceMalaria is still a known health threat, especially in parts of sub-Saharan Africa. It is one of the frequently mentioned issues with hospital admission and outpatient care in Ethiopia. Cucumis ficifolius A. Rich roots are historically used in Ethiopia to treat meningitis, inflammation, and malaria. However, the antimalarial activity of this plant has not been scientifically studied so far. Aim of the studyThis study aimed to determine the in vivo antimalarial activity of 80% methanol extract and solvent fractions of the roots of Cucumis ficifolius against Plasmodium berghei infection in mice. MethodsThe in vivo antimalarial activity of the 80% methanol extract and solvent fractions of Cucumis ficifolius A. Rich was evaluated by standard chemo suppressive, curative and repository tests using Plasmodium berghei (ANKA strain) in Swiss albino mice at doses of 100, 200 and 400 mg/kg/day. The level of parasitemia, survival time, variation in weight, rectal temperature, and packed cell volume of mice were determined to establish the activity of the extracts. ResultThe 80% methanol extract of Cucumis ficifolius A. Rich roots had a promising suppression of parasitemia at 400 mg/kg with a chemosuppression value of 65.21 ± 1.20%. Among the solvent fractions, the chloroform fraction showed the highest antimalarial activity in the four-day suppressive test with a chemosuppression value of 55.9 ± 0.28%, followed by the n-butanol (42.9 ± 0.24%), and aqueous (40.57 ± 0.52%) fractions at a dose of 400 mg/kg. The highest survival times were observed with crude extract (15.4 ± 0.24 days) at 400 mg/kg, and chloroform fraction (13.4 + 0.24 days), though all extracts increased survival time. ConclusionThe findings of the present study collectively indicate the root extract of Cucumis ficifolius has a promising antiplasmodial activity which substantiates the traditional claim of the plant.

Evaluation of Antimalarial Activity of Combination Extract of Citrus aurantifolia and Honey against Plasmodium berghei–İnfected Mice

Previous studies have reported artemisinin resistance. Drugs for malaria treatment have been developed from plants. Citrus aurantifolia was traditionally used to treat ailments. This study aimed to evaluate an antimalarial effect from Citrus aurantifolia, honey and a combination of Citrus aurantifolia and honey&nbsp; against Plasmodium berghei and analyze phytochemicals from the formula.&nbsp; Thirty mice were randomized into five groups. A four-day suppressive test was performed to evaluate the antimalarial activity. Data were analyzed using one- way ANOVA followed by Tukey’s post hoc-test to compare between and within&nbsp; groups. Test results which show a p-value of &lt;0.05 were considered statistically&nbsp; significant. The suppressive model showed a percentage parasite suppression&nbsp; of 67.5, 87.5, 78.8, and 86.2 for Citrus aurantifolia, stingless bee honey, a&nbsp; combination of Citrus aurantifolia-honey, and DHP, respectively. The maximum parasite suppression (87.5%) was exerted by the stingless bee honey group.&nbsp; There were no significant differences in parasite suppression in the DHP group,&nbsp; honey, a combination of honey and Citrus aurantifolia. Phytochemical analysis&nbsp; revealed that stingless bee honey contains saponins, flavonoids, tannins,&nbsp; phenols, and alkaloids, while lime contains several saponins, flavonoids, tannins,&nbsp; phenols, alkaloids, and steroids. A combination of Citrus aurantifolia&nbsp; and honey has potential to produce an antimalarial activity in vivo. However, the&nbsp; dose of Citrus aurantifolia in this study was relatively high and the effect of&nbsp; its extract on internal organs was not yet observed. Further research is required&nbsp; to study to what extent lower doses of Citrus aurantifolia produce an&nbsp; antimalarial activity.&nbsp

Antimalarial efficacy and toxicological assessment of medicinal plant ingredients of Prabchompoothaweep remedy as a candidate for antimalarial drug development

