The herb Artemisia annua has been used for many centuries in Chinese traditional medicine as a treatment for fever and malaria. In 1971, Chinese chemists isolated from the leafy portions of the plant the substance responsible for its reputed medicinal action. This compound, called qinghaosu (QHS, artemisinin), is a sesquiterpene lactone that bears a peroxide grouping and, unlike most other antimalarials, lacks a nitrogen-containing heterocyclic ring system. The compound has been used successfully in several thousand malaria patients in China, including those with both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum. Derivatives of QHS, such as dihydroqinghaosu, artemether, and the water-soluble sodium artesunate, appear to be more potent than QHS itself. Sodium artesunate acts rapidly in restoring to consciousness comatose patients with cerebral malaria. Thus QHS and its derivatives offer promise as a totally new class of antimalarials.

Quinghaosu (artemisin): an antimalarial drug from china

Anti-inflammatory Potential Of The Coral Tree (erythrina Abyssinica): Histological And Immunohistochemical Evidence In Chronic Trypanosomiasis Mouse Model

The high resistance evolution of protozoans to the existing antiparasitic drugs has necessitated the quest for novel and effective drugs against plasmodium and trypanosome parasites. As a result, this study aimed to assess the antiplasmodial and antitrypanosomal potentials of chloroform, ethyl acetate and ethanol leaf extracts of Oedera genistifolia. Standard biochemical procedures were explored for the plant extraction and gas chromatography-mass spectroscopy (GCMS) was used to identify the bioactive compounds in the crude extracts. The cytotoxic effects of the crude extracts were assessed against human cervix adenocarcinoma (HeLa cells) and their antiparasitic activities were investigated against Plasmodium falciparum strain 3D7 and Trypanosoma brucei brucei. GCMS analyses of the crude extracts revealed the bioactive compounds that could be responsible for the biological activities. The extracts had no cytotoxic effect on HeLa cells and demonstrated good antiplasmodial activity (chloroform extract: IC50 = 11.6 µg∙mL−1, ethyl acetate extract: IC50 = 3.3 µg∙mL−1 and ethanol extract: IC50 = 3.7 µg∙mL−1). Likewise, they showed excellent antitrypanosomal activity with IC50 = 0.5 µg∙mL−1 for chloroform and ethyl acetate extracts and IC50 = 0.4 µg∙mL−1 for the ethanol extract. Findings from the present study indicated that O. genistifolia could be a good source of strong antiplasmodial and antitrypanosomal agents.

In Vitro Assessment of Antiplasmodial and Antitrypanosomal Activities of Chloroform, Ethyl Acetate and Ethanol Leaf Extracts of Oedera genistifolia

Introduction. Antimalarial resistance of Plasmodium sp encourage the study of new antimalarial drugs, sush as the traditional medicinal plants used to treat malaria, kembang bulan (Tithonia diversifolia (Hemsley) A. Gray). Kembang bulan ( Tithonia diversifolia (Hemley) A. Gray) ( Asteraceae family) have activity as an antimalarial, anti-inflammatory and analgesic. In vitro, ethanol extract of these leaf had been proven that it was active in inhibiting the growth of P. berghei at doses of 40; 80; 160; and 320 mg/kg body weight with IC 50 values of 114 mg / kg body weight and the IC 90 of 475 mg/kg body weight. Tithonia diversifolia extract contains of substances that could be used as an antimalarial prophylactic and curative in malaria. Objective: to determine the effect of ethanol extract of leaf development as a antimalaria month. Methods is observing the effect of ethanol extract of kembang bulan to parasitemia levels on mice Balb / C before and after infection by the parasite Plasmodium berghei (parasitemia degree of mild, moderate and severe. Result . Based on data from the various percentages of inhibition of extract ethanol of kembang bulan leaf for growth in P. berghei before infected and at various stadium of infection (mild, moderate, and severe), can be seen that in the prophylaxis group had the greatest percentage of inhibition. Conclusion . The Tithonia diversifolia leaves ethanol extract have antimalarial activity in mice Balb/c before inoculated Plasmodium berghei (prophylaxis) and after mild (1%), moderate (5%), and severe (10%).

