Salvianolic acid B in vitro inhibited matrix metalloproteinases-1, -2, and -9 activities

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which as a group can degrade essentially all extracellular matrix components. The proteolytic property of the MMPs is important during wound healing to remove debris and facilitate cell migration. Targeting towards the decreased MMPs activities is a new treatment strategy for healing chronic wounds. Salvia miltiorrhiza is a popular Chinese herb that could promote chronic ulcers healing for topical use. Salvianolic acid B (Sal B) is the most abundant bioactive component in Salvia miltiorrhiza. The research was designed to explore the inhibitory effects of Sal B on MMP-1, MMP-2 and MMP-9 activities.

Pure human interstitial collagenase (MMP-1) or gelatinase A (MMP-2) was activated by p-aminophenylmercuric acetate (APMA), and was incubated with Sal B for 1 h. The activities were observed by quenched fluorescent substrate. Gelatinase B (MMP-9) is rich in polymorphonuclear neutrophils (PMN), so the rat PMN was used as a source of MMP-9 for MMPs activity assays. In vitro MMP-9 from rats' PMN lysate was incubated with Sal B for 1 h, and its activity was tested by gelatin zymography.

Sal B dose-dependently inhibited the human MMP-1 and MMP-2 activities in the range of 0.002 4 to 0.3 g/L, with 50% inhibiting concentration (IC(50)) of (0.090<0.015) g/L and (0.080<0.005) g/L respectively. In the range of 0.003 to 0.3 g/L, Sal B could inhibit the MMP-9 activity (P<0.01).

The broad-spectrum inhibitory effects of Sal B on MMPs may reveal one of the mechanisms for the effects of Salvia miltiorrhiza on chronic wounds.