Riceberry rice bran is the part of rice that has been scrubbed out during coloring process. There are various health benefits with high protein content and antioxidant ability. The hydrolyzed rice bran consists of diverse peptides that provide various bioactive properties. This work aimed to study the effect of hydrolyzed riceberry rice bran extracted on colon cancer cell lines (HT- 29 and SW- 620) compared to normal cell (PCS- 291- 010). The MTT assay result showed that our extract has less cytotoxicity on normal cell (PCS-291-010, IC50 = 6,680.00 µg/ml) compared to the colon cancer cell lines and has more effect on metastatic cancer cell line (SW-620, IC50 = 5,492.31 µg /ml) than non-metastatic cancer cell line (HT-29, IC50 =6,040.76 µg/ml). According to the DNA fragmentation pattern analysis, the ladder pattern indicated that the rice bran extract can induce the apoptosis process in SW-620 cell line. Confirmed the pattern of apoptotic cell by AO/PI double stain test and quantified apoptotic cells by Annexin V. For the cell senescence analysis, SA-β-gal staining technique was performed at 24 h after treatments, HT-29 reached maximum senescence rate at 85.74% while SW-620 had only 17.23% of senescence. And a result of cell cycle analysis, HT-29 were decreased the number of cells in S, M/G2 phase, and increased the number of cells in G0/G1 phase. Furthermore > 50 kDa peptide fraction separated from HRBE has a potent anti-cancer cells (SW-620, IC50 = 4,908 µg/ml). In conclusion, the hydrolyzed riceberry rice bran extract can inhibit colon cancer cell lines with less effect on normal cell. The extracts could induce apoptosis process in metastatic cancer cell and induce senescence process in non-metastatic cancer cell. This observed information will be useful and applicable for medical research and colon cancer treatment in the future.
Riceberry rice bran protein hydrolyzed fractions induced apoptosis, senescence and G1/S cell cycle arrest in human colon cancer cell lines