Main Article Content
Bambe Raymond
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere, Cameroon
Mando Ndou Bertrand
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere, Cameroon.
Amina Mamat
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere, Cameroon3Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plant Studies, P.O. Box 13033 Yaoundé, Cameroon
Koga Mang’dobara
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere 2Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1 P.O. Box 812 Yaoundé, Cameroon.
Sokeng Dongmo Sélestin
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere, Cameroon
Ndjonka Dieudonné
Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Po. Box 454 Ngaoundere, Cameroon.
Abstract
Background: The recent treatment of onchocerciasis remains the use of ivermectin which is the only drug against microfilaria and which resistant strains of veterinary importance are increasingly being revealed. In the aim to found the novel anti-filarial and alternative medicines, the anthelminthic activity of crude ethanolic extracts of leaves and bark of Eucalyptus camaldulensis were investigated on Onchocerca ochengi, a nematode parasite model for Onchocerca volvulus. The chemical compounds and toxicity of the extracts were also assessed.
Methods: E. camaldulensis leaves and bark Crudes extracts were prepared using hydro-ethanolic solvent (30 v distilled water and 70 v ethanol solvent). Anti-Onchocerca activity was determined in vitro on the parasitic nematodes O. ochengi and the viability of the worms was based on the standard method of dimethylthyazol (MTT) formazan test. Acute toxicity of the promising extracts was assessed in Wister rats. The phytochemical compounds of the ethanolic extracts were enrolled by colorimetric analysis using spectrophotometric (UV-visible).
Results: E. camaldulensis ethanolic leaf extract showed the highest anthelmintic activity against the adult male nematode O. ochengi with LC50 of 0.16 ± 0.01 mg/mL, as well as the ethanolic bark extract (LC50 = 0.19 ± 0.00 mg/mL) after 48 h of incubation. The quantitative phytochemical analysis revealed that E. camaldulensis ethanolic extracts showed highest quantity of polyphenols even in leaves (49.29±0.21 mg GAE/g) and barks (36.74±0.25 mg GAE/g). Flavonoids were abundant in the bark (14.56 ± 0.02 mg RE/g) and then 13.93 ± 0.09 mg RE/g for the leaves extract. Condense tannins were highly found in the ethanolic extract of bark (4.77 ± 0.07 mg CE/g) and that of leaves was 3.88 ± 0.07 mg CE/g. Saponins were found with the values of 0.66 ± 0.02 mg and 0.09 ± 0.04 mg respectively for leaves and bark ethanolic extracts of this plant. No critical behavioral changes and death were observed for the acute and sub-acute toxicity study.
Conclusion: This study revealed that E. camaldulensis ethanolic extracts were active against O. ochengi adult worms, demonstrating a possible new source of developing the anti-filarial phytomedicine for the treatment of human onchocerciasis.
Keyword: Anti-Onchocerca, Onchocerca ochengi, Eucalyptus camaldulensis, toxicity, phytochemical