Early and Middle Stage Glycation Reversing Activities of Whole Grains of Selected Wild Oryza Species in Sri Lanka

Wild rice relatives from the genus Oryza offer great potential for improving cultivated rice. Although Sri Lanka is home to five wild Oryza species, their health-promoting properties have been scarcely studied. Our recent research demonstrated that all five wild rice species available in the country have anti-glycation activity. Building on these findings, the present study aimed to investigate the in vitro glycation-reversing potential of two selected species, which showed high anti-glycation activity in our previous studies on the management of diabetes complications. Oryza nivara and Oryza eichingeri were used in the present study. These two species were collected from their natural habitats, Chenkaladi (Batticaloa) and Waulpane (Embilipitiya), respectively. Freeze-dried 70% ethanolic extracts of whole grains were initially evaluated for early-stage (BSA-Glucose) glycation reversing (n=3 each) activity. The middle stage glycation reversing activity (BSA-Methylglyoxal:MGO) was subsequently assessed for the species that exhibited the highest anti-glycation and antioxidant properties in our previous studies. Results showed that both species exhibited dose-dependent early-stage glycation-reversing activity, with no significant difference between them. The EC₅₀ values of Oryza nivara and Oryza eichingeri were 36.61±1.26 and 39.61±1.22 μg/mL, respectively. Furthermore, Oryza eichingeri shows middle-stage glycation-reversing activity (EC₅₀: 173.92±9.29 μg/mL). In conclusion, both species exhibited notable glycation-reversing activity, suggesting their potential for the management of diabetes-related complications.