BackgroundDrug resistance exists in almost all antimalarial drugs currently in use, leading to an urgent need to identify new antimalarial drugs. Medicinal plant use is an alternative approach to antimalarial chemotherapy. This study aimed to explore potent medicinal plants from Prabchompoothaweep remedy for antimalarial drug development.MethodsForty-eight crude extracts from Prabchompoothaweep remedy and its 23 plants ingredients were investigated in vitro for antimalarial properties using Plasmodium lactate dehydrogenase (pLDH) enzyme against Plasmodium falciparum K1 strain and toxicity effects were evaluated in Vero cells. The plant with promising antimalarial activity was further investigated using gas chromatography-mass spectrometry (GC-MS) to identify phytochemicals. Antimalarial activity in mice was evaluated using a four-day suppressive test against Plasmodium berghei ANKA at dose of 200, 400, and 600 mg/kg body weight, and acute toxicity was analyzed.ResultsOf the 48 crude extracts, 13 (27.08%) showed high antimalarial activity against the K1 strain of P. falciparum (IC50 < 10 μg/ml) and 9 extracts (18.75%) were moderately active (IC50 = 11–50 μg/ml). Additionally, the ethanolic extract of Prabchompoothaweep remedy showed moderate antimalarial activity against the K1 strain of P. falciparum (IC50 = 14.13 μg/ml). Based on in vitro antimalarial and toxicity results, antimalarial activity of the aqueous fruit extract of Terminalia arjuna (IC50 = 4.05 μg/ml and CC50 = 219.6 μg/ml) was further studied in mice. GC-MS analysis of T. arjuna extract identified 22 compounds. The most abundant compounds were pyrogallol, gallic acid, shikimic acid, oleamide, 5-hydroxymethylfurfural, 1,1-diethoxy-ethane, quinic acid, and furfural. Analysis of the four-day suppressive test indicated that T. arjuna extract at dose of 200, 400, and 600 mg/kg body weight significantly suppressed the Plasmodium parasites by 28.33, 45.77, and 67.95%, respectively. In the acute toxicity study, T. arjuna extract was non-toxic at 2000 mg/kg body weight.ConclusionsThe aqueous fruit extract of T. arjuna exerts antimalarial activity against Plasmodium parasites found in humans (P. falciparum K1) and mice (P. berghei ANKA). Acute toxicity studies showed that T. arjuna extract did not show any lethality or adverse effects up to a dose of 2000 mg/kg.

Evaluation of Experimental Cerebral Malaria of Curcumin and Kaempferol in Plasmodium berghei ANKA-Infected Mice

Background: Cerebral malaria (CM) is one of the most severe complications of Plasmodium falciparum infection and the leading cause of death from malaria in endemic areas. Natural products with antioxidant and anti-inflammatory activities have become valuable alternative therapeutic options in CM treatment. Therefore, this study aimed to investigate the neuroprotective effects of curcumin and kaempferol in experimental cerebral malaria (ECM) in mice infected with Plasmodium berghei ANKA (PbA). Methods: After PbA infection, mice were divided into 9 groups, namely Group I (negative control (NC)) with 0.5% HPMC, Group II received chloroquine 20 mg/kg, Group III (normal) with aquadest, Groups IV, V, and VI received curcumin at doses of 20, 40, and 80 mg/kg, respectively, Groups VII, VIII, and IX received kaempferol at doses of 20, 40, and 80 mg/kg, respectively. The antimalarial activity was evaluated using Peter's four-day suppressive test. This was conducted to determine the % parasitemia, survival rate, AST and ALT, blood-brain barrier (BBB) leakage, and neurobehavioral disorders in mice with CM. Results: The results showed that all treatments had significant antimalarial activity, with the % suppression depending on the dose. It also indicates that PbA-infected mice had a survival rate of 11-19 days after infection, which was higher than those in the NC group. This suggested that curcumin and kaempferol have a protective effect on the survival of PbA-infected mice. Furthermore, they significantly reduced the AST and ALT concentrations in the sample compared to the NC group. The same was observed in cerebral vessel extravasation, where the Evans Blue stain assay showed significantly less dye extravasation in the brains of PbA-infected mice treated with curcumin and kaempferol. This indicated better-protected integrity of the BBB. Additionally, the results also demonstrated a decrease in neurological disorders arising during ECM in the group treated with curcumin and kaempferol. Conclusion: Considering these results, it is concluded that treatments with curcumin and kaempferol could improve animal survival, prevent AST and ALT elevations, as well as protect the BBB and neurobehavioral disorders associated with CM in PbA-infected mice.

