In vivo antiplasmodial and toxicological effect of crude ethanol extract of Echinops kebericho traditionally used in treatment of malaria in Ethiopia

Bioassay-guided isolation of dehydrocostus lactone from Echinops kebericho as a leishmanicidal drug

Several strains of Leishmania parasite are involved in the occurrence of leishmaniasis infections, which makes its prevention and treatment very challenging. Currently, all forms of leishmaniasis are being treated with chemical drugs, which have limitations and adverse effects. Discovering antileishmanial agents from natural sources can lead to novel drugs against this dreadful disease. The essential oils and nonpolar solvent extracts of the roots of E. kebericho exhibit antileishmanial activity. Thus, the isolation of the leishmanicidal compounds from the roots of E. kebericho through a bioassay-guided technique was carried out in this study. The present finding showed that the essential oil and hexane fraction of crude extract from the roots of E. kebericho possessed significant leishmanicidal activity against L. major and L. tropica. Dehydrocostus lactone (1), one of the major constituents of the essential oil and hexane fraction, was more active than the standard drug miltefosine against L. major and L. tropica promastigotes. The presence of α-methylene, γ-lactone is the responsible moiety of dehydrocostus lactone towards the leishmanicidal activity against the tested Leishmania species. The MTT assay of dehydrocostus lactone showed inactive toxicity against the human cervical carcinoma HeLa cells. In addition, dehydrocostus lactone exhibits a broad spectrum of antibiotic activities. Based on this interesting finding, dehydrocostus lactone was identified as a potential lead for treating infections caused by Leishmania.

The Potentials of Ageratum conyzoides and Other Plants from Asteraceae as an Antiplasmodial and Insecticidal for Malaria Vector: An Article Review

Background

Malaria is a life-threatening disease prevalent in tropical and subtropical regions. Artemisinin combination therapy (ACT) used as an antimalarial treatment has reduced efficacy due to resistance, not only to the parasite but also to the vector. Therefore, it is important to find alternatives to overcome malaria cases through medicinal plants such as Ageratum conyzoides and other related plants within Asteraceae family.

Purpose

This review summarizes the antimalarial and insecticidal activities of A. conyzoides and other plants belonging to Asteraceae family.

Data Source

Google Scholar, PubMed, Science Direct, and Springer link.

Study Selection

Online databases were used to retrieve journals using specific keywords combined with Boolean operators. The inclusion criteria were articles with experimental studies either in vivo or in vitro, in English or Indonesian, published after 1st January 2000, and full text available for inclusion in this review.

Data Extraction

The antimalarial activity, insecticidal activity, and structure of the isolated compounds were retrieved from the selected studies.

Data Synthesis

Antimalarial in vitro study showed that the dichloromethane extract was the most widely studied with an IC50 value <10 μg/mL. Among 84 isolated active compounds, 2-hydroxymethyl-non-3-ynoic acid 2-[2,2']-bithiophenyl-5- ethyl ester, a bithienyl compound from the Tagetes erecta plant show the smallest IC50 with value 0.01 and 0.02 µg/mL in Plasmodium falciparum MRC-pf-2 and MRC-pf-56, respectively. In vivo studies showed that the aqueous extract of A. conyzoides showed the best activity, with a 98.8% inhibition percentage using a 100 mg/kg dose of Plasmodium berghei (NK65 Strain). (Z)- γ-Bisabolene from Galinsoga parviflora showed very good insecticidal activity against Anopheles stephensi and Anopheles subpictus with LC50 values of 2.04 μg/mL and 4.05 μg/mL.

Conclusion

A. conyzoides and other plants of Asteraceae family are promising reservoirs of natural compounds that exert antimalarial or insecticidal activity.

Ethnobotanical study of endemic and non-endemic medicinal plants used by indigenous people in environs of Gullele botanical garden Addis Ababa, central Ethiopia: A major focus on Asteraceae family

