Untargeted Metabolomic Profiling and Bioactivity Evaluation of Browntop Millet (Brachiaria ramosa): Antioxidant and Antidiabetic Potential.

Abstract

The underutilized cereal, Browntop millet (BTM), has a valuable nutritional profile and considerable therapeutic potential. The metabolomic profile of BTM also offered insights into its complex phytochemical profile, aligning with its potential benefits for metabolic health and disease prevention. The liquid chromatography-mass spectrometry analysis identified 349 compounds in BTM, with 257 compounds identified in ChemSpider. Of these, 56 were shown to have medicinal properties, indicating a high degree of diversity in therapeutic potential. These findings highlight the metabolomic complexity and the considerable potential of BTM in health-related fields. Out of these 15 compounds reported to possess antioxidant activity, around 3 enzymes were found to have antidiabetic properties ((-)-ECG-3″-O-ME, a natural inhibitor of α-glucosidase, and 1-Boc-4-(4-Nitrophenyl)piperazine, a potential inhibitor of enzymes like α-Amylase). In this study, the in vitro antioxidant and antidiabetic potential of BTM flour was also studied. Total antioxidant activity of BTM flour was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays, and antidiabetic property was evaluated by α-amylase inhibitory assays. BTM flour exhibited concentration-dependent DPPH scavenging activity, increasing from 14.29% inhibition at 10 µM to 90.00% inhibition at 100 µM, with an IC₅₀ value of 40.77 ± 0.54 µM. The percentage inhibition of the α-amylase assay of BTM and Acarbose was found to be IC₅₀ = 240.91 ± 0.14 µM and 19.36 ± 0.88 µM, respectively. The results suggest that BTM has detectable antioxidant and enzyme inhibitory activities but not as high as the standard reference compounds. In general, the study revealed that BTM contains phytochemicals with possible biological significance. The results are in favor of the potential use of BTM as a functional food ingredient, but additional research is needed to confirm the role of each metabolite and biological efficacy by means of in vivo investigations.