Regulatory effects of Poria on substance and energy metabolism in cold-deficiency syndrome compared with heat-deficiency syndrome in rats.

Recent studies have revealed that the property of drug is mainly associated with the body's substance and energy metabolism. The present study aimed to evaluate the drug property of Poria, called Fuling (FL) in traditional Chinese medicine (TCM), in terms of its effects on the substance and energy metabolism in rat models of cold-deficiency and heat-deficiency syndromes, compared with Aconiti Lateralis Radix Praeparaia, called Fuzi (FZ) in TCM, with hot property, and Anemarrhenae Rhizoma, called Zhimu (ZM) in TCM, with cold property, as reference drugs, respectively. The appearance score, toe and rectal temperatures of the animals treated were assessed at different time points. Several indices in vivo correlated with substance and energy metabolism (glucokinas, phosphoglycerate kinase, cytochrome c reductase, cytochrome c oxydase, and Na+-K+-ATPase), endocrine system (triiodothyronine, thyroxine, and 17-hydroxycorticosteroid), nervous system (acetylcholin esterase), and cyclic nucleotide system were determined. The changes in appearance score and indices in vivo suggested the successful establishment of cold-deficiency and heat-deficiency syndrome models. FZ reversed the decreased levels of indices (substance and energy metabolism and endocrine system) and alleviated the syndrome of cold-deficiency model, and ZM showed obviously therapeutic effect on heat-deficiency syndrome (appearance score, substance and energy metabolism, and endocrine system). FL could alleviate cold-deficiency syndrome and raise the decreased levels of glucokinas, phosphoglycerate kinase, cytochrome c reductase and triiodothyronine in cold-deficiency model, but had no significant effect on heat-deficiency syndrome. Drug property of FL was inferred as trending to "flat and warm", which still need further study. It was advisable to adopt both cold-deficiency and heat-deficiency models to study the drugs with "flat" property.

[Determination of plasma protein binding rate of arctiin and arctigenin with ultrafiltration].

OBJECTIVE: To determine the plasma protein binding rate of arctiin and arctigenin. METHOD: The ultrafiltration combined with HPLC was employed to determine the plasma protein binding rate of arctiin and arctigenin as well as rat plasma and healthy human plasma proteins. RESULT: The plasma protein binding rate of arctiin with rat plasma at the concentrations of 64. 29, 32.14, 16.07 mg x L(-1) were (71.2 +/- 2.0)%, (73.4 +/- 0.61)%, (78.2 +/- 1.9)%, respectively; while the plasma protein binding rate of arctiin with healthy human plasma at the above concentrations were (64.8 +/- 3.1)%, (64.5 +/- 2.5)%, (77.5 +/- 1.7)%, respectively. The plasma protein binding rate of arctigenin with rat plasma at the concentrations of 77.42, 38.71, 19.36 mg x L(-1) were (96.7 +/- 0.41)%, (96.8 +/- 1.6)%, (97.3 +/- 0.46)%, respectively; while the plasma protein binding rate of arctigenin with normal human plasma at the above concentrations were (94.7 +/- 3.1)%, (96.8 +/- 1.6)%, (97.9 +/- 1.3)%, respectively. CONCLUSION: The binding rate of arctiin with rat plasma protein was moderate, which is slightly higher than the binding rate of arctiin with healthy human plasma protein. The plasma protein binding rates of arctigenin with both rat plasma and healthy human plasma are very high.

Simultaneous determination of arctiin and its metabolites in rat urine and feces by HPLC.

Arctiin, an important lignan compound in Fructus Arctii, has been reported to possess various kinds of bioactivities. Previous studies on the pharmacokinetic of arctiin after oral administration showed that it had a rapid absorption phase followed by a sharp but lasting disappearance. To gain deep insight into the action mechanism of arctiin, the excretion and metabolism of arctiin in vivo should be further studied. In this paper, three metabolites were isolated and identified in rat feces as (-)-enterolactone (M-1), (-)-arctigenin (M-2) and [(2R,3R)-2-(3'-hydroxybenzyl)-3-(3″,4″-dimethoxybenzyl)-butyrolactone] (M-3). Based on the structures of three metabolites, possible metabolic pathways of arctiin in rats are proposed. At the same time, the cumulative excretion rate of arctiin and its metabolites in rat urine and feces were determined, indicating that arctiin was excreted 19.84% in urine and 1.80% in feces, respectively, enterolactone, the most main metabolite, was excreted 35.80% in feces. These results provide very important information for understanding the metabolism and excretion of arctiin in vivo and speculating its action mechanism, they can provide useful information and reference for further metabolic investigations on arctiin in humans.