ANTI-SCHISTOSOMA EFFICACY OF Occimum gratissimum (SCENT LEAF) AND Andrographis paniculata (KING OF BITTERS) AGAINST Schistosoma haematobium CERCARIA

Abstract

Anti-schistosomal effect of crude aqueous extract of Occimum gratissimum (scent leaf) and Andrographis paniculata (king of bitters) on Schistosoma haematobium were cercaricidally evaluated over a period of 2 hours (h). The mortality of the cercaria was dose and time dependent. At 100 milligram per milliliter (mg−mL), O. gratissimum and A paniculata exhibited 100% mortality. Statistically, extract concentrations (F = 53.55; P= 0.004) and plant species (F = 10.13; P = 0.049) had significant (p < 0.05) effect on cercaria mortality. Pearson correlation coefficient (R) analysis showed that the results of cumulative mean cercariae mortalities and exposure time were strongly correlated for both plants. Probit analysis, lethal concentration (LC50) of O. gratissimum and A. paniculata against S. haematobium cercaria was 41.50 and 44.10 mg−mL respectively. The median lethal time (LT50) values for O. gratissimum and A. paniculata extract concentrations at 120 minutes treatment implicated 100.0 mg−mL to be the most toxic concentration which generated an LT50 value of 50.47 and 55.0 minutes respectively. While the least effective concentration of A. paniculata was 25.0 mg−mL requiring 115.03 minutes to cause 50% mortality of cercariae. From the study, it can be deduced that O. gratissimum and A. paniculata elicited varying degree of anti-schistosomal properties at all concentrations against S. haematobium. S. haematobium cercariae were more susceptible to toxic effects of O. gratissimum leaf extracts than A. paniculata. Cultivation of these plants along river banks will help in controlling cercariae and possibly miracidia in endemic areas by way of leave shedding since these plants are hydrophilic, biodegradable, readily available and less laborious to cultivate.