Synthesis of a novel adamantyl nitroxide derivative with potent anti-hepatoma activity in vitro and in vivo.

In this study, a novel adamantyl nitroxide derivative was synthesized and its antitumor activities in vitro and in vivo were investigated. The adamantyl nitroxide derivative 4 displayed a potent anticancer activity against all the tested human hepatoma cells, especially with IC50 of 68.1 µM in Bel-7404 cells, compared to the positive control 5-FU (IC50=607.7 µM). The significant inhibition of cell growth was also observed in xenograft mouse model, with low toxicity. Compound 4 suppressed the cell migration and invasion, induced the G2/M phase arrest. Further mechanistic studies revealed that compound 4 induced cell death, which was accompanied with damaging mitochondria, increasing the generation of intracellular reactive oxygen species, cleavages of caspase-9 and caspase-3, as well as activations of Bax and Bcl-2. These results confirmed that adamantyl nitroxide derivative exhibited selective antitumor activities via mitochondrial apoptosis pathway in Bel-7404 cells, and would be a potential anticancer agent for liver cancer.

Effect of food on the pharmacokinetics of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid, in healthy subjects.

OBJECTIVE: The objective of this study was to evaluate the pharmacokinetic parameters of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid (HTB), following a single oral dose of 900 mg in healthy subjects under fed and fasting conditions. METHODS: The study participants (n=12) were randomized to receive one 900 mg triflusal capsule in a fasting condition (no food for 12 hours) or a fed condition (after a high-fat meal); after a 2-week washout period, participants received the same dose of triflusal capsule under the converse condition. Pharmacokinetic parameters were calculated using WinNonlin 6.2 software. Safety was evaluated through assessment of adverse events, standard laboratory evaluations, vital signs, and 12-lead electrocardiography. RESULTS: The mean Cmax of triflusal and HTB were 13.96, 110.2 ug/mL for the fasting state and 9.546, 97.15 ug/mL for the fed state, respectively. The AUC0-144 of triflusal and HTB were 19.66, 5,572 hxµg/mL for the fasting state and 22.20, 5,038 hxµg/mL for the fed state, the AUC0-∞ of triflusal and HTB were 19.79, 6,333 hxµg/mL for the fasting state and 22.44, 5,632 hxµg/mL for the fed state, respectively. The results showed that Cmax and AUCs for triflusal were outside the bioequivalency (BE) interval after food intake, but there was no statistically significant change for HTB. CONCLUSION: High-fat food intake may affect the pharmacokinetics of triflusal capsule in healthy subjects.

Impact on L-carnitine Homeostasis of Short-term Treatment with the Pivalate Prodrug Tenofovir Dipivoxil.

Pivalate-generating prodrugs have been suggested to cause clinically significant hypocarnitinaemia. Tenofovir dipivoxil, a novel ester prodrug of tenofovir, can be used for treatment for hepatitis B and HIV infection and it was necessary to evaluate the effect of its treatment on carnitine homeostasis. We sought to investigate the effect of Class 1 drug tenofovir dipivoxil on endogenous L-carnitine level during a 72-hr test in healthy Chinese volunteers and to establish a suitable dose of L-carnitine nutritional supplement for patients who were administered short-term tenofovir dipivoxil tablets for treatment for hepatitis B and herpes simplex virus infection. Tenofovir dipivoxil was administered in one of eight dosing regimens (single dose 150, 300 and 600 mg, multiple dose 300, 450, and 600 mg, multiple dose 450 (600) mg tenofovir dipivoxil and 0.5 g L-carnitine) to gender-balanced groups of 84 healthy Chinese volunteers. Plasma concentrations of L-carnitine were quantified before, during and after treatment. Plasma L-carnitine concentrations fell during tenofovir dipivoxil dosing. The nadir in L-carnitine concentration was dependent on the dose of tenofovir dipivoxil and it decreased from 6.1 ± 0.6 to 4.4 ± 0.8 µg/ml, 6.1 ± 1.8 to 3.3 ± 1.2 µg/ml, 6.2 ± 0.6 to 2.5 ± 0.5 µg/ml for single doses of 150, 300, 600 mg tenofovir dipivoxil tablets and from 6.0 ± 1.4 to 2.1 ± 1.5 µg/ml, 6.2 ± 0.4 to 0.9 ± 0.5 µg/ml for multiple doses of 450, 600 mg tenofovir dipivoxil tablets, respectively. Short-term administration of tenofovir dipivoxil results in hypocarnitinaemia and increased losses of carnitine in resulting of minor adverse events of decreased food appetite, nausea, abdominal distention and muscle weakness.

