V Belewa1, H Baijnath2, C Frost1, B M Somai1. 1. Department of Biochemistry and Microbiology, Nelson Mandela Metropolitan University, Port Elizabeth, Eastern Cape, South Africa. 2. Ward Herbarium, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa.
Abstract
AIMS: This study investigates the effect that aqueous extracts of Tulbaghia violacea Harv. harbouring plant saponins, phenolics and tannins have on Aspergillus flavus β-(1,3) glucan and chitin synthesis. METHODS AND RESULTS: Aspergillus flavus was treated with various subinhibitory concentrations of an aqueous T. violacea plant extract and the β-(1,3) glucan and chitin content was determined together with glucan synthase and chitin synthase production respectively. CONCLUSIONS: The aqueous extract caused a significant decline (P < 0·05) in β-glucan production in A. flavus in a dose-dependent manner when compared to the untreated sample. Further investigations showed a decrease in β-glucan synthase production as the concentration of the plant extract was increased. A significant reduction in total chitin content corresponding to a decrease in chitin synthase production in the presence of the plant extract was also found. SIGNIFICANCE AND IMPACT OF THE STUDY: The broad spectrum activity and the efficacy of aqueous T. violacea plant extract on both β-glucan and chitin synthesis may limit the potential of the fungus developing resistance towards it and therefore the extract is an ideal candidate for use as a potential antifungal agent.
AIMS: This study investigates the effect that aqueous extracts of Tulbaghia violacea Harv. harbouring plant saponins, phenolics and tannins have on Aspergillus flavus β-(1,3) glucan and chitin synthesis. METHODS AND RESULTS:Aspergillus flavus was treated with various subinhibitory concentrations of an aqueous T. violacea plant extract and the β-(1,3) glucan and chitin content was determined together with glucan synthase and chitin synthase production respectively. CONCLUSIONS: The aqueous extract caused a significant decline (P < 0·05) in β-glucan production in A. flavus in a dose-dependent manner when compared to the untreated sample. Further investigations showed a decrease in β-glucan synthase production as the concentration of the plant extract was increased. A significant reduction in total chitin content corresponding to a decrease in chitin synthase production in the presence of the plant extract was also found. SIGNIFICANCE AND IMPACT OF THE STUDY: The broad spectrum activity and the efficacy of aqueous T. violacea plant extract on both β-glucan and chitin synthesis may limit the potential of the fungus developing resistance towards it and therefore the extract is an ideal candidate for use as a potential antifungal agent.