Evaluation of Vitamin Contents, Antioxidant and Antimicrobial Activities of Different Leaf Extracts of Taraxacum officinale (Dandelion)

Abstract

Methanol and ethyl acetate leaf extracts of Taraxacum officinale (dandelion) were evaluated for phytochemical compounds, vitamins, antioxidant and antimicrobial activities. Phytochemical compounds and vitamins were determined using standard procedures while antioxidant activity was determined using 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) and Ferric reducing/antioxidant power (FRAP) Assay. Antimicrobial activity against various pathogenic bacteria and fungi were screened using disc diffusion method. The results indicated that the bioactive compounds (total phenol, flavonoids, saponins, tannins and alkaloids) determined quantitatively were present in appreciable concentration in both extracts. The result also showed that both extracts contain a variety of vitamins (A, B complex, C and E), with vitamins C and A having the highest concentration while the B-vitamins (B1, B2 and B3) and vitamin E were present in moderate concentrations. Both extracts showed significant scavenging and reducing ability comparable to the reference antioxidant, ascorbic acid in a dose dependent manner, with methanol exhibiting the highest scavenging and reducing capacity. The antimicrobial activity of both extracts showed appreciable broad spectrum activity against the pathogenic bacteria and fungi strains tested at various concentrations. Methanol extract was found to be most effective compared to ethyl acetate extract. These results indicated that the leaf extracts of dandelion possess antioxidant and antibacterial activity against the tested bacteria possibly due to the presence of bioactive compounds and other nutrients.