Phytochemical Analysis, Antimalarial Properties, and Acute Toxicity of Aqueous Extracts of Trisamo and Jatu-Phala-Tiga Recipes.

Drug resistance remains a significant problem that threatens antimalarial drug treatment. Hence, the challenge is to find new effective antimalarial drugs. Based on our previous study, aqueous extracts of trisamo (TSM) and jatu-phala-tiga (JPT) had good in vitro antimalarial activities, and these recipes contain multiple beneficial pharmacological effects that could be useful for malaria therapy. Therefore, this study aimed to investigate the antimalarial activity and toxicity of the aqueous extracts of TSM and JPT in mouse models. The aqueous extractions were carried out using the decoction method. Compound identification was conducted using LC-QTOF-MS analysis. The antimalarial activities of TSM and JPT at doses 200, 400, and 600 mg/kg were evaluated against Plasmodium berghei ANKA infection using a four-day suppressive test. The toxic effects of oral administration of the extracts at 2 g/kg dose were determined using an acute toxicity test. The chemical constituents of TSM contained 83 compounds, whereas JPT contained 84 compounds. All doses of the extracts exhibited a significant suppression (p < 0.05) of the parasite compared to the negative control in a four-day test. The maximum activities were observed at 600 mg/kg dose with 67.02% suppression for TSM and 79.34% for JPT, followed by 400 mg/kg dose (57.63% for TSM and 64.79% for JPT) and then 200 mg/kg dose (52.35% for TSM and 54.46% for JPT). In addition, there were no significant differences (p < 0.05) in the RBC, MCV, and MCH levels of mice receiving JPT extract compared to the uninfected control. The WBC level of mice receiving 400 and 600 mg/kg of TSM, and 200 and 400 mg/kg of JPT, was significantly (p < 0.05) lower than the infected control, and the extracts did not significantly prevent the loss of platelets. For the acute toxicity test, there were no signs of toxicity or deaths in mice, and there were no differences in the histology, weight, or enzyme biochemistry of the liver and kidney between the extract and vehicle groups. However, the platelet count in the extract-treated mice was significantly higher than that in the control group. In conclusion, this study suggests that aqueous extracts of TSM and JPT have potent antimalarial activities and could be promising as new candidates for antimalarial drug development.

Antimalarial activity of the hydroalcoholic crude extract and solvent fractions of Commelina latifolia Hochst. ex C.B.Clarke (Commelinaceae) leaves against Plasmodium berghei in mice

Ethnopharmacological relevanceIn Ethiopia, the indigenous medicinal plant Commelina latifolia Hochst. ex C.B. Clarke leaves are used to treat malaria and wounds. Aim of the studyIn this work, the antiplasmodial activity of Commelina latifolia crude leaf extract and solvent fractions against Plasmodium berghei-infected mice was investigated. Materials and methods80% methanol was used to extract the leaves of C. latifolia, and the crude extract was fractionated using chloroform, pure methanol, and distilled water. All test compounds were undergone an acute oral toxicity test before being put through Peter’s 4-day suppressive test to see if they have antiplasmodial activity. The hydroalcoholic crude extract and chloroform fraction were additionally assessed for antimalarial activity using curative and prophylactic tests in P. berghei-infected laboratory mice. ResultsAll of the tested crude extracts were safe at a dose of 2000 mg/kg. At 400 mg/kg dose both the 80% methanol extract and chloroform fraction exhibited antimalarial activity with parasitemia suppression values of 86.31%, and 76.56% in the four-day suppressive test, 81.97% and 72.05% in Rane's test, and 69.05% and 62.88% in the prophylactic test, respectively. ConclusionCollectively, the oral dose of Commelina latifolia is safe, and reveals promising antimalarial activity. The findings backed up the utilization of the plant in traditional medicine to treat malaria.

