Protective effects of raw and cooked blackcurrant extract on DNA damage induced by hydrogen peroxide in human lymphoblastoid cells

Figures & data

Figure 1. DPPH free radical scavenging activity of BCEs. The ordinate axis indicates the ratio of inhibition of DPPH radicals. In this experiment, 0.016% of DPPH reaction solution and 0 to 1.6 mg of blackcurrant extract from mature fruit (filled circle), heated-mature fruit (opened circle), premature fruit (filled diamond) and heated-premature fruit (opened diamond) were used. Each symbol represents the mean value of three experiments. An asterisk (*) indicates p < 0.05 in the t-test comparing P-BCE and PH-BCE.

Figure 2. Effects of BCEs on H₂O₂-induced DNA damage (DNA migration) in human lymphoblastoid TK6 cells. The effects of BCE extracted from mature fruit (a) and premature fruit (b) are separately presented. In this experiment, 0 to 3.0 mg/mL of blackcurrant extract was treated without or with 300 µM of H₂O₂. Filled square, unheated blackcurrant fruit without H₂O₂-treatment; Opened square without H₂O₂-treatment; Filled circle, unheated blackcurrant fruit with H₂O₂-treatment; Opened circle, heated blackcurrant fruit with H₂O₂-treatment. Each symbol represents the mean value of three experiments. A dagger (†) indicates p < 0.00005 in the t-test comparing H₂O₂-treated (300 μM) and untreated cells. A number sign (#) indicate p < 0.05 in the t-test comparing P-BCE and PH-BCE. An asterisk (*) and two asterisks (**) indicate p < 0.05 and p < 0.005, respectively, in the t-test comparing H₂O₂-treated and H₂O₂ + BCE-treated cells.

Figure 3. Effects of BCEs on H₂O₂-induced chromosomal aberration (micronucleus formation) in human lymphoblastoid TK6 cells. The effects of BCE extracted from mature fruit (a) and premature fruit (b) are separately presented. Dark gray column, H₂O₂ single treatment; Light gray column, H₂O₂ treatment combined with unheated blackcurrant extract; White column, H₂O₂ treatment combined with heated blackcurrant extract. Each column represents the average of three experiments. A dagger (†) indicates p < 0.005 in the t-test comparing H₂O₂-treated (20, 30, 40 μM) and untreated cells. An asterisk (*), two asterisks (**) and three asterisks (***) indicate p < 0.1, p < 0.05 and p < 0.005, respectively, in the t-test comparing H₂O₂-treated and H₂O₂ + BCE (1.0 mg)-treated cells.

Figure 4. Intracellular ROS scavenging activity of BCE. Intracellular ROS was measured using BES-H₂O₂-Ac fluorescent probe. H₂O₂-induced ROS was reduced by BCE (1.0 mg/mL). The ROS-positive cells more than 100 were counted in each treatment. A dagger (†) indicates p < 0.05 in the t-test comparing H₂O₂-treated (300 μM) and untreated cells. An asterisk (*) indicate p < 0.05 in the t-test comparing H₂O₂-treated and H₂O₂ + BCE-treated cells.

Table 1. Total polyphenols, anthocyanins and l-ascorbic acid content in the BCEs.

	Total polyphenols (mg catecin eq/mL)	Anthocyanins (mg/mL)	l-Ascorbic acid (mg/mL)
M-BCE	3.30	0.396	0.540
MH-BCE	3.36	0.146	0.757
P-BCE	3.29	0.008	0.985
PH-BCE	4.31	0.006	1.272