Objective: The global epidemic of type 2 diabetes mellitus (T2DM) has prompted continuing efforts toward development of better therapeutic alternatives to manage the disease. Despite a wide array of plant-derived active components that demonstrated efficacy in providing symptomatic relief in T2DM, considerable research attention has been focusing on the use of polyphenols owing to their encompassing beneficial effects on blood glucose levels. This study aimed to evaluate the nutrigenomic basis of polyphenol-rich fraction (PRF) isolated from Molineria latifolia rhizome on T2DM. Methods: The anti-diabetic potential of PRF was studied using a high fat diet-fed and nicotiamide/streptozotocin-induced diabetic rat model. Results: PRF demonstrated therapeutic efficacy by ameliorating glucose tolerance and lipid profiles in the diabetic rats following a 32-day treatment. Further analyses on the insulin-sensitive adipose, liver and muscle tissues revealed variations in the radical scavenging capability and protection against lipid peroxidation. Transcriptional analyses suggested that PRF exerted concerted modulation of PI3K/Akt and Keap1-Nrf2 signaling pathways in a tissue-specific manner. Conclusion: The present study showed that PRF exerted its anti-diabetic effect by modulating crosstalk between the PI3K/Akt and Keap1-Nrf2 signaling pathways. The study indicates potential in the development and application of PRF as a therapeutic alternative for T2DM management, particularly by benefiting the simultaneous targeting of proximal insulin signaling sensitization and systemic oxidant-antioxidant balance restoration.