Some Pharmacological And Toxicological Activities Of Some Plants Used In Traditional Medicine In Mwanza, Tanzania

ABSTRACT

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 LC50 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 iii 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.