Discovery of Novel MDH2 Inhibitor 28i by Secondary Development of Glibenclamide with Potent Antiaging Activities

Aging is a major public health challenge that urgently requires effective pharmacological interventions. We previously identified mitochondrial malate dehydrogenase 2 (MDH2) as a regulator of aging and discovered that the approved drug glibenclamide (Gli) can inhibit MDH2 and delay aging, but is limited by weak potency and hypoglycemia. Herein, we employed a rational secondary development strategy to optimize Gli and discovered compound 28i, a potent MDH2 inhibitor that extended lifespan and improved healthspan in Caenorhabditis elegans. In multiple mammalian cell models, 28i significantly reduced senescence markers, and in both doxorubicin-induced and naturally aged mice, it alleviated tissue aging and suppressed SASP factors. Importantly, 28i displayed low acute toxicity (LD₅₀ > 1000 mg/kg), minimal hERG channel inhibition (IC₅₀ > 40 μM), and lacked hypoglycemic effect in oral glucose tolerance tests. Collectively, these findings validate 28i as a highly promising nonhypoglycemic MDH2 inhibitor for future clinical translation as a gerotherapeutic candidate.