Abstract
Forty five crude extracts of nine selected medicinal plants, based on their use in respiratory and other disorders in traditional systems of medicine were analyzed for their potential activity against three pathogenic species of Aspergillus. The presence of phenols, tannins, flavanoids, terpenoid, steroids, alkaloids and saponins in the different extracts was established. The crude extracts were examined for antifungal activity in concentration ranging from 5000.0 to 19.53 µg/ml using microbroth dilution assay in which twenty two extracts exhibited the anti-Aspergilli activity. The petroleum ether extract of Justicia adhatoda and water extract of Commelina bengalensis exhibited the maximum activity against Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger. Their in vitro minimum inhibitory concentrations (MICs) were found to be 156.0-312.0 µg/ml by microbroth dilution and spore germination inhibition assays. In disc diffusion assay, at concentration of 10 µg/disc of some crude extracts showed significant activity against Aspergilli. The toxicity (in vitro and in vivo) of bio-active fractions was evaluated, in which the extracts isolated from J. adhatoda were found to be non-toxic. Gas chromatography-mass spectrometry (GCMS) studies were performed for various extracts (petroleum ether, chloroform and acetone) of J. adhatoda which resulted in the identification of several bioactive compounds. The antifungal activity along with acute toxicity, cyto-toxicity as well as genotoxicity of extract fractions from J. adhatoda justifies the use of such screening in the expedition for new drugs.
Keywords: Antifungal, Aspergillus, drugs, Justicia adhatoda, medicinal plants, toxicity.