Anti-malarial activity of the root extract of Euphorbia abyssinica (Euphorbiaceae) against Plasmodium berghei infection in mice

Biogenically synthesized green silver nanoparticles exhibit antimalarial activity

The suboptimal efficacies of existing anti-malarial drugs attributed to the emergence of drug resistance dampen the clinical outcomes. Hence, there is a need for developing novel drug and drug targets. Recently silver nanoparticles (AgNPs) constructed with the leaf extracts of Euphorbia cotinifolia were shown to possess antimalarial activity. Therefore, the synthesized AgNPs from Euphorbia cotinifolia (EcAgNPs) were tested for their parasite clearance activity. We determined the antimalarial activity in the asexual blood stage infection of 3D7 (laboratory strain) P. falciparum. EcAgNPs demonstrated the significant inhibition of parasite growth (EC50 of 0.75 µg/ml) in the routine in vitro culture of P. falciparum. The synthesized silver nanoparticles were seen to induce apoptosis in P. falciparum through increased reactive oxygen species (ROS) ROS production and activated programmed cell death pathways characterized by the caspase-3 and calpain activity. Also, altered transcriptional regulation of Bax/Bcl-2 ratio indicated the enhanced apoptosis. Moreover, inhibited expression of PfLPL-1 by EcAgNPs is suggestive of the dysregulated host fatty acid flux via parasite lipid storage. Overall, our findings suggest that EcAgNPs are a non-toxic and targeted antimalarial treatment, and could be a promising therapeutic approach for clearing malaria infection.

Evaluation of the antimalarial and CD4+ T-cell modulatory effects of leaf methanol extract of Phyllanthus muellerianus (Kuntze) Exell (Phyllanthaceae) in Plasmodium berghei-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus muellerianus (Kunze) Exell, a member of the Phyllanthaceae family, is a medicinal plant widely distributed in Africa. Decoctions from the leaves are used in Nigeria to treat fevers, convulsions, some neurological disorders and malaria.

AIM OF THE STUDY

This study is to evaluate the anti-malarial properties of methanol extract of Phyllanthus muellerianus (MEPM) leaves and its ethyl acetate fraction using a murine malaria model infected with Plasmodium berghei. Additionally, we seek to investigate the potential modulatory effects of this extract and fraction on CD4+ T-cell populations in the context of malaria infection.

MATERIALS AND METHODS

The anti-malarial effects of the leaf methanol extract of Phyllanthus muellerianus (MEPM) were screened using three established in vivo models of anti-plasmodial screening namely the curative, suppressive and prophylactic models. The methanol extract (MEPM) was afterwards fractionated into hexane (HFPM), ethyl acetate (EAFPM), and methanol (MFPM) fractions. In the pilot anti-malarial screening of the fractions, EAFPM exhibited the best antiparasitic activity. Subsequently, EAFPM was screened for anti-malarial activity using the three models above. The effects of the MEPM and EAFPM on haematological indices (Hb and PCV) of the inoculated animals were further screened and the mean survival time (MST) of the animals was monitored. CD4+ T cells of various groups were counted before and after treatment using a flow cytometer. The EAFPM was further subjected to HPLC analysis for identification of its major compounds.

RESULTS

The EAFPM (100 and 200 mg/kg) elicited 88% and 93% cure respectively in the curative model, while artesunate (5 mg/kg,- the positive control) gave 87% protection. The MEPM and EAFPM also gave significant suppression of parasitemia in the suppressive model. The treated groups survived beyond 28 days as against 11 days by the control group (infected but not treated). The treated groups also prevented anaemia seen in the negative control. The EAFPM group significantly modulated the CD4+ T cell. Compounds identified were Gallocatechin, Quercetin -3-O-gallate, Ellagic acid, and Methylellagic acid rhamnoside).

CONCLUSION

The study established that the leaf of Phyllanthus muellerianus possesses antimalarial activity, thus lending support to its use in the folkloric treatment of malaria.

In vitro antileishmanial activities of hydro-methanolic crude extracts and solvent fractions of Clematis simensis fresen leaf, and Euphorbia abyssinica latex

As a result of increasing drug resistance, crossover resistance development, prolonged therapy, and the absence of different agents with innovative methods for implementation, the efficacy of recent antileishmanial medications is severely declining. So, it is vital to look for other medications from botanical remedies that have antileishmanial activity. The latex of Euphorbia abyssinica (E abyssinica) and the leaves of Clematis simensis fresen (C simensis) were macerated in methanol (80%). In vitro antileishmanial activity of the preparation was tried on promastigotes of Leishmania aethiopica (L aethiopica) and Leishmania donovani (L donovani) using resazurin assay, and fluorescence intensity was measured. One percent of dimethyl sulfoxide (DMSO) and media as negative control and amphotericin B as positive control were used. Additionally, hemolytic & phytochemical tests of the preparation were done. The mean and standard errors of each extract were evaluated and interpreted for statistical significance using one-way analysis of variance. From sigmoidal dose-response curves of % inhibition, half maximal inhibitory concentration (IC50) values were determined by GraphPad Prism and Microsoft Excel; outcomes were presented as mean ± standard error of mean of triplicate trials. P < .05 was statistical significance. The phytochemical screening of C simensis and E abyssinica confirmed the existence of steroids, phenols, tannins, saponins, alkaloids, terpenoids, flavonoids and glycosides. C simensis possesses antileishmanial activity with IC50 outcomes of 46.12 ± 0.03 and 8.18 ± 0.10 µg/mL on the promastigotes of L aethiopica and L donovani, respectively. However, E abyssinica showed stronger activity with IC50 outcomes of 16.07 ± 0.05 µg/mL and 4.82 ± 0.07 µg/mL on L aethiopica and L donovani, respectively. C simensis and E abyssinica have a less hemolytic effect on human red blood cells at low concentrations. The outcomes from this investigation demonstrated that the preparation of C simensis and E abyssinica indicated significant antileishmanial activity. Therefore, further in vivo assessment of antileishmanial, cytotoxicity activity and quantitative identification of secondary metabolites are highly recommended.

