Reexploring 5-methoxyindole-2-carboxylic acid (MICA) as a potential antidiabetic agent.

5-Methoxyindole-2-carboxylic acid (MICA) is a potent hypoglycemic agent that inhibits gluconeogenesis in the liver. It is also a well-known inhibitor of mitochondrial dihydrolipoamide dehydrogenase. MICA was extensively studied in the 1960s and 1970s and was once tested for its antidiabetic effect in diabetic Chinese hamsters, whereby MICA was shown to exhibit pronounced glucose-lowering ability while also leading to increased rate of death of the diabetic animals. Since then, MICA's potential ability in lowering blood glucose in diabetes has never been revisited. In my opinion, MICA should be comprehensively reexplored for its antidiabetic properties in a variety of rodent diabetes models. For a given animal model, its dose-dependent effect and the effects of different routes of administrations as well as its synergistic effects with other glucose-lowering drugs should also be investigated. More studies in the future on this chemical may provide novel insights into its role as an antidiabetic agent.