Gamma-oryzanol (GO), a nutriactive phytochemical naturally occurring in crude rice bran oil, is an antioxidant compound used to treat hyperlipidemia, disorders of menopause and to increase the muscle mass. γ-Oryzanol is a potent DNA methyltransferases (DNMTs) inhibitor in the striatum of mice. γ-Oryzanol significantly inhibits the activities of DNMT1 (IC50=3.2 μM), DNMT3a (IC50=22.3 μM).
From the proliferation assay using MTT reagent, the effect of gamma-oryzanol on DU145 and PC3 are slightly different with an IC50 after 7 days of exposure at 0.52±0.06 and 0.40±0.08 mg/ml, respectively. For in vitro condition in proliferation assay, IC50 values seem to be high in the scale of mg/ml. gamma-oryzanol may affect to prostate cancer cells through the down regulation of some antioxidant genes, CAT and GPX[1].
In tumor-bearing mice, gamma-oryzanol can reduce tumor mass associated with pro-angiogenic biomarkers[1]. Gamma-oryzanol is not carcinogenic and are safe for animals. In vivo trials proved gamma-oryzanol to be powerful antioxidant and also appears to be a very promising anticancerogenic compound. Supplementation of gamma-oryzanol in diabetic patients may improve metabolic dysfunctions such as hyperglycaemia, hypercholesterolaemia, hypertriglyceridaemia, insulin resistance and may alleviate diabetic complications resulting from lipid peroxidation and free radicals[3].
[1] Klongpityapong P, et al. Asian Pac J Cancer Prev. 2013, 14(9):5421-5. [2] Chotimarkorn C, et al. Phytomedicine. 2008, 15(11):951-8. [3] Szcze?niak KA, et al. J Anim Physiol Anim Nutr (Berl). 2016, 100(4):601-17.