Prenylated C6–C3 compounds from the fruits of Illicium simonsii

Two new prenylated C₆–C₃ compounds, 4-epi-illicinone E-12-shikimate (1) and 3-hydroxyillifunone B (2), together with five known prenylated C₆–C₃ compounds (3–7), were isolated from the fruits of Illicium simonsii. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D and 2D NMR, CD spectra, and ESI-MS analysis.     

Lack of correlation between formation of reactive metabolites and thymic atrophy caused by 3, 4, 3′, 4′-tetrachlorobiphenyl in C57BL/6N mice

The possible role of active metabolites of 3, 4, 3, 4-tetrachlorobiphenyl (TCB) in causing thymic atrophy was investigated using inbred strains of mice. The generation of reactive species which bind covalently to cellular proteins was used to monitor the formation of active TCB metabolites. The amount of in vitro covalent binding of TCB to proteins by liver microsomes was increased markedly by pretreatment of AHH-responsive C57BL/6N mice with either 3-methylcholanthrene (MC) or TCB itself, although these two inducers were not effective in AHH-nonresponsive DBA/2N mice. MC treatment also caused an induction of microsomal TCB-binding activity in all of the (C57BL/6N x DBA/2N) F₁ mice. Moreover, among 38 individuals of [(C57BL/6N) (DBA/2N) F₁ x DBA/2N] backcross, 23 mice responded to MC with respect to microsomal TCB-binding activity while others did not. These results suggest that the conversion of TCB to protein-bound metabolites is mediated by particular form(s) of cytochrome P-450 which is (are) induced by an Ah receptor mechanism. In order to ascertain wheter the active TCB metabolites play a role in causing thymic atrophy, ¹⁴C-labeled TCB was administered IP to C57BL/6N mice and the amount of covalent binding of radioactive metabolites to tissue proteins was determined. The in vivo binding was evident in the liver, particularly in the microsomal fraction, on the basis of protein content. In contrast, the thymic proteins contained no measurable amounts of bound radioactivity even when the mice showed marked thymic atrophy. These data suggest that thymic atrophy caused by TCB is not likely to result from the generation of reactive metabolites.Abbreviations Used TCB 3, 4, 3, 4-tetrachlorobiphenyl - PCB polychlorinated biphenyl(s) - TCDD 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin - MC 3-methylcholanthrene - PB phenobarbital - AHH aryl hydrocarbon hydroxylase     

Reduction of circulating and selective limbic brain levels of (3α,5α)-3-hydroxy-pregnan-20-one (3α,5α-THP) following forced swim stress in C57BL/6J mice

Rationale

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, and GABAergic neuroactive steroids contribute to homeostatic regulation of this circuitry. Acute forced swim stress (FSS) increases plasma, cortical, and hypothalamic (3α,5α)-3-hydroxy-pregnan-20-one (3α,5α-THP) levels in rats. However, there have not been systemic investigations of acute stress on changes in plasma and brain levels of 3α,5α-THP in mouse models.

Objectives

The present experiments aimed to assess circulating and local brain levels of 3α,5α-THP following acute FSS in C57BL/6J mice.

Methods

Mice were exposed to FSS (10 min), and 50 min later, blood and brains were collected. Circulating pregnenolone and 3α,5α-THP levels were assessed in serum. Free-floating brain sections (40 μm, four to five sections/region) were immunostained and analyzed in cortical and limbic brain structures.

Results

FSS decreased circulating 3α,5α-THP (?41.6?±?10.4 %) and reduced 3α,5α-THP immunolabeling in the paraventricular nucleus of the hypothalamus (?15.2?±?5.7 %), lateral amygdala (LA, ?31.1?±?13.4 %), and nucleus accumbens (NAcc) shell (?31.9?±?14.6). Within the LA, vesicular glutamate transporter 1 (VGLUT1) and vesicular GABA transporter were localized in 3α,5α-THP-positively stained cells, while in the NAcc shell, only VGLUT1 was localized in 3α,5α-THP-positively stained cells, suggesting that both glutamatergic and GABAergic cells within the LA are 3α,5α-THP-positive, while in the NAcc shell, 3α,5α-THP only localizes to glutamatergic cells.

Conclusions

The decrease in circulating and brain levels of 3α,5α-THP may be due to alterations in the biosynthesis/metabolism or changes in the regulation of the HPA axis following FSS. Changes in GABAergic neuroactive steroids in response to stress likely mediate functional adaptations in neuronal activity. This may provide a potential targeted therapeutic avenue to address maladaptive stress responsivity.     

