OBJECTIVETo 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.

METHODThe 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.

RESULTLiver 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).

CONCLUSIONTetrahydropalmatine 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.

Animals ; Cytochrome P-450 CYP3A ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Interactions ; Drugs, Chinese Herbal ; analysis ; pharmacokinetics ; Male ; Microsomes, Liver ; chemistry ; drug effects ; enzymology ; Rats ; Rats, Wistar ; Testosterone ; analysis ; pharmacokinetics

OBJECTIVETo investigate the effect of Shao Yao-Gan Cao-Tang on function and expression of P-glycoprotein (P-gp) in Caco-2 cells.

METHOD3H-digoxin (Dig), a substrate of P-glycoprotein, was used as a probe to measure the P-gp-mediated drug efflux transport, which indicated the function of P-gp in Caco-2 cells, while Verapamil (Ver) was used as a positive P-gp inhibitor. P-gp expression in Caco-2 cells was tested by immunohistochemistry staining. Inhibition effect of SGT on P-gp-mediated drug efflux transport and P-gp expression were investigated.

RESULTDig was shown a positive absorption mode in Caco-2 cell monolayer, characterized as the ratio of apparent permeabilities (Papp) from basolateral side to apical side Papp (BL-->AP) and from apical side to basolateral side Papp (AP-->BL) of Dig was 27.07. Addition of Ver into Dig transport media significantly inhibited P-gp activity which was indicated by increasing the Papp (AP-->BL) of Dig by 3.82 times, whereas Ver had no significant effect on Papp (BL-->AP). SGT (at the concentrations of 1/25 IC5, 1/5 IC5, IC,) could promote Papp (AP-->BL) of Dig by 159.83%, 217.95% ,160.26%. Papp (AP-->BL) of Dig was mildly increased by 59.16%, 50.73% by SGT at 1/25 IC5, 1/5 IC, respectively. Immunohistochemistry staining showed that SGT inhibited the expression of P-gp of Caco-2 cells.

CONCLUSIONSGT showed the potential inhibition to the function and expression of P-gp, leading to the increase absorption of P-gp's substrates.

ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; Biological Transport ; drug effects ; Caco-2 Cells ; Drug Interactions ; Drugs, Chinese Herbal ; pharmacology ; Humans

OBJECTIVETo investigate the fetotoxicity of monocrotaline.

METHODMouse whole embryo culture (WEC) was applied. Post-implantation (8.5 d) mouse embryos were isolated from their mothers and put into the medium of immediately centrifuged serum (ICS) prepared from rats. Different concentrations of monocrotaline (100, 50, 25, 12.5 mg x L(-1)) were added into the WEC. Development (yolk sac diameter, crown-rump length, head length, somite number) and organic morphodifferentiation (yolk sac circulation, allantois, embryonic flexion, heart, brain, optic-otic-olfactory organ, branchial arch, maxillary, mandible, bud) of embryos were observed at 48 h after treatment.

RESULTObvious fetotoxicity could be observed in various monocrotaline treatment groups in a dose-dependent manner. Development of embryos was delayed significantly at dose 12.5-100 mg x L(-1). Malformations were shown in all organic morphodifferentiation indice, especially in opti-otic organ, mandible and bud.

CONCLUSIONMonocrotaline had obvious fetotoxicity in vitro WEC, indicating that exposure of pregnant mice to monocrotaline may have potential risk on fetus.

Animals ; Cell Differentiation ; drug effects ; Culture Media ; Embryo, Mammalian ; drug effects ; physiology ; Female ; Male ; Mice ; Monocrotaline ; toxicity

OBJECTIVETo explore arsenic accumulation and toxicity mechanism following long-term use of realgar and provide scientific basis for safety use of realgar in clinic.

METHODThe realgar which was used in the study contains 90% insoluble asenic sulfide (As2S2) and 1.696 mg x kg(-1) soluble arsenic. Two separate experiments were performed: 1) Twenty-eight fasting SD rats were orally given a single dose of realgar at the dose of 0.8 g x kg(-1) and the other four rats were given ultra-filtrated water served as control group. Blood, hearts, livers, kidneys, lungs and brains of four rats were taken out at 0.5, 1, 2, 4, 8, 16, 36 h respectively after treatment. Asenic quantity of each organ or blood sample was measured. 2) Forty SD rats were randomly divided into four groups: control group and realgar 0.02, 0.08, 0.16 g x kg(-1) groups, each group containing 5 females and 5 males. The rats were intra-gastrically treated with realgar once a day for successively 90 days, while the control group was given ultra-filtrated water. Asenic amount in blood, liver, kidney and brain of each rat was measured in fasting rats at 16 h after last dosing.

