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Aim: To study the metabolic kinetics of MN9202 in Beagle dog liver microsome., Methods: Beagle dog liver microsomes were prepared by using ultracentrifuge method. After incubating 0.4 micromol x L(-1) MN9202 with 1 g x L(-1) microsomes for 30 min at 37 degrees C, the reaction was terminated by adding 0.5 mL alkalization. The RP-HPLC was used to determine the drug in the incubation mixture. The Michaelis-Menten parameters Km, and Vmax in Beagle dog liver microsomes were initially estimated by analyzing Lineweave-Brurk plot. Various selective CYP inhibitors were used to investigate their inhibitory effect on the metabolism of MN9202., Results: The Km, Vmax and CLint of MN9202 were (22.6 +/- 8.0) micromol x L(-1), (0.54 +/- 0.17) micromol x g(-1) x min(-1) and (0.0242 +/- 0.0009) L x g(-1) x min(-1), respectively. The metabolism of MN9202 was significantly inhibited by ketoconazole (Ket) and troleandomycin (Tro) in Beagle dog liver microsomes. Tranylcypromine (Tra) could inhibit the metabolism of drug as well. While other inhibitors showed little inhibitory effect on the metabolism of MN9202., Conclusion: It was shown that CYP3A and CYP2C19 were involved in MN9202 metabolism. The inhibitors of human CYP3A and CYP2C19 may have potential interaction with MN9202, and this can reduce the metabolism rate and increase the toxicity of MN9202.

Aim: To study the pharmacokinetics of genistein at different doses in Beagle dogs., Methods: Suspended in 0.5% CMC-Na solution, genistein was orally administered to Beagle dogs at doses of 2.67, 5.34 and 10.68 mg.kg(-1). At various time intervals, 1.5 mL of blood was drawn from the femoral vein of dogs in their front legs. The plasma was treated with beta-glucuronidase. The genistein in plasma was extracted twice by vortexing with 2.0 mL mixture of methyl tert-tubtyl ether and pentane (v/v = 8:2). The organic phase was removed into the tubes and then evaporated in ventilation cabinet. The residue was dissolved in 50 microL of methanol. 20 microL solution was drawn and detected by high-performance liquid chromatography. The pharmacokinetic parameters were calculated by 3P97 software., Results: The plasma drug concentration-time data were fitted to the two-compartment model. When the dose was 2.67 mg.kg(-1), the MRT and AUC of parent compound were 52.9 min and 6.7 mg.min. L(-1), respectively. When the dose rose to 5.34 mg.kg(-1), the MRT and AUC of parent compound became 224.8 min and 26.1 mg.min.L(-1), respectively. However, when the dose increased to 10.68 mg .kg(-1), the MRT and AUC of parent compound increased to 267.7 min and 33.2 mg.min L(-1), respectively. The AUC of glucuronidated genistein was 33.9, 70.1 and 140.5 mg.min.L(-1) at the dose of 2.67, 5.34 and 10.68 mg.kg(-1), respectively., Conclusion: Due to significant first pass metabolism, the drug was mainly existed in the form of glucuronidated genistein in the plasma. With the increase of dose, the absorption of genistein became saturated and the half life prolonged.

Aim: To observe the effect of Angelica polysaccharides on effector molecule production by peritoneal macrophages., Methods: Macrophages were isolated from the peritoneal cavity of BALB/c mice and the primary culture was performed. MTT colorimetry and spectrophotometry were used to examine the effects of Angelica polysaccharides on the releases of effector molecules, such as nitric oxide(NO), tumor necrosis factor-alpha(TNF-alpha), and reactive oxygen species(ROS) as well as inducible nitric oxide synthase (iNOS) and lysozyme(LSZ) activity by peritoneal macrophages., Results: Angelica polysaccharides could promote the releases of NO, TNF-alpha and ROS from macrophages and improved iNOS and LSZ activities in macrophages. However, Angelica polysaccharides had no direct cytotoxicity to tumor cells, but the cultural supernatant of macrophages cocultured with Angelica polysaccharides could kill L929 cells., Conclusion: Angelica polysaccharides can promote the releases of NO, TNF-alpha and ROS by macrophages. Angelica polysaccharides may indirectly play the role of anti-tumors through increased TNF-alpha production by macrophages.

