Chemical characterization of Melilotus messanensis (L.) All.: antioxidant, antidiabetic and antimutagenic effects in Alloxan induced diabetic rats

Abstract Melilotus Mill. species have been used in various traditional medical systems. Recent studies suggested that Melilotus species may have pharmacological significance against diabetes mellitus; however, none of them associated their bioactive virtues with chemical identity. The current study aims to reveal the chemical profile of the Melilotus messanensis (L.) All. extracts and their biological evaluation. Petroleum ether extract (PEE) was analyzed by GC/MS assay which revealed the characterization of 32 metabolites. Moreover, the chromatographic investigation of defatted aqueous methanol extract (DAME) led to the isolation of fifteen phenolics, from which, fourteen compounds have been isolated for the first time from M. messanensis. Also, LC-ESI-MS chemical profiling managed to detect additional sixteen metabolites. The aqueous methanol extract (AME), PEE and DAME were subjected to antioxidant, antidiabetic and antimutagenic assays. Diabetes mellitus was induced using a single dose of Alloxan (150 mg/kg b.wt.) and exhibited as DM_rats model. Potential activities of AME, PEE and DAME (100 mg/kg b.wt. i.p.) in treating DM_rats were investigated and exhibited a significant antioxidant activity with % of change 10, 11 and 13, respectively, compared to vitamin E (9%) and negative control DM_rats (45%). Additionally, they showed anti-diabetic activities (blood glucose levels) after four weeks with % change 53, 52 and 60, respectively, in comparison with metformin (5 mg/kg b.wt. i.g.) group (69%). Also, all extracts showed high inhibitory indices of bone marrow and sperm cells aberrations in DM_rats. The prominent antihyperglycemic and antigenotoxic activities could be attributed to the abundant identified flavonoids and fatty acids.