Improvement of vascular dysfunction by argirein through inhibiting endothelial cell apoptosis associated with ET-1/Nox4 signal pathway in diabetic rats.

Endothelial cell apoptosis plays an important role in the pathophysiological mechanism of vascular complications in type 2 diabetes mellitus (T2DM). Argirein, a new synthetic compound was demonstrated to inactivate NADPH oxidase to alleviate cardiac dysfunction in T2DM. Here, we investigated whether argirein medication attenuated the vascular dysfunction in T2DM by inhibiting endothelial cell apoptosis which was associated with NADPH oxidase. The rat aortic endothelial cells (RAECs) were incubated with glucose (30 mM) for 48 hour in vitro. It was shown that high glucose significantly increased the protein expression of BAX (Bcl-2 Associated X protein) and Caspase-3 and decreased Bcl2 (B-Cell Leukemia/Lymphoma 2) protein level in RAECs, which was normalized by argirein medication. The annexin V-FITC bound cell percentage and DNA fragments in agarose electrophoresis were markedly suppressed by argirein to confirm the anti-apoptotic property of argirein in RAECs. Furthermore, we found that argirein blocked the endothelin (ET)-1/Nox4 signal-dependent superoxide (O2-.) generation, which regulated endothelial cell apoptosis in RAECs. In vivo, argirein intervention relieved the vasodilatory response to acetylcholine and restored the expressions of Nox4 and BAX in the aorta endothelium of high-fat diet (HFD)-fed rats following streptozocin (STZ) injection. For the first time, we demonstrated that argirein could inhibit vascular endothelial cell apoptosis, which was attributed to blocking ET-1/Nox4 signal-dependent O2- generation in RAECs. This current study revealed the therapeutic effects of argirein to prevent the vascular complication in T2DM through inhibiting endothelial cell apoptosis which was associated with the anti-oxidative property of argirein.

Argirein alleviates vascular endothelial insulin resistance through suppressing the activation of Nox4-dependent O2- production in diabetic rats.

BACKGROUND: Insulin resistance in endothelial cells contributes to the development of cardiovascular disease in type 2 diabetes mellitus (T2DM). Therefore, there are great potential clinical implications in developing pharmacological interventions targeting endothelial insulin resistance. Our previous studies indicated that argirein which was developed by combining rhein with L-arginine by a hydrogen bond, could substantially relieved stress related exacerbation of cardiac failure and alleviated cardiac dysfunction in T2DM, which was associated with suppressing NADPH oxidase activity. However, it is unclear whether argirein treatment attenuates the vascular lesion and dysfunction in T2DM and its underlying mechanisms. METHODS AND RESULTS: The rat aortic endothelial cells (RAECs) were used to treat with palmitic acid (PA), a most common saturated free fatty acid, which could induce insulin resistance. It was showed that argirein increased glucose uptake and glucose transporter-4 (Glut4) expression and reversed the phosphorylation of IRS-1-ser307 and AKT-ser473, consequently resulting in the increase of the production of eNOS and NO in PA-induced RAECs. We further found that argirein blocked the Nox4-dependent superoxide (O2-.) generation, which regulated glucose metabolism in RAECs during PA stimulation. In vitro, argirein increased the release of endothelial NO to relieve the vasodilatory response to acetylcholine and insulin, and restored the expression of Nox4 and pIRS-1-ser307 in the aorta endothelium of high-fat diet (HFD)-fed rats following an injection of streptozocin (STZ). CONCLUSION: These results suggested that argirein could improve endothelial insulin resistance which was attributed to inhibiting Nox4-dependent redox signaling in RAECs. These studies thus revealed the novel effect of argirein to prevent the vascular complication in T2DM.

[Evaluation of implementation effect of clinical practice guideline on traditional Chinese medicine therapy alone or combined with antibiotics for acute tonsillitis].

