Zinc ionophores isolated from Terminalia bellirica fruit rind extract protect against cardiomyocyte hypoxia/reoxygenation injury

The study aimed to isolate and characterize zinc ionophores from Terminalia bellirica fruit using a liposome assay and test its utility in H9c2 rat cardiomyoblasts cells subjected to hypoxia/reoxygenation. Ethyl acetate extract that exhibited zinc ionophore activity was resolved to yield three polyphenols that were characterized as epicatechin-3-gallate (ECG), epigallocatechin-3-gallate (EGCG) and epigallocatechin (EGC) by nuclear magnetic resonance and electrospray ionization-mass spectra. The polyphenols enhanced the uptake of zinc into the liposomes and increased FluoZin-3 fluorescence. These polyphenols in the presence of 10 mu M ZnCl2 enhanced the zinc import into H9c2 cells, whose intracellular zinc levels were otherwise lowered upon hypoxia/reoxygenation. EGCG proved to be more potent than ECG, which indeed was more effective than EGC in improving cellular zinc levels and in attenuating the apoptosis of H9c2 cells after hypoxia/reoxygenation injury. The polyphenols required zinc for anti-apoptotic effect. The cardioprotective effect is indeed due to enhanced zinc uptake mediated by these polyphenols.

Automated summary

The study revealed that polyphenols from Terminalia bellirica fruit can enhance zinc uptake, improve intracellular zinc levels, and attenuate cardiomyoblasts apoptosis after hypoxia/reoxygenation injury, with EGCG showing the most potent effect.