Manilkara zapota L. extract topical ointment application to skin wounds in rats speeds up the healing process

Poor circulation, unresolved inflammation, neuropathy, and infection make wound care difficult. Manilkara zapota (M. zapota) antibacterial and antioxidant properties may help speed up the healing process. The present investigation aimed to evaluate the wound healing activity of M. zapota bark ethanolic extract (MZE) by employing in-vitro migration scratch assay and in-vivo animal models. Wistar albino rats were used for the in-vivo wound healing models. No treatment was given to Group I; Group II received povidone-iodine (5% W/W); Group III received MZE (5% W/W); and Group IV received MZE (10% W/W). Linear incision models and excision wound models were used to induce injury. The ointments were applied immediately to the wounds after causing the injury. The percentage of wound contraction, the length of the epithelization period, and the wound's tensile strength were all calculated. The scratch assay assessed the test drug's potential for wound healing in-vitro. H₂O₂ and DPPH scavenging assays were used to measure antioxidant activity. A p < 0.05 was used to define statistical significance. On days 4, 8, 12, 16, and 20, the wound contraction potential of animals treated with MZE ointment was significantly higher (p < 0.001) than that of the control group. On day 20, the proportion of wound contraction in MZE-treated animals was 99.88%, compared to 83.86% in untreated animals. The test group had a significantly (p < 0.01) faster time to full epithelization than the control group. In the incision model, the control group had considerably lower mechanical strength (p < 0.001) than animals treated with MZE. In addition, MZE caused a significant increase (p < 0.001) in total protein and hydroxyproline levels. In the scratch experiment, test drug-treated cells showed a higher rate of cell migration than untreated cells. Furthermore, animals treated with MZE showed increased levels of epithelial tissue, collagen proliferation, and keratinization. To summarize, the current study found that M. zapota improved wound healing activity both in vitro and in vivo, as evidenced by the study results. M. zapota extract has significant wound-healing potential and could be a viable source of wound-healing nutraceuticals.

Evaluation of the Anti-Malarial Activity of the Crude Root Extract and Solvent Fraction of Sesamum indicum (Fabaceae)

Background

A major cumbersome factor in malaria control measure is the new coming antimalarial drug resistance strains. The increase of resistance to the available marketed antimalarial agents dictates the scientific community to search new alternative antimalarial agent from traditional plants. Therefore, our study assesses the antimalarial activity of the crude root extract and solvent fraction of Sesamum indicum in mice.

Methods

The roots of Sesamum indicum were extracted by 80% methanol and fractionated using three solvents with different polarities. The in vivo antimalarial activity was assessed at 200 mg/kg, 400 mg/kg, and 600 mg/kg of the root crude extract and solvent fraction using the 4-day suppressive test. Similarly, the n- butanol fraction extract, which showed better suppression potential in 4-day suppressive test from other fractions was also evaluated in the curative model to assess its curative potential. The % parasitemia suppression, mean survival time, body weight change, rectal temperature change, and packed cell volume change were also evaluated in both models.

Results

Our finding revealed that the crude extract and solvent fraction treated groups had a statistical significant parasitemia suppression and mean survival time improvement as compared to the negative control (p<0.001) in both models in a dose-dependent fashion. The higher dose n-butanol fraction treated group (600mg/kg) showed the highest suppression effect and mean survival time prolongation in both tests from the other two fractions. However, the lowest suppressive effect was observed in 200 mg/kg aqueous fraction extract-treated groups in the 4-day suppressive test.

Conclusion

The crude root extract and solvent fractions of Sesamum indicum possessed a dose dependent antimalarial activity and a significant change in other parameters in both models that strengthen the traditional claim.

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

BACKGROUND

Drug 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.

METHODS

Forty-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.

RESULTS

Of 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.

CONCLUSIONS

The 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.

Suppressive, Curative, and Prophylactic Effects of Maesa lanceolata Forssk. against Rodent Malaria Parasite Plasmodium berghei

The artemisinin partial resistance is believed to be spread to artemisinin-based combination therapy partner drugs. As a result, new antiplasmodial compounds are required to treat resistant malaria infections. In the invention of antimalarial substances, claimed medical plants are precious resources. So, the current study was designed to assess the antiplasmodial effects of Maesa lanceolata in mice. In this study, preliminary phytoconstituent and in vivo acute oral toxicity tests were done. Early infection, established infection, and residual infection tests were employed to determine the antimalarial effects of the test drugs. Three doses (200, 400, and 600 mg/kg) of the extracts were provided orally to the test mice. Analysis of variance (one-way) followed by post hoc Tukey's test was used to analyze the difference between and within groups. Terpenoids, tannins, saponins, flavonoids, and alkaloids were detected in the phytochemical constituent analysis. Both 80% methanolic crude extract and solvent fractions had no toxic result at the 2000 mg/kg dose. All test drug doses suppressed parasite levels in a significant manner at all tests. The activity of chloroform fraction (maximum percentage suppression, 81.28%) overwhelms the crude extract activity. The curative effects of 80% methanolic crude extract, with a maximum of 80.22% parasitemia suppression, were greater than its suppressive and prophylactic effects. The 400 mg/kg dose of chloroform fraction resulted in a maximum survival period (18 days) than other doses of tested materials. The results of this investigation provide support for the activity of M. lanceolata leaf extract against malaria.

