Evaluation of antitrypanosomal and anti inflammatory activities of selected Nigerian medicinal plants in mice.

The extracts of nine selected Nigerian medicinal plants were investigated on Trypanosoma brucei brucei infected mice. The anti-inflammatory properties of hexane fraction of the most promising U. chamae extract was assessed by acute oedema of the mice paw model while the modulatory effect of the extract on Delayed-Type Hypersensitivity (DTH) response on in vivo leucocytes mobilization was evaluated. 'Dose-probing acute toxicity tests' established an oral and intraperitoneal LD50 for T. ivorensis stem bark as >1600 < 5000 mg/kg and 100 mg/kg respectively, while the oral LD50 of Uvaria. chamae was >5000 mg/kg. Extracts of Khaya senegalensis, Harungana madagascariensis, Terminalia ivorensis, Curcuma longa, Ocimum gratissimum and Alcornea cordifolia showed weak anti-trypanosomal effect and did not exhibit significant clearance in parasitemia at the test dose administered compared with the positive control (Diminal®). However, the leaf extract of U. chamae and its hexane fraction demonstrated a significant response (P < 0.01). The fraction at 1000 mg/kg inhibited oedema by 107%. Uvaria. chamae demonstrated both antitrypanosomal and anti-inflammatory properties by increasing the survival time of infected mice due to reduction in parasitemia caused by T. brucei brucei.

Preliminary studies on the prevalence and distribution of urinary schistosomiasis in Ondo State, Nigeria.

The prevalence of S. haematobium infection in 18 Local Government Area (LGA) in Ondo state was determined by examining pupils from randomly selected schools in the state. A total of 4266 urine samples were examined and 1303 (30.5%) were infected with the parasite. The infection was recorded in both rural and urban communities in each LGA. The overall prevalence was significantly higher in males (33.7%) than in females (26.0%) (P = -0.001). The LGA exhibiting the highest overall prevalence of infection was Akure north (86.2%; Cl, 0.82-0.9). The infection was most common in subjects between the ages of 11 and 15 years. Seven species of aquatic snails were encountered and B. (P). globosus was the most abundant and widespread species. The Owena river/dam in Idanre LGA was richest in molluscan fauna. B. (P). globosus and Biomphalaria pfeifferi shedding cercariae were recovered from Owena river and dam. The study shows that there were spatial heterogeneities in the prevalence of infections in both human population and the snail intermediate hosts. The implications of the clustering nature of the disease, for a successful control program in the state, were discussed.

Formulation of an effective mosquito-repellent topical product from lemongrass oil.

Ointment and cream formulations of lemongrass oil in different classes of base and the oil in liquid paraffin solution have been evaluated for mosquito repellency in a topical application. Mosquito repellency was tested by determining the bite-deterrence of product samples applied on an experimental bird's skin against a 2-day starved culture of Aedes aegypti L. mosquitoes. The 1%v/v solution and 15%v/w cream and ointment preparations of the oil exhibited > or =50% repellency lasting 2-3 h, which may be attributed to citral, a major oil constituent. This activity was comparable to that of a commercial mosquito repellent. Base properties of the lemongrass oil formulations influenced their effectiveness. The oil demonstrated efficacy from the different bases in the order of hydrophilic base > emulsion base > oleaginous base.