In vivo: |
Xenobiotica. 2013 May;43(5):479-85. | Isolation and identification of phase I metabolites of resibufogenin in rats.[Pubmed: 23153055] | 1. Resibufogenin (1), a major bufadienolide of Chinese medicine Chan Su, had a wide range of pharmacological activities. In present work, the metabolism of 1 in male Sprague-Dawley rats was investigated by identifying the metabolites of resibufogenin excreted in rat bile.
METHODS AND RESULTS:
2. Following an oral dose of 60 mg/kg resibufagenin, nine metabolites were isolated from bile of rats, and their structures were identified as 3-keto- resibufogenin (2), 3-epi-resibufogenin (3), 5β-hydroxy-3-epi-resibufogenin (4), 1α, 5β-dihydroxy-3-epi-resibufogenin (5), 3α, 5β, 14α, 15β-tetrahydroxyl-bufa- 20, 22-dienolide (6), 3α, 14α, 15β-trihydroxy-bufa-20, 22-dienolide (7), 3-epi- 5β-hydroxy-bufalin (8), 12α, 16β-dihydroxy-3-epi-resibufogenin (9), and 5β, 16β-dihydroxy-3-epi-resibufogenin (10), respectively, on the basis of widely spectroscopic methods including 2D-NMR technology. It is first time to describe the metabolites of 1 in vivo, and metabolites 5-7 and 9-10 are novel.
CONCLUSIONS:
3. On the basis of these identified metabolites, a possible metabolism pathway for 1 in rats has been proposed. This is the first systematic study on the phase I metabolites of resibufogenin. | Hypertens Pregnancy. 2010 Jan;29(1):1-9. | Resibufogenin prevents the manifestations of preeclampsia in an animal model of the syndrome.[Pubmed: 19277924 ] | We have developed a rat model of preeclampsia which is based upon excessive volume expansion and includes hypertension, proteinuria and intrauterine growth restriction. In this model, the urinary excretion of the circulating steroid inhibitor of Na +/ K+ ATPase, marinobufagenin, is increased prior to the development of hypertension and proteinuria. An analogue of marinobufagenin, resibufogenin, successfully treats the hypertension and proteinuria.
METHODS AND RESULTS:
We administered resibufogenin early in pregnancy in this model, prior to the development of the syndrome.
We found that resibufogenin not only prevented the advent of hypertension and proteinuria, but also the development of intrauterine growth restriction.
CONCLUSIONS:
These results may have relevance to the human condition.
| PLoS One . 2015 Jun 29;10(6):e0129851. | Resibufogenin Induces G1-Phase Arrest through the Proteasomal Degradation of Cyclin D1 in Human Malignant Tumor Cells[Pubmed: 26121043] | Abstract
Huachansu, a traditional Chinese medicine prepared from the dried toad skin, has been used in clinical studies for various cancers in China. Resibufogenin is a component of huachansu and classified as bufadienolides. Resibufogenin has been shown to exhibit the anti-proliferative effect against cancer cells. However, the molecular mechanism of resibufogenin remains unknown. Here we report that resibufogenin induces G1-phase arrest with hypophosphorylation of retinoblastoma (RB) protein and down-regulation of cyclin D1 expression in human colon cancer HT-29 cells. Since the down-regulation of cyclin D1 was completely blocked by a proteasome inhibitor MG132, the suppression of cyclin D1 expression by resibufogenin was considered to be in a proteasome-dependent manner. It is known that glycogen synthase kinase-3β (GSK-3β) induces the proteasomal degradation of cyclin D1. The addition of GSK-3β inhibitor SB216763 inhibited the reduction of cyclin D1 caused by resibufogenin. These effects on cyclin D1 by resibufogenin were also observed in human lung cancer A549 cells. These findings suggest that the anti-proliferative effect of resibufogenin may be attributed to the degradation of cyclin D1 caused by the activation of GSK-3β. |
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