Abstract:
Ethanolic extract from the fruits of the yellow-berried nightshade, Solanum
xanthocarpum Schrad & Wendl., also known as Makhua khurn, was investigated for
its molluscicidal activity against Biomphalaria glabrata, the snail vector of
Schistosoma mansoni, and Indoplanorbis exustus, the snail vector of intestinal
echinostomiasis and S. spindale, together with the larvicidal activity against the larvae
of Aedes aegypti, the mosquito vector of dengue hemorrhagic fever and Culex
quinquefasciatus, the mosquito vector of urban bancroftian filariasis. The bioassays
were carried out according to the recommendations of the World Health Organization.
Additionally, the toxic effect on non-target organisms was studied with guppy fish,
Poecilia reticulata, under procedures outlined by the Organization for Economic
Co-operation and Development.
For the molluscicidal activities, the LC50 against B. glabrata and I. exustus
were reported at 163.85 and 198.00 mg/l while the LC90 were 219.33 and 236.80 mg/l,
respectively. Regarding the mosquito larvicidal activities, the LC50 for the larvae of
Ae. aegypti and Cx. quinquefasciatus were 788.10 and 573.20 mg/l while the LC90
were 1,288.91 and 1,066.93 mg/l, respectively. Toxic effect was tested in guppy fish
by applying the LC90 of 236.80 mg/l (as reported in I. exustus) and 1,288.91 mg/l (as
reported in Ae. Aegypti). The mortality rates were 100% at both concentrations.
The result of this study suggests that S. xanthocarpum ethanolic extract can
be used in the control of snail and mosquitoes larvae vectors but is limited in field
application. A preparation of ingredients from this plant may be an alternative in
applying this biological molluscicide/larvicide in the field.