Exploring Potential Antimalarial Candidate from Medicinal Plants of Kheaw Hom Remedy

The Kheaw Hom remedy is a traditional Thai medicine widely used to treat fevers. Some plant ingredients in this remedy have been investigated for their antimicrobial, antiviral, anti-inflammatory, and antioxidant activities. However, there have been no reports on the antimalarial activities of the medicinal plants in this remedy. Therefore, this study focuses on identifying potential antimalarial drug candidates from the medicinal plant ingredients of the Kheaw Hom remedy. Eighteen plants from the Kheaw Hom remedy were extracted using distilled water and ethanol. All extracts were investigated for their in vitro antimalarial activity and cytotoxicity. An extract that exhibited good in vitro antimalarial activity and low toxicity was selected for further investigation by using Peter’s 4-day suppressive test and an acute oral toxicity evaluation in mice. Based on the in vitro antimalarial activity and cytotoxicity studies, the ethanolic extract of Globba malaccensis rhizomes showed promising antimalarial activity against the Plasmodium falciparum K1 strain (IC50 = 1.50 µg/mL) with less toxicity to Vero cells (CC50 of >80 µg/mL). This extract exhibited a significant dose-dependent reduction in parasitemia in P. berghei-infected mice. The maximum suppressive effect of this extract (60.53%) was observed at the highest dose administered (600 mg/kg). In a single-dose acute toxicity test, the animals treated at 2000 mg/kg died within 48 h after extract administration. In conclusion, our study indicates that the ethanolic extract of G. malaccensis rhizomes exhibited in vitro and in vivo antimalarial activities, which could serve as a promising starting point for antimalarial drug.

In Vivo Antimalarial Activity of the Leaf Extract of Osyris quadripartita Salzm. ex Decne and Its Major Compound (-) Catechin

Background

The leaves of Osyris quadripartita Salzm. ex Decne, endemic to Ethiopia, are traditionally used for the treatment of malaria. Previous phytochemical investigations of Osyris species showed the presence of flavonoids, anthracene derivatives, and sesquiterpene lactones as the main constituents. The aim of the present study was to investigate the antimalarial activity of the leaf extract of O. quadripartita and its isolated constituent against mice infected with Plasmodium berghei.

Methods

Isolation of a compound was carried out on silica gel column chromatography of the extract eluting with gradient mixtures of CHCl3/MeOH. Structural elucidation of the isolated compound was achieved by ESI-MS and 1D-and 2D-NMR spectral data. Peter's 4-day suppressive test method was used to determine the antimalarial activity of the test substances. Level of parasitemia, survival time, and body weight change were used to determine the antimalarial activity of the test substances.

Results

(-) Catechin was isolated and characterized from the hydroalcoholic extract of O. quadripartita. At a concentration of 400 mg/kg, both the extract and (-) catechin exhibited antimalarial activity with the highest chemosuppression values of 70.61% and 64.26%, respectively.

Conclusion

These findings indicate that O. quadripartita is endowed with genuine antimalarial activity attributed in part, to its (-) catechin content. Hence, the present study may validate the traditional use of the plant for the treatment of malaria.

In Vivo Anti-Malarial Activity of the Aqueous Root Extract of Euclea divinorum Hiern (Ebenaceae) against Plasmodium berghei ANKA

Background

Drug resistance is a universal challenge to malaria control measures. As a result, the development and discovery of new chemotherapeutic agents from medicinal plants having anti-malarial traditional claims are very important. This work, therefore, attempted to evaluate the anti-malarial activity of the aqueous root extract of E. divinorum using a rodent model of malaria.

Methods

The roots of E. divinorum were extracted by hot decoction using distilled water. Anti-malarial activity of various doses (100 mg/kg, 200 mg/kg, and 600 mg/kg) of the root aqueous extract was evaluated using the 4-day suppressive test as well as curative and repository tests. Parasitemia, rectal temperature, body weight, PCV, and MST were also determined.

Results

The finding showed that there were a dose-related significant parasitemia chemo-suppression and increment in survival time as compared to the negative control (p < 0.001) in all tests. The chemo-suppression effect was higher at 400 mg/kg extract-treated groups in the 4-day suppressive test followed by the curative test. The lowest chemo-prophylaxis effect was observed in 100 mg/kg extract-treated groups in the repository test. Regarding the other parameters, the extract prevented weight loss, temperature drop, and hemolysis in all models but not in a consistent manner.

Conclusion

The current study showed that the aqueous root extract of E. divinorum possessed a varying degree of anti-malarial activity in all three tests, with greater parasitemia suppression observed in the 4-day suppressive test. The extract produced higher parasitemia chemo-suppression and longer survival time in early infections followed by established and then residual infection.