A Discovery-Based Metabolomic Approach Using UPLC-Q-TOF-MS/MS Reveals Potential Antimalarial Compounds Present in Artemisia annua L.

In 1972, Nobel laureate Youyou Tu's research team conducted clinical trials on the dried material of Artemisia annua L. from Beijing extracted by ether and then treated with alkali (called "ether neutral dry"), which showed that artemisinin was not the only antimalarial component contained. The biosynthesis of sesquiterpenoids in A. annua has increased exponentially after unremitting cultivation efforts, and the plant resources are now quite different from those in the 1970s. In consideration of emerging artemisinin resistance, it is of great theoretical and practical value to further study the antimalarial activity of A. annua and explore its causes. The purpose of this study is to clarify scientific questions, such as "What ingredients are synergistic with artemisinin in A. annua?", and "Are there non-artemisinin antimalarial ingredients in A. annua?". In this paper, Beijing wild A. annua was used as a control and two representative cultivation species of A. annua were selected to evaluate the antimalarial activity of the herbal medicine. The antimalarial activity of different extracts on mice was studied using the Peters' four-day suppressive test. UPLC-Q-TOF-MS was used to obtain mass spectrum data for all samples, and a UNIFI platform was used for identification. A multivariate statistical method was used to screen the different compounds with positive correlations. The antimalarial activity of different components from the ether extract and alkali treatments was determined and antimalarial components other than artemisinin were obtained. A total of 24 flavonoids, 68 sesquiterpenoids and 21 other compounds were identified. Compounds associated with differential antimalarial activity were identified. The material basis for the antimalarial activity of A. annua was clarified. The antimalarial components of A. annua include two categories: first, artemisinin and non-artemisinin antimalarial active components, of which the non-artemisinin antimalarial active components may include 5α-hydroperoxy-eudesma-4(15),11-diene; second, several antimalarial synergistic ingredients in A. annua, including arteanniun B, arteanniun B analogues and polymethoxy flavonoids.

Lumefantrine solid dispersions with piperine for the enhancement of solubility, bioavailability and anti-parasite activity

Crystallinity and P-glycoprotein (P-gp) mediated efflux of drugs with low aqueous solubility collaboratively contributes to erratic absorption resulting in low/variable bioavailability. Herein, the amorphous solid dispersions (SD) of lumefantrine (LUMF) containing piperine (PIP), a P-gp and CYP3A4 inhibitor, were formulated with Soluplus (Sol), Klucel (Klu) and Lutrol F68 (Lut), polymeric carriers, to improve solubility and bioavailability of LUMF following oral administration. The LUMF-PIP-SD prepared with Sol exhibited higher aqueous solubility of LUMF in concentration dependent manner and LUMF-PIP-Sol demonstrating maximum aqueous LUMF solubility were characterized by DSC, FTIR and XRD. The DSC thermogram and XRD diffractogram of LUMF-PIP-SD confirmed the loss of crystallinity of LUMF ensuing improved dissolution while possible interaction of LUMF with PIP and /or Sol was evident in FTIR spectrum. DSC and dissolution studies confirmed the stability for LUMF-PIP-Sol SD stored for 90 days under stressed conditions of humidity and temperature. An in situ single-pass intestinal perfusion study in rats indicated 2.2-fold increase in intestinal permeation of LUMF co-administered with PIP. Improved bioavailability of LUMF was evidenced by increased AUC0-∞ and Cmax for LUMF in SD compared to alone LUMF or LUMF with PIP. Peter’s four-day suppressive test indicated improved antimalarial activity for LUMF-PIP-Sol SD. Overall, the data suggest that the SD of LUMF incorporated with P-gp inhibitor PIP, improves the bioavailability as well as antimalarial efficacy of LUMF.

