Riceberry Rice Bran Protein Hydrolyzed Fractions Induced Apoptosis, Senescence and G1/S Cell Cycle Arrest in Human Colon Cancer Cell Lines

Abstract

Riceberry rice bran is the part of rice that has been scrubbed out during the coloring process. There are various health benefits to be gained from foods with a high protein content. This work aimed to study the effect of hydrolyzed riceberry rice bran extracts on colon cancer cell lines compared to normal cells. The MTT assay result showed that our extract has lower cytotoxicity effects on normal cells (PCS-201-010, IC50 = 6745 µg/mL) compared to colon cancer cell lines and has a greater effect on metastatic cancer cell lines (SW-620, IC50 = 5468 µg/mL) than non-metastatic cancer cell lines (HT-29, IC50 = 6054 µg/mL). The apoptotic inductive effects of HRBE on SW-620 were observed after 72 h at a maximum rate of 76% and at maximum concentration. According to the result of the cell senescence analysis after 24 h of HRBE treatment, the percentage of HT-29 (86%) expressing SA-β-gal was much higher than that of SW-620 (32%). Consequently, the decrease in the cell population in the S and M/G2 phases indicated cell cycle arrest in HT-29 cells after being treated with HRBE. Focusing on the peptide fraction size of HRBE, the largest (>50 kDa) fraction showed the highest anticancer activity compared to other fractions. In conclusion, the hydrolyzed riceberry rice bran extract induced the apoptosis process in the metastatic cancer cells and induced the senescence process in the non-metastatic cancer cells. This observed information will be useful and applicable for medical research and colon cancer treatment in the future.

Recent trends of potential medicinal uses of rice bran with its composition and bibliographic analysis

“…Applying hydrolyzed riceberry bran extract on the colon cancer cell lines causes apoptosis and senescence in SW‐620 and HT‐29 cell types, respectively, and reduces the cell numbers in the S and G2/M cell cycle phase. This reduced cell numbers in S and M/G2 cell phase lead to enhanced cell numbers in the G0/G1 cell cycle phase (Wattayagorn et al, 2022). Similar results were also reported in the acute myeloid leukaemia (HL‐60), breast adenocarcinoma (MCF‐7), and Colonic carcinoma (Caco‐2) cells on treating these cell lines with extract of riceberry bran through the suppression of cell proliferation and enhancing apoptosis and cell cycle arrest (Leardkamolkarn et al, 2011).…”