Antimalarial Activity of Crude Extract and Solvent Fractions of Leaves of Solanum nigrum L. (Solanaceae) against Plasmodium berghei in Mice

Background. Current malaria treatment is associated with continued development of drug resistance. Thus, there is a need to develop safe and effective new treatments from different sources. Solanum nigrum L. (Solanaceae) is a plant used for the treatment of malaria in Ethiopian traditional medicine. This study was aimed at evaluating of antimalarial activity of the crude extract and fractions of S. nigrum L. (Solanaceae) leaves against P. berghei infection in mice. Method. Both prophylactic and suppressive models were used in evaluating antimalarial activity using the ANKA Plasmodium strain. In these models, male mice were randomly grouped into eleven groups (n = 5). Mice in group I were given 4% Tween-80, mice from group II up to X were given 100, 200, and 400 mg/kg of plant extract, and the last group (XI) was treated with chloroquine (25 mg/kg). Data were analyzed using one-way ANOVA followed by post hoc Tukey’s multiple comparison test. Results. Crude extract of leaves of S. nigrum showed chemosuppression of 30.68 ( $P<0.05$ ), 42.42 ( $P<0.01$ ), and 50.75% ( $P<0.001$ ) at 100, 200, and 400 mg/kg doses of the extract, respectively. At doses of 100, 200, and 400 mg/kg, the chloroform fraction produced a chemosuppressive effect of 40.15% ( $P<0.01$ ), 53.78% ( $P<0.001$ ), and 65.15% ( $P<0.001$ ) and a chemoprophylactic effect of 42.7% ( $P<0.05$ ), 51.84% ( $P<0.001$ ), and 67.17% ( $P<0.001$ ) when compared with negative control. In the suppressive model, the ethyl acetate fraction demonstrated a mean chemosuppression of 56.81% ( $P<0.001$ ), 65.9% ( $P<0.001$ ), and 70.83% ( $P<0.001$ ). Similarly, in the prophylactic model, the fraction showed suppression of 42.70% ( $P<0.05$ ), 53.11% ( $P<0.001$ ), and 71.03% ( $P<0.001$ ) at 100, 200, and 400 mg/kg doses. On the acute oral toxicity test, the extracts were safe at 2 g/kg dose. Conclusion. S. nigrum L. has antimalarial activity and supports the traditional medical practice.

A Network Pharmacology Analysis of Cytotoxic Triterpenes Isolated from Euphorbia abyssinica Latex Supported by Drug-likeness and ADMET Studies

Euphorbia plants have been identified as potential sources of antitumor lead compounds. The current study aimed to isolate and identify the main active constituents of Euphorbia abyssinica latex followed by a cytotoxic evaluation. A network pharmacology approach was employed to predict the underlying mechanism. Finally, drug-likeness and ADMET studies were conducted for active compounds. The phytochemical investigation of the latex of E. abyssinica resulted in the isolation of two triterpenes, 3-acetyloxy-(3α)-urs-12-en-28-oic methyl ester (1) and lup-20(29)-en-3α,23-diol (2). The dichloromethane extract displayed potent cytotoxic activity against the MCF7 cell line with an IC₅₀ value of 4.27 ± 0.12 μg/mL but weak activity against HepG2 and HeLa cell lines (IC₅₀ = 20.47 ± 1.17 and 26.73 ± 2.99 μg/mL, respectively) compared to doxorubicin. Compound 1 showed an encouraging cytotoxic effect against MCF7 with IC₅₀ = 4.20 ± 0.20 μg/mL, followed by compound 2 (IC₅₀ = 5.8 ± 0.35 μg/mL). The network analysis revealed that the two isolated compounds are linked to 68 targets of human nature, among which 51 genes are linked to breast carcinomas and 5 targets (AR, CYP19A1, EGFR, PGR, and PTGS2) might be the top therapeutic targets of isolated compounds on breast cancer. Furthermore, the gene-enrichment analysis revealed that E. abyssinica could play a role in the treatment of breast cancer by striking 51 potential targets via mainly three signaling pathways: P13K-AKT, Wnt, and VEGF. Therefore, isolated triterpenes could be considered effective antitumor agents for breast cancer by elucidating their candidate target to alleviate breast cancer and related signaling pathways of the targets.

Evaluation of the antimalarial activity and toxicity of Mahanil-Tang-Thong formulation and its plant ingredients

Background

Novel potent antimalarial agents are urgently needed to overcome the problem of drug-resistant malaria. Herbal treatments are of interest because plants are the source of many pharmaceutical compounds. The Mahanil-Tang-Thong formulation is a Thai herbal formulation in the national list of essential medicines and is used for the treatment of fever. Therefore, this study aimed to evaluate the antimalarial activity of medicinal plants in the Mahanil-Tang-Thong formulation.

Methods

Nine medicinal plant ingredients of the Mahanil-Tang-Thong formulation were used in this study. Aqueous and ethanolic extracts of all the plants were analyzed for their phytochemical constituents. All the extracts were used to investigate the in vitro antimalarial activity against Plasmodium falciparum K1 (chloroquine-resistant strain) by using the lactate dehydrogenase (pLDH) method and cytotoxicity in Vero cells by using the 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, an extract with potent in vitro antimalarial activity and no toxicity was selected to determine the in vivo antimalarial activity with Peters’ 4-day suppressive test against the Plasmodium berghei ANKA strain. Acute toxicity was evaluated in mice for 14 days after the administration of a single oral dose of 2000 mg/kg.

Results

This study revealed that ethanolic extracts of Sapindus rarak DC., Tectona grandis L.f., Myristica fragrans Houtt. and Dracaena loureiri Gagnep. exhibited potent antimalarial activity, with half-maximal inhibitory concentration (IC50) values of 2.46, 3.21, 8.87 and 10.47 μg/ml, respectively, while the ethanolic of the formulation exhibited moderate activity with an IC50 value of 37.63 μg/ml and its aqueous extract had no activity (IC50 = 100.49 μg/ml). According to the in vitro study, the ethanolic wood extract of M. fragrans was selected for further investigation in an in vivo mouse model. M. fragrans extract at doses of 200, 400, and 600 mg/kg body weight produced a dose-dependent reduction in parasitemia by 8.59, 31.00, and 52.58%, respectively. No toxic effects were observed at a single oral dose of 2000 mg/kg body weight.

