Effect of salvia miltiorrhiza Bge on left ventricular hypertrophy and the expression of tumor necrosis factor-α in spontaneously hypertensive rats

Abstract

The effects of salvia miltiorrhiza Bge (SMB) on left ventricular hypertrophy (LVH) and the expression of tumor necrosis factor-alpha (TNF-alpha) in the left ventricle of spontaneously hypertensive rats and the action mechanism were investigated. Normal Wistar-kyoto (WKY) rats were used as negative control, and spontaneously hypertensive rats (SHR) were randomly assigned to receive placebo or SMB. SMB (1 g/kg.d) was injected intraperitoneally for 12 weeks. Systolic blood pressure (SBP) and left ventricular mass index (LVMI) were measured. HE, VG and immunohistochemical staining combined with computed morphometry were employed to evaluate the cardiomyocyte size, diameter, the collagen volume fraction (CVF), perivascular circumferential area (PVCA), and tumor necrosis factor-alpha (TNF-alpha) expression in the left ventricular tissue. The results showed, as compared with WKY rats, the SBP, LVMI, cardiomyocyte size, diameter, CVF, PCVA, and TNF-alpha expression were increased markedly in the 20-week-old spontaneously hypertensive rats. SMB decreased LVMI (P<0.01), size of cardiomyocytes (P<0.01), collagen volume fraction (P<0.01), perivascular circumferential area (P<0.01), and TNF-alpha expression (P<0.01), but had no effect on SBP (P>0.05). It was suggested that chronic administration of SMB could inhibit and reverse the development of LVH in spontaneously hypertensive rats independent of BP. TNF-alpha may be involved in the reversal mechanism of LVH by SMB.