Unpolished Thai rice, colon precancer lesions and cancer cells
What it found
In rats given a colon cancer trigger, unpolished Thai rice in the diet reduced the number of early precancerous lesions in the colon.
In human colon cancer cells grown in the lab, the rice extract increased cell death and shifted the cells' oxidation balance.
What they found
Animal and lab studies
Fewer precancerous lesions
Rats given AOM and no rice had many ACF in their colons. Rats given 20% or 70% unpolished Thai rice in the diet had fewer ACF, and the reduction was greater with the higher dose.
Less severe dysplasia
In AOM-treated rats, 81.81% of ACF were dysplastic. Rice treatment at 20% and 70% lowered the proportion of dysplastic ACF to 78.13% and 57.14%, respectively. High-grade dysplasia, the type most linked to cancer, dropped to 34.38% and 21.43% with the low and high rice doses.
Mucin depletion reduced
Mucin depletion in ACF is associated with colon cancer development. AOM-treated rats had 84.61% mucin-depleted ACF. Rice treatment at 20% and 70% reduced this to 66.67% and 57.15%, respectively.
Cancer cell death in lab
In CaCo-2 human colon cancer cells grown in the lab, rice extract at 5 and 7.5 mg/ml increased the percentage of apoptotic (dying) cells from 10.45% in untreated cells to 49.94% and 59.74%, respectively.
Oxidants increased in cells
The same rice extract increased cellular oxidants in CaCo-2 cells, measured as fluorescence intensity, to 111.43% and 120.96% of untreated levels at 5 and 7.5 mg/ml.
Glutathione balance shifted
Rice extract lowered the level of reduced glutathione (GSH) in CaCo-2 cells in a dose-dependent way. Oxidized glutathione (GSSG) was only detected at the higher dose of 7.5 mg/ml. This changed the GSH/GSSG ratio, which the authors link to oxidative stress and cell death.
What the authors conclude
“Our study suggests that UTR supplementation may be a useful strategy for CRC prevention with the inhibition of precancerous progression, with induction of cancer cell apoptosis through redox alteration.”
Also in their conclusions
- They conclude that unpolished Thai rice may help prevent ACF formation and inhibit precancerous progression in AOM-induced rats.
- They also state that it induces cancer cell apoptosis through alteration of the GSH/GSSG ratio.
- They suggest that unpolished Thai rice may be a candidate for developing pharmaceutical products for colorectal cancer prevention.
How it was done
The authors note that oxidative stress is linked to colon cancer development, including the formation of aberrant crypt foci (ACF), which are precancerous lesions. They wanted to see whether unpolished Thai rice, which is rich in phenolic compounds, could affect these lesions and cancer cell behaviour.
They fed rats a standard diet or a diet containing 20% or 70% unpolished Thai rice. Some rats were injected with azoxymethane (AOM) to induce colon lesions. After 38 weeks, the rats' colons were examined for ACF. They also treated human colon cancer (CaCo-2) cells in the lab with rice extract at 5 and 7.5 mg/ml for 24 hours and measured cell death, oxidants, and glutathione levels.
What it can’t tell you
- These are animal and lab cell studies. They cannot show what happens in people.
- The rat study used a chemical to induce colon lesions, so the results may not apply to people without that exposure.
- The cell experiments used extract concentrations that may not be reached in the human body through diet.
Who paid
- Authors work at
- Mahidol University, Thailand E-mail :
The paper
- Title
- Unpolished Thai rice prevents ACF formation and dysplastic progression in AOM-induced rats and induces apoptosis through redox alteration in CaCo-2 cells
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Tammasakchai A, Chaiyasut C, Riengrojpitak S, Suwannalert P (2015). Unpolished Thai rice prevents ACF formation and dysplastic progression in AOM-induced rats and induces apoptosis through redox alteration in CaCo-2 cells. Asian Pacific journal of cancer prevention. doi:10.7314/apjcp.2015.16.7.2827Free full textPubMed 25854369DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error