RESULTAsenic amount of blood, liver, kidney, heart, lung and brain increased after single dosing of realgar at dose of 0.16 g x kg(-1), with the order from high to low blood > kidney > lung > liver > heart > brain. Asenic amount was much higher in blood than that in other organs. The feature of asenic distribution in blood following realgar administration may be the basis for its use for leukemia Ninety-day oral treatment of realgar led to significant accumulation of asenic in blood, kidney, liver and brain. The highest asenic accumulation times was found in kidney followed by liver, which was assumed to be associated with nephrotoxicity and hepatotoxicity of realgar. The highest amount of asenic was observed in blood after 90 day's administration of realgar, and the amount of asenic in organs was in the order of blood > kidney > liver > brain.

CONCLUSIONAsenic can be absorbed and extensively distributed in various organs or tissesses after realgar administration in rats. Long-term use of realgar caused high asenic accumulation in various tissueses, including blood, kidney, liver, and brain. The nephrotoxicity and hepatotoxicity of realgar could be associated with the asenic accumulation in relative organs. Blood is the target of the most highest distribution and accamulation of asenic after realgar treatment, that could be associated with the efficacy of realgar on the treatment of leakemia.

Animals ; Arsenic ; analysis ; chemistry ; pharmacokinetics ; toxicity ; Arsenicals ; administration & dosage ; adverse effects ; chemistry ; Female ; Male ; Rats ; Rats, Sprague-Dawley ; Solubility ; Sulfides ; administration & dosage ; adverse effects ; chemistry ; Time Factors

OBJECTIVETo investigate the toxicity of realgar and provide the scientific basis for safety use of realgar in clinic.

METHODAcute toxicity was tested by single oral administration. Chronic toxicity of realgar was tested at different dose levels (5, 10, 20, 80, 160 mg x kg(-1) x d(-1)) which correspond to 1/2, 1, 2, 8, 16 times of human dose levels. The rats were treated with the test substances through oral administration once daily for successively 90 days. Urinary qualitative test, blood routine examination, serum chemistry measurement, and histomorphologic observation were conducted at day 30, 60 and 90. Toxic changes related to the treatment of realgar and no-observed adverse effect level (NOAEL) was evaluated.

RESULTWith the content of 90% total arsenic and 1.696 mg x g(-1) soluble asenic, LD50 of Realgar with oral administration was 20.5 g x kg(-1) (corresponding to 34.8 mg x kg(-1) soluble arsenic), equivalent to 12 812 times of clinical daily dose for an adult. Realgar can cause kidney toxicity or/and liver toxicity after administration for over 30, 60 or 90 days respectively. The kidney was more sensitive to realgar than liver. Based on repeated dose toxicity study, NOAELs were 160 mg x kg(-1) x d(-1) for 30 day's administration, 20 mg x kg(-1) x d(-1) for 60 day's administration, 10 mg x kg(-1) x d(-1) mg x kg(-1) x d(-1) for 90 day's administration respectively. Thus, for safety use of realgar, it is recommended that the daily doses of realgar (with soluble arsenic < or = 1.7 mg x g(-1)) for an adult of the body weight about 60 kg could be 10-160 mg depending on the variation of the treatment duration.

CONCLUSIONLong term use of realgar can cause kidney and liver pathological change, so the doses and administration duration should be limited. The suggestion is as follows: realgar which contains soluble arsenic < or = 1.7 mg x g(-1) should be used less than 2 weeks at daily dose 160 mg, less than 4 weeks at the dose of 20 mg and less than 6 weeks at the dose of 10 mg.

Administration, Oral ; Animals ; Arsenicals ; administration & dosage ; chemistry ; Dose-Response Relationship, Drug ; Female ; Kidney ; drug effects ; Liver ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Solubility ; Sulfides ; administration & dosage ; chemistry ; toxicity ; Time Factors ; Toxicity Tests, Acute ; methods ; Toxicity Tests, Chronic ; methods