Pharmacokinetics and effects of demographic factors on blood 25(OH)D3 levels after a single orally administered high dose of vitamin D3.

AIM: To examine the biological consequences and demographic factors that might affect the pharmacokinetics of vitamin D3 after a single high dose intervention in a young Chinese population with vitamin D insufficiency status. METHODS: A total of 28 young subjects (25 to 35 years old) with vitamin D insufficiency status [serum 25(OH)D <30 ng/mL] was recruited in Shanghai, China. The subjects were orally administered a single high dose of vitamin D3 (300 000 IU). Baseline characteristics and blood samples were collected at d 0, 1, 2, 3, 7, 28, 56, 84 and 112 after the intervention. The blood biomarker levels were determined with standardized methods. RESULTS: The intervention markedly increased the blood 25(OH)D3 levels within the first five days (mean Tmax=5.1±2.1 d) and sustained an optimal circulating level of 25(OH)D3 (≥30 ng/mL) for 56 d. After the intervention, body weight and baseline 25(OH)D3 levels were significantly correlated with circulating 25(OH)D3 levels. No adverse events and no consistently significant changes in serum calcium, creatinine, glucose, parathyroid hormone, vitamin D binding protein, or the urinary calcium/reatinine ratio were observed. However, there was a significant increase in phosphorus after the vitamin D3 intervention. Total cholesterol and triglyceride levels were decreased at the end of the trial. CONCLUSION: The pharmacokinetics of vitamin D after intervention were influenced by baseline 25(OH)D3 levels and the body weight of the subjects. The results suggest that a single high oral vitamin D3 intervention is safe and efficient for improving the vitamin D status of young Chinese people with vitamin D insufficiency.

[Yinxingye Capsule Intervened Vascular Endothelial Cell Apoptosis of Hyperhomocysteinemia Rats: an Experimental Study].

OBJECTIVE: To explore targets of Chinese herbal medicine at cellular and molecular leve1s through an experimental study on Yinxingye Capsule (YC) intervening vascular endothelial cell apoptoeis of hyperhornocysteinemia (HHcy) rats. METHODS: The HHcy model was prepared in male Wistar rats. Totally 42 rats were randomly divided into 4 groups, i.e., the control group (n =10), the model group (n = 11), the YC group (n =11), the folic acid group (n =10). Carboxy methyl cellulose (CMC) solution (1%) was administered to rats in the control group by gastrogavage.3% methionine suspension at 1. 5 g/kg was administered to rats in the model group by gastrogavage. 3% methionine suspension at 1. 5 g/kg and folic acid suspension at 0. 06 g/kg was administered to rats in the folic acid group by gastrogavage. 3% methionine suspension at 1. 5 g/kg and YC at 0. 02 g/kg was administered to rats in the YC group by gastrogavage. Morphological changes of aortic tissue were observed by hematoxylin eosin (HE) staining. The plasma homocysteine (Hcy) level was detected in each group. The endothelium-dependent diastolic functions of the thoracic aorta on different concentrations of sodium nitroprusside (SNP) and acetylcholine (Ach) were detected. Gene expressions of Bcl-2-associated X protein (BAX), inducible nitric oxide synthase (iNOS), c-Fos, cellular inhibitor of apoptosis protein 2 (c-IAP2) were detected by real time polymerase chain reaction (RT-PCR). RESULTS: Pathological results showed that thickening aortic endothelium, swollen and desquamated endothelial cells. Few foam cells could be seen in the model group. Myoma-like proliferation of smooth muscle cells in tunica media could also be seen. These pathological changes were milder in the YC group and the folic acid group. Compared with the control group, plasma Hcy levels increased in the model group (P <0. 05). The endothelium-dependent diastolic rates at 10(-6) and 10(-4)mol/L Ach and 10(-7) -10(-3)mol/L SNP all decreased in the model group (P <0. 01, P <0. 05). Gene expressions of Bax, c-Fos, and iNOS increased, but c-IAP2 gene expressions decreased in the model group (all P <0. 05). Compared with the model group, plasma Hcy levels decreased in the YC group and the folic acid group (P <0. 05). The endothelium-dependent diastolic rates increased in the YC group and the folic acid group at various SNP concentrations except 10(-6) mol/L SNP in the folic acid group. The endothelium-dependent diastolic rates increased in the YC group and the folic acid group at 10(-6) and 10(-4)mol/L Ach (all P <0. 05). Gene expressions of Bax, c-Fos, and iNOS decreased in the YC group and the folic acid group, but c-IAP2 gene expression increased in the folic acid group (all P <0. 05). CONCLUSION: YC could reduce plasma Hcy levels, down-regulate gene expressions of Bax, c-Fos, and iNOS, thereby reducing apoptosis of vascular endothelial cells, improving vascular endothelial function, and delaying atherosclerotic process.