Conclusion

This study demonstrates that M. fragrans is a potential candidate for the development of antimalarial agents.

Biosynthesis, characterisation and antimicrobial activity of zinc oxide and nickel doped zinc oxide nanoparticles using Euphorbia abyssinica bark extract

Biosynthesis of metallic oxide nanoparticles is being used and preferred over physical and chemical methods of synthesis since it is simple, inexpensive, environmentally friendly, and green. The aim of this study was to synthesise ZnO and nickel doped ZnO nanoparticles using Euphorbia abyssinica bark extract for antimicrobial activity studies via agar disk diffusion method against some selected microbes. The synthesised nanoparticles were characterised using X-ray diffraction (XRD), ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. The study results revealed that the biosynthesised nanoparticles had good crystalline nature, with crystal sizes in the range of nanoparticles and structures of hexagonal wurtzite. Both undoped ZnO and nickel doped ZnO nanoparticles demonstrated antibacterial and antifungal activity against four bacterial strains and two fungal genus. Generally, nickel doped ZnO NPs were found to possess more antimicrobial activities than undoped ZnO NPs. Specially, 4% and 5% nickel doped ZnO NPs showed significantly enhanced activity against Enterococcus faecalis, Staphylococcus aureus, Aspergillus and Fusarium.

Cancer Chemopreventive Potential and Chemical Profiling of Euphorbia abyssinica Endowed with Docking Studies

Chemical profiling of both fruit and aerial part extracts of Euphorbia abyssinica via ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) showed them to be a rich source of diverse compounds. A total of 39 compounds in both extracts including flavonoids and phenolic compounds were identified as predominant metabolites. The antioxidant activity of both extracts was evaluated using three different in vitro assays (DPPH, ABTS, and FRAP assays). The E. abyssinica fruit extract demonstrated more potent activity compared to the aerial part extract (IC₅₀ of 85.1 ± 1.07 and 562.3 ± 1.01 μg/mL, respectively) in the DPPH assay. Furthermore, using ABTS and FRAP assays, the antioxidant capacities of the fruit extract were 1063.03 ± 37.8 and 1476.5 ± 95.6, respectively, calculated as μM Trolox equivalent/mg extract. One of the existing markers for cancer chemoprevention is the induction of phase II detoxifying enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1), which plays a vital role in cytoprotection against oxidative damage. The extracts were assessed to test their chemopreventive potential via NQO1 enzyme induction. The methanolic extract of fruits demonstrated a concentration-dependent increase in the cancer chemopreventive marker enzyme NQO1 at the protein expression level in a murine hepatoma cell line (Hepa1c1c7). The interaction with Kelch-like ECH-associated protein 1 (KEAP1) is an essential transcription factor that controls the expression of the NQO1 enzyme. The demonstrated induction of NQO1 by the fruit extract is consistent with a molecular docking study of the effect of dereplicated compounds on the KEAP1 target. Among the dereplicated compounds, hesperidin, naringin, and rutin have been established as promising inducer compounds for the chemopreventive marker NQO1. Our results highlight the E. abyssinica fruit extract as a future chemopreventive lead.

Digalloyl Glycoside: A Potential Inhibitor of Trypanosomal PFK from Euphorbia abyssinica J.F. Gmel

Human African trypanosomiasis is an endemic infectious disease caused by Trypanosoma brucei via the bite of tsetse-fly. Most of the drugs used for the treatment, e.g., Suramin, have shown several problems, including the high level of toxicity. Accordingly, the discovery of anti-trypanosomal drugs from natural sources has become an urgent requirement. In our previous study on the anti-trypanosomal potential of Euphorbia species, Euphorbia abyssinica displayed significant anti-trypanosomal activity. Therefore, a phytochemical investigation of the methanolic extract of E. abyssinica was carried out. Twelve compounds, including two triterpenes (1, 2); one sterol-glucoside (4); three ellagic acid derivatives (3, 9, 11); three gallic acid derivatives (5, 6, 10); and three flavonoids (7, 8, 12), were isolated. The structures of isolated compounds were determined through different spectroscopic techniques. Compound (10) was obtained for the first time from genus Euphorbia while all other compounds except compound (4), were firstly reported in E. abyssinica. Consequently, an in silico study was used to estimate the anti-trypanosomal activity of the isolated compounds. Several compounds displayed interesting activity where 1,6-di-O-galloyl-d-glucose (10) appeared as the most potent inhibitor of trypanosomal phosphofructokinase (PFK). Moreover, molecular dynamics (MD) simulations and ADMET calculations were performed for 1,6-di-O-galloyl-d-glucose. In conclusion, 1,6-di-O-galloyl-d-glucose revealed high binding free energy as well as desirable molecular dynamics and pharmacokinetic properties; therefore, it could be suggested for further in vitro and in vivo studies for trypanosomiasis.

