Antimalarial Activity of Tanzanian Medicinal Plants<sup>1</sup>

Weenen, Hugo; Nkunya, Mayunga H.H.; Bray, Dorothy; Mwasumbi, Leonard; Kinabo, L. S.; Kilimali, V.A.E.B.

doi:10.1055/s-2006-960984

Cited by 156 publications

(88 citation statements)

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“…The antimalarial activities of a number of Tanzanian plants, many of which also occur in Kenya, have been reviewed by (17). Only 2 of 49 plants from that review (Gardenia jovis-tonantis and T. asiatica) were also used by the Kenyan Pokot herbalists.…”

Section: Discussionmentioning

confidence: 99%

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Gakunju

Mberu

Dossaji

et al. 1995

Antimicrob Agents Chemother

116

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Bioassay-guided fractionation of extracts of Toddalia asiatica, a plant used by the Pokot tribe of Kenya to treat fevers, has yielded the alkaloid nitidine as the major antimalarial component. Fractions containing nitidine have in vitro 50% inhibitory concentrations against Plasmodium falciparum in the range of 9 to 108 ng/ml for a range of chloroquine-susceptible and -resistant strains. The results show a lack of cross-resistance between chloroquine and nitidine.Although malaria is in principle preventable and curable, in practice the majority of the population at risk cannot pay for modern treatment and the disease remains a major cause of childhood mortality in the developing world. Recent results with the vaccine sPf66 show a mean protective effect of only 30%, with very wide confidence limits (1). The rapid spread of resistance to chloroquine and related quinoline-based antimalarial agents has greatly increased the risk of malaria to many rural populations, so that there is an urgent need for affordable treatment. One possible source of such treatment lies in the traditional herbal remedies used by ethnic groups, but treatment with these remedies has suffered from a number of deficiencies. Diagnosis is often a problem, identification of plant material may be insecure, and the chemical content of extracts may vary considerably. We have set out to overcome these barriers to effective treatment by systematically evaluating the effectiveness of some of the remedies used by an ethnic group of Kenyan farmers.The Pokot traditionally inhabit a highland plateau, west of the Rift Valley in Kenya. However, the present study concerned a group of Pokot who live on Ol Ari Nyiro Ranch, Laikipia, Kenya, a plateau to the east of the Rift Valley, and who have previously been described in some detail (5).In interviews, the Pokot herbalist Cheptosai Selale, who is 90 years old, described the use of 26 plants for the treatment of malaria and fever, of which only 14 were available at the time of collection (see Table 1). Two of the 14 plants produced extracts with significant antimalarial activity against laboratory strains of Plasmodium falciparum. Bioassay-guided fractionation of the extract from Toddalia asiatica gave a pure alkaloid, nitidine, which has potentially useful antimalarial activity. MATERIALS AND METHODSPlant material. Plant material was collected from Ol Ari Nyiro Ranch and was botanically authenticated by Christine Kabuye and Joshua Muasya of the Herbarium, National Museums of Kenya, where voucher specimens were deposited. Information provided by the herbalist included the required part of the plant, the precise locality for collection, and the time when curative potency was maximal. Plant material for study was dried at room temperature, pulverized, and stored dry in plastic bags until extracts were obtained.Preparation of aqueous crude extracts for preliminary analysis. Aqueous crude extracts (10%) were prepared in a manner analogous to that used by the herbalist. Powdered plant material (10 g) was weighed in...

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Section: Discussionmentioning

confidence: 99%

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Gakunju

Mberu

Dossaji

et al. 1995

Antimicrob Agents Chemother

116

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“…Clarkson et al (2004) reported that an extract of L. camara L. leaves demonstrated in vitro anti-plasmodial activity against a chloroquine-sensitive strain (D10) with an IC50 value of 11 µg/mL. The non-polar extract of root-bark also displayed high anti-malarial activity against the multidrug resistant K1 strain (Weenen et al, 1990). An ethanol extract of L. cujabensis Schauer showed lower activity when tested against chloroquine-resistant and chloroquine-sensitive strains of P. falciparum (IC50 14.7 µg/mL and 23.3 µg/ mL, respectively) (Desjardins, 1979).…”

Section: Anti-protozoal Activity (Anti-plasmodial Anti-malarial and mentioning

confidence: 99%

Genus Lantana: chemical aspects and biological activities

Sousa¹,

Costa²

2012

Rev. bras. farmacogn.

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Species of the genus Lantana, belonging to the family Verbenaceae, is among the various species studied scientifically. These species are mainly native to the tropical and subtropical regions of the Americas. Currently, they are present in various countries, where they are often grown as ornamental plants. For decades, species of Lantana have been of great interest for phytochemical, biological and pharmacological studies, which have been recently intensified. The components isolated from different species of Lantana cited in the literature constitute the focus of this review. Information ethnopharmacology of Lantana, as well as the activities of their different phytochemicals are discussed. In this review, it was observed that the genus Lantana has been widely studied in relation to its phytochemical components and terpenoids, flavonoids and phenylpropanoids are the more common secondary metabolites in Lantana. All these aspects, considered in this review, allow an evaluation of the ethnopharmacological potential of Lantana for the utilization of the large biomass of these plants.

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“…The naphthoquinones [3] in the roots and stem bark of K. africana possess anti-trypanosomal [4] and anti-microbial activities [5] and are cytotoxic against melanoma and renal carcinoma cells [6]. The aqueous extract of its leaves and fruits was found to have anti-diarrhoeal, antileprotic, anti-malarial, and anti-implantation activities [7]. The whole plant is accounted for its analgesic, anti-inflammatory, anti-molluscidal and antioxidative properties [8,9].…”

Section: Introductionmentioning

confidence: 99%

Isolation and Characterization of Limonoids from Kigelia africana

Jabeen

Riaz

2013

Zeitschrift Für Naturforschung B

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Two new limonoids, 1-O-deacetyl-2α-methoxykhayanolide (1) and kigelianolide (2), together with deacetylkhayanolide E (3), 1-O-deacetyl-2α-hydroxykhayanolide E (4) and khayanolide B (5) were isolated from the ethyl acetate-soluble fraction of the methanolic extract of Kigelia africana. The structures of these limonoids (1-5) were elucidated by the combination of 1D ( 1 H and 13 C NMR) and 2D (HMQC, HMBC and COSY) NMR spectroscopy and mass spectrometry (EIMS, HREIMS), and in comparison with literature data of related compounds. The structure of compound 1 was further confirmed by X-ray crystallography, and the absolute stereochemistry of compounds 1 and 2 was determined by electronic circular dichroism (ECD) spectroscopy. Limonoids 1-5 showed weak inhibitory activities against the enzymes acetylcholinesterase (AChE), butyrycholinesterase (BChE) and lipoxygenase (LOX) in a concentration-dependent manner with IC 50 values in the ranges 137.5 -225.2 µ M for AChE, 185.4 -241.5 µ M for BChE and 281.2 -189.6 µ M for LOX.

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Antimalarial Activity of Tanzanian Medicinal Plants¹

Cited by 156 publications

References 1 publication

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Genus Lantana: chemical aspects and biological activities

Isolation and Characterization of Limonoids from Kigelia africana

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Antimalarial Activity of Tanzanian Medicinal Plants1

Cited by 156 publications

References 1 publication

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Potent antimalarial activity of the alkaloid nitidine, isolated from a Kenyan herbal remedy

Genus Lantana: chemical aspects and biological activities

Isolation and Characterization of Limonoids from Kigelia africana

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Product

Resources

About

Antimalarial Activity of Tanzanian Medicinal Plants¹