The purpose of this article is to evaluate the clinical effect of clinical practice guideline on traditional Chinese medicine therapy alone or combined with antibiotics for acute tonsillitis. The applicability and application of the Guideline were evaluated based on the clinicians by using the electronic questionnaire. Questionnaires about 538 on application evaluation and 502 questionnaires on applicability evaluation were completed from April 28 to July 9, 2018. The subjects in the questionnaires include the clinicians with junior title, intermediate title, and senior title that have used this Guideline. The descriptive statistical analysis of the collected questionnaire was carried out. In the applicability evaluation, according to the classification of professional titles, the application rate was highest in intermediate title clinicians (26.77%), followed by junior (23.98%) and deputy senior (19.33%) professional title clinicians. In the quality evaluation, the rationality of application scope (98.61%) and the terminology accuracy (98.81%) scores were higher, and the rationality of differentiation and classification (96.05%) was the lowest. The applicability evaluation suggested that clinicians believed this Guideline had high safety (98.42%), reasonable content (98.03%), significant effect (99.6%), reduced use of antibiotics in Western medicine (93.89%), and a high applicability ratio (96.44%). In the application evaluation, Department of lung disease showed the highest application rate (44.24%); rationality of the Guideline was more than 97% in treatment rules and prophylaxis except the syndrome differentiation (92.75%); a high ratio of clinicians believed the recommended scheme was good: curative effect 97.4%, safety 97.59%, and economy 93.87%. The study shows that the clinical practice guideline on traditional Chinese medicine therapy alone or combined with antibiotics for acute tonsillitis is of good quality, high clinical use and good effect. It can be used as a standardized treatment scheme for acute tonsillitis in traditional Chinese medicine. But there are some unsuitable contents and need to be further improved. The Guideline should strengthen the revision on differentiation of symptoms and signs as well as prophylaxis.

[Advantages and evidence of Chinese medicine in prevention and treatment of adult acute tonsillitis].

Though evaluation and analysis on the relevant literatures at home and abroad in recent years, the total number of retrieved literature was 2 664. According to the inclusion criteria and exclusion criteria,the literatures were screened out, and the results were as follows：374 literatures. To analyse the advantages and evidence of Chinese medicine in the prevention and treatment of adult acute tonsillitis. It is found to be effective, convenient and practical for the treatment of acute tonsillitis by traditional Chinese medicine (TCM) like treatment according to syndrome differentiation, Chinese patent drug, self Chinese medicine prescription and external treatment. TCM has obvious advantages in the prevention and treatment of acute tonsillitis, has the function of supplementing or substituting antibiotics, and has the function of regulating the defense function of organism.

Argirein alleviates stress-induced and diabetic hypogonadism in rats via normalizing testis endothelin receptor A and connexin 43.

AIM: Argirein (rhein-arginine) is a derivative of rhein isolated from Chinese rhubarb (Rheum Officinale Baill.) that exhibits antioxidant and anti-inflammatory activities. In the present study we investigated the effects of argirein on stress-induced (hypergonadotrophic) and diabetic (hypogonadotrophic) hypogonadism in male rats. METHODS: Stress-induced and diabetic hypogonadism was induced in male rats via injection of isoproterenol (ISO) or streptozotocin (STZ). ISO-injected rats were treated with argirein (30 mg·kg(-1)·d(-1), po) or testosterone replacement (0.5 mg·kg(-1)·d(-1), sc) for 5 days, and STZ-injected rats were treated with argirein (40-120 mg·kg(-1)·d(-1), po) or aminoguanidine (100 mg·kg(-1)·d(-1), po) for 4 weeks. After the rats were euthanized, blood samples and testes were collected. Serum hormone levels were measured, and the expression of endothelin receptor A (ETA), connexin 43 (Cx43) and other proteins in testes was detected. For in vitro experiments, testis homogenate was prepared from normal male rats, and incubated with ISO (1 µmol/L) or high glucose (27 mmol/L). RESULTS: ISO injection induced hyper-gonadotrophic hypogonadism characterized by low testosterone and high FSH and LH levels in the serum, whereas STZ injection induced hypogonadotrophic hypogonadism as evidenced by low testosterone and low FSH and LH levels in the serum. In the testes of ISO- and STZ-injected rats, the expression of ETA, MMP-9, NADPH oxidase and pPKCε was significantly increased, and the expression of Cx43 was decreased. Administration of argirein attenuated both the abnormal serum hormone levels and the testis changes in ISO- and STZ-injected rats, and aminoguanidine produced similar actions in STZ-injected rats; testosterone replacement reversed the abnormal serum hormone levels, but did not affect the testis changes in ISO-injected rats. Argirein (0.3-3 µmol/L) exerted similar effects in testis homogenate incubated with ISO or high glucose in vitro. CONCLUSION: Two types of hypogonadism of male rats exhibit increased expression of ETA and depressed expression of Cx43 in testes, despite different patterns of serum FSH and LH. Argirein alleviates the two types of male hypogonadism via normalizing ETA and Cx43 in testes.

