The activity of Hou-Po-Da-Huang-Tang is improved through intestinal bacterial metabolism and Hou-Po-Da-Huang-Tang selectively stimulate the growth of intestinal bacteria associated with health

Hou-Po-Da-Huang Tang (HPDHT) was used for the treatment of intestinal tract diseases in China. However, the underlying mechanisms via the intestinal bacteria remain largely unclear. Therefore, the aim of this study was to evaluate the metabolism of HPDHT by the human intestinal bacteria and its modulating effect on the intestinal bacteria. As a result, a total of 34 compounds were identified in HPDHT and transformed HPDHT (T-HPDHT). Among them, 12 metabolites were proved to be transformed by human intestinal bacteria. In vitro assays showed that T-HPDHT exhibited more significant elevation of free radical scavenging activity and suppression on the production of nitric oxide (NO) and TNF-α when comparing to HPDHT. Additionally, in vivo experiment confirmed that HPDHT significantly increased activity of superoxide dismutase (SOD), attenuated the malondialdehyde (MDA) and TNF-α levels in the conventional rats compared with that of pseudo germ-free (PGF) rats. In addition, HPDHT could significantly enhance the mean counts of Bifidobacterium and Lactobacillus and inhibit the growth of Clostridium, and Enterobacteriaceae, relative to controls. Due to the transformation of HPDHT being dependent on the bacterial strain, the effect of HPDHT on the selective growth of Bifidobacterium bifidum 29521 and Lactobacillus plantarum 8014 was evaluated. The kinetic parameters of microbial growth and prebiotic activity scores indicated that HPDHT could selectively stimulate the growth of the strains Bifidobacterium bifidum 29521 and Lactobacillus plantarum 8014. Taken together, metabolism of HPDHT by intestinal bacteria is a critical step towards the emergence of their anti-oxidation, anti-inflammation and prebiotic activities. This study provided valuable information for further pharmacological research on HPDHT.

Intestinal bacterial metabolism may play a key role in the biological activities of Hou-Po-Da-Huang-Tang.180