Gullele Botanical Garden (GBG) in Addis Ababa, Ethiopia is a joint venture of Addis Ababa government and the university. The garden has been built mainly to conserve the endemic plants and to advance the research on the endemic and non-endemic plants collected from different part of Ethiopia. Many traditional healers from the environs of GBG and different subcities of Addis Ababa depend on the garden for their practice of traditional medicine but there is no systematic documentation of the traditional medicinal knowledge of these healers. The main objective of the present study is to comprehensively document the ethnobotanical and ethnomedicinal information from the traditional healers of different ethnic and cultural groups depending on GBG and to create a database of the endemic plants used by these healers. The ethnobotanical and ethnomedicinal data obtained from 60 traditional healers have been analyzed both qualitatively and quantitatively. A total of 81 medicinal plants belonging to 47 families have been identified. Majority of the plants used belonged to Asteraceae (12) family. The most frequently used plant form and plant parts are herbs and leaves. The major method adopted by the healers for preparation and administration of traditional medicine is crushing and topical, respectively. Skin and general diseases are the most important ailments treated by the healers. The three most cited plants used to treat diseases are Echinops kebericho Mesfin (60), Hagenia abyssinica (Bruce) J.F.Gmel (60) and Laggera tomentosa (A.Rich.) Sch.Bip. ex Oliv. & Hiern (58). The present study is the first systematic, qualitative, and quantitative ethnobotanical analysis and documentation done on the use of the medicinal plants from GBG for traditional medicine. In addition, our study reveals that E. kebericho is endemic and endangered plant and is highly used in traditional medicine. Therefore, GBG authorities should take steps for the propagation and restoration of this plant. Further it is suggested that the pharmacological properties of the roots and leaves of E. kebericho should be compared to find the possibility of use of leaves in place of roots for the preparation of traditional medicine which would help in conserving this endemic plant of Ethiopia.

Medicinal plants used in traditional treatment of malaria in Ethiopia: a review of ethnomedicine, anti-malarial and toxicity studies

Background

Malaria is extremely common in Ethiopia, and it is one of the country's most serious public health and economic problems. Traditional medicines have long been utilized in Ethiopia by people of various ethnic groups. As a result, the goal of this study is to record the use of Ethiopian medicinal herbs that have been used to treat malaria. Also, a critical review of the literature on the therapeutic properties of these and other Ethiopian medicinal plants that have been tested against Plasmodium spp. parasites was conducted with the goal of highlighting neglected studies and fostering further research in this area.

Methods

A comprehensive literature search was performed in Scopus, Web of Science Core Collection, PubMed, Science Direct, Google Scholar, and Scientific Electronic Library Online (SciELO) from August 2021 to October 2021. The study databases included original articles published in peer reviewed journals covering anti-malarial plants, dated until October 2021.

Results

The review looked at 51 plant species (28 families) that have been used to treat malaria in Ethiopia. The most often used ethnobotanical plant species for the treatment of malaria were Allium sativum, Croton macrostachyus, Carica papaya, and Lepidium sativum. Leaves were used more frequently as a therapeutic preparation than other parts. Plant extracts were found to have very good, good, and moderate anti-malarial activity in mice with rodent Plasmodium species. The most active species were Ajuga remota and Capsicum frufescens, which suppressed parasitaemia by 77.34% and 72.65%, respectively, at an oral dose of 100 mg/kg and an LD50 of above 2000 mg/kg. The compound Aloinoside reported from Aloe macrocarpa leave latex was the most potent; it suppressed parasitaemia by 100% at 400 mg/kg oral dose of Plasmodium berghei infected mice, and its LD50 was above 2000 mg/kg. Toxicity was shown to be safe in 84% of the plant extracts.

Conclusion

In Ethiopia, medicinal plants have a significant part in reducing the severity of malaria due to their widespread use. As a result, more studies are needed to identify and develop effective novel drugs that could be employed in broader malaria eradication efforts.

Endemic medicinal plants of Ethiopia: Ethnomedicinal uses, biological activities and chemical constituents

ETHNOPHARMACOLOGICAL RELEVANCE

Around 80% of Ethiopians rely on traditional medicinal plants to treat a variety of ailments, and the country is home to a number of endemic plants, making it part of East Africa's hotspot of biodiversity. Despite widespread acceptance of endemic medicinal plants among the local community, comprehensive documentation of their therapeutic uses and phytochemistry is lacking. This review thus provides the first comprehensive appraisal of traditional use, pharmacological properties and phytochemistry of Ethiopian endemic medicinal plants. By storing and preserving indigenous and scientific knowledge about the medicinal benefits of the plants, such documentation generates information database for the future. It also aids the conservation of key medicinal plants along with translational research to accelerate the development of pharmaceuticals.

AIM OF THE REVIEW

The aims of this review are to collect and document current information on the ethnopharmacological uses, phytochemistry, and biological activities of Ethiopian endemic medicinal plants, identify research gaps, and provide perspectives and suggestions for future research on the plants as potential sources of pharmaceuticals.

MATERIALS & METHODS

A comprehensive literature review using electronic databases such as Medline, Web of Science, Google Scholar, ScienceDirect, SpringerLink, and Wiley Online Library was conducted for collecting relevant information. The World Flora Online (WFO) database and the International Plant Names Index (IPNI) were utilized to authenticate the taxonomic information of the plants. Chemical structures were drawn using ChemBioDraw Ultra 12.1 and verified via PubChem.

