A Survey on the Effect of ethanol Pluchea dioscoridis Leaf Extract on Lipase Gene Expression in otomycotic Aspergillus niger via Real-time PCR

The present study focused on the inhibitory effects of Pluchea dioscoridis ethanol leaf extract on growth, survival and lipase gene expression of otomycotic Aspergillus niger. There is no report regarding the effects of P. dioscoridis or its mechanism of action on pathogenic Aspergillus lipase gene. Ethanol leaf extract of P. dioscoridis was assessed for its antifungal activity against A. niger, also the minimal inhibitory concentration (MIC) for P. dioscoridis extract was measured. After harvesting the fungi, its mRNA was extracted and cDNA synthesized by using two specific primers. The quantitative change in the lipase expression was analyzed via real-time PCR. The fungal growth decreased with increasing concentrations of P. dioscoridis extract and it recorded a low minimal inhibitory concentration value (MIC=20mg/ml). At this concentration, lipase gene expression was reduced from 100 % to 7% and 19% than that obtained from untreated A. niger as documented by quantitative RT-PCR analysis. Overall we concluded that the P. dioscoridis could inhibit the lipase gene expression and consequently the lipase enzyme activity that play a role in the pathogenecity of A. niger in otomycosis infection