Aim: To study the pharmacokinetics of m-nifedipine (m-Nif) in Beagle dogs., Methods: The Beagle dogs were divided into two groups. m-Nif was intravenously administered to the Beagle dogs in group 1 at the dose of 0. 288 mg x kg(-1), and it was orally administered to the Beagle dogs in group 2, 3 and 4 at the dose of 1.152, 3.456 and 10.370 mg x kg(-1), respectively. m-Nif in plasma was detected by reversed phase high performance liquid chromatography. The pharmacokinetic parameters were calculated by 3P97 software., Results: When m-Nif was intravenously administered, the plasma concentration-time curve was fit to a two-compartment model and T1/2beta was 117 min. When m-Nif was orally administered, the plasma concentration-time curve was fit to a one-compartment model. T1/2 (Ke) and Cmax were 147 min and 20 microg x L(-1); at the low dose of 1.152 mg x kg(-1). T1/2 (Ke) was 122 min and Cmax was 36 microg x L(-1) at the middle dose of 3.456 mg x kg(-1). T1/2 (Ke) was 144 min and Cmax was 69 microg x L(-1) at the high dose of 10.37 mg x kg(-1), respectively., Conclusion: It was showed that the speed of elimination of m-Nif was high in Beagle dogs. The absolute bioavailability of m-Nif given orally was very low.

Aim: To study the effects of Rheum tanguticum polysaccharide(-1) (RTP(-1)) on ulcerative colitis in rats induced by 2, 4, 6-trinitrophene sulphonic acid (TNBS) and their possible mechanism., Methods: RTP1 (200 mg.kg(-1), i.g.) extracted from Rheum tanguticum Maxim. ex Regel was administrated to rats with colitis induced by TNBS for 5 d, 7 d, 10 d and 14 d, respectively. The effects of RTP1 and dexamethasone (DX, 0.2 mg.kg(-1), i.g.) were contrastively investigated. The MPO level and SOD activity were determined by chromatometry. The expansion and protein expression of CD4+T lymphocytes isolated from colon mucosae and mesenteric lymph nodes of colitis rats were performed by immunohistochemical analysis and Western-blot methods., Results: Treatments of RTP1 (200 mg.kg(-1), i.g.) significantly reduced diarrhea, mortality, colon mass, ulcer areas and MPO level in colon mucosae on days 5, 7, 10 and 14 (5.2+/-1.4, 5.4+/-0.7, 5.2+/-1.8, P<0.05. 3.4+/-0.8, P<0.01. 16.1+/-12.1, P<0.01. 31.8+/-8.6, 17.7+/-5.3, 12.7+/-4.1, P<0.05). The effects of RTP1 were similar to those noted above in DX group, but there were no immunosuppressive effects of DX in RTP(-1) group, such as body mass loss, thymus and spleen atrophy. The decreased number and down-regulated protein levels of CD4+T cells isolated from the colon of colitis rats treated with RTP1 were found., Conclusion: RTP1 shows significantly protective effects but lower side effects on rats with colitis induced by TNBS. The mechanism may be due to the resistance to over expansion of CD4.

Aim: To study the pharmacokinetics of genistein in Beagle dogs., Methods: Genistein, suspended in 0.5% CMC-Na solution, was orally administered to Beagle dogs at the dose of 5.34 mg.kg-1. At various time intervals, 1.5 mL of blood was drawn from the vein of dogs in their front legs. At the same time, urine and feces were collected. After the collection, the feces were homogenized with physiological saline (to 1 g feces, 10 mL physiological saline were added). The genistein in plasma, urine and homogenized feces was extracted twice by vortexing with 2.0 mL mixture of methyl tert-butyl ether and pentane (8:2). The organic phase was transferred into tubes and evaporated in ventilation cabinet. The residue was dissolved in 50 microL of methanol and 20 microL of the solution was drawn and detected by high-performance liquid chromatography. The pharmacokinetic parameter was calculated by 3P97 software., Results: The plasma concentration-time curve was fitted to a one-open-compartment model. The peak time was 0.29 h, and the elimination half-life was 0.52 h. After genistein was administered, 10.79% of genistein were excreted from urine and 21.55% from feces within 24 h. It was also found that 13.00% genistein were excreted from urine and 52.46% from feces within 60 h., Conclusion: It showed that the speed of absorption and elimination of genistein was high in Beagle dog, and genistein was mainly excreted in the form of parent compound in urine and feces.