Antimalarial Activity of the Crude Extract and Solvent Fractions of the Stem of Momordica Charantia in Plasmodium Berghei Infected Mice

ntroduction:The emergence and rapid spread of multidrug-resistant Plasmodium strains, especially Plasmodium falciparum, has become a major concern for health professionals when it comes to malaria prophylaxis and treatment, limiting medication options, necessitating the search for new antimalarial drugs derived from plants. In mice infected with Plasmodium berghei, the antimalarial function of Momordica charantia stem crude methanolic extract and solvent fractions (hexane, ethyl acetate, and aqueous) was examined. Method:Starting on the day the infection was identified, the extract and fractions were administered continuously for four days. Tween 80 (0.3 ml) was given to the control group, while the standard reference drugs were chloroquine (10 mg/kgbw) and arteether (3 mg/kgbw) which were given for three days. The crude extract and fractions were tested for antimalarial activity in Plasmodium berghei infected mice using a four-day suppressive test. Result: At 500 mg/kgbw, the crude extract, hexane fraction, ethyl acetate fraction, and aqueous fraction developed 80.62, 90.09, 91.23, and 81.72 per cent chemosuppression respectively, on day 6 after infection. Chemosuppression was 100% for chloroquine and 90% for arteether. Conclusion: These results showed that the crude extract and solvent fractions of Momordica charantia stem had antiplasmodial efficacy comparable to the reference drug, indicating that the plant could be used as a natural antimalarial agent.

Petasites japonicus extract exerts anti-malarial effects by inhibiting platelet activation

BackgroundNew antimalarial agents are needed to combat emerging resistance to the currently available drugs. In the pathology of cerebral malaria, platelets play a central role by binding infected and uninfected red cells and the endothelium. Since Petasites japonicus extract was reported as an effective inhibitor of platelet activation, we examined the antimalarial activities of the P. japonicus extract. PurposeThis study aimed to evaluate the impact of P. japonicus extract prepared from whole plants on malarial infection. MethodsThe P. japonicus extract were characterized by high‐performance liquid chromatography (HPLC) profiling. Antimalarial activity of the P. japonicus ethanolic extract was evaluated in vitro using chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) P. berghei strains. Also, the in vivo activity of the extract was evaluated in P. berghei-infected mice via oral administration followed by a four-day suppressive test to measure the hematological parameters. In addition, platelet activation signaling induced by the P. japonicus extract in P. berghei infection was evaluated. Results: In HPLC study, catechin, rutin, liquiritin, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid were identified in P. japonicus extract. Exposure to the P. japonicus extract significantly inhibited both CQ-sensitive (3D7) and resistant (Dd2) strains of P. falciparum with IC50 values of 8.48 ± 1.70 and 7.83 ± 6.44 μg/ml, respectively. Administration of the P. japonicus extract also resulted in potent antimalarial activities in P. berghei-infected mice with no associated toxicity. The treatment also improved the hematologic parameters. In addition, the survived mice from P. berghei infection exhibited the inhibition of collagen-induced platelet aggregation by attenuated glycoprotein VI (GPVI) downstream signaling. Conclusion:P. japonicus extracts promote antimalarial effects both in vitro and in vivo. In addition, the effects appear to be induced by the inhibition of collagen-induced platelet activation related to attenuated GPVI downstream signaling. Further studies to identify and characterize the antimalarial compounds in P. japonicus will promote the development of new drugs.

