Rice bran chemical profiles differ across rice varieties and have not yet been analysed for differential chemopreventive
bioactivity. A diverse panel of seven rice bran varieties was analysed for growth inhibition
of human colorectal cancer (CRC) cells. Inhibition varied from 0% to 99%, depending on the variety of bran
used. Across varieties, total lipid content ranged 5–16%, individual fatty acids had 1.4- to 1.9-fold differences,
vitamin E isoforms (a-, c-, d-tocotrienols, and tocopherols) showed 1.3- to 15.2-fold differences,
and differences in c-oryzanol and total phenolics ranged between 100–275 ng/mg and 57–146 ng GAE/
mg, respectively. Spearman correlation analysis was used to identify bioactive compounds implicated
in CRC cell growth inhibitory activity. Total phenolics and c-tocotrienol were positively correlated with
reduced CRC cell growth (p < 0.05). Stoichiometric variation in rice bran components and differential
effects on CRC viability merit further evaluation elucidate their role in dietary CRC chemoprevention.
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