The water-soluble component of Salvia miltiorrhiza Bge can promote macrophage synthesis of C4 in vivo and in vitro.

A water-soluble component extracted from Salvia miltiorrhiza Bge has been used for many years in traditional Chinese medicine ('huo xie hua yu') for the treatment of the hyperviscosity syndrome. We demonstrate here that this extract promotes macrophage proliferation in vitro and enhances macrophage synthesis of the C4 component of complement. No increase in synthesis of other complement components by macrophages was observed. In a group of 20 patients with the hyperviscosity syndrome treated with an aqueous extract of Salvia, serum levels of C4 rose significantly over the course of treatment (mean pretreatment level 37.4 mg%, mean posttreatment level, 43.5 mg%; p < 0.01). The rise in C4 levels closely correlated with the disappearance of the patients' clinical symptoms.