Identification of lobetyolin as a major antimalarial constituent of the roots of Lobelia giberroa Hemsl

Lobelia giberroa Hemsl. is an endogenous Ethiopian medicinal plant with a long history of use in the treatment of malaria, bacterial and fungal diseases, and cancer. Here, we present the in vivo bioassay-guided fractionation of the 80% methanol extract of L. giberroa roots, which led to the isolation of lobetyolin. L. giberroa roots were extracted with 80% methanol, and the dried 80% methanol extract was fractionated with hexane, ethyl acetate, methanol, and water. Acute oral toxicity study was conducted according to the Organisation for Economic Co-operation and Development Guideline 425 by using female Swiss albino mice. Antimalarial activity was assessed in Plasmodium berghei-infected Swiss albino mice. Through in vivo bioassay-guided fractionation processes lobetyolin, a C14-polyacetylene glucoside, was isolated from the methanol fraction by silica gel column chromatography as the main active ingredient from the plant. The chemical structure of lobetyolin was elucidated by interpretation of spectroscopic data (1HNMR, 13CNMR, IR. MS) including two dimensional NMR. The plant extract was considered safe for administration up to 2000 mg/kg. In the four-day suppressive test, the 80% methanol extract (400 mg/kg), methanol fraction (400 mg/kg), and lobetyolin (100 mg/kg) exhibited antimalarial activity, with chemosuppression values of 73.05, 64.37, and 68.21%, respectively. Compared to the negative control, which had a mean survival time of 7 days, the lobetyolin (100 mg/kg) and methanol fraction (400 mg/kg) treated groups had mean survival times of 18 and 19 days, respectively. The current study supports the traditional use of the plant for the treatment of malaria. The structural differences between lobetyolin and existing antimalarials, as well as its previously unknown antimalarial activity, make it of interest as an early lead compound for further chemical optimization.

Fitness of sulfadoxine-resistant Plasmodium berghei harboring a single mutation in dihydropteroate synthase (DHPS)

Genetic changes conferring drug resistance are generally believed to impose fitness costs to pathogens in the absence of the drug. However, the fitness of resistant parasites against sulfadoxine/pyrimethamine has been inconclusive in Plasmodium falciparum. This is because resistance is conferred by the complex combination of mutations in dihydropteroate synthase (dhps) and dihydrofolate reductase (dhfr), which makes it difficult to separately assess the extent and magnitude of the costs imposed by mutations in dhps and dhfr. To assess the fitness costs imposed by sulfadoxine resistance alone, we generated a transgenic rodent malaria parasite, P. berghei clone harboring an A394G mutation in dhps (PbDHPS-A394G), corresponding to the causative mutation for sulfadoxine resistance in P. falciparum (PfDHPS-A437G). A four-day suppressive test confirmed that the PbDHPS-A394G clone was resistant to sulfadoxine. PbDHPS-A394G and wild-type clones showed similar growth rates and gametocyte production. This observation was confirmed in competitive experiments in which PbDHPS-A394G and wild-type clones were co-infected into mice to directly assess the survival competition between them. In the mosquitoes, there were no significant differences in oocyst production between PbDHPS-A394G and wild-type. These results indicate that the PbDHPS-A394G mutation alters the parasites to sulfadoxine resistance but may not impose fitness disadvantages during the blood stages in mice and oocyst formation in mosquitoes. These results partly explain the persistence of the PfDHPS-A437G mutant in the natural parasite populations.

Antimalarial Effect of the Total Glycosides of the Medicinal Plant, Ranunculus japonicus.

