M.Sc. Dissertation
Three medicinal plants, Albizia anthelmintica, Salvadora persica and Vernonia
amygdalina used in traditional medicine in Magu district, Mwanza were investigated
for antimicrobial and anthelmintic activity. Informal interviews carried out in two
villages of Nassa ginnery and Mwanangi, revealed several plants used in traditional
medicine to treat humans and livestock diseases. These plants were alleged to be
effective in treating abdominal pains, worm infestations including schistosomiasis,
malaria and eye conditions. Toxicity studies and phytochemical screening of the
study plants were also carried out.
Antimicrobial activity study showed highest
zone of inhibition with B.subtilis (23 mm) MIC = 7.8125 mg/ml) for the aqueous
extract of Vernonia amygdalina. The ethanolic extract of the same plant had highest
zone of inhibition of 26 mm, MIC = 62.50 mg/ml with B.anthracis. The other two
plants tested showed some activity against some of the tested bacteria with
decreased zone of inhibition and higher MIC values. In the in vitro anthelmintic
activity studies, aqueous extract of Albizia anthelmintica had highest activity against
the egg hatchability and larval survival. The highest percentage hatchability
inhibition was 94.67%. The antischistosmal activity of S. persica in naturally
infected calves showed 77.47% faecal egg count reduction. The brine shrimp
lethality assay gave LC 50 values greater than 20 μgml -1 , which is the cut-off point
for a substance to be regarded as acutely toxic to biological systems.
The
phytochemical screening of the study plants, revealed the presence of tannins,
flavonoids, terpenoids, cardiac glycosides and saponins. From the findings of this
study it can be concluded that, the study plants contains some bioactive principles which may be responsible for their alleged activities. The study confirms some of
the alleged effects of the studied plant preparations. Traditional medicine
preparations from the studied plants have been proved efficacious and safe; this
justifies their continued use without adverse effects.