Phase I study on the pharmacokinetics and tolerance of ZT-1, a prodrug of huperzine A, for the treatment of Alzheimer's disease.

AIM: Huperzine A isolated from the Chinese herb Huperzia serrata (Thunb) Trev is a novel reversible and selective AChE inhibitor. The aim of this study was to evaluate the pharmacokinetics and tolerance of single and multiple doses of ZT-1, a novel analogue of huperzine A, in healthy Chinese subjects. METHODS: This was a double-blinded, placebo-controlled, randomized, single- and multiple-dose study. For the single-dose study, 9 subjects were randomly divided into 3 groups receiving ZT-1 (0.5, 0.75 or 1 mg, po) according to a Three-way Latin Square Design. For the multiple-dose study, 9 subjects receiving ZT-1 (0.75 mg/d, po) for 8 consecutive days. In the tolerance study, 40 subjects were randomly divided into 5 groups receiving a single dose of ZT-1 (0.5, 0.75, 1, 1.25 or 1.5 mg, po). Plasma and urine concentrations of ZT-1 and Hup A were determined using LC-MS/MS. Pharmacokinetic parameters, including Cmax, AUC0-72 h and AUC0-∞ were calculated. Tolerance assessments were conducted throughout the study. RESULTS: ZT-1 was rapidly absorbed and converted into huperzine A, thus the plasma and urine concentrations of ZT-1 were below the limit of quantification (<0.05 ng/mL). After single-dose administration of ZT-1, the mean tmax of huperzine A was 0.76-0.82 h; the AUC0-72 h and Cmax of huperzine A showed approximately dose-proportional increase over the dose range of 0.5-1 mg. After the multiple-dose administration of ZT-1, a steady-state level of huperzine A was achieved within 2 d. No serious adverse events were observed. CONCLUSION: ZT-1 is a pro-drug that is rapidly absorbed and converted into huperzine A, and ZT-1 is well tolerated in healthy Chinese volunteers.

Pharmacokinetics and tolerance of dehydroandrographolide succinate injection after intravenous administration in healthy Chinese volunteers.

AIM: Dehydroandrographolide succinate (DAS) is extracted from herbal medicine Andrographis paniculata (Burm f) Nees. DAS injection is used in China for the treatment of viral pneumonia and upper respiratory tract infections. The aim of this study is to investigate the pharmacokinetics and tolerance of DAS injection in healthy Chinese volunteers. METHODS: This was a single-center, randomized, single-dose, three-way crossover design study. Nine eligible subjects were randomly divided into 3 groups, and each group sequentially received 80, 160, or 320 mg of DAS infusion according to a three-way Latin square design. Plasma and urine samples were collected and determined using an LC-MS/MS method. Safety and tolerability were determined via clinical evaluation and adverse event monitoring. RESULTS: For the 80, 160, and 320 mg dose groups, the mean C(max) were 4.82, 12.85, and 26.90 mg/L, respectively, and the mean AUC(0-12) were 6.18, 16.95, and 40.65 mg·L(-1)·h, respectively. DAS was rapidly cleared, with a mean T(max) of 0.94-1.0 h and a t(1/2) of approximately 1.51-1.89 h. Approximately 10.1%-15.5% of the intravenous DAS dose was excreted unchanged in urine within 24 h in the 3 groups, and more than 90% of unchanged DAS was excreted between 0 and 4 h. The pharmacokinetic profile was similar between male and female subjects. No serious or unexpected adverse events were found during the study, but one mild adverse event (stomachache) was reported. CONCLUSION: This study shows that DAS has nonlinear pharmacokinetic characteristics. To guarantee the effective concentration, mul¬tiple small doses are recommended in clinical regimens.

