Effects of Dendrobium huoshanense on expressions and activities of hepatic microsomal cytochrome P450s in mice / 中国中药杂志

This study was carried out to investigate the effect of oral administration of Dendrobium huoshanense on the expressions and activities of hepatic microsomal cytochrome P450s in mice, and to provide a reference for the evaluation of drug-drug interactions between D. huoshanense and clinical drugs. The C57BL/6 mice were randomly divided into blank control group, D. huoshanense low dose group (crude drug 1.25 g·kg⁻¹), D. huoshanense high dose group (crude drug 7.5 g·kg⁻¹), and phenobarbital positive control group (0.08 g·kg⁻¹). Each group was intragastrically administered with drugs for 2 weeks. The mice were sacrificed and their liver microsomes were prepared. The expressions of major subtypes of P450 enzyme were determined by Western blot and the probe drugs were used to detect the enzyme activities of P450 subtypes with protein expression changes. Western blot analysis showed that the protein expressions of CYP1A1, CYP1A2 and CYP2B in liver tissues were up-regulated in D. huoshanense-treated group. In vitro enzyme activity tests showed that there were no significant difference in metabolism of 7-ethoxyresorufin (a probe drug for CYP1A1) and bupropion (a probe drug for CYP2B) between D. huoshanense group and control group. The metabolism of phenacetin (a probe drug for CYP1A2) showed a statistical difference in rate Vmax, and it was significantly increased by approximately 20% in D. huoshanense group as compared with the blank control group, and the clearance CLint in treated group was also increased by about 32%. Therefore, oral administration of D. huoshanense had no effects on the activities of most hepatic P450 enzymes in mice, with no drug-drug interaction related to the P450 enzyme system in most clinical drugs theoretically. However, oral administration of D. huoshanense may accelerate the metabolism of CYP1A2-catalyzed drugs, which needs to be considered in clinical practice.

Protective effects of five different types of Dendrobium on CCl4-induced liver injury in mice / 中国中药杂志

This study aims to investigate the protective effect of Dendrobium huoshanense, D.officinale(Huoshan), D.officinale(Yunnan), D.moniliforme and D. henanense on CCl4-induced hepatic damage in mice. C57BL/6 mice were randomly divided into control group, model group, high-dose(7.5 g•kg⁻¹) and low-dose (1.25 g•kg⁻¹) groups of the five Dendrobium. Each group was intragastrically administered with drugs for 2 weeks. The control group was intraperitoneally injected with Olive oil solution, while the other groups were intraperitoneally given 0.5%CCl4combined with Olive oil solution 2 h later after the last administration. Subsequently, ALT and AST activities in serum, SOD activities and MDA contents in liver tissues were determined in all groups 16 h later after administration. The liver index was calculated, and hepatic histopathological examination was performed. The mRNA expressions of IL-1β, IL-6 and TNF-α were analyzed by Real-time PCR. Compared with the CCl4 model group, the activities of ALT and AST in serum decreased significantly in the five different Dendrobium groups. Meanwhile, in liver tissues, the levels of MDA reduced obviously, while the SOD activities markedly increased. Furthermore, liver tissue damage induced by CCl4 was ameliorated according to the histopathological examination. IL-1β, IL-6 and TNF-α mRNA expressions in D.huoshanense-treated liver tissues were significantly decreased. In conclusion, the five different Dendrobium groups showed hepatoprotective effects on CCl4-induced acute liver injury in mice. However, there were differences among Dendrobium of different types and origins. The protect effect of D.huoshanense is the most obvious, and the order of the protective effect of the other Dendrobium from high to low is D.officinale(Yunnan), D. officinale(Huoshan), D.henanense and D.moniliforme. The differences between the different types of Dendrobium might be related to their chemical components.