Sida acuta Burm.f. leaves ethanol extract ameliorates haematological and biochemical alterations induced by Plasmodium berghei ANKA-65 in mice

Background

Malaria has continued to be a threat to man and his wellbeing, especially Africans and Asians. New antimalarial drugs are urgently needed to mitigate malaria treatment failure due to resistant Plasmodium species. Medicinal plants used by indigenous Nigerians for treating fever and malaria such as Sida acuta Burm.f. (Malvaceae) could be a promising source of lead compounds for developing new generations of antimalarial drugs. The effects of ethanol extract of S. acuta leaves (EESAL) on malaria parasitemia, haematological and biochemical status of P. berghei-infected mice were investigated, using the 4-day curative test.

Methodology

EESAL was prepared by maceration method. The phyto-constituents and acute toxicity profile of the extract were evaluated using standard protocols. In addition, malaria parasitemia and chemo-suppression, and indicators of haematological and biochemical status of P. berghei-infected mice treated with EESAL were assessed.

Results

At 200, 400 and 600 mg/kg/d b.w., p.o doses for 4 consecutive days, EESAL significantly (p < 0.05) decreased parasitaemia and suppressed malaria parasite by 89.64%, 95.95% and 97.38%, respectively comparable to negative control. The reduction in percentage malaria parasitemia by EESAL is comparable to Artemether (140 mg/kg/d b.w., p.o) used as standard antimalarial drug in this study. The packed cell volume (PCV), haemoglobin (Hb) concentration, and red blood cell (RBC) and white blood cell (WBC) counts of negative control are significantly (p < 0.05) higher than normal control. However, parasitized-EESAL-treated mice have significantly (p < 0.05) higher PCV value, Hb concentration and RBC and WBC counts than negative control. Similarly, treatment of parasitized mice with EESAL restored some indicators of the antioxidant, lipid peroxidation, lipid profile and liver status altered by malaria. In addition, EESAL was tolerable up to 5000 mg/kg b.w., p.o.

Conclusion

These results indicate that the EESAL possesses antimalarial activity and normalizes alterations in haematological and biochemical status of malaria-infected mice.

Antiplasmodial Activity of the Crude Extract and Solvent Fractions of Stem Barks of Gardenia ternifolia in Plasmodium berghei-Infected Mice

Background

The evolution of resistance to currently used malaria medicines together with the severe economic burden of malaria initiates the search for novel antimalarial drugs. Thus, the present experiment was intended to assess the in vivo antiplasmodial effect of Gardenia ternifolia based on the traditional claims and in vitro antimalarial effect of the plant.

Methods

For the crude extraction of stem barks of G. ternifolia, a cold maceration method using hydromethanol as a solvent was employed. The hydroalcoholic extract was then fractionated by three solvents (chloroform, n-butanol, and aqueous solvent) with different polarity indexes. Swiss albino mice infected with the chloroquine-sensitive malaria parasite (Plasmodium berghei) were used in this study. Acute oral toxicity study was done according to standard protocols. Four-day suppressive (hydromethanolic crude extract and solvent fractions), Rane's (crude extract), and repository (crude extract) tests were used to examine the antiplasmodial effects of the study plant.

Results

The chemosuppressive study revealed that all doses of the crude extract and its fractions displayed a significant (P < 0.001) inhibition of parasitemia compared with the vehicle (negative control). The crude extract's highest dose (600 mg/kg) showed the maximum (57.84%) parasitemia suppression during the chemosuppressive test. The crude extract also produced significant (P < 0.001) curative and prophylactic effects at all doses in Rane's and repository tests compared with the negative control. In the 4-day test, the n-butanol fraction produced parasitemia suppression higher than the chloroform fraction but lower than the crude extract. Of these, water fractions demonstrated the lowest chemosuppressive effect. Anthraquinone, alkaloids, flavonoids, saponins, steroids, tannins, and terpenoids were qualitatively detected in the plant material.

Conclusion

The current results showed that the hydromethanolic extract and fractions of G. ternifolia stem barks have antiplasmodial action with a high curative effect. Chloroform and n-butanol fractions were more active among the fractions, indicating that the nonpolar and semipolar constituents of the plant are responsible for the antimalarial effects.

In Vitro and In Vivo Antimalarial Activities and Toxicological Assessment of Pogostemon Cablin (Blanco) Benth

The aim of this study was to investigate the antimalarial activities and toxicity of Pogostemon cablin extracts. In vitro activities against the chloroquine-resistant Plasmodium falciparum K1 strain were assessed by using the Plasmodium lactate dehydrogenase enzyme (pLDH) assay, while in vivo activity against the Plasmodium berghei ANKA strain in mice was investigated using a 4-day suppressive test. The in vitro and in vivo toxicity were determined in Vero cells and mice, respectively. The ethanolic extract possessed antimalarial activity with an IC₅₀ of 24.49 ± 0.01 µg/ml, whereas the aqueous extract showed an IC₅₀ of 549.30 ± 0.07 µg/ml. Cytotoxic analyses of the ethanolic and aqueous extracts revealed a nontoxic effect on Vero cells at a concentration of 80 µg/ml. Based on a preliminary study of in vitro antimalarial activity, the ethanolic extract was chosen as a potential agent for further in vivo antimalarial activity analysis in mice. The ethanolic extract, which showed no toxic effect on mice at a dose of 2000 mg/kg body weight, significantly suppressed parasitemia in mice by 38.41%, 45.12% and 89.00% at doses of 200, 400 and 600 mg/kg body weight, respectively. In conclusion, this study shows that the ethanolic P. cablin extract possesses in vitro and in vivo antimalarial activity without toxic effects.

