1H NMR-based urinary metabonomic study of the antidiabetic effects of Rubus Suavissimus S. Lee in STZ-induced T1DM rats

• Suavissimus S. Lee (RS), a traditional Chinese medicine, has hypoglycemic effects. • The mechanism of action of RS was examined in a rat model of T1DM by metabonomic approach. • 1 H NMR revealed 9 metabolites whose levels were altered in T1DM rats vs normal rats. • RS treatment restored the altered metabolites levels in T1DM rats. • RS mediated synergistically disturbance of the metabolic pathways in STZ-induced T1DM model. Long-term hyperglycemia associated with diabetes mellitus (DM) causes damage to various organs and tissues, including the eyes, kidneys, heart, blood vessels and nerves. Rubus Suavissimus S. Lee (RS), a shrub whose leaves are used in traditional Chinese medicine (TCM), has been shown to exert hypoglycemic effects in DM patients. However, the underlying mechanism is unclear. This was investigated in the present study in a rat model of streptozotocin-induced type 1 diabetes mellitus (T1DM) by 1 H NMR analysis. We identify 9 metabolites whose levels were altered in T1DM rats compared to control rats, namely, lactate, acetate, pyruvate, succinate, 2-oxoglutarate, citrate, creatinine, allantoin, and hippurate, which are mostly related to glycolysis/gluconeogenesis, pyruvate metabolism, TCA cycle, and other metabolism. The observed pathologic changes in the levels of these metabolites in T1DM rats were reversed by treatment with RS. Thus, RS exerts effects in T1DM rats by regulating the three abnormal metabolic pathways synergistically. These findings provide supporting evidence for the therapeutic efficacy of this TCM formulation in the treatment of DM.