Simultaneous determination of six alkaloids and one monoterpene in rat plasma by liquid chromatography-tandem mass spectrometry and pharmacokinetic study after oral administration of a Chinese medicine Wuji Pill.

A simple and sensitive method for simultaneous determination of seven active constituents, jatrorrhizine, berberine, coptisine, palmatine, evodiamine, rutacarpine and paeoniflorin, from a Chinese medicine Wuji Pill in rat plasma was developed based on a liquid chromatography and tandem mass spectrometry method. The separation of these seven compounds was carried out on a Shiseido CAPCELL PAK C(18) column using a mobile phase consisting of acetonitrile (containing 0.1% formic acid and water (containing 0.1% formic acid and 10 mmol/L ammonium acetate) and carbamazepine as an internal standard. Electrospray ionization in positive-ion mode and multiple reaction monitoring was used to identify and quantitate active components. All calibration curves gave good linearity (r>0.993) over the concentration range from 0.42-208.0 ng/mL to 4.18-418.0 ng/mL for all components. The precision of the in vivo study was evaluated by intra- and inter-day assays and the percentages of relative standard deviation were all within 15%. The method was successfully applied to pharmacokinetic study of all six alkaloids and one monoterpene in rat plasma after oral administration of the Wuji Pill.

Pharmacokinetics of magnesium lithospermate B after intravenous administration in beagle dogs.

AIM: To develop a specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the pharmacokinetic study of magnesium lithospermate B (MLB), and study the pharmacokinetics of MLB after i.v. administration in beagle dogs. METHODS: Each beagle dog was iv administered MLB 3, 6, and 12 mg/kg random. The serum drug concentration was determined by specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. The pharmacokinetic parameters were calculated by Drug and Statistics version 1.0 program. RESULTS: The calibration curve for MLB was linear over a range of 16-4096 microg/L with coefficients of correlation >0.999. The intra- and inter-day precisions (CV) of analysis were <10 %, and accuracy ranged from 90 % to 113 %. After i.v. administration of MLB at the doses of 3, 6, and 12 mg/kg, the C(0) values for MLB were estimated to be of 24, 47, and 107 mg/L, respectively. The AUC increased with the increasing doses for iv administration, and the mean AUC(0-t) values were 109.3, 247.9, and 582.4 mg x min x L(-1), respectively. MLB was distributed and eliminated quickly from central compartment, the mean T(1/2alpha) values for MLB at doses of 3, 6, 12 mg/kg were 2.2, 2.7, and 2.9 min, and the mean T(1/2beta) values were 43, 42, and 42 min, respectively. CONCLUSION: This LC-MS/MS method is rapid, sensitive, and specific for the pharmacokinetic study of MLB. The kinetic process of MLB in beagle dogs in vivo was best fitted to a two-compartment model. For i.v. administration, the pharmacokinetic parameters of C(0) and AUC have good linearity among the doses, and MLB was distributed and eliminated quickly in beagle dogs.

Contents of four active components in different commercial crude drugs and preparations of danshen (Salvia miltiorrhiza).

AIM: To detect the contents of four active components of Salvia miltiorrhiza in various commercially available danshen crude drugs and preparations. METHODS: Commercially available danshen crude drugs from different sources, as well as danshen pills and intravenous injection preparations containing danshen alone or in combination with other herbs were collected. The composition of these danshen samples was analyzed using HPLC. Specifically, the amounts of magnesium tanshinoate B (MTB), danshensu, isotanshinone HA, and cryptotanshinone were determined. In some of these samples, the content of MTB was further confirmed by liquid chromatography-tandem mass spectrometer (LC-MS)/MS method. RESULTS: There were great variations in the amount of the four active ingredients in the commercially available danshen crude drugs and drug preparations in this study. The amount of MTB was the highest among the four components measured in the crude drugs. However, the amounts of MTB in all danshen preparations were much lower than those in crude drugs. The 2 lipophilic components, isotanshinone HA and cryptotanshinone, were very low or not detectable in both injection and oral preparations. CONCLUSION: MTB can be used to standardize the various forms of danshen crude drugs and drug preparations from different sources. In view of the variation in the amounts of MTB and other components, improvement in the production methods of danshen preparations is essential to ensure consistent amount of its active ingredients and reproducible pharmacological actions.