Search

Resistance of human malaria parasites to existing chemotherapeutic drugs remains a global challenge to malaria control. This study was an evaluation of the gametocyte dynamics and the potential roles of aqueous and ethanolic leaf extracts of Lophira lanceolata in the transmission of Plasmodium parasites using mice experimentally infected with P. berghei as a model. A total of 192 experimental mice divided into 15 groups in a randomized block design and replicated four times with four mice in each group were used for this study. Thirty-six (36) mice were used for acute toxicity test, 32 mice each for curative antiplasmodial assay, prophylactic assay and gametocyte evaluation, and analyses. Experimental mice were inoculated intraperitoneally with standard inoculum of 1 x 107P.berghei parasitized red blood cells on first day (DO). Body weights of mice were taken using sensitive digital weighing balance. Blood sample was collected by cardiac puncture using sterile needle and 5ml syringe and preserved in ethylene diaminetetraacetic acid (EDTA) bottle. Haematological components were determined using an autohaematology analyzer SYSMEX KX21. Data analysis was done using student's t-test and one way analysis of variance with multiple comparison tests. Phytochemical screening revealed the presence of phenols, terpenoids, tannins, saponins, alkaloids, flavonoids, steroids, oxalates and cardiac glycosides. The flavonoids had the largest concentrations of 388.24mg/ml, and 350.00mg/ml in ethanolic and aqueous extracts respectively. LD50 was found to be ≥ 5000mg/kg body weight in both extracts. At ≥ 100mg/kg body weight, infected treated mice experienced body weight increases while infected untreated mice experienced decreases in mean body weight from 23.33g to 20.08g (mean 10% weight loss). Aqueous and ethanolic leaf extracts produced variations in number of gametocyte from mice infected with P.berghei. On days 7, 14, 21, and 28, the mean gametocytes of the parasite in the control group were 18, 21, 22, and 20 respectively which were significantly (p < 0.05) higher compared with the mean gametocytes in the groups of mice treated with aqueous extract, ethanolic extract and chloroquine drugs. The dose level of 10mg/kg body weight of aqueous extract produced the mean gametocyte counts of 10, 10, 8 and 6 on days 7, 14, 21 and 28 respectively which were significantly (p < 0.05) lower than the mean gametocyte counts of the control. [ABSTRACT FROM AUTHOR]

Background: This study was to determine the effects of Lophira lanceolata leaf extracts on haematological, biochemical, and histopathological parameters of the mice in the transmission of Plasmodium parasites using mice infected with P.berghei as a model. A total of 196 experimental mice divided into 15 groups in a randomized block design and replicated four times with four mice in each group were used for this study. Thirty six (36) mice were used for acute toxicity test, 50 each for haematological, biochemical, and histopathological analyses. Experimental mice were inoculated intraperitoneally with standard inoculum of 1 x 107 P.berghei parasitized red blood cells on first day (DO). Results: Data analysis was done using student's t-test and one way analysis of variance with multiple comparison tests. Aqueous leaf extract exerted significant (p < 0.05) non-dose dependent reduction in parasitaemia level with chemosuppression of 48.79%, 24.26%, 29.38% and 80.32% at 10, 100, 200 mg/kg body weight and 5mg/kg body weight chloroquine treated groups respectively. Dose level of 10, 100, 200 mg/kg body weight of both aqueous and ethanolic leaf extract produced significant increase in aspartate amino transferase, alanine amino transferase, total bilirubin, cholesterol, triglycerides and urea profiles of infected treated mice compared with the control. At 200mg/kg body weight of aqueous extract there was a significant decrease (p < 0.05) in weight of liver and kidney organs in the infected treated mice compared with the control. The results of histopathological examinations of the liver organs of the mice were characterized by tissue stromal proliferation, enlarged hepatocytes and disorganized sinusoids and lamina of hepatic cells. The results of histopathological examination of kidneys showed no histopathological changes. The aqueous and ethanolic leaf extracts of Lophira lanceolata plant showed significant antiplasmodium activities comparable to chloroquine drugs. Conclusions: The leaf extracts of Lophira lanceolata plant had gametocytocidal action on P. berghei. The results of the haematological, biochemical and histopathological examinations indicated that caution should be exercised while taking the plant extract as an antimalarial agent. [ABSTRACT FROM AUTHOR]