Biological Activity of Anthocyanins and Total Flavonoids in Pigment Extraction Residue from Ipomoea batatas L.

Abstract:

Anthocyanins and total flavonoids present in pigment extraction residue obtained from Ipomoea batatas L. were evaluated for their biological activity. Inhibitory effects on Escherichia coli and Staphylococcus aureus were studied by filter paper diffusion, antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging ratio, and growth inhibition of human breast cancer cell line was determined by MTT assay. The results showed that proliferation of E. coli, S. aureus, and human breast cancer cell line, MDA-MB-231 was significantly inhibited, while significant DPPH radical-scavenging activity was also observed. The minimal inhibitory concentration (MIC) of anthocyanins and total flavonoids for E. coli and S. aureus was 400 and 4.0 mg/mL, respectively. Additionally, the values of half-maximal inhibitory concentration (IC50) and standard control (Vc) for DPPH radicals were 42.32 and 44.65 μg/mL for anthocyanins, and 0.023 and 0.011 μg/mL for flavonoids, respectively. The IC50 for MDA-MB-231 within 24, 48, and 72 h were 202.12, 58.01, and 0.232 μg/mL for anthocyanins, and 0.42, 12.05 and 12.11 mg/mL for flavonoids, respectively. These results demonstrate potential for value-added utilization of the residue after pigment extraction of Ipomoea batatas L.