The antitrypanosomal activity of methanolic extracts of Anogeissus leiocarpus and Terminalia avicennoides were evaluated in vitro against four strains of Trypanosoma species with minimum inhibitory concentration (MIC) value range of 12.5-50 mg/ml. Successive fractionations of the two plant extracts in water, butanol and ethyl acetate gave a range of activity (MIC, 20 to > or =50 microg/ml). Activity-guided and chromatographic analysis of butanolic fractions on Sephadex LH-20 column followed by high-performance liquid chromatography, nuclear magnetic resonance analysis and both ultraviolet and thin layer chromatography revealed hydrolysable tannins with a range of activity (MIC, 7.5-27.5 microg/ml or 14-91 microM). Effect of the compounds on fibroblasts did not reveal serious toxicity at moderate concentration but is concentration dependent.

In vitro antiplasmodial activity of methanolic extracts of 16 medicinal plants was evaluated by fluorometric assay using PicoGreen. The IC50s, as determined by parasite DNA concentration, ranged from <11 to >200 and <13 to >200 μg/ml for Plasmodium falciparum 3D7 and K1, respectively; and the most active extracts were those from Anogeissus leiocarpus and Terminalia avicennoides (<11-≥14 μg/ml). Aqueous, butanolic, ethyl acetate, and methanolic fractions of these two extracts revealed butanolic fraction to have a relatively better activity (IC 50 , 10-12 μg/ml). Activity-guided chromatographic separation of the butanolic fraction on Sephadex LH-20 followed by nuclear magnetic resonance and correlation high-performance liquid chromatography revealed the presence of known hydrolysable tannins and some related compoundscastalagin, ellagic acid, flavogallonic acid, punicalagin, terchebulin, and two other fractions. The IC 50 s of all these compounds ranged between 8-21 μg/ml (8-40 μM) against both the strains. Toxicity assay with mouse fibroblasts showed all the extracts and isolated compounds to have IC 50 ≥1500 μg/ml, except for Momordica balsamina with <1500 μg/l. All the extracts and isolated compounds did not affect the integrity of human erythrocyte membrane at the observed IC 50 s. However, adverse effects manifest in a concentration-dependent fashion (from IC 50 ≥500 μg/ml).

Stem barks of Anogeissus leiocarpus and Terminalia avicennoides widely used in Africa for treatment of some parasitic diseases were collected and made into methanolic extracts. The extracts were tested on four strains of promastigote forms of Leishmania in vitro. Solvent fractionation in aqueous, butanolic, and ethyl acetate layer indicated butanol and aqueous fractions to have a superior leishmanicidal activity. Chromatographic separation of the butanolic fraction on Sephadex LH-20 followed by nuclear magnetic resonance and correlation high-performance liquid chromatography revealed the presence of known hydrolyzable tannins and some related compounds-with castalagin as the major compound. The observed activity ranged from 62.5 to > or =150, 112.5 to > or =500, and 55 to >150 microg/ml for the crude methanolic extract, different solvent fractions, and the isolated compounds, respectively, on the four different Leishmania strains.

Lentinus squarrosulus (Mont.) Singer, a basidiomycete also known as a white rot fungi, was immobilized on sodium alginate and tested for the effectiveness to degrade wood sawdust (WSD). Untreated and 0.1 M HCl-pretreated WSD samples were separately reacted in a micro-carrier bioreactor (µCBR) and the extent of degradation to form protein, glucose and ethanol was investigated. Pretreatment enhanced the production of both proteins and ethanol by average value of 72.0% over untreated WSD samples, after hydraulic retention time of 72 h. The maximum production of protein observed was 0.94 mg/ml-reaction volume and that of ethanol was 6.6 mg/ml-reaction volume, whereas glucose concentration fluctuated due to interconversion to ethanol. This report shows that L. squarrosulus (Mont.) Singer have the potentials of degrading WSD samples to important chemical compounds that are not hazardous to the environment.

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