Effect Tithonia Divesifolia (Hemley) a. Gray) Ethanol Extract as Antimalarial on Mice Strain Balb/C Before and After Infected by Plasmodium Berghei

Leishmaniasis is a major public health problem globally. Visceral leishmaniasis is known to be fatal if left untreated, while cutaneous leishmaniasis is the most neglected. The first-line treatment of leishmaniasis is based on pentavalent antimonial drugs which are expensive, requiring inpatient treatment and toxic. The Plants containing active compounds against other protozoan diseases may offer alternatives against leishmania parasites. This study determined the in vitro Original Research Article Wafula et al.; IJTDH, 41(23): 30-43, 2020; Article no.IJTDH.64250 31 antileishmanial activity of Olea europaea, Kigelia africana, Terminalia mollis, Croton macrostachyus and Bridella micrantha extracts. The plant samples were dried, pulverized into fine powders and extracted using ethanol at the Center for Traditional Medicine and Drugs Research, KEMRI. The in vitro assays were carried out at the Leishmania laboratory, Centre for Biotechnology Research and Development, KEMRI. In invitro assays the inhibitory concentrations (IC50) and Minimum Inhibition Concentration (MIC) on L. major promastigotes, percentage rates of macrophages infected by amastigotes and cytotoxicity on Vero cells were determined. For each parameter analyzed, differences among treatment groups exposed to different drugs were tested by logistic regression. Results showed that promastogote and amastigote growth inhibition was significantly affected by the crude extracts from the plants (P < 0.05) after 24 hours of exposure where the most effective drug was the standard drug (Amphotericin B) while among the crude extracts of the herbal drugs, T. mollis was the most effective against amastigote followed by C. macrostachyus while O. europaea was the least effective. Mammalian cell viability was significantly affected by the various test compounds (P < 0.05) after 24 hours exposure where % cell viability of herbal drugs, B. microstachyus, O. africana resulted to the most toxic effects by reducing the % cell viability to less than 50%. The study recommends the use of T. mollis in management of leishmaniasis in areas they occur. Further analysis of the active compounds that that affect efficacy of the plant extracts is advised.

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In Vitro Antileishmanial Activities of Olea europaea, Kigelia africana, Terminalia mollis, Croton Macrostachyus and Bridella micrantha, Kenyan Medicinal Plants

Malaria is a deadly disease caused by a protozoan parasite whose mode of transmission is through a female Anopheles mosquito. It affects persons of all ages; however, pregnant mothers, young children, and the elderly suffer the most due to their dwindled immune state. The currently prescribed antimalarial drugs have been associated with adverse side effects ranging from intolerance to toxicity. Furthermore, the costs associated with conventional approach of managing malaria are arguably high especially for persons living in low-income countries, hence the need for alternative and complementary approaches. Medicinal plants offer a viable alternative because of their few associated side effects, are arguably cheaper, and are easily accessible. Based on the fact that studies involving antimalarial medicinal plants as potential sources of efficacious and cost-effective pharmacotherapies are far between, this research was designed to investigate antiplasmodial and cytotoxic activities of organic and aqueous extracts of selected plants used by Embu traditional medicine practitioners to treat malaria. The studied plants included Erythrina abyssinica (stem bark), Schkuhria pinnata (whole plant), Sterculia africana (stem bark), Terminalia brownii (leaves), Zanthoxylum chalybeum (leaves), Leonotis mollissima (leaves), Carissa edulis (leaves), Tithonia diversifolia (leaves and flowers), and Senna didymobotrya (leaves and pods). In vitro antiplasmodial activity studies of organic and water extracts were carried out against chloroquine-sensitive (D6) and chloroquine-resistance (W2) strains of Plasmodium falciparum. In vivo antiplasmodial studies were done by Peter’s four-day suppression test to test for their in vivo antimalarial activity against P. berghei. Finally, cytotoxic effects and safety of the studied plant extracts were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) rapid calorimetric assay technique. The water and methanolic extracts of T. brownii and S. africana and dichloromethane extracts of E. abyssinica, S. pinnata, and T. diversifolia leaves revealed high in vitro antiplasmodial activities ( ). Further, moderate in vivo antimalarial activities were observed for water and methanolic extracts of L. mollissima and S. africana and for dichloromethane extracts of E. abyssinica and T. diversifolia leaves. In this study, aqueous extracts of T. brownii and S. africana demonstrated high antiplasmodial activity and high selectivity indices values ( ) and were found to be safe. It was concluded that T. brownii and S. africana aqueous extracts were potent antiplasmodial agents. Further focused studies geared towards isolation of active constituents and determination of in vivo toxicities to ascertain their safety are warranted.

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Nelson Elias

Papers

Antiplasmodial and Cytotoxic Activities of Extracts of Selected Medicinal Plants Used to Treat Malaria in Embu County, Kenya.