[Interaction between four herb compounds and a western drug by CYP3A4 enzyme metabolism in vitro].

OBJECTIVE: To explore the interaction between herbal medicines and western drugs based on CYP3A4 enzyme metabolism by using testotesrone as a probe in liver microsome metabolism system in vitro. METHOD: The mixed liver microsome enzymatic system consisting of rat liver microsomes by ultra-high-speed centrifuge was established. The substrate testosterone was added into the system and enzyme CYP3A4 metabolic activity was expressed by the output of 6beta-hydroxy-testosterone which was measured by HPLC method. The proper conditions for testotesrone metabolism in liver microsome system included substrate concentration, incubation time, pH and incubation temperature. When the conditions in vitro were determined, three kinds of Chinese herbal medicinal ingredients (Tetrahydropalmatine, neferine, panax notoginseng saponins) were diluted into different concentrations and incubated with testotesrone in the liver microsomes incubation system, respectively. The results were measured through metabolite production with or without the presence of Chinese medicines. We assessed the Chinese herbal medicinal ingredients effect on the metabolism of CYP3A4 enzyme through 6beta-hydroxy metabolite of testosterone production. RESULT: Liver microsomes were incubated in the system, the testosterone metabolited into 6beta-hydroxy testosterone. The metabolism conditions were proper at the concentration of testosterone 200 micromol x L(-1) which was incubated for 3.5 hours at 37 degrees C in pH 7.0, PBS 0.1 mol x L(-1). The inhibition of tetrahydropalmatine and panax notoginseng saponins on testotesrone were weak with IC50 > 100 micromol x L(-1). The neferine had a little inhibition on testotesrone metabolism, IC50 < 100 micromol L(-1). CONCLUSION: Tetrahydropalmatine and panax notoginseng saponins had no obvious effect on testotesrone metabolism. Neferine had a little effect on testotesrone metabolism. It prompted that drug-interaction could not be apparent between two kinds of Chinese medicines and the CYP3A4 enzyme substrate, Neferine could bring about drug-interaction.

[Experimental study of chronic renal tubular-interstitial injury induced by Radix Aristolochiae Fangchi Extract in rats].

OBJECTIVE: Following the former report, we continue to observe the chronic renal tubular-interstitial injury induced by Radix Aristolochiae Fangchi Extract(RAFE) in rats in order to understand whether RAFE in different doses causes the renal tubular-interstitial injury or not. METHOD: RAFE at the dose of 25.0 mg x kg(-1) x d(-1), 120.0 mg kg(-1) x d(-1) and 200.0 mg x kg(-1) x d(-1) and aristolochic acid (AA, 10.0 mg x kg(-1) d(-1)) was interruptedly administrated by gastric tube for 22 w and 4 w durg withdrawal. Blood, urine and kidney were taken out respectively in 17 w, 22 w and 26 w to measure the indexes of renal function. The morphology of kidney was observed, and Masson staining of kidney were made respectively to compare RAFE groups with AA group. RESULT: Pathological changes of renal tissue forms were as follows: All RAFE groups and AA group could develop the pathological process of renal tubular injury-chronic renal interstitial fibrosis. The pathologic changes of RAFE were similar with AA. CONCLUSION: RAFE at all doses administrated interruptedly by gastric tube above 13 w caused chronic renal tubulo-interstitium fibrosis. The renal injury in functions and tissue forms in rats were similar with AA closely. The results showed that AA was the main toxic composition of RAFE.

[Experimental study of chronic renal tubular-interstitial injury induced by radix aristolochiae fangchi extract in rats].

OBJECTIVE: To observe the acute and chronic renal toxicity induced by Radix Aristolochiae Fangchi Extract (RAFE) in different doses in rats. METHOD: The conventional method of acute toxicity was used. RAFE at the dose of 25.0 mg x kg(-1) x d(-1), 120.0 mg x kg(-1) x d(-1) and 200.0 mg x kg(-1) x d(-1) and aristolochic acid (AA, 10.0 mg x kg(-1) x d(-1)) were interruptedly administrated to rats for 13 week by gastric tube, and the sample of blood, urine and kidney were collected at 4 week, 8 week and 13 week respectively. The indexes of renal function were measured and the morphology of kidney was observed. RESULT: LD50 of RAFE was 36.8 g x kg(-1) (the crude drug) and the 95% confidence limit was 38.8 - 28.9 g x kg(-1). The changes of renal functions were azotemia, massive proteinuria and the increase of urinary NAGase (beta-N-acetylglucosaminidase) in the earlier period of administration with RAFE in rats. Pathological changes of renal tissue were as follows: acute renal tubular necrosis mainly in the boundary of cortex and medulla was observed in the earlier period, and with the elongation of administration, the pathological process of renal interstitial fibrosis observed in the middle and high groups of RAFE and AA group. CONCLUSION: RAFE at middle and high doses administrated by interrupted gavage above 13 week can cause the injury of renal tubular functions in rats. NAGase can be used as one of observation targets in the earlier period of renal injury.