Isoproterenol induced stressful reactions in the brain are characterized by inflammation due to activation of NADPH oxidase and ER stress: attenuated by Apocynin, Rehmannia complex and Triterpene acids.

Inflammatory changes in the cerebral network are present in early mechanisms involved in neurodegenerative disease, Alzheimer disease (AD), and aging brain. We intended to verify that these are likely due to an activation of NADPH oxidase (NOX) and endoplasmic reticulum (ER) stress. Apocynin (APO) an inhibitor of NOX is potential to ameliorate these changes. Rehmannia complex (Reh) a famous prescription in China and the triterpene acids (TTA) isolated from Reh may relieve the isoproterenol (ISO) induced chronic inflammation in the brain, compared with APO. Rats were administered with ISO for 10 days and astrocytes were incubated with ISO for 24 h. Changes in neural MMP (matrix metalloproteinase), Cx43, AQP4 (aquaporin 4), NFκB, IκBß, and p-PERK (PKB like kinase) were conducted and intervened with APO, Reh and TTA, in vivo and in vitro, respectively. An increased MDA and upregulated NOX subunit p47phox, ETA, PERK in association with abnormal MMP-2/9 and Cx40/43 were found in cerebral tissue of ISO-injected rats. Astrocytes incubated with ISO exhibited upregulated APQ4, IκBß, NFκB and p-PERK/PERK and downregulated Cx43. These were significantly abrogated by APO and Reh, in vivo, and APO and TTA in vitro. In conclusion, neural damages induced by ISO were characterized by inflammatory changes in cerebral tissue and astrocytes, which were blunted significantly by APO, Reh and TTA, respectively. Reh and TTA are potential in alleviating the early pathogenesis in neurodegenerative changes in AD in the clinical settings through suppressing NOX and ER stress in the brain.

Hypoxia alters pharmacokinetics of argirein because of mitochondrial dysfunction that is alleviated by apocynin.

OBJECTIVES: Pharmacokinetics (PK) of argirein might be changed in response to mitochondrial (MITO) dysfunction and activated nicotinamide adenine dinucleotide phosphate oxidase (NOX) on hypoxia. We hypothesized that hypoxic changes in MITO and NOX could alter PK and tissue distribution of argirein. We tested if these changes in PK of argirein by hypoxia could be relieved by apocynin (APO), a blocker of NOX, through normalizing MITO and NOX. METHODS: Male Sprague-Dawley rats were exposed to hypoxia (O2 10% ± 5% 8 h per day) for 7 days and treated with APO (80 mg/kg, i.g.) in the last 4 days. The PK and tissue distribution of argirein were monitored by measuring its main metabolite rhein using HPLC analysis. Manganese superoxide dismutase (MnSOD) and NOX were assayed. KEY FINDINGS: The PK parameters and concentrations of rhein in the kidney, liver, heart and testes were significantly altered under hypoxia, accompanied with a reduced MnSOD and upregulated NOX compared with the normal. Altered argirein PK and distribution in these organs were relieved following APO administration. CONCLUSION: Abnormal PK and distribution of argirein by assaying its metabolite rhein are significant, consequent to hypoxic injury that is significantly ameliorated by APO through normalizing MITO and NOX.