RESULTS

The present review has identified 412 Ethiopian endemic plants. Out of the 412 endemic plants species recorded for Ethiopia 44 are medicinally valuable to mitigate a myriad of diseases, and nine (27.3%) of them are endangered. Our literature survey also found out that a total of 74 compounds were isolated and characterized from the endemic plants, with phenolics accounting for the majority of them (66.2%). The plants exhibited antimalarial, antimicrobial, anticancer, anthelmintic, mosquitocidal, antidiabetic, antioxidant, and anti-inflammatory properties.

CONCLUSION

The work has resulted in an up-to-date inventory of Ethiopia's endemic flora, as well as the identification of species with traditional medicinal uses. The pharmacological activity and phytochemistry of numerous endemic plants with various traditional therapeutic claims are yet to be researched scientifically. Scientific validation of the herbal remedies, including evidence-based safety and efficacy studies are, therefore, crucial. The endangered medicinal plants must be conserved in order for local communities to have access to them in the future.

Antitrypanosomal Effect of Hydromethanolic Extract of Solanum anguivi Lam on Field Isolates of Trypanosoma congolense Infected Mice

INTRODUCTION

Trypanosomiasis is one of the world's most serious infectious diseases caused by Trypanosoma parasites. Concern about resistance to conventional antitrypanosomal drugs, mosquito vector resistance to existing insecticide side effects of existing antitrypanosomal drugs justifies the urgent need for more effective, tolerable, and affordable drugs.

OBJECTIVE

The present study is aimed at determining the in vivo antitrypanosomal effect of the hydromethanolic extracts of Solanum anguivi fruit extracts against the field isolates of T. congolense.

METHODS

The 80% methanol extracts of S. anguivi fruits were prepared by cold maceration technique. In vivo curative tests were done to check the effect of plant extract against T. congolense in Swiss albino mice. Plant extracts were administered at doses of 100, 200, and 400 mg/kg/body weight. Acute toxicity of the extracts at 2000 mg/kg was performed according to OECD guidelines. Data obtained from the experiment were analyzed using one-way ANOVA followed by Tukey test.

RESULTS

This study indicated that extract did not exhibit any sign of acute toxicity up to 2000 mg/kg/body weight. In curative test, extracts reduced parasitemia, preventing the drop in packed cell volume and body weight significantly (p < 0.05), compared to control. Groups provided with the extract before infection got prolonged incubation period with chemoprophylactic effect at the doses of 100, 200, and 400 mg/kg. Phytochemical analysis showed presence of flavonoids, steroids, triterpens, saponins, glycosides, tannins, and alkaloids.

CONCLUSION

The extract showed promising curative. Further effort is required to isolate and purify specific compounds responsible for antitrypanosomal activity of studied plant.

Studies on Activities and Chemical Characterization of Medicinal Plants in Search for New Antimalarials: A Ten Year Review on Ethnopharmacology

Malaria is an endemic disease that affected 229 million people and caused 409 thousand deaths, in 2019. Disease control is based on early diagnosis and specific treatment with antimalarial drugs since no effective vaccines are commercially available to prevent the disease. Drug chemotherapy has a strong historical link to the use of traditional plant infusions and other natural products in various cultures. The research based on such knowledge has yielded two drugs in medicine: the alkaloid quinine from Cinchona species, native in the Amazon highland rain forest in South America, and artemisinin from Artemisia annua, a species from the millenary Chinese medicine. The artemisinin-based combination therapies (ACTs), proven to be highly effective against malaria parasites, and considered as “the last bullet to fight drug-resistant malaria parasites,” have limited use now due to the emergence of multidrug resistance. In addition, the limited number of therapeutic options makes urgent the development of new antimalarial drugs. This review focuses on the antimalarial activities of 90 plant species obtained from a search using Pubmed database with keywords “antimalarials,” “plants” and “natural products.” We selected only papers published in the last 10 years (2011–2020), with a further analysis of those which were tested experimentally in malaria infected mice. Most plant species studied were from the African continent, followed by Asia and South America; their antimalarial activities were evaluated against asexual blood parasites, and only one species was evaluated for transmission blocking activity. Only a few compounds isolated from these plants were active and had their mechanisms of action delineated, thereby limiting the contribution of these medicinal plants as sources of novel antimalarial pharmacophores, which are highly necessary for the development of effective drugs. Nevertheless, the search for bioactive compounds remains as a promising strategy for the development of new antimalarials and the validation of traditional treatments against malaria. One species native in South America, Ampelozyzyphus amazonicus, and is largely used against human malaria in Brazil has a prophylactic effect, interfering with the viability of sporozoites in in vitro and in vivo experiments.

