A crude extract of Loxostylus alata is as effective in treating aspergillosis in poultry as a commercial drug

Leaf extracts of several South African tree species with activity against Cryptococcus neoformans were evaluated for activity against Aspergillus fumigatus the causal agent of aspergillosis, an economically important disease in birds. The Loxostylis alata acetone leaf extract had a good inhibitory activity with an MIC of 50 ug/mL [1]. The main antifungal agent present in the extract, lupeol had a lower activity than the crude extract against A. fumigatus (MIC of 92 ug/mL) indicating strong synergistic effects. The toxicity and antifungal activity of the crude L. alata acetone leaf extract was evaluated in broiler chicks. Experimental aspergillosis was induced by intraperitoneal infection with A. fumigatus. Because the extract had some toxicity at a dose of 300mg/kg, lower doses were used. Antifungal activity was assessed by comparing degree and severity of clinical signs, lesion scores, fungal re-isolation and a series of biochemical and haematological indices observed between chicks treated with the extract and not-treated chicks. The extract at the doses of 100 and 200mg/kg significantly reduced the lesions induced by the aspergillosis, as well as the number of fungal colonies isolated from infected chick lungs (p ≤0.05) in a dose dependent manner. The crude extract proved to be as effective as the positive control ketoconazole dosed at 60mg/kg, the highest non-toxic dose. The results indicate that a crude extract of L. alata leaves has potential as an antifungal agent to protect poultry against avian aspergillosis.

Acknowledgements: The National Research Foundation of South Africa provided funding.

References: 1. Suleiman MM. et al. (2010) S. Afr, Jl Botany 76:64–71.