Male hypogonadism induced by high fat diet and low dose streptozotocin is mediated by activated endoplasmic reticulum stress and IκBß and attenuated by argirein and valsartan.

Male hypogonadism is frequently accompanied with type 2 diabetes due to testicular dysfunction, but the origin of the pathogenesis is not known. We measured whether pro-inflammatory factors including endoplasmic reticulum (ER) stress chaperones and inhibitory κBß (IκBß) contribute to testis damage in type 2 diabetic rats produced by a high-fat diet (HFD) and low dose streptozotocin (STZ). We determined whether these can be attenuated by the anti-inflammatory activity of argirein a derivative of rhein as compared to valsartan. Reduced testosterone and LH (luteinizing hormone) levels in serum were significant in association with a decrease in the levels of mRNA and steroidogenic acute regulatory protein (StAR), insulin receptor substrate (IRS-1), activated IκBß and ER stress chaperone C/EBP homologous protein (CHOP) in the diabetic testis and sperm count, motility and sexual behaviors were reduced in vivo. Additionally, Leydig cells cultured with high glucose showed upregulated IκBß, ER stress sensor PERK (PKR-like ER kinase) and p-Akt/Akt in vitro. These changes may be due to a component of inflammation linked to activated NADPH oxidase and were significantly alleviated by either argirein or valsartan. In conclusion, diabetic testopathy induced by a HFD and low STZ is characterized by an entity of inflammation and is alleviated by argirein and valsartan through normalizing activated IκBß and ER stress.

Hepatosteatosis and hepatic insulin resistance are blunted by argirein, an anti-inflammatory agent, through normalizing endoplasmic reticulum stress and apoptosis in diabetic liver.

OBJECTIVES: Insulin resistance represents a mechanism underlying defect metabolism of carbohydrate and lipid linked to inflammatory reactions in diabetic liver. We hypothesized that the changes may be secondary to endoplasmic reticulum (ER) stress, which could be alleviated by either argirein or valsartan. METHODS: Hepatosteatosis in diabetic liver was induced in rats fed with a high-fat diet (HFD) for 12 weeks combined with a single low dose of streptozotocin (STZ 35 mg/kg, ip). Interventions (mg/kg/d, po)with either argirein (50, 100 and 200) or valsartan (12) were conducted in the last 4 weeks. KEY FINDINGS: In diabetic liver fat was significantly accumulated in association with elevated hepatic glucose, serum insulin and homeostasis model assessment of insulin resistance value. Downregulated glucose transporter 4, insulin receptor substrate-1 and leptin receptor (P < 0.01) were found relative to normal, where DNA ladder, downregulated B cell lymphoma/leukemia-2, upregulated B cell lymphoma/leukemia-2 Associated X protein and upregulated ER stress chaperones such as Bip/GRP78 (also known as Binding Protein, BiP), PKR-like ER kinase (PERK), p-PERK/PERK and C/EBP homologous protein were significant. These abnormalities were significantly ameliorated by argirein and valsartan. CONCLUSIONS: Hepatosteatosis induced by HFD/low STZ manifests insulin resistance and apoptosis, linked to an entity of low-grade inflammation due to activated ER stress sensors. With anti-inflammatory activity either argirein or valsartan blunts hepatosteatosis through normalizing ER stress and apoptosis in the diabetic liver.

Argirein alleviates corpus cavernosum dysfunction by suppressing pro-inflammatory factors p66Shc and ER stress chaperone Bip in diabetic rats.

