Kanokwan Jarukamjorn

Regulation of the expression of two female-predominant CYP3A mRNAs (CYP3A41 and CYP3A44) in mouse liver by sex and growth hormones

A second female-predominant murine CYP3A, CYP3A44, was isolated from liver and its mRNA expression was compared with that of the previously described CYP3A41. The expression of CYP3A44 was relatively constant after birth in females, whereas it gradually declined in males after 5 weeks of age. The expression of CYP3A41 increased with age in females after 3 weeks of age, whereas it gradually declined in males after 5 weeks of age. Hypophysectomy and growth hormone replacement indicated that expression of both CYP3A mRNAs in females was dependent on the feminine plasma growth hormone profile. Estradiol induced the expression of both mRNAs and the effect was dependent on the presence of the pituitary gland. These observations suggest that endocrine control of expression might be similar, but not identical, for two female-predominant CYP3A mRNAs.

Evaluation of extraction methods for the simultaneous analysis of simple and macrocyclic trichothecenes

The article is concerned with the simultaneous determination of simple and macrocyclic trichothecenes using high-performance liquid chromatography (LC) coupled to UV and mass spectrometric (MS) detection. Emphasis is put on the liquid-liquid extraction (LLE) and solid phase extraction (SPE) procedure from plant material such as wheat, comparing SPE cartridges packed with different stationary phases based on silica and polymer sorbents. In this coherence a polymeric material on the basis of poly(glycidyl methacrylate-divinylbenzene) (GMA-DVB) is developed with special regard on synthesis procedures to enhance the extraction recovery of trichothecenes in a broad polarity range. Evaluation of extraction techniques showed that the introduced material is competitive with commercially available high quality SPE materials. Percentage recovery is 82% for polar compounds, 89% for medium polar compounds and 98% for lipophilic compounds.

Sex-associated expression of mouse hepatic and renal CYP2B enzymes by glucocorticoid hormones

The expression of Cyp2b9 and Cyp2b10 genes was investigated in kidney, liver, and cultured hepatocytes of adult C57BL/6NCrj mice. The constitutive expression level of CYP2B mRNA in kidney was higher in female than in male mice, as it was in the liver where more CYP2B9 than CYP2B10 was expressed in the females, and more CYP2B10 was expressed in the males. After treatment with dexamethasone (Dex), induction of CYP2B10 mRNA and protein in the kidneys was far greater in male than in female mice. In contrast to Dex, phenobarbital (PB), pregnenolone-16 alpha-carbonitrile (PCN), and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) did not induce the expression of the Cyp2b gene in the kidneys of either sex. In the liver, PB, PCN, and DDT induced both CYP2B9 and CYP2B10 in both sexes to the same extent, whereas Dex induced only CYP2B10 and simultaneously suppressed CYP2B9. Dex-inducible expression of CYP2B mRNA was decreased by 11 beta-[4-dimethylamino]phenyl-17 beta-hydroxy-17-[1-propynyl]estra-4,9-dien-3-one (RU-486), in both the kidneys and liver from male mice, and in cultured hepatocytes. However, RU-486 itself induced the expression of CYP2B mRNA in female liver and cultured hepatocytes. Interestingly, RU-486 increased PB-inducible expression of these species in cultured hepatocytes. Gonadectomy increased the expression of CYP2B mRNA in untreated male liver, but suppressed Dex-induced expression in the kidneys of both sexes. These observations suggest that (a) there are multiple regulatory pathways in the expression of Cyp2b genes, one of which used by Dex is mediated via the glucocorticoid receptor, which is different from that used by PB, and (b) sex hormones play a role in the regulation of the sex-dependent expression of Cyp2b genes in the mouse.

Synergistic increases of metabolism and oxidation-reduction genes on their expression after combined treatment with a CYP1A inducer and andrographolide.

