Antifungal Activity of Capsicum frutescens and Allium cepa against Aspergillus spp.: An Application of Scientific Process Skills by High School Students

Abstract

Aspergillus niger and Aspergillus flavus are known to induce risks including aspergillosis in humans and common crop drought to plants. Allium cepa (white onion) and Capsicum frutescens (cayenne pepper) have been reported as having some antifungal potential. Thus, to practice scientific process skills, high school biology students investigated whether A. cepa and C. frutescens extracts are effective antifungal agents against these two pathogens. Sensitivity testing using Kirby-Bauer assay revealed that C. frutescens was more effective against A. niger and A. flavus. C. frutescens extract alone produced an inhibition zone of 19.29 mm for A. niger and 10.47 mm for A. flavus. Using t-test and repeated measures ANOVA (95% level of confidence), the results were comparable to an antifungal drug miconazole. It is therefore concluded that C. frutescens or the mixture of C. frutescens and A. cepa extracts (50-50 v/v) can be effectively used as an antifungal agent against A. niger. This study possibly serves as a model for students to learn the scientific method practically and to experience different process skills essential in biological research tangibly.