OBJECTIVES: The aim was to investigate whether argirein, which releases rhein and L-arginine after medication, could improve erectile dysfunction (ED) in diabetic rats through normalising the abnormalities of nitric oxide synthase (NOS), p66Shc and immunoglobulin heavy-chain binding protein (Bip), in the corpus cavernosum (CC). METHODS: SD rats were randomly divided into six groups. Except for the control group, rats were injected with streptozotocin (STZ) (60 mg/kg, i.p.) once. During weeks 5-8 following STZ injection, except for STZ-injected untreated rats, others were treated with aminoguanidine (AMG; 100 mg/kg/day, i.g.), or argirein at three doses (50, 100 and 200 mg/kg/day, i.g.). The vascular activity and biomarkers of the cavernosum were examined. KEY FINDINGS: Constrictive and dilative activity was abnormal in the CC, associated with decreased nitric oxide (NO) in serum in the diabetic (DM) group. Increased expression of p66Shc, Bip and inducible nitric oxide synthase (iNOS) and decreased endothelial nitric oxide synthase (eNOS) in the CC were significant in DM rats. Argirein and AMG improved these abnormities significantly. CONCLUSIONS: We concluded that vascular activity of the cavernosal tissue was impaired due to upregulated p66Shc and Bip in the diabetic CC. Argirein alleviates the vascular dysfunction of the CC by suppressing these upregulated pro-inflammatory proteins caused by diabetic lesions.

[Comparative study on decoction and dissolution of crude and processed corni fructus].

To compare and study the decoction and dissolution of active constituents in crude and processed Corni Fructus. HPLC, the traditional Chinese medicine (TCM) decoction method and the dissolution methods were adopted to compare and study the decoction yield and dissolution rate of loganin and morroniside, active constituents in crude and processed Corni Fructus. The results showed that the content of active constituents loganin and morroniside in crude and processed Corni Fructus did not change significantly; compared with crude Corni Fructus, processed Corni Fructus (decoction) contained much higher loganin, with no obvious change in morroniside; compared with crude Corni Fructus, processed Corni Fructus (extracts) showed no significant difference in loganin dissolution, but notable increase in morroniside dissolution in intestinal fluid; in gastric fluid, processed Corni Fructus showed significant increase in loganin and morroniside dissolutions. However, in comprehensive consideration of the decoction dose in clinical administration, and calculated on the basis of the formula of the decoction yield x dissolution rate = decoction-dissolution product, it showed increase in the decoction-dissolution products of both of the active constituents loganin and morroniside, with significant difference. This suggested that processed Corni Fructus is superior to crude Corni Fructus in clinical application. In this article, we proposed to compare the changes in decoction and dissolution of active constituents in crude and processed Corni Fructus, study the decoction-dissolution product, and then apply it in the quality evaluation of crude and processed Corni Fructus.

Novel software-based method to classify structurally similar compounds combined with high performance liquid chromatography-quadrupole time of flight mass spectrometry to identify complex components of herbal medicines.

The components of herbal medicines (HMs) are usually extremely complex, belonging to hundreds of compound classes with diverse chemical and physical properties. Full characterization of HMs is hugely important in order to identify the individual chemical constituents and provide a first step toward determining which components are responsible for the therapeutic effects of a particular medical plant. In this study, a novel software-based approach was developed to classify structurally similar compounds, and this was combined with high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) to identify the individual components in an extract of Mentha haplocalyx. A total of 33 compounds were tentatively identified in samples of M. haplocalyx extract, including 9 new minor constituents reported for the first time. Semi-quantitative analysis of the extract sample was also carried out. Software validation and robustness tests were performed. The results of this study demonstrate the enormous potential of this strategy, using classification based on structural similarity together with HPLC-QTOF-MS, for the identification and quantification of complex components in HMs and related products.

Activation of AQP4, p66Shc and endoplasmic reticulum stress is involved in inflammation by carrageenan and is suppressed by argirein, a derivative of rhein.

OBJECTIVES: We investigated the effect of argirein on acute inflammation edema and examined that aquaporin 4 (AQP4), p66Shc and activating transcription factor (ATF-6) might be involved in carrageenan-induced rat paw inflammation and be reversed by argirein, rhein and indometacin, but not L-arginine. METHODS: Inflammation was produced by carrageenan injected into rat paw and treated orally with argirein (100 mg/kg), rhein (100 mg/kg), L-arginine (100 mg/kg) or indometacin (5 mg/kg). Inflammatory oedema and biomarkers were examined. KEY FINDINGS: Swelling was reduced by argirein, rhein and indometacin; argirein was more effective than rhein at 1 h following medication. Activation of AQP4, p66Shc, ATF-6, NADPH oxidase subunits p22phox, gp91phox and matrix metalloproteinase 2 (P < 0.01) was significant and was suppressed by arginine, rhein and indometacin but not by l-arginine. CONCLUSIONS: Activated AQP4, endoplasmic reticulum stress and p66Shc were actively implicated in the inflammation and these were suppressed by argirein, and its activity is favorable due to synergism in combination with L-arginine.