We previously reported that andrographolide greatly enhanced the expression of CYP1A1. Since andrographolide is a major constituent of Andrographis paniculata, which has been employed for centuries in Asia and Europe as a folk remedy, we further analyzed genes whose expression was modified by andrographolide using primary-cultured mouse hepatocytes in a microarray assay. With the threshold for modification set at 2-fold, andrographolide up-regulated 18 genes among 28,853 genes, most of them related to metabolism/oxidation/reduction. Meanwhile, 5 genes, related to protein binding or calcium ion binding, were down-regulated. A combination of beta-naphthoflavone (beta-NF), a CYP1A inducer, and andrographolide modified the expression of 45 genes (27 up-regulated and 18 down-regulated), although beta-NF single treatment up-regulated 4 genes. The affected genes were again mostly related to metabolism and oxidation-reduction. Among P450 isoforms, andrographolide by itself induced CYP1A1, CYP2A4, CYP2B9, and CYP2B10 expression. Synergistic expression of CYP1A1 and CYP1B1 mRNA was confirmed by quantitative RT-PCR. These observations suggest that drug interaction and risk assessment with the use of andrographolide or A. paniculata should be elucidated.

Effects of Pueraria mirifica and miroestrol on the antioxidation-related enzymes in ovariectomized mice

The influences of Pueraria candollei var. mirifica (PM), a Thai medicinal plant with long tradition of medicinal consumption among menopausal women for rejuvenation and estrogen hormone replacement, on oxidative status in ovariectomized (OVX) mice were determined.

Alteration of hepatic glutathione peroxidase and superoxide dismutase expression in streptozotocin-induced diabetic mice by berberine

Context: Diabetes mellitus (DM), a chronic disease, has been increasing and subsequently devastates the quality of life and economic status of the patients. Oxidative stress participates in development and progression of diabetes, in which levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were changed in diabetic mice. Berberine has been widely used as an alternative medicine and proved to be effective for treatment of DM and dyslipidemia. Objective: Impacts of berberine on regulation of GPx and SOD messenger RNAs (mRNAs), and glutathione (GSH) content were examined in diabetic mice to clarify its antioxidative stress potential. Materials and methods: Noninsulin-dependent diabetes was induced in mice by a single intraperitoneal streptozotocin injection. Diabetic mice were daily treated with metformin (100 mg/kg/d) or berberine (200 mg/kg/d) for 2 weeks. The fasting blood glucose and GSH content were monitored. GPx and SOD mRNA expression were semi-quantified by reverse transcription-polymerase chain reaction. Results: Berberine showed the same hypoglycemic potential as metformin, a hypoglycemic drug. Interestingly, berberine did not change levels of GPx, copper-zinc SOD (CuZn-SOD), and manganese SOD (Mn-SOD) mRNA in the normal mice but significantly recovered these levels in the diabetic mice to nearly the same levels as the normal. The GSH contents, including total GSH and reduced/oxidized GSH contents, were restored to the normal level by berberine, corresponded to GPx levels. Discussion and conclusion: Berberine conveyed antioxidative effect via down- and up-regulation of GPx and CuZn-SOD expression, respectively. Therefore, use of berberine as a hypoglycemic compound for alternative treatment of DM could bring extra-beneficent consequence according to its antioxidative stress.

Improvement of superoxide dismutase and catalase in streptozotocin–nicotinamide-induced type 2-diabetes in mice by berberine and glibenclamide

Abstract Context: Diabetes mellitus (DM) type 2 is a chronic disease characterized by hyperglycemia and insulin resistance. Oxidative stress participates in development and progression of DM, in which changes of superoxide dismutase (SOD) and catalase (CAT) were noted in DM mice. Berberine has been widely used as an alternative medicine and proved to be effective for the treatment of DM and dyslipidemia. Objective: Impacts of berberine on transcriptional regulation of SOD and CAT and their enzyme activities, including the level of malondialdehyde (MDA) formation, were examined in the DM type 2-induced mice to clarify its antioxidation potential, compared with a common hypoglycemic drug, glibenclamide. Materials and methods: Noninsulin-dependent diabetes was induced in mice by a single intraperitoneal streptozotocin–nicotinamide injection. Diabetic mice were treated daily with glibenclamide (10 mg/kg/d) and/or berberine (100 mg/kg/d) for 2 weeks. The fasting blood glucose and the MDA levels in the mouse liver, brain and kidneys were monitored using Glucometer® (Accu-Check® Advantage II Performa kits, Roche Diagnostics, Germany) and thiobarbituric acid substance assay, respectively. The expression of SOD and CAT mRNA were determined in the mouse liver and the activities of SOD and CAT enzymes were determined in mouse liver, brain and kidneys, respectively. Results: Berberine exhibited similar hypoglycemic potential as glibenclamide to lower area under the curve of the fasting blood glucose. In DM type 2 mice, berberine increased the hepatic CuZn-SOD mRNA expression and the kidney SOD and CAT activities to normal levels. Moreover, DM-induced lipid peroxidation by increasing of MDA levels in both the liver and brain and lipid peroxidation status was restored by berberine. Conclusion: Berberine possessed hypoglycemic properties and strong potential to improve the oxidant–antioxidant balance, though the combination treatment of berberine and glibenclamide did not show additional benefit over the treatment with berberine alone.

