Verification of the formulation and efficacy of Danggui Buxue Tang (a decoction of Radix Astragali and Radix Angelicae Sinensis): an exemplifying systematic approach to revealing the complexity of Chinese herbal medicine formulae

Abstract

This article exemplifies a systematic approach to revealing the complexity of Chinese herbal medicine formulae through three levels of scientific research: standardization of herbs, verification of ancient formulae and mechanism studies. We use Danggui Buxue Tang (DBT) as an example for this approach. Among thousands of traditional Chinese medicine herbal formulae, almost all of which consist of multiple herbs, DBT is one of the simplest. Containing only two herbs, namely Radix Astragali (RA) and Radix Angelicae Sinensis (RAS), DBT is traditionally used to treat ailments in women. The weight ratio of RA to RAS in DBT was prescribed to be 5:1 as early as in 1247 AD. In addition to advanced chemical analysis of herbal constituents, DNA genotyping techniques have been developed for reliable standardization of RA and RAS. Chemical evaluation shows that main active constituents in DBT, including astragaloside IV, calycosin, formononetin and ferulic acid, were most abundant after extraction at the RA to RAS ratio of 5:1, whereas other tested RA to RAS ratios only gave sub-optimal levels of the active constituents. Biological evaluation indicates that bioactivities of DBT, e.g. immuno-modulatory, oesteotropic and estrogenic effects are also best exerted at the RA to RAS ratio of 5:1. Correlation analysis demonstrates statistically significant relationship between the tested chemical constituents and tested bioactivities. Up-and down-regulation of expression of some genes as potential biomarkers has been detected by using gene chip technology. This systematic approach on the basis of herbal standardization, chemical and biological verification and mechanism studies, as exemplified in this article, will be useful to reveal the complexity of not only DBT but also other Chinese medicine herbal formulae.

The expression of erythropoietin triggered by Danggui Buxue Tang, a Chinese herbal decoction prepared from Radix Astragali and Radix Angelicae Sinensis, is mediated by the hypoxia-inducible factor in cultured HEK293T cells

“…Pharmacologically, DBT has been shown to stimulate bone cell differentiation, T-cell proliferation, platelet aggregation and estrogenic activity in cultured cells (Gao et al, 2007b), as well as its effect in animal studies (Mak et al, 2006). The RA-derived saponin, flavonoid and polysaccharide, as well as RAS-derived ferulic acid and polysaccharide, except ligustilide (Zheng et al, 2009), are all considered to be the major active components in DBT Gao et al, 2007b).…”

“…The RA-derived saponin, flavonoid and polysaccharide, as well as RAS-derived ferulic acid and polysaccharide, except ligustilide (Zheng et al, 2009), are all considered to be the major active components in DBT Gao et al, 2007b). Our preliminary results suggest that the flavonoids derived from RA including formononetin, ononin, calycosin and calycosin-7-O-␤-d-glucoside are highly active in inducing the expressions of HIF-1␣ and EPO mRNAs: those flavonoids could be considered as a means of DBT in the induction of hematopoietic functions (Zheng et al, unpublished results).…”

“…*p < 0.05. cosin and formononetin) and two others in RAS (ferulic acid and ligustilide) were used to standardize the chemical property of DBT. The standardized DBT should contain no less than 0.186 mg calycosin, 0.155 mg formononetin, 0.351 mg ferulic acid and 0.204 mg ligustilide per 1 g dried weight of DBT, as reported previously Gao et al, 2007b;Choi et al, 2009). Finally, the extracts were dried by lyophilization and stored at −20 • C.…”

“…Values are expressed as the percentage of increase to basal reading (untreated culture), and in mean ± SD, where n = 4, each with triplicate samples. *p < 0.05; **p < 0.01. with the weight ratio of 5:1 for RA to RAS in the ancient preparation, and the two herbs have to be boiled together as to achieve the maximum activity (Gao et al, 2007b;Choi et al, 2009). Erythropoietin (EPO) is an erythrocyte-specific hematopoietic growth factor being majorly produced by kidney, while small amount of EPO is synthesized in liver (Dame et al, 1998).…”

Effects of Nanpao, a Kampo Medicine, on Peripheral Blood Flow and Surface Skin Temperature in Aged Female Rats

“…Furthermore, aqueous extracts of Astragali radix and Ginseng radix induce nitric oxide generation in cultured rat vascular smooth muscle cells [4,5], and 50% ethanolic extracts of Rehmanniae radix increase the amount of the blood flow in the veins and peripheral circulation [16]. Moreover, Danggui buxue tang, which contains only Astragali radix and Angelicae radix, induces estrogen-driven promoter activity in vitro and stimulates blood flow in vivo [6]. Taking account of these findings, the inhibitory effect of Nanpao on decreased skin surface temperature after cooling may be mainly due to increasing peripheral blood flow volume by additive or synergistic pharmacologic effects of the various herbs contained in Nanpao.…”