Evaluation of Antiplasmodial Activity of Hydroalcoholic Crude Extract and Solvent Fractions of Zehneria scabra Roots Against Plasmodium berghei in Swiss Albino Mice

Background

Since drug resistance makes controlling malaria parasites a major challenge, these pioneering researchers explore and discover new novel drugs from a variety of sources. As a result, this study aimed to assess the anti-plasmodial activity of hydroalcoholic crude extract and solvent fractions of Zehneria scabra roots in mice infected with Plasmodium berghei.

Methods

The antimalarial activity and safety profile of Zehneria scabra extracts were tested in a mouse model using four-day suppressive, prophylactic, and rane’s tests against chloroquine-sensitive Plasmodium berghei. Mice were divided into five groups at random: group I received distilled water (10 mL/kg), group II, III, and IV received 200, 400, and 600 mg/kg of the extract, respectively, and group V received chloroquine (25 mg/kg). The antimalarial activity of the extract was determined using parasitemia levels, survival time, rectal temperature, and weight variation.

Results

At all dose levels, the crude extract and solvent fractions of Zehneria scabra showed significant (p<0.05 to p<0.001) chemosuppression, with the crude extract and butanol fraction showing the highest chemosuppression (73.09% and 74.09%, respectively). Apart from suppressing parasitemia, the extract also increased survival time and secured packed cell volume reduction substantially (p<0.05 to p<0.001), while the crude extract had no significant impact on body weight or rectal temperature reduction in four-day suppressive and prophylactic models.

Conclusion

The result designated that Zehneria scabra is endowed with significant antimalarial activity. These results thus support the traditional use of Zehneria scabra, for the treatment of malaria.

In Vivo Antimalarial Activity of Leaf Latex of Aloe melanacantha against Plasmodium berghei Infected Mice

Background

Malaria is a major health concern in the world in general and developing countries in particular. Nowadays, the control of malaria has ended up steadily more complex due to the spread of drug-resistant parasites. Medicinal plants are the verifiable source of compelling antimalarial drugs. The present study was aimed to assess the in vivo antimalarial activity of leaf latex of A. melanacantha against Plasmodium berghei in mice.

Methods

Acute oral toxicity study of the leaf latex was assessed in mice up to a dose of 2,000 mg/kg. A four-day suppressive model was utilized to investigate the antimalarial activity of the plant. Three extract doses, 100, 200, and 400 mg/kg/day, doses of the plant leaf latex, chloroquine, 10 mg/kg (positive control) and distilled water, and 10 mL/kg (negative control) were administered to mice. Percent parasitemia suppression, packed cell volume, mean survival time, body weight, and rectal body temperature were used to determine antimalarial activity.

Results

Test groups treated with 100, 200, and 400 mg/kg of the latex showed a significant parasitemia suppression in dose dependent manner compared to the negative control with an IC₅₀ of 22.63 mg/ml. Mice treated with 100, 200, and 400 mg/kg have shown parasitemia suppression of 14.86%, 29%, and 43.2%, respectively. The chemosuppression was significant (P < 0.05) at all doses compared to the negative control. Similarly, mice treated with 100 mg/kg, 200 mg/kg, and 400 mg/kg have shown a significant survival time compared to the negative control. At the same time, weight loss reduction was observed within the test groups treated with 100 mg/kg and 200 mg/kg of the latex while the test groups treated with 400 mg/kg had showed almost no weight loss reduction. The latex also reversed the PCV reduction significantly (P < 0.05) at 200 mg/kg and 400 mg/kg doses and prevented rectal temperature dropping significantly (P < 0.05) at all doses.

Conclusion

The leaf latex of A. melanacantha has shown significant antimalarial activity against P. berghei in mice supporting the genuine traditional antimalarial usage of the plant.

Wound Healing Activity of 80% Methanol Leaf Extract of Zehneria scabra (L.f) Sond (Cucurbitaceae) in Mice

Background

Zehneria scabra is one of the folklore plants of Ethiopia frequently used for external wound treatment in humans. Nevertheless, pharmacological investigations have not been performed to substantiate activity of the plant extract in wound healing. Hence, this study attempted to explore the activity of leaf extract of Z. scabra in wound healing using a mice model.

Materials and Methods

The air-dried leaf from Z. scabra was pulverized and extracted with 80% methanol and prepared with 5% and 10% extract ointments. An acute dermal toxicity study of the extract was conducted in female mice by observing the signs of toxicity. Then 5% and 10% (w/w) ointments of the extract were applied topically to investigate their wound healing activity in incision and excision wound models. Parameters such as wound contraction, period of epithelialization, and tensile strength were determined.

Results

Upon the application of 10% w/w extract ointment, no signs of dermal toxicity were observed in mice. Both 5% and 10% (w/w) extract ointment formulations increased percentage wound contraction and tensile strength, and shortened the epithelialization period.

Conclusion

The findings of this study collectively showed that the leaf extract of Z. scabra possessed significant wound healing activity, upholding the folkloric use of the experimental plant.