The effect of staggered administration of zinc sulfate on the pharmacokinetics of oral cephalexin.

AIMS: To investigate the effect of zinc sulfate on pharmacokinetics of cephalexin when administered concurrently or at strategically spaced dosing times designed to avoid the potential interaction in healthy volunteers. METHODS: In this study, all subjects (n= 12) were randomized to receive the following four treatments, separated by a wash-out period of 7 days: cephalexin 500mg alone, concomitantly with zinc 250mg, 3h after zinc 250mg or 3h before zinc 250mg. RESULTS: All subjects completed the study safely. Zinc supplements administered concurrently with cephalexin significantly decreased the peak serum concentration (C(max) ), area under the plasma concentration-time curve from zero to infinity (AUC(0-∞) ) and the time for which the plasma concentration of the drug remained above the minimal inhibitory concentration of the pathogenic organism (T > MIC) of cephalexin [mean percentage decrease (95% confidence intervals) of 31.05% (22.09-40.01%), 27.40% (18.33-36.47%) and 22.33% (12.51-32.16%), respectively; P < 0.05] compared with administration of cephalexin alone. Also, administration of zinc 3h before cephalexin decreased the C(max) , AUC(0-∞) and T > MIC of the drug compared with administration of cephalexin alone [mean percentage decrease (95% confidence intervals) of 11.48% (3.40-19.55%), 18.12% (9.63-26.60%) and 23.75% (14.30-33.20%), respectively; P < 0.05]. In contrast, the pharmacokinetics of cephalexin was not notably altered by administration of zinc 3h after cephalexin dosing (P > 0.05). CONCLUSIONS: The significant interaction between zinc and cephalexin might affect the clinical outcome of cephalexin therapy. The dosing recommendation is that zinc sulfate can be safely administered 3h after a cephalexin dose.

Neuroprotective effect of osthole on MPP+-induced cytotoxicity in PC12 cells via inhibition of mitochondrial dysfunction and ROS production.

BACKGROUND: The 1-methyl-4-phenylpyridinium ion (MPP(+)), an inhibitor of mitochondrial complex I, has been widely used as a neurotoxin because it causes a severe Parkinson's disease-like syndrome accompanied by increased levels of intracellular reactive oxygen species (ROS) and apoptotic death. In the present study, we investigated the protective effects of osthole, a coumarin compound extracted from the plant-derived medicine Cnidium monnieri, on MPP(+)-induced cytotoxicity in cultured rat adrenal pheochromocytoma (PC12) cells. METHODS: PC12 cells were treated with MPP(+) 2h after treated with different concentrations of osthole. 24h later, the cell viability, the release of lactate dehydrogenase, the activity of caspase-3 and cytochrome c, the expression ratio of Bax/Bcl-2 and the generation of intracellular ROS were detected. RESULTS: We found that pretreatment with osthole on PC12 cells significantly reduced the loss of cell viability, the release of lactate dehydrogenase, the activity of caspase-3 and cytochrome c, the increase in Bax/Bcl-2 ratio and the generation of intracellular ROS induced by MPP(+). Moreover, our HPLC analysis of cell extracts confirmed that extracellular osthole does penetrate the cell membrane. Thus osthole may function as an intracellular antioxidant to reduce oxidative stress induced by MPP(+). CONCLUSIONS: Therefore, the present study supports the notion that osthole may be a promising neuroprotective agent for the treatment of neurodegenerative disorders such as Parkinson's disease.

1-Methyl-1,2,3,4-tetra-hydro-carbolin-2-ium-3-carboxyl-ate.

The title compound, C(13)H(14)N(2)O(2), is a natural product isolated from Cicer arietinum L. (chickpea). The benzene ring and pyrrole rings display planar conformations and the piperidine ring has a half-chair conformation. Inter-molecular C-H⋯π inter-actions between a methyl H atom and the pyrrole ring of an adjacent mol-ecule are present in the crystal structure.