Malaria remains a major public health concern which affects millions of people, particularly in SubSaharan Africa. The need for the development of alternate treatment means has become critical because of the emergence of resistance to nearly all antimalarial drugs (Kim and Schneider, 2013). Trema orientalis (L.) Blume (Ulmaceae) is used locally for the treatment of malaria. This study was designed to determine the anti-plasmodial activity of the acetone extract of T. orientalis and carry out a bio-guided separation of the extract. Acetone extract of T. orientalis leaves was investigated for its antimalarial activity in a mouse model of Plasmodium berghei using the 4 day suppressive test. Bioguided investigation was carried out by using column chromatographic fractions for in-vivo antiplasmodial screening. Preliminary spectroscopic profile of the most active fraction was obtained. Treatment with graded doses (100 to 800 mg/Kg) of acetone extract of T. orientalis resulted in significant chemosuppression of parasite growth that ranged from 44.0 to 83.8%. The most active fraction which was identified as M6 showed significant schizontocidal activity (P < 0.001). 1 H NMR and Infrared spectra data indicated that the most active fraction contained flavonoids. This study justified the folkloric use of T. orientalis. Compounds from this plant could be a potential source of antimalarial agents.

Antioxidants have been reported to prevent oxidative damage caused by free radicals and can be used to ameliorate conditions in cardiovascular and inflammatory diseases. Ethnobotanical study revealed that the leaves of Lonchocarpus cyanescens are traditionally used in Africa to treat ulcer and arthritis. This study investigates the antioxidant activities of its extract and fractions. Acetone leaf extract of L. cyanescens was screened for 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing power (FRAP), total phenol content and total flavonoid content using catechin as standard antioxidant. Bioguided column chromatographic separation was carried out and the resultant fractions were screened for antioxidant activities. Preliminary spectroscopic profile of the most active fraction was obtained. DPPH and FRAP methods showed that L. cyanescens had antioxidant activity which correlated with its phenolic and flavonoid contents. There was a higher correlation of the total phenol/flavonoid content to the antioxidant activity by the DPPH method [r2 = 0.9906, 9926 respectively] than the FRAP method [0.8635, 8840 respectively]. Bioactivity guided fractionation identified fraction F5 as the most active. 1 H and Infrared spectra indicated that the most active fraction contained flavonoids. Comprehensive in-vivo studies and toxicity profile of the extract will be required before considerations for development as a phyto-drug.