Simultaneous determination of four bioactive compounds in Verbena officinalis L. by using high-performance liquid chromatography.

BACKGROUND: Verbena officinalis L., called mabiancao in Chinese, is derived from the aerial part of Herba Verbanae. It is a traditional Chinese medicine commonly used in China and northern Europe, which is widely used for clearing away heat and detoxicating, promoting blood circulation, and removing blood stasis. This paper describes a sensitive and specific assay for the determination of four bioactive compounds in V. officinalis L. MATERIALS AND METHODS: In this paper, the four components were separated on an Agilent Zorbax Extend C(18) column (250 mm × 4.6 mm × 5 µm) and detected by a diode array detector. The mobile phase was composed of (a) aqueous phosphoric acid (0.1%, v/v) and (b) acetonitrile using a gradient elution. Analytes were performed at 30°C with a flow rate of 1.0 ml/min and UV detection at 203, 238, and 331 nm. RESULTS: All calibration curves showed good linear regression (r(2) ≥ 0.9999) within tested ranges. Overall intra- and interday variations were less than 1.84%, and the average recoveries were 97.32-102.81% for analytes. DISCUSSION AND CONCLUSION: The proposed method would be sensitive enough and reliable for comprehensive quality control for clinical use and modernization of V. officinalis L.

Pharmacokinetic behavior of argirein, derived from rhein, is characterized as slow release and prolonged T1/2 of rhein in rats.

AIM: Rhein is an effective ingredient from Rheum palmatum L., Polygonum cuspidatum Sielb.et Zucc., Polygonum multiflorum Thunb. and has anti-inflammatory activity, however, plasma levels are too high and T(1/2) is not long enough following oral medication. Therefore, a modification of the rhein moiety was encouraged to improve the pharmacokinetic behavior. Argirein was produced by connecting rhein with l-arginine through hydrogen bond, which releases both rhein and L-arginine while getting into the body. The present study was to verify if the pharmacokinetic profile of argirein by measuring the released rhein is improved against those of untreated rhein administered alone. METHODS: A reversed-phase HPLC with a mobile phase of methanol mixed with acetate buffer was conducted. Rhein was monitored after arginine administration by i.g. and i.v. routes. Rhein alone was also administered and compared. RESULTS: The C(max) and AUC(0-48) of the released rhein following argirein medication were less than those following rhein administered. The bioavailability of argirein was 18.5-20.8% against 22.77-25.22% of rhein. A delayed T(max), a reduced C(max) and AUC(0-t) and an increased T(1/2) were significant in the argirein group as compared with those in the rhein group. CONCLUSION: The pharmacokinetic behavior of oral argirein presents a slow release property against those following oral rhein in rats. The released rhein following oral argirein is suitable in suppressing chronic inflammatory reactions attributed to prolonged T(1/2) and delayed T(max) due to its slow release pharmacokinetic characteristics.

ER stress, p66shc, and p-Akt/Akt mediate adjuvant-induced inflammation, which is blunted by argirein, a supermolecule and rhein in rats.

