Characterization of nutrient-rich Browntop millet (Urochloa ramosa (L) T.Q. Nguyen) hydroalcoholic extract, and assessment of the impact of malting on antioxidant potential, and anti-proliferative efficacy against breast- and colorectal cancer cell lines

Millets are climate-resilient cereals rich in bioactive secondary metabolites, offering significant potential for translation into nutraceuticals. This study investigated the impact of soaking (S) and malting (24 h (M24) – 96 h (M96)) of Browntop millet (BTM) on the phytochemical remodelling and the resulting in vitro antiproliferative potential against the breast (MDA-MB-231) and colorectal (HCT-15) cancer cell lines. Although the unprocessed native extract (N) contained significantly higher polyphenolic content (p < 0.0001), the 72 h malted extract (M72) demonstrated comparable antioxidant and in vitro antiproliferative potential. The Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) profiling revealed distinct shifts in the relative abundances of potential bioactive metabolites, including luteolin, kaempferol, vanillin, and 9-oxo-10(E),12(E)-octadecadienoic acid (9-Oxo-ODE). Screening of in vitro antiproliferative potential demonstrated a selective and differential effect across the cancer cell lines. The native extract decreased the viability of MDA-MB-231 cells more effectively, with an IC 50 of 0.24 ± 0.02 mg/mL, while M72 extract showed better cytotoxicity against HCT-15 with an IC 50 of 0.30 ± 0.02 mg/mL. Mechanistically, the native extract predominantly induced an S-phase cell cycle arrest, while M72 extract showed a G2/M phase arrest in both the cell lines. A dose-dependent increase in apoptotic population provided further validation for the cytotoxic potential of the extracts. Further, the M72 extract demonstrated a better in vitro anti-migratory potential when tested against the MDA-MB-231 cell line. To the best of our knowledge, our study is the first to screen the impact of malting of Browntop millet on in vitro antioxidant, antiproliferative and anti-migratory potential.