Abstract

CHARACTERIZING THE ANTIOXIDANT AND ANTICANCER PROPERTIES OF SECONDARY METABOLITES FROM RED AND WHITE CABBAGES BRASSICA OLERACEA L. VAR. CAPITATA

Alaa A. Gaafar*, Hanan F. Aly, Zeinab A. Salama and Khaled M. Mahmoud

Abstract

Vegetables belongs to Brassicaceaeare rich in polyphenols, flavonoids, glucosinolates, vitamin C and their hydrolysis products which may have antioxidant and anticancer properties.This study was carried out to evaluate and differentiate the total phenolic content, total flavonoids, vitamin C and their antioxidant potential activities and cytotoxic effects between red and white cabbages after extraction with two different solvents (80% methanol and aqueous extracts). The total phenolic and total flavonoid contents varied from 29.13 to 11.44 mg/gdw and from 11.44 to 4.37 mg/gdw for red and white cabbage respectively that extracted with 80% methanol. Levels of total phenolic and flavonoids extracted with water were ranged from 21.38 to 10.36 mg/gdw and from 12.33 to 3.69 mg/gdw for red and white cabbages respectively. While, vitamin C ranged from 64.87 to 44.25 mg/100gfw. Red cabbage was the richest sources of dietary antioxidants, while their content was the lowest in white cabbage. Phenolic compounds present in the extracts showed antioxidant activities investigated using DPPH.radical scavenging activity, iron chelating and reducing power. The extract of red cabbage exhibited a stronger ability to scavenge DPPH. radicalas compared to white cabbage. Iron chelating and reducing power activities were also stronger in red cabbage. Results of the HPLC analysis indicated that, among phenolic compounds, luteolin and rutin were the main constituents in red cabbage extracted with 80% methanol. Red and white cabbages were tested for their anti-cancer activity using three cancer cell lines; hepatocellular cell line(HePG2), colon cell line (HCT116), breast cell line (HCF7) and a normal cell line (human dermal fibroblast cell line). Each extract is evaluated cytotoxicity inhibition effects. Red cabbage aqueous extract showed cytotoxic inhibition effects of 46.40, 31.20 and 22.40 % for HePG2, HCT116 and MCF-7, respectively. Red cabbage seems to be a very good source of dietary antioxidants possessing high antioxidant and anticancer activities. Thus, it could be concluded that,Brassica vegetables contain bioactive substances such as phenolic and vitamin C with potential cancer preventive effects.

Keywords: Red cabbage, White cabbage, Antioxidant, Anticancer.