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.

Modulations of cytochrome P450 expression in diabetic mice by berberine.

Berberine, an isoquinoline alkaloid isolated from medicinal plants such as Berberis aristata, Coptis chinesis, Coptis japonica, Coscinium fenestatun, and Hydrastis Canadensis, is widely used in Asian countries for the treatment of diabetes, hypertension, and hypercholesterolemia. Interaction between berberine and the cytochrome P450 enzymes (CYPs) has been extensively reported, but there are only a few reports of this interaction in the diabetic state. In this study, the effect of berberine on the mRNA of the CYPs in primary mouse hepatocytes and in streptozotocin (STZ)-induced diabetic mice was investigated. In primary mouse hepatocytes, berberine suppressed the induction of Cyp1a1, Cyp1a2, Cyp2e1, Cyp3a11, Cyp4a10, and Cyp4a14 mRNA expression by their prototypical inducers in a concentration-dependent fashion. However, berberine treatment alone increased the expression of Cyp2b9 and Cyp2b10 mRNA. In vivo, berberine showed the same hypoglycemic activity as metformin, an established hypoglycemic drug. The hepatic mRNA levels of Cyp1a1, Cyp2b9, Cyp2b10, Cyp3a11, Cyp4a10, and Cyp4a14 were increased in STZ-induced diabetic mice. Interestingly, berberine itself suppressed the expression of Cyp2e1, an adverse hepatic event-associated enzyme, while the expression of Cyp3a11, Cyp4a10, and Cyp4a14 were restored to normal levels by berberine. In conclusion, berberine has the potential to modify the expression of CYPs by either suppression or enhancement of CYPs' levels. Consumption of berberine as an anti-hyperglycemic compound by diabetic patients might provide an extra benefit due to its potential to restore the expression of Cyp2e1, Cyp3a, and Cyp4a to normal levels. However, an herb-drug interaction might be of concern since any berberine-containing product would definitely cause pronounced interactions based on CYP3A4 inhibition.

Different AhR binding sites of diterpenoid ligands from Andrographis paniculata caused differential CYP1A1 induction in primary culture in mouse hepatocytes.

Andrographis paniculata has been employed as a folklore remedy. Andrographolide (Andro), 14-deoxy-11,12-didehydroandrographolide (DHA), andrographiside (AS), and neoandrographolide (Neo), are major diterpenoids isolated from this plant. In the present study, influence of the four diterpenoids on CYP1A1 mRNA expression was investigated in primary cultured mouse hepatocytes. Additionally, binding of these compounds to aryl hydrocarbon receptor (AhR) was examined using molecular docking analysis to clarify mechanism of CYP1A1 induction. Andro and DHA induced CYP1A1 expression by itself, and co-treatment with a CYP1A1 inducer (BNF, beta-naphthoflavone) showed a synergistic increase of CYP1A1 expression. Andro demonstrated higher enhancing activity than DHA at every similar concentration. On the other hand, Neo suppressed BNF-induced CYP1A1 expression, but AS did not modify the induction. Results from molecular docking analysis of BNF and four diterpenoids on ligand binding domain of AhR were consistent with levels of CYP1A1 mRNA expressions. Furthermore, difference of binding sites of BNF in the presence of diterpenoids might affect the synergism or inhibition of CYP1A1 expression. These results suggest that use of A. paniculata as a health supplement should be concerned in term of herb-drugs interactions or risk of carcinogenesis, according to its ability to influence CYP1A1 expression.

Modified expression of aryl hydrocarbon receptor-related genes by deoxymiroestrol, a phytoestrogen, in mouse hepatocytes in primary culture.

ETHNOPHARMACOLOGICAL RELEVANCE: Deoxymiroestrol (DM), a strong phytoestrogen from Pueraria candollei Wall. ex Benth. var. mirifica (family Leguminosae). This plant has long been used in traditional medicine for rejuvenation. MATERIALS AND METHODS: The expression of aryl hydrocarbon receptor-related genes in mouse hepatocytes in primary culture was quantified by real-time RT-PCR and hepatic microsomal P450 activity was assessed by using ethoxyresorufin O-dealkylation. RESULTS: The mRNA expression of the aryl hydrocarbon receptor (AhR), AhR nuclear translocator, and CYP1A1 was suppressed, whereas that of CYP1B1, estrogen receptor α (ERα), CYP2B9, and glutathione-S-transferase a2 (GSTa2) was increased. The effects of DM on the gene expression depended on treatment period and concentrations, and were similar to those of ß-estradiol (E2). DM and E2 at pharmacological concentrations had a marked synergistic effect on CYP1A1 expression after combined treatment with a typical CYP1 inducer, ß-naphthoflavone (ßNF), at the level of both transcription and enzymatic activity. DM enhanced the inducible mRNA expression of CYP1A1 and CYP1B1 similar to E2. Meanwhile, the expression of ERα mRNA was not affected by ßNF, which, on the contrary, completely eliminated the DM-induced mRNA expression of ERα, CYP2B9, and GSTa2. CONCLUSION: The findings that DM modified the expression of several metabolism-related genes suggest the need for caution when using health supplements having phytoestrogenic activity.

Suppression of beta-naphthoflavone induced CYP1A expression and lipid-peroxidation by berberine.

Impacts of berberine, a major isoquinoline alkaloid in herbal plants, on beta-naphthoflavone (BNF)-induced CYP1A expression were determined both in primary mouse hepatocytes and in vivo. Berberine concentration-dependently suppressed BNF-induced CYP1A expression in mouse hepatocyte and it significantly down-regulated BNF-induced CYP1A in mouse liver via suppression of mRNA and protein expression, and decreases of EROD and MROD activities. Moreover, berberine showed significant potential on suppression of BNF-induced lipid peroxidation in mouse hepatic microsome. Therefore, using berberine as a health supplement or an alternative medication might provide extra-benefit due to its inhibitory regulation on CYP1A expression and anti-lipid peroxidation activity.

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.

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.