Evaluation of Antimalarial Activity of 80% Methanolic Root Extract of Dorstenia barnimiana Against Plasmodium berghei-Infected Mice

BACKGROUND

Due to resistance of parasites, costs, and safety issues with currently available drugs, there is a need to discover new antimalarials. Medicinal plants are one of the most important sources of new drugs. The purpose of this study was to evaluate the antimalarial activity of a methanolic root extract of Dorstenia barnimiana in Swiss albino mice infected with Plasmodium berghei.

METHODS

Four-day suppressive, curative, and prophylactic tests were performed on mice infected with P. berghei to evaluate the antimalarial activity of a methanolic root extract of the plant. Parasitemia suppression, survival time, body-weight change, rectal temperature change, and packed-cell volume were used to evaluate the activity of the extract. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test for comparisons between and within groups, with P<0.05 considered statistically significant.

RESULTS

The D. barnimiana root extract showed significant (P<0.01) parasitemia-suppressive activities in all models compared to the negative control. The extract increased mean survival time and prevented weight loss, reduction in temperature, and anemia significantly in all tested doses in 4-day suppressive and curative tests.

CONCLUSION

Based on these findings, D. barnimiana root has promising antimalarial activity and can considered a potential source to develop new agents.

Intervention of standardized ethanol leaf extract of Annickia polycarpa, (DC.) Setten and Maas ex I.M. Turner. (Annonaceae), in Plasmodium berghei infested mice produced anti-malaria action and normalized gross hematological indices

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is a global public health burden due to large number of annual infections and casualties caused by its hematological complications. The bark of Annickia polycarpa is an effective anti-malaria agent in African traditional medicine. However, there is no standardization parameters for A. polycarpa. The anti-malaria properties of its leaf are also not known.

AIM OF THE STUDY

To standardize the ethanol leaf extract of A. polycarpa (APLE) and investigate its anti-malaria properties and the effect of its treatment on hematological indices in Plasmodium berghei infected mice in the Rane's test.

MATERIALS AND METHODS

Malaria was induced by inoculating female ICR mice with 1.0 × 107P. berghei-infected RBCs in 0.2 mL (i.p.) of blood. Treatment was commenced 3 days later with APLE 50, 200, 400 mg/kg p.o., Quinine 30 mg/kg i.m. (Standard drug) or sterile water (Negative control) once daily per group for 4 successive days. Anti-malarial activity and gross malaria indices such as hyperparasitemia, mean change in body weight and mean survival time (MST) were determined for each group. Changes in white blood cells (WBCs), red blood cells (RBCs), platelets (PLT) counts, hemoglobin (HGB) concentration, hematocrit (HCT) and mean corpuscular volume (MCV) were also measured in the healthy mice before infection as baseline and on day 3 and 8 after inoculation using complete blood count. Standardization was achieved by UHPLC-MS chemical fingerprint analysis and quantitative phytochemical tests.

RESULTS

APLE, standardized to its total alkaloids, phenolics and saponin contents, produced significant (P < 0.05) dose-dependent clearance of mean hyperparasitemia of 22.78 ± 0.93% with the minimum parasitemia level of 2.01 ± 0.25% achieved at 400 mg/kg p.o. on day 8. Quinine 30 mg/kg i.m. achieved a minimum parasitemia level of 6.15 ± 0.92%. Moreover, APLE (50-400 mg/kg p.o.) evoked very significant anti-malaria activity of 89.22-95.50%. Anti-malaria activity of Quinine 30 mg/kg i.m. was 86.22%. APLE also inverse dose-dependently promotes weight gain with the effect being significant (P < 0.05) at 50 mg/kg p.o. Moreover, APLE dose-dependently increased the MST of malaria infested mice with 100% survival at 400 mg/kg p.o. Quinine 30 mg/kg i.m. also produce 100% survival rate but did not promote (P > 0.05) weight gain. Hematological studies revealed the development of leukocytopenia, erythrocytosis, microcytic anemia and thrombocytopenia in the malaria infected mice which were reverted with the treatment of APLE 50-400 mg/kg p.o. or Quinine 30 mg/kg i.m. but persisted in the negative control. The UHPLC-MS fingerprint analysis of APLE led to identification of one oxoaporphine and two aporphine alkaloids (1-3). Alkaloids 1 and 3 are being reported in this plant for the first time.

CONCLUSION

These results indicate that APLE possessed significant anti-malaria, immunomodulatory, erythropoietic and hematinic actions against malaria infection. APLE also has the ability to revoke deleterious physiological alteration produced by malaria and hence, promote clinical cure. These properties of APLE are due to its constituents especially, aporphine and oxoaporphine alkaloids.

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.