In traditional Chinese medicine, Ranunculus japonicus has been used to treat various diseases, including malaria, and the young stem of R. japonicus is consumed as a food in the Republic of Korea. However, experimental evidence of the antimalarial effect of R. japonicus has not been evaluated. Therefore, the antimalarial activity of the extract of the young stem of R. japonicus was evaluated in vitro using both chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains; in vivo activity was evaluated in Plasmodium berghei-infected mice via oral administration followed by a four-day suppressive test focused on biochemical and hematological parameters. Exposure to extracts of R. japonicus resulted in significant inhibition of both chloroquine-sensitive (3D7) and resistant (Dd2) strains of P. falciparum, with IC50 values of 6.29 ± 2.78 and 5.36 ± 4.93 μg/mL, respectively. Administration of R. japonicus also resulted in potent antimalarial activity against P. berghei in infected mice with no associated toxicity; treatment also resulted in improved hepatic, renal, and hematologic parameters. These results demonstrate the antimalarial effects of R. japonicus both in vitro and in vivo with no apparent toxicity.

Choline and PEG dually modified artemether nano delivery system targeting intra-erythrocytic Plasmodium and its pharmacodynamics in vivo

Objective The choline derivative (CD) and polyethylene-glycol (PEG) dually modified artemether (ARM) nanostructured lipid carriers (CD-PEG-ARM-NLC) have been designed to prolong the circulation of ARM in blood, as well as to develop targeting for new permeability pathways (NPPs) and erythrocyte choline carriers (ECCs) that are expressed on the Plasmodium-infected erythrocyte membrane. Significance The CD-PEG-ARM-NLC constructed in this study was found to be able to target endoerythrocytic Plasmodium by increasing the drug concentration and residence time in the infected erythrocytic microenvironment and minimizing toxicity and side effects. Methods CD-PEG-ARM-NLC was prepared using high-pressure homogenization followed by physicochemical characterization. The targeting ability of CD-PEG-NLC to infected erythrocytes probed by coumarin-6 was investigated by using fluorescence microscopy imaging. The SYBR Green I assay for parasite nucleic acid was adapted in order to assess the efficacy of inhibition against parasite growth in vitro. The antimalarial activity of ARM-loaded NLCs was evaluated by a Pearson four-day suppressive test in Pyy265BY-bearing mice. Results In vitro imaging indicated that the intracellular delivery of CD-PEG-ARM-NLC was efficiently taken up by the infected erythrocytes via ECCs and NPPs, which could be inhibited by addition of furosemide (an inhibitor of NPPs) and excessive choline (native substrate of ECCs). Moreover, in vitro and in vivo studies that evaluated antimalarial activity suggested that CD-PEG-ARM-NLC exhibited higher antimalarial activity in comparison to ARM-NLC and PEG-ARM-NLC. Conclusion These findings suggested that choline and PEG dually modified NLC could be promising preparations for the production of hydrophobic antimalarial drugs, particularly for ARM.

Antimalarial Activity of the Leaf Latex of Aloe weloensis (Aloaceae) against Plasmodium berghei in Mice.

Background Emergence of drug resistance and lack of therapeutic efficacy of modern antimalarial drugs are the most triggering factors for the searching of new lead compounds with different mechanisms of action. Medicinal plants with documented traditional uses are a viable option for treatment of malaria. Traditionally, the leaf latex of Aloe weloensis has been used in the treatment of malaria in Ethiopia. Hence, this study was undertaken to investigate the antimalarial activity of the leaf latex of Aloe weloensis in Plasmodium berghei-infected mice. Methods A four-day suppressive test was employed to evaluate the antimalarial effect of the leaf latex of the plant against P. berghei in Swiss albino mice. Mice were randomly assigned in five groups of five animals in each and given 100, 200, and 400 mg/kg of the leaf latex, chloroquine 25 mg/kg, and distilled water. The level of parasitemia, packed cell volume, survival time, temperature, and body weight was used to determine the antimalarial activity. Results The acute toxicity study indicated that the leaf latex of A. weloensis caused neither mortality nor signs and symptoms of toxicity at a dose of 2000 mg/kg. Furthermore, the 4-day suppressive test indicated that the latex of the plant exhibited a significant parasitemia reduction in a dose-dependent manner as compared to negative control. The leaf latex of the plant exhibited a percent inhibition of 13.05%, 41.87%, and 66.84% at doses of 100 mg/kg, 200 mg/kg, and 400 mg/kg, respectively. The chemosuppression of the antimalarial activity was statistically significant at 100 mg/kg (p < 0.05), 200 mg/kg (p < 0.01), and 400 mg/kg (p < 0.01) as compared to negative control. All doses of the leaf latex prevented weight loss and reduction in temperature and packed cell volume and increased the survival time of infected mice. Conclusion The results of this study demonstrated that the leaf latex of Aloe weloensis possessed antiplasmodial activity confirming the genuine traditional use of the plant as an antimalarial agent.

