Researchers from the universities of Phayao, Mahidol, and Walailak tested polished and unpolished Yoom Noon rice extracts in HCT116 and HT29 colorectal cancer cells. They observed reduced viability, apoptosis, cell-cycle arrest, and lower migration/invasion in vitro, plus genotoxicity and anti-genotoxicity signals in V79 cells. These crude-extract, cell-based results cannot support dietary or cancer-treatment recommendations.
Key findings
- At 48 hours, polished and unpolished extracts produced HCT116 IC50 values of 626.74 and 736.85 µg/mL, whereas both HT29 IC50 values exceeded 1,000 µg/mL.
- The extracts reduced colony formation in HCT116 and HT29 cells and reduced HCT116 migration and invasion at non-cytotoxic doses.
- Dose-related apoptosis and S-phase arrest in HCT116 cells supported an antiproliferative mechanism at the cellular level.
- Extracts at 250–750 µg/mL did not increase micronuclei in V79 cells after 24 hours and reduced micronuclei versus mitomycin C alone during co-treatment.
Why this matters globally
The study places a Southern Thai rice variety into a natural-product discovery pipeline and motivates compound isolation and mechanism studies. Functional-food or drug translation requires achievable exposure, safety, bioavailability, animal evidence, and eventually human trials.
Thai researcher contribution
Ratsada Praphasawat and Buntueng Yana of the University of Phayao, Witchuda Payuhakrit and Chatsuda Surachaijarin of Mahidol University, and corresponding author Sarawoot Palipoch of Walailak University form an all-Thai team linking a Royal Initiative rice variety with cell-based cancer biology.
Limitations to consider
This in-vitro study used two cancer lines and V79 cells, not human tissue or patients. The extracts were crude and required hundreds of µg/mL; active compounds, bioavailability, metabolism, normal-cell selectivity, and safe dosing remain unknown. A negative 24-hour micronucleus result is not comprehensive safety evidence.