Aim: To evaluate the effects of molecular weight of dextran on drug-release of conjugate in vitro by screening colon-specific conjugates., Methods: The conjugates, synthesized with different molecular-weight dextran and dexamethasone, were incubated in the contents of different parts of rat gastrointestinal tract at 37 degrees C. The release of dexamethasone(Dex) and dexamethasonehemisuccinate was determined by HPLC. The mobile phase consisted of 35% acetonitrile and 65% trisodium citrate (50 mmol.L-1, adjusted to pH 4.1 with phosphoric acid)., Results: There was no release of dexamethasone or dexamethasonehemisuccinate from conjugates in the stomach contents. The amount of Dex (including dexamethasonehemisuccinate) released from DexD26 in the contents of colon and cecum was shown to be 4.0 times higher than that released in the contents of proximal and distal small intestine while the amount of Dex (including dexamethasonehemisuccinate) released from DexD50 was shown to be 3.6 times higher. The amount of Dex (including dexamethasonehemisuccinate) released from DexD2 in the contents of colon and cecum and from DexD7.6 were 2.0 times and 1.9 times higher, respectively, than that released in contents of proximal and distal small intestine., Conclusion: The molecular weight of dextran showed marked effect on drug-release of the conjugate in vitro, and the conjugates with larger molecular-weight dextran have great potential in colon-specific delivery of dexamethasone.

Objective: To evaluate the effects of Tanguticum Maxim polysaccharide (TMP-1) on TNBS-induced colitis in rats., Method: Rats with TNBS/ethanol-induced colitis were used and treated with TMP-1 and dexamethasone (DX). Seventy-two rats, including animals with TNBS-induced colitis, were treated with saline, TMP-1 (100, 200, 400 mg.kg-1) and DX. White blood cells were counted on the fifth day and the rats were killed by ether on the sixth day. SOD activity in serum, MPO and SOD activity of colonic tissue were measured., Result: The remarkable effects of TMP-1 at dosage of 200, 400 mg.kg-1 on TNBS-induced colitis were observed. The ulcerative area was diminished and weight of colon was reduced. White blood cell population was reduced, SOD activity in serum and SOD activity of colon tissue were remarkably increased, and, MPO activity of colonic tissue was reduced., Conclusion: TMP-1 has significant effects on TNBS-induced colitis in rats with lower side effects, which suggests the effective component of rhubarb on colitis perhaps is TMP. The mechanism of the actions of TMP may relate to its antiflammation, antioxidation and immunoloregulation.

AIM:To observe the effects of ricin (RT) with and without chemical modification on both hepatotoxicity of mice and activity against hepatocellular cancer (HCC), and evaluate the possibility to improve RT anticancer activity via chemical modification.METHODS:RT was modified with N-succinimidyl3(2-pyridyldithio) propionate (SPDP),a heterobifunctional cross-linker, and SPDP derivative of RT (PDP-R) was obtained.The serum glutathione-s-transferase (SGST) activity,as an index of liver damage, was determined in mice intoxicated with RT and PDP-R,at various doses and time.The tissue damage of HCC in the nude mice ip injected with PDP-R was compared with that with RT at the same dose by immunohistochemical method, the relative content of both RT and PDP-R in the HCC tissues was measured by computerized image-analysis. RESULTS:The SGST activities increased with doses or/and time intoxicated with both RT and PDP-R, and the increase in the value of RT group was more significant than that in the PDP-R group; the SGST activity of RT group was 2.8-fold (P < 0.01) of PDP-R group at a dose of 12.5&mgr;g/kg for 42h, showing the much lower toxicity of R-PDP than that of RT. Under an optical microscope, hemolysis and necrosis of massive cells in the HCC tissues of PDP-R group were observed and the ratio of necrosis mounted to 90.5% while the corresponding value of RT group only to 62.5%.With computerized image-analysis, the average relative content of RT and PDP-R in the HCC tissues,represented as greyness, was 140.06 plus minus 3.43 and 169.10 plus minus 2.74, respectively. There was significant difference between the two (P< 0.05), indicating the higher content of PDP-R in the HCC tissue than that of RT.CONCLUSION:The hepatotoxicity of PDP-R to mice may be reduced by chemical modification with SPDP, but both the affinity of PDP-R to the HCC tissues and ability to kill it may be stronger than that of RT. So this might be a valuable attempt to improve the anticancer activity of RT.