Antibacterial Activities of Echinops kebericho Mesfin Tuber Extracts and Isolation of the Most Active Compound, Dehydrocostus Lactone

Echinops kebericho Mesfin is traditionally used for the treatment of various infectious diseases. This study investigated antibacterial activity of the essential oil (EO) and the different fractions of ethanol extract. The most active component was isolated and identified. Isolation and purification was accomplished using chromatographic techniques while identification was done by spectroscopic method. Minimum inhibitory concentration (MIC) was determined using the broth micro-dilution method. In bioactive-guided isolation, percent inhibition was determined using optical density (OD) measurement. The MICs of the essential oil ranged from 78.125 μg/ml to 625 μg/ml, and its activity was observed against methicillin-resistant Staphylococcus aureus (MRSA, NCTC 12493). Ethyl acetate fraction showed high activity against MRSA (NCTC 12493), MIC = 39.075 μg/ml followed by Enterococcus faecalis (ATCC 49532), MIC = 78.125 μg/ml and was least active against Klebsiella pneumoniae (ATCC 700603), MIC = 1,250 μg/ml. MIC of hexane fraction ranged from 156.2 µg/ml to Escherichia coli (ATCC 49532) to 1,250 μg/ml to E. coli (NCTC 11954). The MICs of chloroform fraction ranged from 312.5 to 2500 μg/ml; while butanol fraction could be considered pharmacologically inactive as its MIC value was 2,500 μg/ml for all and no activity against E. coli (NCTC 11954). Dehydrocostus lactone was successfully isolated and identified whose MIC was 19.53 μg/ml against MRSA. Dehydrocostus lactone isolated from E. kebericho M. showed noteworthy antibacterial activity which lends support to ethnopharmacological use of the plant. Further optimization should be done to improve its antibacterial activities and pharmacokinetic profile.

In Vitro and In Vivo Antitrypanosomal Activities of Methanol Extract of Echinops kebericho Roots

Microbial resistance to the few conventional antitrypanosomal drugs, increasing resistance of vectors to insecticides, lack of effective vaccines, and adverse effects of the existing antitrypanosomal drugs justify the urgent need for effective, tolerable, and affordable drugs. We assessed antitrypanosomal effects of the hydromethanolic extract of Echinops kebericho Mesfin roots against Trypanosoma congolense field isolate using in vitro and in vivo techniques. Parasite load, packed cell volume (PCV), body weight, and rectal temperature in Swiss albino mice were assessed. This finding is part of the outcomes of drug discovery research for neglected tropical diseases. The extract arrested the motility of trypanosomes within 40 min at 4 and 2 mg/mL concentration, whereas in the untreated control, motility continued for more than 160 min. The extract also reduced parasitemia and prevented drop in PCV and body weight significantly (p < 0.05), as compared to control. Phytochemical analysis showed the presence of flavonoids, triterpenes, steroids, saponins, glycosides, tannins, and alkaloids. It is observed that this extract has activity against the parasite. Isolation and purification of specific compounds are required to identify hit compounds responsible for the antitrypanosomal activity of the studied medicinal plant.

Acute and sub-acute toxicity of Echinops kebericho decoction in rats

BACKGROUND

Echinops kebericho is widely used for treatment of a variety of diseases including infectious, non-infectious disease and fumigation during child birth. Antibacterial, antimalarial, anti-leshimania, anti-diarrheal and insect repellent activities have been elucidated. Its toxicity profile is not yet investigated and thus this study was to investigate acute and sub-acute toxicity of E. kebericho decoctions.

METHODS

Acute toxicity study was performed in female Wistar albino rats with single oral dose and followed up to 14 days. The sub-acute oral dose toxicity studies were conducted in rats of both sexes in accordance with the repeated dose 28-day oral toxicity study in rodent OECD guidelines. Physical observations were made regularly during the study period while body weight was measured weekly. Organ weight, histopathology, clinical chemistry and hematology data were collected on the 29th day. Results were presented as mean ± standard deviation. One-way analysis of variance (ANOVA) was performed if assumptions were met; otherwise Kruskal-Wallis analysis was performed.

RESULT

Oral administration of E. kebericho decoction showed no treatment-related mortality in female rats up to the dose of 5000 mg/kg. In sub-acute toxicity studies, no significant treatment-related abnormalities were observed compared to negative controls. Food consumption, body weight, organ weight, hematology, clinical chemistry, and histopathology did not show significant variation between controls and treatment groups. However, creatinine, relative lung weight, triglycerides, and monocytes were lower in treated compared to control groups. Significant variations between male and female groups in food consumption, relative organ weight, hematology, clinical chemistry were observed. Histolo-pathology of high-dose treated groups showed fatty liver.

CONCLUSION

Echinops kebericho showed LD₅₀ of greater than 5000 mg/kg in acute toxicity study and is well tolerated up to the dose of 600 mg/kg body weight in sub-acute toxicity study.

