biostudies-literatureUnknown43(1)Huang JHarmine is a β-carboline alkaloid isolated from Banisteria caapi and Peganum harmala L with various pharmacological activities, including antioxidant, anti-inflammatory, antitumor, anti-depressant, and anti-leishmanial capabilities. Nevertheless, the pharmacological effect of harmine on cardiomyocytes and heart muscle has not been reported. Here we found a protective effect of harmine on cardiac hypertrophy in spontaneously hypertensive rats in vivo. Further, harmine could inhibit the phenotypes of norepinephrine-induced hypertrophy in human embryonic stem cell-derived cardiomyocytes in vitro. It reduced the enlarged cell surface area, reversed the increased calcium handling and contractility, and downregulated expression of hypertrophy-related genes in norepinephrine-induced hypertrophy oActa pharmacologica Sinica50-63https://www.ebi.ac.uk/biostudies/studies/S-EPMC8724320biostudies-literatureHarmine is an effective therapeutic small molecule for the treatment of cardiac hypertrophy.PMC8724320Xun ZXZheng QYLiu YSun NQin LLi EMHuang JChen HYXu CChen JXLu XYZhu WJfalseHarmine is an effective therapeutic small molecule for the treatment of cardiac hypertrophy.Harmine is a β-carboline alkaloid isolated from Banisteria caapi and Peganum harmala L with various pharmacological activities, including antioxidant, anti-inflammatory, antitumor, anti-depressant, and anti-leishmanial capabilities. Nevertheless, the pharmacological effect of harmine on cardiomyocytes and heart muscle has not been reported. Here we found a protective effect of harmine on cardiac hypertrophy in spontaneously hypertensive rats in vivo. Further, harmine could inhibit the phenotypes of norepinephrine-induced hypertrophy in human embryonic stem cell-derived cardiomyocytes in vitro. It reduced the enlarged cell surface area, reversed the increased calcium handling and contractility, and downregulated expression of hypertrophy-related genes in norepinephrine-induced hypertrophy o2022-01-01T00:00:00Z2022 Jan2026-06-18T08:45:52.45Z2025-04-06T09:41:32.947ZS-EPMC87243203378586010.1038/s41401-021-00639-y