An in-vitro Analysis of the Antioxidant and Antimicrobial Properties of the Methanol Extract of Hypoxis hemerocallideacorm (MEHHC) from Botswana
N. Mannathoko *
Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
S. George
Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
S. Souda
Department of Pathology, Faculty of Medicine, University of Botswana, Gaborone, Botswana
K. Chabaesele
Department of Biological Sciences, Faculty of Sciences, University of Botswana, Gaborone, Botswana
I. Goercke
School of Allied Health Professions, University of Botswana, Gaborone, Botswana
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate the antimicrobial and antioxidant activity of the methanol extract of Hypoxis hemerocallidea corm (MEHHC) with different assays.
Study Design: In vitro evaluation of antibacterial and antioxidant activities of the MEHHC.
Location and Duration of Study: Department of Biological Sciences (Faculty of Sciences) and Faculty of Health Sciences, University of Botswana from Jan.2015 to Sep. 2016.
Methodology: The MEHHC was prepared and evaluated for total phenolic content (TPC) and antioxidant properties with DPPH and ABTS methods. Phytochemical screening was conducted to detect bioactive constituents. Antimicrobial activity was determined with diffusion assays, minimum inhibitory concentration and minimum bactericidal concentration assays.
Results: The MEHHC exhibited antioxidant activity and the ability to scavenge DPPH radicals. A relatively high TPC was observed and there was a strong association between antioxidative activities and phenolic compounds (R=0.871), suggesting that the constituent phenolic compounds may confer the antioxidative activities to the MEHHC. The MEHHC exhibited anti-fungal activity against C. albicans and variable antibacterial activity against the Gram positive and Gram negative bacteria. There was more pronounced activity against the tested Gram positive bacteria, particularly S. aureus (including the MRSA ATCC 430043 strain) whereas E. coli, S. typhimurium and K. pneumoniae displayed the lowest susceptibility to the MEHHC.
Conclusion: The results indicate that the MEHHC has considerable antioxidant and anti-microbial properties. Potentially the MEHHC is appropriate for pharmaceutical purposes both as an antioxidant and antimicrobial agent.
Keywords: Antioxidants, antimicrobial, total phenolic content, radical scavenging activity, diffusion assay, minimum inhibitory concentration