Evaluation of Antimalarial Activity of Hydromethanolic Crude Extract and Solvent Fractions of the Leaves of Nuxia congesta R. Br. Ex Fresen (Buddlejaceae) in Plasmodium berghei Infected Mice

BACKGROUND

In Ethiopia, malaria control has been complicated due to resistance of the parasite and its vectors to the current drugs. Therefore, new drugs are required to avert the problem posed by drug-resistant Plasmodium strains. There is need to investigate alternative sources of antimalarial agents and plants are potential source of antimalarial drugs. This study aimed to investigate the antimalarial activity of the leaves of N. congesta crude extract (hydromethanolic extract) and solvent fractions (n-hexane, chloroform, and aqueous fractions of crude extract) traditionally used to treat malaria in many parts of Ethiopia.

METHODS

Acute oral toxicity of the leaves of N. congesta extract was assessed in mice up to a dose of 5,000 mg/kg body weight. Antiplasmodial activities of crude extract and solvent fractions were assessed in P. berghei infected female Swiss albino mice models using the Peter's 4-day suppressive test. The curative activities of crude extract and fractions were evaluated using Rane's test.

RESULTS

Plant extract exhibited no signs of toxicity on mice at a dose of 5,000 mg/kg body weight. Crude extract showed significant parasitemia suppressions at doses of 500 mg/kg (P<0.05), 750 mg/kg (P<0.01), and 1,000 mg/kg (P<0.001) as compared to negative control in the Peter's 4-day suppressive test, but failed to reach a significant level at 500 mg/kg and 750 mg/kg in the curative test (Rane's test). Aqueous fraction showed significant parasitemia suppression at a dose of 400 mg/kg (P<0.05) in curative test and 600 mg/kg (P<0.05) in Peter's 4-day suppressive and curative tests. Maximum suppressive effects of extract (58.13%) and aqueous fraction (44.9%) were observed at the highest doses administered.

CONCLUSION

Hydromethanolic leaf extract of N. congesta and its aqueous fraction exhibited antimalarial activities. The antimalarial activity and lack of acute toxicity are suggested to uphold the earlier claims made by the Ethiopian traditional practitioners.

The Genus Echinops: Phytochemistry and Biological Activities: A Review

The genus Echinops belongs to the family of Asteraceae and comprises about 130 species. Many species belonging to the genus Echinops are traditionally used as medicinals mainly in Africa and Asia. The genus is reported to contain diverse secondary metabolites. The aim of this review is to critically evaluate the available research reports on the genus and systematically organize the findings. Information for this study was obtained using various search engines including PubMed and Google Scholar. This review revealed that the genus is used traditionally to treat pain, inflammation, respiratory diseases, diseases caused by different microorganisms, as an aphrodisiac, to fasten expulsion of placenta, and for removal of renal stones. More than 151 secondary metabolites have been reported from the genus in which thiophenic compounds held the biggest share. Various extracts, essential oils, and isolated compounds from members of this genus are shown to exhibit different biological effects mainly anti-microbial, anti-proliferative, and anti-inflammatory. However, there are a number of species in this genus that are claimed to have traditional medicinal uses but their biological effect not yet been evaluated.

Antiplasmodial activity of two medicinal plants against clinical isolates of Plasmodium falciparum and Plasmodium berghei infected mice

Malaria is an infectious and deadly parasitic disease, associated with fever, anaemia and other ailments. Unfortunately the upsurge of plasmodium multidrug resistant constrained researchers to look for new effective drugs. Medicinal plants seem to be an unquenchable source of bioactive principles in the treatment of various diseases. The aim of this study was to assess the antiplasmodial activity of two Ivorian medicinal plants. The in vitro activity was evaluated against clinical isolates and Plasmodium falciparum K1 multidrug resistant strain using the fluorescence based SYBR green I assay. The in vivo bioassay was carried out using the classical 4 day suppressive and curative tests on Plasmodium berghei infected mice. Results showed that the in vitro bioassay of both plant extracts were found to exhibit a promising and moderate antiparasitic effects on clinical isolates (5 µg/mL < IC50 < 15 µg/mL) and Plasmodium falciparum multidrug resistant K1 strain (15 µg/mL < IC50 < 50 µg/mL). Furthermore, the in vivo antiplasmodial screening of both extracts showed a significant decrease in parasitemia, which was dose-dependent. Body temperature in mice treated with both extracts at experimental doses increased, compared to the negative control group and was dose-dependent. As for mice body weight a significant decrease (p < 0.001) was noticed in the negative control group compared to tested groups of animals. The hydroethanolic stem bark extract of Anthocleista djalonensis A Chev and leaves extract of Ziziphus mauritiana Lam exhibited anti-malarial activities. Therefore, the bioactive compounds of both plant extracts need to be investigated.

