Effects of neutral sulfate berberine on LPS-induced cardiomyocyte TNF-α secretion, abnormal calcium cycling, and cardiac dysfunction in rats
Abstract
Aim: To evaluate the effect of neutral sulfate berberine on cardiac function, tumor
necrosis factor α (TNF-α) release, and intracellular calcium concentration ([Ca2+]i)
in cardiomyocytes exposed to lipopolysaccharide (LPS). Methods: Primary cultured
rat cardiomyocytes were prepared from ventricles of 3–4-day old Sprague-
Dawley rats. TNF-α concentrations in cell-conditioned media were measured by
using a Quantikine enzyme-linked immunosorbent assay kit, and cardiomyocyte
[Ca2+]i was measured by using Fura-2/AM. The isolated rat hearts were perfused
in the Langendorff mode. Results: LPS at doses of 1, 5, 10, and 20 μg/mL markedly
stimulated TNF-α secretion from cardiomyocytes, and neutral sulfate berberine
inhibited LPS-induced TNF-α production. Intracellular calcium concentration was
significantly decreased after LPS stimulation for 1 h, and increased 2 h after LPS
treatment. Pretreatment with neutral sulfate berberine reversed the LPS-induced
[Ca2+]i alterations, although neutral sulfate berberine did not inhibit a rapid increase
in cardiomyocyte [Ca2+]i induced by LPS. Perfusion of isolated hearts with
LPS (100 μg/mL) for 20 min resulted in significantly impaired cardiac performance
at 120 min after LPS challenge: the maximal rate of left ventricular pressure rise and
fall (±dp/dtmax) decreased compared with the control. In contrast, ±dp/dtmax at 120
min in hearts perfused with neutral sulfate berberine (1 μmol/L) for 10 min followed
by 20 min LPS (100 μg/mL) was greater than the corresponding value in the LPS
group. Conclusion: Neutral sulfate berberine inhibits LPS-stimulated myocardial
TNF-α production, impairs calcium cycling, and improves LPS-induced contractile
dysfunction in intact heart.
Keywords:
necrosis factor α (TNF-α) release, and intracellular calcium concentration ([Ca2+]i)
in cardiomyocytes exposed to lipopolysaccharide (LPS). Methods: Primary cultured
rat cardiomyocytes were prepared from ventricles of 3–4-day old Sprague-
Dawley rats. TNF-α concentrations in cell-conditioned media were measured by
using a Quantikine enzyme-linked immunosorbent assay kit, and cardiomyocyte
[Ca2+]i was measured by using Fura-2/AM. The isolated rat hearts were perfused
in the Langendorff mode. Results: LPS at doses of 1, 5, 10, and 20 μg/mL markedly
stimulated TNF-α secretion from cardiomyocytes, and neutral sulfate berberine
inhibited LPS-induced TNF-α production. Intracellular calcium concentration was
significantly decreased after LPS stimulation for 1 h, and increased 2 h after LPS
treatment. Pretreatment with neutral sulfate berberine reversed the LPS-induced
[Ca2+]i alterations, although neutral sulfate berberine did not inhibit a rapid increase
in cardiomyocyte [Ca2+]i induced by LPS. Perfusion of isolated hearts with
LPS (100 μg/mL) for 20 min resulted in significantly impaired cardiac performance
at 120 min after LPS challenge: the maximal rate of left ventricular pressure rise and
fall (±dp/dtmax) decreased compared with the control. In contrast, ±dp/dtmax at 120
min in hearts perfused with neutral sulfate berberine (1 μmol/L) for 10 min followed
by 20 min LPS (100 μg/mL) was greater than the corresponding value in the LPS
group. Conclusion: Neutral sulfate berberine inhibits LPS-stimulated myocardial
TNF-α production, impairs calcium cycling, and improves LPS-induced contractile
dysfunction in intact heart.