ABSTRACT
Objective To assess the toxic potential of Dissotis rotundifolia (D. rotundifolia) whole plant extract in Spraque–Dawley rats within a 2-week period of administration. Methods Methanolic extract of D. rotundifolia was administered orally once daily at dose levels of 0, 100, 300 and 1 000 mg/kg body weight for 14 days. Toxicity was assessed using mortality, clinical signs, body and organ weights, hematological indices, serum chemistry parameters and histopathological analyses. Results There were no treatment-related mortalities or differences in clinical signs, hematology and serum biochemistry. This was confirmed by micrographs obtained from histopathological analysis. Conclusions The results obtained from the sub-acute toxicological assessment of D. rotundifolia extract suggest that the extract is non-toxic at doses up to 1 000 mg/kg/day administered for a period of 14 days.
ABSTRACT
Objective: To investigate the effect of pre-existing Schistosoma haematobium (S. haematobium) infection on malaria disease severity. Methods: The study involved the use of twenty-five imprinting control region mice, fifteen of which were initially infected with S. haematobium. Five of the remaining ten schisto-uninfected mice together with five schisto-infected mice were infected with Plasmodium berghei (P. berghei) after four weeks (acute stage) of schistosoma infection. The remaining five schisto-uninfected mice together with five schisto-infected mice were also infected with P. berghei after seven weeks (chronic stage) of schistosoma infection. The last five schisto-infected mice were used as control group. They were then monitored for changes in P. berghei parasitaemia on Days 3, 5, 7, 9 and 11 post-infection. Records on their survivability were also taken. Results: The co-infected mice had significantly higher malaria parasitaemia, compared with the mono-infected mice during acute S. haematobium infection. In contrast, the coinfected mice had significantly lower malaria parasitaemia during chronic S. haematobium infection and a higher survival rate. Conclusions: Co-infection of mice with P. berghei during acute S. haematobium infection resulted in rapid P. berghei development and increased malaria parasitaemia. However, the co-infection resulted in slower P. berghei development and decreased malaria parasitaemia with enhanced survivability of the mice during chronic S. haematobium infection. Therefore, pre-existing chronic S. haematobium infection may provide some protection to the host by reducing parasitaemia.