Treatment of malaria and related symptoms using traditional herbal medicine in Ethiopia

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have always been an integral part of different cultures in Ethiopia in the treatment of different illnesses including malaria and related symptoms. However, due to lack of proper documentation, urbanization, drought, acculturation and deforestation, there is an increased risk of losing this traditional knowledge. Hence, the use of the indigenous knowledge should be well documented and validated for potential future use.

AIM OF THE STUDY

To gather and document information on medicinal plants which are used in the traditional treatment of malaria and related symptoms in Ethiopia.

MATERIALS AND METHODS

First, an ethnomedicinal survey of plants was conducted in 17 districts of Jimma zone, the Oromia national regional state of Ethiopia. Jimma zone is malarious and rich in natural flora. A total of 115 traditional healers were interviewed using a semi-structured questionnaire containing personal data of the respondents, and information on medicinal plants used to treat malaria and related symptoms. In addition, a literature search using Medline/PubMed, Google Scholar, ScienceDirect and HINARI was conducted on the indigenous use, in-vitro/in-vivo anti-malarial activity reports, and the chemical characterization of medicinal plants of Ethiopia used against malaria.

RESULTS

From ethnomedicinal survey, a total of 28 species of plants used in the traditional treatment of malaria and related symptoms in Jimma Zone were collected, identified and documented. In addition, the literature search revealed that 124 medicinal plant species were reported to be traditionally used in the treatment of malaria in Ethiopia. From both ethnomedicinal survey and the literature search, Asteraceae and Fabaceae were the most represented families and Allium sativum L., Carica papaya L., Vernonia amygdalina Del., Lepidium sativum L. and Croton macrostachyus Del. were the most frequently reported plant species for their anti-malarial use. The dominant plant parts used in the preparation of remedies were leaves. About 54% of the medicinal plants documented in the survey have been reported as an anti-malarial plant in the literature search. Furthermore, the in-vitro and in-vivo anti-plasmodial activity reports of extracts from some of plant species were found to support the traditional claim of the documented plants. Moreover, literatures indicate that several secondary metabolites isolated from certain plant species that are traditionally used for the treatment of malaria and related symptoms in Ethiopia demonstrate strong anti-plasmodial activity.

CONCLUSIONS

The result of the current study showed that traditional knowledge is still playing an important role in the management of malaria and related symptoms in Ethiopia. Allium sativum L., Carica papaya L., Vernonia amygdalina Del., and Lepidium sativum L. are the most commonly reported species as anti-malarial plants and the traditional claim of some species was supported by known anti-plasmodial activity and bioactivity reports. The finding of this study is important in the rational prioritization of plant species which are potentially used for investigating new compounds, which could be efficacious for malaria treatment.

Traditional Consumption of the Fruit Pulp of Chrysophyllum albidum (Sapotaceae) in Pregnancy may be Serving as an Intermittent Preventive Therapy against Malaria Infection

Background

The bark of Chrysophyllum albidum is reported to possess antimalarial property. The fruit pulp of C. albidum consumed by pregnant women of south eastern Nigeria may also possess antimalarial activity. The present preliminary study investigated the antimalarial potential of the pulp juice and seed of C. albidum.

Methods

Schizonticidal activity was evaluated using the Peter's 4-day suppressive test. The prophylactic and curative antimalarial activities of the extracts were evaluated in Albino mice inoculated with Plasmodium berghei.

Results

The oral acute toxic dose of the pulp extract is beyond 5000 mg/kg. The seed and pulp possess both suppressive and curative properties. The seed extract suppressed early infection by 72.97% and 97.30%, at 500 and 1000 mg/kg, respectively. The pulp juice recorded 72.97% and 81.08%, at 500 and 1000 mg/kg, respectively. At 500 mg/kg dose, the level of parasite control on Day 7 was the same (96.10%) for both seed and pulp.

Conclusion

This study demonstrates the presence of antimalarial constituents in the chemically uncharacterized samples (fruit pulp and seed) of C. albidum. Its ethnomedicinal use may be valuable in pregnancy where it may possibly serve as an intermittent preventive therapy against malaria.

ANTIMICROBIAL ACTIVITY OF Echinops kebericho AGAINST HUMAN PATHOGENIC BACTERIA AND FUNGI

BACKGROUND

Traditional medicine remains the primary source of health care in developing countries. Echinops kebericho Mesfin is a well known endemic medicinal plant in Ethiopia and is traditionally used to treat both infectious and non-infectious diseases. The aim of this study was to evaluate antibacterial and antifungal activities of water, ethanol and methanol based crude extracts of E. kebericho Mesfin against selected human pathogenic bacteria and fungi.

