Plant density-dependent variations in bioactive markers and root yield in Australian-grown Salvia miltiorrhiza Bunge.

The plant density-dependent variations in the root yield and content, and the yield of biomarkers in Australian grown Salvia miltiorrhiza Bunge, a commonly used Chinese medicinal herb for the treatment of cardiovascular diseases, were investigated in a field trial involving six different plant densities. The key biomarker compounds cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B were quantified by a validated RP-HPLC method, and the root yields were determined per plant pair or unit area. There were significant variations (p<0.05) in the root yields and contents and the yields of the biomarkers between the different plant densities. Positive linear correlations were observed between the contents of the three tanshinones, whereas negative linear correlations were revealed between the contents of the tanshinones and salvianolic acid B. The highest root yield per plant pair was achieved when the plants were grown at 45×30 cm or 45×40 cm, whereas the highest root production par unit area was obtained for a plant density of 30×30 cm. The highest contents of the three tanshinones and the most abundant production of these tanshinones per unit area were achieved when the plants were grown at 30×30 cm. However, the highest content of salvianolic acid B was found for a density of 45×40 cm, while its highest yield per unit area was obtained for densities of 30×40 cm or 45×30 cm. The findings suggest that the plant density distinctly affects the root yield and content and the yield of tanshinones and salvianolic acid B in Australian grown S. miltiorrhiza, which may be used as a guide for developing optimal agricultural procedures for cultivating this herb.

HPLC profiles and biomarker contents of Australian-grown Salvia miltiorrhiza f. alba roots.

Salvia miltiorrhiza f. alba (Baihua Danshen) is a Chinese medicinal herb commonly used for treating cardiovascular disease. It has been grown in Australia, although the quality of its main medicinal part (dried root) has not been assessed. In this study, we investigated HPLC profiles and biomarker contents of Australian-grown S. miltiorrhiza f. alba roots. Patterns of HPLC profiles were established in MeOH, and aqueous extracts in terms of number of common characteristic peaks and their relative retention times. The contents of three tanshinone biomarkers (cryptotanshinone (3), tanshinone I (1), and tanshinone IIA (2)) were significantly higher (p<0.05) in the roots of one-year-old plants than those of two-year-old plants. In contrast, salvianolic acid B (4) content was significantly higher in the roots of two-year-old plants than in those of one-year-old plants. The findings suggest that the biomarker contents in Australian-grown S. miltiorrhiza f. alba roots vary with the growth periods of the plants, which may be important in determining the optimal harvest time for the plant roots with targeted levels of tanshinones and salvianolic acid B (4).

Seasonal variations in bioactive marker contents in Australian-grown Salvia miltiorrhiza roots.

Seasonal variations in contents of bioactive markers in Australian-grown Salvia miltiorrhiza roots were investigated in a two-year field trial. Cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B were quantitatively determined by reversed-phase (RP) HPLC. Similar accumulation patterns were observed for the three tanshinones throughout the trial period, although roots harvested in the first year was found to contain relatively higher contents of these compounds. In contrast, the content of salvianolic acid B was peaked at 250 days after planting in the first year, and subsequently maintained at a plateau level in the second-year period. Linear correlations between the contents of individual tanshinones were observed, but not between those of tanshinones and salvianolic acid B. The findings suggest that tanshinones and salvianolic acid B have different accumulation patterns in Australian-grown Salvia miltiorrhiza roots, which should be critically considered for optimum harvesting of the roots for pharmaceutical applications.

Cultivar variations of Australian-grown Danshen (Salvia miltiorrhiza): bioactive markers and root yields.

Danshen (Salvia miltiorrhiza Bunge, Lamiaceae) is a commonly used and highly valued Chinese medicinal herb grown widely in China. In the present work, we studied cultivar variations of Australian-grown Danshen in order to select optimal cultivars for local herbal production. Root yields of seven cultivars, V1-V7, were monitored in a one-year field trial, and bioactive markers, including cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B, were quantitatively determined using a validated RP-HPLC method. Significant variations were found in root yields, root production efficiencies, and contents of the bioactive marker compounds. Linear correlations were observed among the contents of three tanshinones but not among those of tanshinones and salvianolic acid B. Among the cultivars, V6 was the best cultivar for production of tanshinones, and V4 and V5 were best for production of salvianolic acid B. The findings indicate that it is possible to achieve optimal root yields, and high contents of tanshinones and salvianolic acid B by selecting specific Danshen cultivars.