ABSTRACT

Anthelmintic and acaricidal activities of the acetone extracts of Chromolaena odorata leaves and Mangifera indica stem bark were evaluated using standard in-vitro and in-vivo methods. Concentrations of 5, 10 and 20 mg/ml of the plant extracts were used for the in-vitro study while albendazole 25µg/ml was used as positive control and distilled water as negative control. Also, doses of 125, 250 and 500 mg/kg b.w. of both plants were used for the in-vivowork using Albendazole 25 mg/kg b.w. as positive control and distilled water as negative control. From the study, the plant extracts were found to contain several chemical components including, alkaloids, anthraquinones, phenolics, saponins, tannins, steroids, flavonoids and Glycosides. The acute toxicity of the plant extracts evaluated showed that the LD₅₀ of C. odorata and M. indica were 1788.85 and 2408.3 mg/kg b.w. respectively. The in-vitro egg hatch test showed that percentage hatchability inhibition of M. indica was 94.2 % compared to C. odorata 78.5 % at the highest concentrations. In the in-vivo faecal egg count of infected outbred albino mice, the result showed that C. odorata in doses of 250 and 500 mg/kg caused a significant (p<0.05) FECR of the infected mice by 75.3 % and 78.4 % respectively while the M. indica significantly (p<0.05) reduced the FEC by 73.8 %, 89.4 % and 95.5 %, in a dose dependent manner. The albendazole at 25 mg/kg b.w. also showed a significant (p<0.01) FECR of 52.6 % though lower than the extracts. The total worm burden of the infected mice at 125, 250 and 500 mg/kg b.w. showed that M. indica had 8.05±0.57, 5.66±0.33 and 1.33±0.88 while C. odorata had 21.66±3.71, 13.33±1.20 and 10.33±0.33 adult worms respectively when compared to the negative group that had 64.33±19.06. The acaricidal effects of C. odorata and its fractions result showed that after 12 hours of exposure, the extracts caused a significant (p<0.01) and concentration dependent death of the ticks when compared to the negative control. There was also a time dependent effect of the extract and the fractions with the highest activities of each fraction being significant (p<0.05) at 72 hours and 160 mg/ml; crude extract 92.00 ± 2.54 %, pet ether 70.00 ± 3.54 % and chloroform had 63.00 ± 3.39%, while only the M. indica crude showed a moderate acaricidal effect of 57.00 ± 2.54 (160 mg/ml) at 72 hrs.In conclusion, the leaf extract of C. odorata and stem bark of M. indica showed significant anthelmintic and acaricidal activities in this study.