Effects of three Chinese medicinal herbs on erythrocyte deformability

Abstract

In the People’s Republic of China a number of herbal extracts are known to be vasoactive and are prescribed to promote blood circulation and relieve hemostasis. The object of this study was to examine whether the effects of three particular extracts, derived originally from the herbs Anisodus tanguticus, Chuanxiong rhizome and Injectio salvia miltiorrhizae, are linked to alterations in erythrocyte deformability. Erythrocytes from 16 normal donors were incubated for 1 hour at 37.5°C in solutions of extracts of these herbs at various concentrations. Subsequently, dilute suspensions of the exposed cells and paired, unexposed controls were subjected to graded levels of shear stress in a rheoscope. Two indices of deformability derived from rheoscopic observations were the shear-induced elongation of freely suspended, steadily tank-treading cells and the rate of transient shape recovery following abrupt cessation of shear. The results indicate significant increases (10 to 20%) in extensibility under an applied shear stress of 40 dyn/cm2 and significantly faster (7 to 25%) shape recovery in cells exposed to the herbal solutions. A separate series of experiments on normal erythrocytes demonstrated that the herbal solutions produced no significant changes in mean cellular volume, thus ruling out increases in cell surface-to-volume ratio as a basis for deformability enhancement. Hence, the observed enhancement appears to be attributable to changes in membrane mechanical properties.