dc.description.abstract | Schistosomiasis is one of the most widespread paras
itic infections and the
third most prevalent parasitic disease in the world
in terms of overall
morbidity, socioeconomic and public health importan
ce. It is the most
prevalent of water borne and parasitic diseases and
it affects over 240
million people worldwide. One approach to the contr
ol of the disease is
the elimination of the intermediate host responsibl
e for its transmission.
The use of synthetic molluscicides is becoming unpo
pular owing to their
high cost and enviromental pollution. As a result,
plant molluscicides have
received considerable attention in the search for c
heaper alternatives to
chemotherapy and synthetic molluscicides in schisto
somiasis control. The
aim of this study was to determine the molluscicida
l activity of aqueous
and ethanol extracts from five plant species;
Ocimum americanum,
Sonchus luxurians, Aloe secundiflora, Bridelia micr
antha
and
Croton
megalocarpus
against
Biomphalaria pfeifferi
adult and juvenile snails.
Dried plant materials were ground into powder. They
were extracted using
ethanol and water. Phytochemicals were detected whi
ch include;
flavonoids, saponins, tannins, alkaloids, glycoside
s, steroids and
triterpenes.
Adult and juvenile snails were subjected to concent
rations of 5 mg/l,
10 mg/l, 20 mg/l and 40 mg/l of the aqueous and eth
anol plant extracts.
Generally, only
B. micrantha
which had molluscicidal effect against adult
and juvenile snails.
B. micrantha,
extracts that were found to have mollus-
cicidal effects, were screened for their miracicida
l and cercaricidal activity xiv
against
Schistosoma mansoni
miracidia and cercariae. Concentrations of
5 mg/l, 10 mg/l, 20 mg/l and 40 mg/l were used. The
ability of
B.micrantha
aqueous extract to immobilise miracidia and cercari
ae was
greater than that of the ethanol extract. From this
study,
B.micrantha
demonstrated molluscicidal, miracicidal and cercari
cidal effects. | en_US |