Evaluation of the Antimalarial Activity of the Hydroalcoholic Extract of Leaf of Leonotis ocymifolia (Burm. f.) Iwarsson (Lamiaceae) against Plasmodium berghei in Mice.

Malaria's global impact, fueled by resistance to several antimalarial drugs, has necessitated a quest to new antimalarial drugs from several sources with traditional medicinal plants being one of them. This study was conducted to assess the antimalarial activity of a traditionally used medicinal plant, Leonotis ocymifolia, against Plasmodium berghei. The plant has been extracted using maceration technique, and doses ranging from 100–800 mg/kg of Leonotis ocymifolia were used to test its antimalarial activity. Tween 80 (2% in water) and chloroquine 25 mg/kg were used as negative and positive controls, respectively. The antimalarial activities of the plant were determined by measuring parasitemia, survival time, packed cell volume, temperature, and weight. The plant's hydroalcoholic extract, as compared to negative control, maximally decreased parasite load by 41.4% at 800 mg/kg (p < 0.001). This parasite suppression was followed by longer survival time in the groups taking 400 mg/kg (p < 0.05) and 800 mg/kg (p < 0.05) in a four-day suppressive test and in those taking 800 mg/kg (p < 0.05) in Rane's test. The plant did not prevent weight and PCV reduction but prevented temperature reduction at 400 mg/kg (p < 0.05) and 800 mg/kg (p < 0.05) in a four-day suppressive model, and at 800 mg/kg (p < 0.05) in Rane's model. The average but consistent antimalarial activity of the plant across the test models corroborates the folkloric antimalarial use of the plant. The study recommends further pharmacological screenings, isolation, and identification of active compound(s) of the plant Leonotis ocymifolia.

Self-nanoemulsifying drug delivery systems (SNEDDS) for oral delivery of Garcinia kola seeds ethanolic extract: formulation and in vivo antimalarial activity

Context: Garcinia kola seeds are widely used in Congolese traditional medicine to treat uncomplicated malaria. While the ethanolic extract of these seeds (GK) is reputed for oral antimalarial activity, some of its constituents have shown poor water solubility, which might compromise further phytopharmaceutical developments. Aims: To develop a self-nanoemulsifying drug delivery system (SNEDDS) for oral delivery of GK, since SNEDDS are promising vehicles for enhancing drug product solubility. Methods: GK was loaded into liquid SNEDDS (solution and suspension) and solid SNEDDS (S-SNEDDS), and the resultant formulations were characterized using dynamic light scattering and electron microscopy. The antimalarial activity of SNEDDS (200 mg/kg × 4 days, oral) was evaluated in Plasmodium berghei-infected mice using a conventional four-day suppressive test. Results: The characterization of SNEDDS formulations revealed the presence of nanosized structures of spherical morphology and negative surface charge. Data from in vivo study showed reduced parasite growth by 77.9, 73.8 and 74.2% for GK-SNEDDS solution, GK-SNEDDS suspension and GK-S-SNEDDS, respectively. The activity of GK-SNEDDS was found to be greater than that of a licensed GK-based syrup (N’sansiphos®) used at the same dose (p&lt;0.05). Conclusions: These findings demonstrate the potential of SNEDDS formulations as a promising alternative for enhancing the antimalarial efficacy of GK following oral administration. The SNEDDS technology holds the promise of improving the oral delivery of herbal-based products for malaria therapy.