Anti-invasive Activity against Cancer Cells of Phytochemicals in Red Jasmine Rice (Oryza sativa L.)

Red rice contains pharmacological substances including phenolics, oryzanol, tocotrienol and tocopherol.Recently, red rice extract has been employed as a source of antioxidants for inhibition of tumor growth. Thisstudy was carried out to evaluate the anti-invasion effects of red rice extract fractions on cancer cells. It wasfound that at 100 μg/ml of crude ethanolic extract (CEE), hexane fraction (Hex) and dichloromethane fraction(DCM) could reduce HT1080 and MDA-MB-231 cancer cell invasion. Hex and DCM revealed higher potencylevels than CEE, whereas an ethyl acetate fraction (EtOAc) had no effect. Gelatin zymography revealed thatHex decreased the secretion and activity of matrix metalloproteinase-2 and -9 (MMP-2 and-9). In contrast, theDCM fraction exhibited slightly effect on MMPs secretion and had no effect on MMPs activity. Collagenaseactivity was significantly inhibited by the Hex and DCM fractions. High amounts of γ-oryzanol and γ-tocotrienolwere found in the Hex and DCM fractions and demonstrated an anti-invasion property. On the other hand,proanthocyanidin was detected only in the CEE fraction and reduced MDA-MB-231 cells invasion property.These observations suggest that proanthocyanidin, γ-oryzanol and γ-tocotrienol in the red rice fractions mightbe responsible for the anti invasion activity. The red rice extract may have a potential to serve as a food-derivedchemotherapeutic agent for cancer patients.