Gender-associated modulation of inducible CYP1A1 expression by andrographolide in mouse liver

We previously observed a strong synergistic effect on polycyclic aromatic hydrocarbon (PAH)-induced CYP1A1 expression by andrographolide, a major constituent of an herbal medicine derived from the plant Andrographis paniculata, in mouse hepatocytes in primary culture. The present paper describes confirmation of an enhancing effect of andrographolide on the CYP1 family in vivo in the PAH-responsive C57BL/6 mouse. Andrographolide did not alter CYP1 expression in the PAH-nonresponsive DBA/2 mouse. The enhanced expression induced by andrographolide was observed in male C57BL/6 mice, but not in intact or ovariectomized females, or in orchiectomized male mice. However, treatment with testosterone restored the effect in both orchiectomized males and ovariectomized females. These observations indicate a male hormone-related system to be a crucial mediator of the modulation of CYP1 expression by andrographolide. Precautions should be taken regarding the use of A. paniculata as an alternative medication or health promotion, according to its distinctive characterization on sexually dimorphic modulation of CYP1A1 expression.

Sexual dimorphic expression of mouse hepatic CYP2B: alterations during development or after hypophysectomy

The constitutive expression of CYP2B mRNA in the livers of mice in the prepubertal stage was sex-independent, with CYP2B9 as the principal isoform. During the maturation stage, CYP2B10 was expressed in both sexes, whereas CYP2B9 was diminished markedly in the males, resulting in a sexually dimorphic expression in adult mice. Hypophysectomy eliminated the sexual dimorphism in the mouse CYP2B subfamily by markedly increasing the expression of both CYP2B9 and CYP2B10 in males to levels similar to those in females.

Bimodal action of miroestrol and deoxymiroestrol, phytoestrogens from Pueraria candollei var. mirifica, on hepatic CYP2B9 and CYP1A2 expressions and antilipid peroxidation in mice.

Miroestrol and deoxymiroestrol are phytoestrogens isolated from Pueraria candollei var. mirifica. The influence of miroestrol and dexoymirosestrol on hepatic cytochrome P450 (P450) enzymes and antioxidative activity in brain was examined in C57BL/6 mice compared with that of a synthetic female sex hormone estradiol. We hypothesized that miroestrol and deoxymiroestrol would induce CYP2B9 expression, whereas CYP1A2 expression would be suppressed compared with estradiol. Miroestrol and deoxymiroestrol treatment significantly increased uterus weight and volume. In addition, both of these phytoestrogens induced the expression of CYP2B9 and suppressed the expression of CYP1A2, as expected. Hepatic P450 activities correspondingly showed that both compounds increased benzyloxyresorufin O-dealkylase activity, whereas methoxyresorufin O-dealkylase activity was reduced. These observations suggested that miroestrol and deoxymiroestrol might affect hepatic P450 enzymes, including the CYP2B9 and CYP1A2 P450 isoforms. Assessment of lipid peroxidation demonstrated that miroestrol and deoxymiroestrol markedly decreased levels of malondialdehyde formation in the mouse brain. This is the first report suggesting miroestrol and deoxymiroestrol as potential alternative medicines to estradiol because of their distinctive ability to regulate mouse hepatic P450 expression and their beneficial antioxidative activities.