MATERIALS AND METHODS

Crude extracts of E. kebericho Mesfin were prepared by maceration method. Disc diffusion assay of the extracts was carried out in four different concentrations against three different bacterial species and two clinically isolated fungal species. Agar dilution method was used to determine minimum inhibitory concentration, minimum bactericidal and fungicidal concentrations of the extracts.

RESULTS

Water based extracts exhibited the lowest antimicrobial activity when compared the ethanol and methanol based extracts (P< 0.05). Among the tested microorganisms, S. aureus, C. albicans and A. flavus were the most sensitive to alcohol based extracts. The minimum inhibitory concentration of the alcohol based extract ranged from 3.12 to 25μg/ml while those of the water based extracts were 100μg/ml and above. The lowest bactericidal and fungicidal concentrations of the ethanol and methanol based extracts were observed to be 6.25μg/ml against S. aureus and C. albicans and 37.5μg/ml against E. coli.

CONCLUSIONS

The traditional use of E. kebericho by local people in treating various types of infectious and non-infectious diseases was supported by this study. Antimicrobial activity of the medicinal plant varied with those of extraction solvents and against tested microorganisms.

Antimalarial activity of 80 % methanolic extract of Brassica nigra (L.) Koch. (Brassicaceae) seeds against Plasmodium berghei infection in mice

Background

Resistances to currently available drugs and insecticides, significant drug toxicities and costs and lack of vaccines currently complicated the treatment of malaria. A continued search for safe, effective and affordable plant-based antimalarial agents thus becomes crucial and vital in the face of these difficulties. The aim of the study was to evaluate the antimalarial activity of 80 % methanolic extract of the seeds of Brassica nigra against Plasmodium berghei infection in mice.

Method

Chloroquine sensitive Plasmodium berghei (ANKA strain) was used to test the antimalarial activity of the extract. In suppressive and prophylactic models, Swiss albino male mice were randomly grouped into five groups of five mice each. Group I mice were treated with the vehicle, group II, III and IV were treated with 100, 200, and 400 mg/kg of the extract, respectively and the last group (V) mice were treated with chloroquine (10 mg/kg). The level of parasitemia, survival time and variation in weight of mice were used to determine the antimalarial activity of the extract.

Results

Chemosuppressive activities produced by the extract of the seeds of Brassica nigra were 21.88, 50.00 (P < 0.01) and 53.13 % (P < 0.01), while the chemoprophylactic activities were 17.42, 21.21 and 53.79 % (P < 0.05) at 100, 200 and 400 mg/kg of the extract, respectively as compared to the negative control. Mice treated with 200 and 400 mg/kg extract were significantly (P < 0.05) lived longer and gained weight as compared to negative control in 4-day suppressive test.

Conclusion

From this study, it can be concluded that the seed extract of Brassica nigra showed good chemosuppressive and moderate chemoprophylactic activities and the plant may contain biologically active principles which are relevant in the treatment and prophylaxis of malaria, thus supporting further studies of the plant for its active components.

Antimalarial and antioxidant activities of Indigofera oblongifolia on Plasmodium chabaudi-induced spleen tissue injury in mice

Malaria is still one of the most common infectious diseases and leads to various public health problems worldwide. Medicinal plants are promising sources for identifying novel agents with potential antimalarial activity. This study aimed to investigate the antimalarial and the antioxidant activities of Indigofera oblongifolia on Plasmodium chabaudi-induced spleen tissue injury in mice. Mice were divided into five groups. The first group served as a vehicle control; the second, third, fourth, and fifth groups were infected with 1 × 10(6) P. chabaudi-parasitized erythrocytes. Mice of the last three groups were gavaged with 100 μl of I. oblongifolia leave extract (IOLE) at a dose of 100, 200, and 300 mg IOLE/kg, respectively, once daily for 7 days. IOLE was significantly able to lower the percentage of parasitemia. The most effective dose was the 100 mg IOLE/kg, which could reduce the parasitemia from about 38 to 12 %. The infection induced spleen injury. This was evidenced by disorganization of spleen white and red pulps, appearance of hemozoin granules and parasitized erythrocytes. These changes in spleen led to the increased histological score. Also, the infection increased the spleen oxidative damage where the levels of nitrite/nitrate, malondialdehyde, and catalase were significantly altered. All these infection-induced parameters were significantly improved during IOLE treatment. In addition, the mRNA expression of inflammatory cytokines interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha were upregulated after infection with P. chabaudi, whereas IOLE significantly reduced the expression of these genes. Our results indicate that I. oblongifolia leaves extract exhibits a significant antimalarial and antioxidant effects, and protects host spleen tissue from injuries induced by P. chabaudi.