Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 51: 3583 - 3590. Published March 29, 2012.
In vitro antimicrobial and antioxidant analysis of Dioscorea dumetorum (Kunth) Pax and Dioscorea hirtiflora (Linn.) and their bioactive metabolitesfrom Nigeria
Mubo Adeola Sonibare*, Rebecca Busayo Abegunde
Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan Nigeria
RESUME
Objectives: To analyze total phenols, flavonoids, antioxidant potential and antimicrobial activity of tuber extracts of two Dioscorea species.
Methodology and results: 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay and Folin-Ciocalteu reagent were used to determine total antioxidant activity and total phenolic content of tuber extracts of D. dumetorum (edible and wild species) and D. hirtiflora. Total Flavonoids were determined by repeatedly extracting 1 g of powdered tuber sample with 10ml of 80% aqueous methanol at room temperature for 2-4 hours. Anti-microbial activity was determined by Agar diffusion and pour plate methods. Quantitative analysis of bioactive components revealed that total phenols are the major bioactive constituents found in the extracts expressed as mg of GAE per gram, which ranged from 22.83 ± 0.33mg/g to 64.33 ± 2.55mg/g. Mean concentrations of flavonoids ranged from 7.53± 0.07 mg/g to 25.60 ± 0.39 mg/g. Anti-oxidant efficiency was higher in D. hirtiflora and non-edible D. dumetorum than edible D. dumetorum when compared to standard antioxidants like Ascorbic acid. Antimicrobial activity profile showed direct influence of concentrations of bioactive components.
Conclusion and application of findings: The results of our study confirmed the folkloric uses of the studied plants and provided evidence that tuber extracts of D. dumetorum and D. hirtiflora might indeed be potential sources of natural antioxidant and antimicrobial agents.
Key words: Dioscorea, antimicrobial activity, antioxidant activity, bioactive compounds.
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