We investigated the anti-inflammatory activities of argirein and rhein on inflammatory edema in rat paw which was caused by complete adjuvant, compared with ibuprofen. We hypothesized that the adjuvant-induced inflammation is attributed to upregulation of activating transcript factor 6 (ATF6; a chaperone for endoplasmic reticulum (ER) stress), p66Shc (an adaptive protein modulating oxidative stress), and NADPH oxidase subunits p22phox and gp91phox in the inflamed tissues. Biomarkers were measured in the rat paw in association with monitoring swellings. The primary inflammatory edema of the injected paw occurred rapidly and sustained over a couple of days, and the secondary inflammation developed 2 weeks later. The inflammatory edema was accompanied by upregulation of cytokines including ATF6, p66Shc, p22phox, gp91phox, and MMP-2 and an increase in ratio of p-Akt/Akt in the afflicted paw. These were suppressed by either argirein and rhein or ibuprofen. These findings indicate that ER stress, upregulated p66Shc, and phosphorylated Akt are actively implicated in the inflammatory zone caused by adjuvant injection. These biomarkers were causal factors responsible for inflammation of the afflicted paw and were suppressed by a supermolecule argirein and rhein, and the anti-inflammatory activities of the two compounds were comparable to that of ibuprofen.

Isoproterenol-induced FKBP12.6/12 downregulation is modulated by ETA and ETB receptors and reversed by argirhein, a derivative of rhein.

AIM: To investigate which endothelin receptors mediated isoproterenol (ISO)-induced downregulation of FKBP12.6/12 in cardiomyocytes and study whether argirhein, a novel compound containing rhein and L-arginine that has anti-inflammatory activity, could reverse the downregulation of FKBP12.6/12 induced by ISO. METHODS: Neonatal rat cardiomyocytes were incubated with ISO to downregulate FKBP12.6/12. Then the cells were treated with a selective ET(A) blocker (PD156707) and a ET(B) blocker (IRL1038), a dual ET(A)/ET(B) antagonist (CPU0213), and argirhein, respectively. FKBP12.6/12 expression was assayed by RT-PCR, Western blot, and immunocytochemistry. RESULTS: The expression of FKBP12.6 mRNA was reduced by 37.7% (P<0.01) and 28.9% (P<0.05) relative to the control by ISO 1 and 0.1 µmol/L, respectively, but no response to ISO 0.01 µmol/L was observed in vitro. FKBP12.6/12 protein expression was reduced by 47.2% (P<0.01) and 37.8% (P<0.05) by ISO 1 and 0.1 µmol/L, respectively. This decrease was reversed significantly by PD156707, or IRL1038, and CPU0213. CPU0213 was more potent than either PD156707 or IRL-1038. Argirhein 10 µmol/L blunted the downregulation of FKBP12.6/12 by ISO, as demonstrated by the rising mRNA and protein levels and by the fluorescent density of the ISO-incubated cardiomyocytes. CONCLUSION: In cardiomyocytes, the ISO induced downregulation of FKBP12.6/12 is modulated by both ET(A) and ET(B). A new compound, argirein, reversed the down-regulation of FKBP12.6/12 expression in myocardial cells stimulated with ISO.

Conversion of puerarin into its 7-O-glycoside derivatives by Microbacterium oxydans (CGMCC 1788) to improve its water solubility and pharmacokinetic properties.

Microbacterium oxydans strain NJ 6 isolated from soil samples converted puerarin into two novel compounds, puerarin-7-O-glucoside and puerarin-7-O-isomaltoside, via an unreported O-glycosylation of the phenolic hydroxyl group at the 7-position of puerarin. Sucrose, maltotriose, and maltose could be used as glucosyl donors for glycosylation of puerarin, but uridine-diphosphate glucose, glucose, fructose, lactose, cyclodextrin, and starch could not. Regardless of the position of B-ring in the (iso)flavonoids core structure, the glycosylation of the phenolic hydroxyl group at the 7-position of (iso)flavonoids was governed by the presence or absence of a glucosyl residue at 8-C. The apparent solubility of puerarin-7-O-glucoside and puerarin-7-O-isomaltoside was approximately 18 and 100 times that of natural puerarin, respectively. Like parent puerarin, puerarin-7-O-glucoside maintained its physiological ability to relax the contractions of isolated rat thoracic aortic rings in vitro induced by phenylephrine. However, puerarin-7-O-glucoside was able to maintain higher plasma concentrations and have a longer mean residence time in the blood than the parent puerarin.