Leaf and cortex extracts of Mikania scandens (Asteraceae) exhibit cytotoxic effects against Spironucleus meleagridis trophozoites from turkey-cock and antibacterial properties

Among infectious diseases with medical and economic importance in lifestock production, parasitic protozoa show a wide spectrum of infestation of different domestic animals. The plant used for this study is the Climbing Hempweed Mikania scandens (Asteraceae), a climbing liana-like plant from rainforests in North and South America. In the indigenous folk medicine, parts of the plant are used against infections, inflammation and other diseases. M. scandens was imported and grown in horticulture. Leaf and cortex material was fractionated by column chromatography with different solvents (water, MeOH, EtOH, acetone, petrol ether). Trophozoites of Spironucleus meleagridis, the causative agent of a severe enteritis disease in poultries, were isolated by a veterinarian from the intestinal tract of turkey-cock and stored in suspension culture. Cysts of the same parasite were collected from faeces of infested animals. Trophozoites and cysts were then incubated in the presence of the Mikania scandens extracts in different concentrations. The acetone extracts showed IC₅₀ values in the range of 9–14µg/mL against the vegetative stage. Additionally, 50µg/mL of the acetone extract caused microscopically visible lesions in the surface structure of the cysts.

The antibacterial properties of all extracts were also tested against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Campylobacter jejuni, and Proteus mirabilis by measuring their proliferation photometrically. The acetone extracts showed IC₅₀ values in the range of 8–17µg/mL against the tested microorganisms. In both bioassays, the petrol ether fraction which was inactive, while the toxicity against trophozoites as well as the antibacterial activity increased in parallel with the hydrophobicity.

Acknowledgements:Sabine Priebe (Berlin) for technical assistance and advice in plant breeding, Sächsische Landesanstalt für Landwirtschaft (Dresden) for supply of plant material, and Mattox BioTech (Chemnitz) for technical support.