Effect Of Pentoxifylline On Lipopolysaccharide-induced Tumor Necrosis Factor-alpha Production In Neonatal Rat Cardiomyocytes

Objective TNF-αhas played important roles in the development and progression of chronic heart failure. Several lines of reports indicated that the levels of circulating TNF-αwere elevated in patients with congestive heart failure. Pentoxifylline, a xanthin-derived agent, has been showed to improve clinical status in chornic heart failure patients by several clinical trials. Animal studies has showed that pentoxifylline reduced TNF-αproduction in human macrophages as an immunomodulatory agent. Therefore, we studied the effects of pentoxifylline on TNF-αproduction in neonatal rat cardiac myocytes stimulated with lipopplysaccharide to valuate the mechanism underlying pentoxifylline on the protection of rat hearts.Materials and methods Neonatal rats cardiomyocytes were cultured and divided into four groups as follows: control group (A group, cells pretreated with diluent), 1μg/ml pentoxifylline group (B group), 10μg/ml pentoxifylline group (C group) and 100μg/ml pentoxifylline group (D group). Primary cultured cells were pretreated with diluent or various concentration of pentoxifylline for indicated times, then stimulated with lipopplysaccharide for another 6 hours. Then the culture medium and cells were collected for analysis. The level of secreted TNF-αwas measured by enzyme-linked immunosorbent assay (ELISA) and TNF-αmRNA expression was determined by semiquantitative reverse transcriptional polymerase chain reaction(RT-PCR).Results After pretreated with pentoxifylline, TNF-αrelease was significantly decreased in pentoxifylline group. Pentoxifylline reduced TNF–αproduction in a dose dependent manner. With increasing concentration of pentoxifylline (1μg/ml, 10μg/ml, 100μg/ml), TNF-αsecretion showed a liner decrease: (83.37±16.39) pg/ml, (35.43±2.60) pg/ml, (19.72±5.19) pg/ml, lower than control group (98.50±7.99) pg/ml (P<0.05). Pentoxifylline also inhibited TNF-αmRNA expression in neonatal rat cardiomyocytes. There is an inverse relationship between TNF-αmRNA expression and pentoxifylline concentration. Pretreated with different concentration (1μg/ml, 10μg/ml, 100μg/ml ) of pentoxifylline, the TNF-αmRNA expression determined by semi-quantitive RT-PCR was [(0.78±0.02) , (0.71±0.04), (0.62±0.04)], lower than control group (0.90±0.02) (P<0.05).Conclusions Pentoxifylline can effectively inhibit the production of TNF–αand reduced TNF-αmRNA expression in neonatal rat cardiomyocytes stimulated with lipopplysaccharide in a dose-dependent manner. It showed that pentoxifylline reduced TNF–αproduction at least by blocking transcriptional activation, which may provide the experimental basis for the use of pentoxifylline in the therapy of chronic heart failure.