Growth-inhibitory effects of pigmented rice bran extracts and three red bran fractions against human cancer cells: relationships with composition and antioxidative activities.
We determined the phenolic, anthocyanin, and proanthocyanidin content of three brown, purple, and red rice brans isolated from different rice varieties using HPLC-PDA with the aid of 27 standards of known structure and matching unknown peaks to a spectral library of known compounds. Antioxidative capacities were determined by DPPH and ORAC and cell-inhibiting effects using an MTT assay. Based on the calculated IC(50) values, the light-brown bran had no effect, the purple bran exhibited a minor effect on leukemia and cervical cancer cells, and the red bran exhibited strong inhibitory effects on leukemia, cervical, and stomach cancer cells. High concentrations of protocatechuic acid and anthocyanins in purple bran and proanthocyanidins in red bran were identified. The red bran was further fractionated on a Sephadex column. Fraction 3 rich in proanthocyanidin oligomers and polymers had the greatest activity. Red bran has the potential to serve as a functional food supplement for human consumption.
Dale Bumpers National Rice Research Center, Agricultural Research Service, U.S. Department of Agriculture, 2890 Highway 130 East, Stuttgart, Arkansas 72160, USA. ming.chen@ars.usda.gov
Ming-Hsuan
MH
Chen
Suk Hyun
SH
Choi
Nobuyuke
N
Kozukue
Hyun-Jeong
HJ
Kim
Mendel
M
Friedman
D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004043:Dietary Fiber / Q000032:analysis / Q000494:pharmacology*; D006131:Growth Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D012275:Oryza / Q000737:chemistry*; D010858:Pigmentation; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
D000975:Antioxidants; D004043:Dietary Fiber; D006131:Growth Inhibitors; D010936:Plant Extracts