Antidepressant-like effect of PRE-084, a selective σ1 receptor agonist,in Albino Swiss and C57BL/6J mice

PRE-084, a selective σ receptor agonist, exhibited an antidepressant-like effect in the forced swim test (FST) in Albino Swiss and C57BL/6J mice. This effect was counteracted by BD 1047 (5 and 10 mg/kg) but not by SM-21 (3 and 10 mg/kg), which are σ₁- and σ₂-receptor antagonists, respectively. The results indicated that PRE-084 has an antidepressant-like effect in C57BL/6J and, to a lesser extent, in Albino Swiss mice. These results support the idea that σ₁-receptors, but not σ₂-receptors, contribute to the mechanism of antidepressant activity of σ agonists in FST.     

Hydrolysis of the Prodrug, 2′, 3′, 5′ -Triacetyl-6-azauridine

Purpose. The purposes were to study the kinetics of hydrolysis of 2,3,5-triacetyl-6-azauridine ( 1 ) in aqueous solution (µ = 0.5) and to identify the main intermediates and products of the reaction. Methods. A stability indicating isocratic LC assay was used to study the rate of degradation of 1 A gradient LC assay was used to study the time courses of the degradants. The products of hydrolysis were isolated by preparative liquid chromatography and identified by ¹H-NMR and CI-MS. The pK_a value was obtained by potentiometric titration. Results. At 36.8°C, the pH-rate profile of 1 in water was adequately described by a four-term rate equation. The intermediates were identified as the primary and secondary di-acetates, and the primary and secondary mono-acetates. The final product was 6-azauridine. Conclusions. A simplified kinetic scheme could be used to describe the concentration-time profiles of 1, the intermediates and the final product.     

Does age matter? Comparison of neurobehavioral effects of paraquat exposure on postnatal and adult C57BL/6 mice

Epidemiological studies have revealed that environmentally relevant low levels of paraquat (PQ) exposure is listed on the etiology of neurological disorders such as Parkinson’s disease (PD). The behavioral effects of PQ are of current interest, especially when exposure occurs in the period of early stage of life. To characterize whether and how age affects neurobehavioral performances of mice after PQ exposure, 21 days postnatal (PN21) and adult male C57BL/6 mice were daily administrated by oral gavage with 0?mg/kg (saline, control), 5?mg/kg or 10?mg/kg of PQ for 28 consecutive days. Survival rate and body weight were analyzed. Subsequently, mice were subjected to Morris water maze tests (MWM). The results showed that mice exposed to PQ had significantly longer latencies than those in the control group, with a dose-dependent manner. Furthermore, PN21 mice tended to have longer latencies than adult mice in the same dose group. Our data suggested that PQ exposure induced significant learning and memory impairment and more severely in PN21 mice when compared with adult mice.     

New flav-3-en-3-ol glycosides, kaempferiaosides C and D, and acetophenone glycosides, kaempferiaosides E and F, from the rhizomes of Kaempferia?parviflora

Two new flav-3-en-3-ol glycosides, kaempferiaosides C (3) and D(4), and two new acetophenone glycosides, kaempferiaosides E (5) and F (6), were isolated from the Thai natural medicine Krachai Dum, the rhizomes of Kaempferia parviflora Wall. ex Baker. Their structures were established mainly on the basis of 1D and 2D NMR spectral data.     

Effects of growth hormone deficiency and rhGH replacement therapy on the 6β-hydroxycortisol/free cortisol ratio,a marker of CYP3A activity,in growth hormone-deficient children

Objective To determine the effect of both growth hormone deficiency (GHD) and rhGH replacement therapy on CYP3A activity as well as the potential influence of gender.Methods The sample consisted of 35 GHD children (16 males and 19 females), aged 2.9–13.1 years, and a control group of 35 healthy children matched for age and sex. The urinary ratio 6-hydroxycortisol/free cortisol was used as a marker of CYP3A activity. In patients, urine samples were collected at two times, prior to starting rhGH replacement treatment and 30 days after beginning therapy.Results A significantly higher metabolic activity in GHD children was observed in relation to controls (P=0.0001) without sex differences. Paired comparisons demonstrated a sexually dimorphic effect of rhGH therapy on the CYP3A activity. While boys displayed a significant decrease (P=0.003), girls showed no significantly different values of CYP3A marker (P>0.05). Unpaired comparison between controls and GHD children after therapy demonstrated absence of significant differences in boys (P>0.05) and a strikingly higher activity in girls (P=0.0001).Conclusions The data suggests that: (a) GHD in children increases CYP3A activity in a non-sex-dependent manner, (b) rhGH treatment for 30 days to GHD children results in a sexually dimorphic effect on CYP3A activity, with a significant decrease in males toward normalization in relation to controls and non-significant changes in females. The results of this study may have important clinical implications for GHD children, since changes in CYP3A activity importantly affect the metabolism of both steroid hormones and CYP3A substrate drugs.     

