Philippine E-Journals

The Genetic Diversity of Brown and Red Rice Samples and their Antioxidant Activities, Anticancer, and Low Glycemic Properties

Yariv Brotman | Cindy Llorente | Saurabh Badoni | Glenn Oyong | Gopal Misra | Roslen Anacleto | Sabiha Parween | Erstelle Pasion | Rhowell N. Tionzon | Joanne J. Anonuevo | Maria K. Deguzman | Edwige GN. Mbanjo | Lesley A. Boyd | Alisdair R. Fernie | Nese Sreenivasulu

 

Abstract:

The double burden nutrition problem (i.e. lack of essential nutrients and calorie-rich food) is a growing epidemic in Asia and around the globe, where cancer and diabetes are part of the major causes of death. Hence, bringing diet-based nutritional intervention by identifying rice varieties with grains rich in nutrient density is becoming increasingly significant. In this research, a metabolome-wide association study (mWAS) was conducted by linking the metabolites with ultra-dense genotyping data of 1.7 million single nucleotide polymorphisms (SNPs). It revealed novel genetic regions and/or candidate genes influencing the levels of various amino acids and catechin as pivotal molecules in determining the nutritional quality of brown and red rice. Importantly, the novel genetic variants identified through mWAS which was found to affect catechin accumulation on chromosome 7 (6.06-6.43 Mb region), co-located with GWAS peaks of red color and amylopectin composition and thereby the glycemic index. Contrasting lines resulted from mWAs analysis were used to extract the free and bound phenolic components. Red rice extract has higher phenolic content thereby, effective antioxidant activities than brown rice extract in concordance with its potent antiproliferative property against different cancer cell lines. The extract of red rice exhibited strong anti-proliferative activity with mean IC50 values of 8.25, 17.13, and 24.47 mg/mL while the brown rice extract with mean IC50 values of 1580.57, 23007.56, and 55400.58 mg/mL against HT-29, MCF-7, and HepG2, respectively. Further, in vitro GI analysis has demonstrated a lower glycemic index in milled red rice with high resistant starch. The selected rice samples may be used as a functional food to address diabetes and certain forms of cancer.