Anti-allergic effects of salvianolic acid A and tanshinone IIA from Salvia miltiorrhiza determined using in vivo and in vitro experiments.

Salvia miltiorrhiza root has been used in Asian traditional medicine for the treatment of cardiovascular diseases, asthma, and other conditions. Salvianolic acid B from S. miltiorrhiza extracts has been shown to improve airway hyperresponsiveness. We investigated the effects of salvianolic acid A, tanshinone I, and tanshinone IIA from S. miltiorrhiza in allergic asthma by using rat RBL-2H3 mast cells and female Balb/c mice. Antigen-induced degranulation was assessed by measuring β-hexosaminidase activity in vitro. In addition, a murine ovalbumin-induced allergic asthma model was used to test the in vivo efficacy of salvianolic acid A and tanshinone IIA. Tanshinone I and tanshinone IIA inhibited antigen-induced degranulation of mast cells, but salvianolic acid A did not. Administration of salvianolic acid A and tanshinone IIA decreased the number of immune cells, particularly eosinophils in allergic asthma-induced mice. Histological studies showed that salvianolic acid A and tanshinone IIA reduced mucin production and inflammation in the lungs. Administration of salvianolic acid A and tanshinone IIA reduced the expression and secretion of Th2 cytokines (IL-4 and IL-13) in the bronchoalveolar lavage fluid and lung tissues of mice with ovalbumin-induced allergic asthma. These findings provide evidence that salvianolic acid A and tanshinone IIA may be potential anti-allergic therapeutics.