Pharmacokinetics of two formulations of alendronate sodium/cholecalciferol (vitamin D3) tablets 70 mg/5600 IU: An open-label,randomized, single-dose,two-treatment,two-period,two-sequence,cross-over,bioequivalence study

Abstract

A fixed dose combination of alendronate and cholecalciferol (vitamin D₃) 70?mg/5600?IU tablets has been indicated for the treatment of osteoporosis. This study was aimed to assess bioequivalence between test and reference formulations of alendronate sodium/cholecalciferol (vitamin D₃) tablets 70?mg/5600?IU in 110 healthy adult male volunteers under fasting conditions. This was an open label, randomized, single dose, two way cross-over study, separated by a washout period of 14 days. All possible efforts were made to stabilize the baseline endogenous levels of cholecalciferol. Blood samples were collected from 96?h pre-dose to 96?h post-dose and 0–24?h for cholecalciferol and alendronate, respectively. Quantification of alendronate and cholecalciferol was done using distinct validated LC-MS/MS methods. Two baseline adjusted methods, method-I (subtraction of the average concentration from each post-dose concentration) and method-II (subtraction of the individual AUC from post-dose AUC) were applied for deriving the AUC_0–t parameter of cholecalciferol, among which bioequivalence was concluded based on data obtained using method-I. The 90% CI of C_max and AUC_0–t for alendronate and baseline adjusted cholecalciferol were within the regulatory acceptance limit of 80.00–125.00% and considered as bioequivalent.     

Effects of GM-CSF, IL-3, and GM-CSG/IL-3 fusion protein on apoptosis of human myeloid leukemic cell line Tf-1 induced by irradiation

AIM: To observe the effects of three cytokines on the apoptosis of Tf-1 cells induced by y irradiation and investigate the relationship between apoptosis and caspase-3 activity. METHODS: Different cytokines GM-CSF, IL-3 and GM-CS/IL-3 fusion protein were added into the irradiated Tf-1 cells. MTT assay, morphology, flow cytometry, and DNA fragmentation assay were used to observe the effects of cytokines on apoptosis. The caspase-3 activity was determined with a fluorocytometer. RESULTS: Irradiated Tf-1 cells showed typical morphological characteristic of apoptosis demonstrated by transmission electron microscopy and were accumulated in G0/G1 phase. In the groups treated with growth factors after irradiation, three cytokines significantly increased the viability rate, distinctly decreased the apoptosis rate and the proportion of DNA fragmentation. When Tf-1 cells were irradiated by y     

Absorption, excretion, and metabolism of a potential GABA-A α2/3 receptor modulator in rats

4-Amino-8-(2,5-dimethoxyphenyl)-N-propylcinnoline-3-carboxamide (AZD6280) is a selective GABA-A(α2/3) receptor modulator under development for the treatment of generalized anxiety disorders. Absorption, metabolism, and excretion of [(14)C]-AZD6280 was studied in rats following a single oral (7 mg/kg) or intravenous (i.v., 1 mg/kg) administration of [(14)C]-AZD6280. The results from the bile duct-cannulated study revealed that AZD6280 was well-absorbed in rats. The pharmacokinetic analysis was conducted using unlabelled parent drug that was rapidly absorbed (plasma T(max) ~1 h) and exhibited a mean apparent terminal half-life of ~4.2 h. The overall mean recoveries in the excreta were 98.6% and 100.3% after oral and i.v. administration of [(14)C]-AZD6280, respectively. The major route for elimination of [(14)C]-AZD6280 and its metabolites was through faeces. The radiochromatographic analysis of the excreta demonstrated that AZD6280 underwent extensive biotransformation. A total of 28 metabolites of AZD6280 were detected and profiled in urine, bile, and faeces in this study. The structures of metabolites were elucidated by high-resolution tandem mass spectrometry. Similar metabolite profiles were observed in rats given AZD6280 orally or intravenously.