Anti-obesity, antioxidant and in silico evaluation of Justicia carnea bioactive compounds as potential inhibitors of an enzyme linked with obesity: Insights from kinetics, semi-empirical quantum mechanics and molecular docking analysis

Obesity is a global health problem characterized by excessive fat deposition in adipose tissues and can be managed by targeting pancreatic lipase (PL) activity. In the present study, we investigated the in vitro antioxidant and anti-obesity potentials of methanolic leaf extract of Justicia carnea(MEJC) using lipase inhibition kinetics model. In silico evaluations of MEJC bioactive compounds as potential drug-like agents and inhibitors of PL were also investigated using SwissADME prediction tool, semi-empirical quantum mechanics(SQM), molecular electrostatic potential(MEP) and molecular docking analysis. Gas chromatography-mass spectrometry(GC-MS) revealed presence of campesterol, stigmasterol, beta-amyrin etc. MEJC scavenged reactive species and inhibited PL activity via a mixed inhibition pattern (K_i = 107.69 μg/mL; K_ii = 398.00 μg/mL) with IC₅₀ > orlistat's IC₅₀. Molecular docking of GC-MS identified compounds with porcine PL showed compounds 8,10,12 and 14 having high PL-binding affinity and similar binding pose with orlistat. Hydrophobic interactions and van der Waals forces were predominantly involved in the ligands' interactions with some key catalytic site amino acid residues (Ser-153,His-264). Compounds 10,12,13 and 14 indicated high drug-likeness, bioavailability, electronegativity, E_LUMO-E_HOMO energy gaps and MEP. Our findings show that MEJC is a rich natural source of antioxidant and anti-obesity agents which could be optimized for development of new anti-obesity drugs.

Medicinal plants as a fight against murine blood-stage malaria

OBJECTIVE

Malaria is an infectious parasitic disease affecting most of countries worldwide. Due to antimalarial drug resistance, researchers are seeking to find another safe efficient source for treatment of malaria. Since many years ago, medicinal plants were widely used for the treatment of several diseases. In general, most application is done first on experimental animals then human. In this article, medicinal plants as antimalarial agents in experimental animals were reviewed from January 2000 until November 2020.

MATERIALS AND METHODS

In this systematic review published articles were reviewed using the electronic databases NCBI, ISI Web of knowledge, ScienceDirect and Saudi digital library to check articles and theses for M.Sc/Ph.D. The name of the medicinal plant with its taxon ID and family, the used Plasmodium species, plant part used and its extract type and the country of harvest were described.

RESULTS AND CONCLUSION

The reviewed plants belonged to 83 families. Medicinal plants of families Asteraceae, Meliaceae Fabaceae and Lamiaceae are the most abundant for use in laboratory animal antimalarial studies. According to region, published articles from 33 different countries were reviewed. Most of malaria published articles are from Africa especially Nigeria and Ethiopia. Leaves were the most common plant part used for the experimental malaria research. In many regions, research using medicinal plants to eliminate parasites and as a defensive tool is popular.

In Vivo Antimalarial Activity of Crude Fruit Extract of Capsicum frutescens Var. Minima (Solanaceae) against Plasmodium berghei-Infected Mice

BACKGROUND

The alarming spread of parasite resistance to current antimalarial agents is threatening malaria controlling efforts. This, consequently, urged the scientific community to discover novel antimalarial drugs. Successful and most potent antimalarial drugs were obtained from medicinal plants. Capsicum frutescens is claimed to possess an antiplasmodial activity in Ethiopian and Ugandan folkloric medicine. However, there is a lack of pharmacological evidence for its antiplasmodial activity. This study, hence, was aimed at evaluating the in vivo antiplasmodial activity of C. frutescens in a mouse model.

METHODS

The dried fruits of the plant were extracted with 80% methanol using cold maceration. A 4-day suppressive test was employed to ascertain the claimed antiplasmodial effect of the plant. Following inoculation with P. berghei, mice in treatment groups were provided with three dose levels (100, 200, and 400 mg/kg) of the extract, while 2% Tween 80 and chloroquine served as the negative and positive controls, respectively. Weight, temperature, packed cell volume, parasitemia, and survival time were then monitored.

RESULTS

The acute oral toxicity study revealed that the crude extract caused no mortality and revealed no overt sign of toxicity. In the 4-day suppressive test, all dose levels of the extract were found to exhibit a significant (p < 0.05) inhibition of parasitemia compared to those of the negative control. Maximum parasite suppression (93.28%) was exerted by the highest dose (400 mg/kg/day) of extract. Also, the extract significantly (p < 0.05) prolonged survival time and prevented body weight loss and reduction in temperature and anemia compared to the vehicle-treated group.

CONCLUSION

This investigation found strong evidence that the fruit extract of C. frutescens is endowed with promising antiplasmodial activity. Hence, the plant could serve as a potential source of a newer antimalarial agent.

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.

A Review on Onychine and its Analogs: Synthesis and Biological Activity

BACKGROUND

Onychine is a 4-azafluorenone alkaloid isolated from the Annonaceae family, in low concentrations. Onychine and its analogs exhibit a wide range of pharmacological activities such as antifungal, antibacterial, anticancer, and antimalarial. Because of the high bioactivity of some 4-azafluorenone derivatives, several synthetic methods have been developed for their procurement.

OBJECTIVE

Considering the importance of these alkaloids, we aim to present the main synthetic approaches to onychines and its derivatives and the biological activity of some 4-azafluorenones.

METHODS

The most prominent methodologies for the synthesis of onychines were reviewed.

RESULTS

In this work, we cover many synthetic approaches for the synthesis of onychine and 4-azafluorenone derivatives including intramolecular cyclizations, multicomponent reactions, microwave-assisted multicomponent reactions, Diels-alder reactions, among others. Moreover, we also review the biological activity of 4-azafluorenones.

CONCLUSION

4-azafluorenones have risen as prominent structures in medicinal chemistry; however, most of the time, access to new derivatives involves toxic catalysts, harsh reaction conditions, and long-step procedures. Therefore, the development of new synthetic routes with more operational simplicity, simple purification procedure, good yields, and low environmental impact, is desirable.