Simultaneous estimation of five biomarkers of neuroprotective herb Ashwagandha NMITLI-118R AF1 in rat plasma and brain using LC-ESI-MS/MS: Application to its pharmacokinetic and stability studies.

Withania Somnifera (WS) is a popular nutritional supplement in the USA, Europe, and Asia, known for its pharmacological effects on neurological disorders. However, the bioanalytical method development, validation, and pharmacokinetics of WS NMITLI-118R AF1 biomarkers Withanolide A (WLD A), Withanone (WNONE), Withanolide B (WLD B), Withaferin A (WF A), and 12 Deoxywithastramonolide (12 DEOXY) in rats have not been comprehensively explored. This study aimed to develop and validate a sensitive and selective LC-ESI-MS/MS method for these biomarkers in male Sprague Dawley rats plasma and brain matrix. Rats were divided into eight groups, each containing five rats. A plant extract of NMITLI-118R AF1 at 50 mg/kg was orally administered to the rats for in-vivo pharmacokinetic investigation. All the analytes had a linear calibration curve (r2 > 0.999), and intra-day and inter-day precision (%) were found in the range of 2.46 - 13.71% and accuracy were within the acceptable range (±15%). The biomarkers of NMITLI-118R AF1 were found stable in in-vitro plasma and simulated gastro-intestinal fluids. The observed (Cmax) and (Tmax) values for the biomarkers in the systemic circulation were WLD A (5.59 ± 0.34 ng/mL, Tmax 1.00 ± 0.00 h), WNONE (6.28 ± 0.41 ng/mL, Tmax 0.95 ± 0.11 h), WLD B (6.45 ± 2.87 ng/mL, Tmax 0.95 ± 0.11 h), WF A (6.50 ± 0.27 ng/mL, Tmax 1.00 ± 0.00 h), and 12 DEOXY (5.68 ± 0.39 ng/mL, Tmax 1.00 ± 0.00 h). In contrast to the old method, our approach exhibits a lower limit of quantification (LLOQ), shorter run time (less than10 min), and enables the detection of WF A and WNONE in fresh rat plasma by other quantitative analysis of mass spectrometry (m/z) [M]+. Shows high sample volumes for both, larger plasma volumes, costlier sample collection techniques dried blood spot (DBS), more expensive solid phase extraction techniques (SPE) and longer analysis time 14 min. Moreover, our method requires a smaller sample volume 10 µL, offers faster analysis time 4 min, and achieves a higher sensitivity 1 ng/mL. This is the first report of a comprehensive study on in-vitro and in-vivo pharmacokinetics of NMITLI-118R AF1 biomarkers, which may aid in further pre-clinical and clinical trial investigations.

Myrtenal and ß-caryophyllene oxide screened from Liquidambaris Fructus suppress NLRP3 inflammasome components in rheumatoid arthritis.

BACKGROUND: Liquidambaris Fructus (LF) is the infructescence of Liquidambar formosana. In Traditional Chinese Medicine, LF has been used to treat joint pain, a common symptom of arthritis and rheumatism; however, a lack of pharmacological evidence has limited its applications in modern clinics. Therefore, this study aims to explore the protective effect of LF on rheumatoid arthritis (RA) and to identify its active ingredients. METHODS: Rats with adjuvant-induced arthritis (AIA) were divided into 4 groups and administered petroleum ether extract of LF (PEL), ethyl acetate extract of LF (EEL), water extract of LF (WEL), or piroxicam (PIR) respectively for 3 weeks. Two additional groups were used as normal control (NC) and model control (MC) and administered distilled water as a placebo. The clinical scores for arthritis, bone surface, synovial inflammation and cartilage erosion were used to evaluate the therapeutic efficacy of each treatment. The serum IL-1ß and TNF-α level and the expression of NLRP3, IL-1ß and caspase-1 p20 in the synovial tissue of AIA rats were evaluated by ELISA and Western blot. The active ingredients of LF were investigated using network pharmacology and molecular docking methods, and their inhibition of NLRP3 inflammasome activation was verified in the human rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) model. RESULTS: PEL could alleviate paw swelling, bone and joint destruction, synovial inflammation and cartilage erosion in the AIA rats, with significantly superior efficacy to that of EEL and WEL. PEL reduced IL-1ß and TNF-α serum levels, and attenuated the upregulation of NLRP3, IL-1ß and caspase-1 p20 expression in the synovial tissue of AIA rats. Network pharmacology and molecular docking results indicated that myrtenal and ß-caryophyllene oxide were the main two active ingredients of PEL, and these two compounds showed significant inhibition on TNF-α, NLRP3, IL-1ß and caspase-1 p20 expression in RA-FLS. CONCLUSIONS: Myrtenal and ß-caryophyllene oxide screened from PEL could suppress the activation of NLRP3 inflammasome, thereby alleviating RA symptoms.

Aloe vera and Honey Solution and Their Ethanolic Extraction Solution Could Act on Metastasis-Regulating Processes in Walker 256 Tumor Tissues In Vivo?

Research has shown that both Aloe vera and honey have anticancer and nutrition properties, including the inhibition of metastasis. In order to evaluate the effect of a solution of Aloe vera and honey (A) and their ethanolic fraction (F) on metastasis-regulating processes in primary tumors, Wistar rats were subcutaneously implanted with Walker 256 tumors and treated with A and F (670 µl/kg by gavage, daily for 21 days). An analysis of the primary tumor tissues of these animals showed a decrease in N-cadherin expression in groups WA and WF, with a concomitant increase in E-cadherin expression in group WA compared to the control group. Cathepsin D activity was also decreased in the tumor tissues from groups WA and WF. In addition, the number of blood vessels and their diameter significantly reduced in tumor tissues from groups WA and WF compared to those from control group. UHPLC-ESI-MS/MS analysis of the samples A and F, suggested presence of molecules with verified antitumor activity, including caffeic acid, ferulic acid, mannose, aloin A, aloin B, pinocembrin, chrysin, and kaempferol. These data showed that treatment with A and F could reduce the metastatic propensity of tumors by modulating neoangiogenesis and the process of epithelial-to-mesenchymal transition.

Inhibition of NF-κB and the oxidative stress -dependent caspase-3 apoptotic pathway by betaine supplementation attenuates hepatic injury mediated by cisplatin in rats.

BACKGROUND: Cisplatin is a major anti-cancer drug commonly used in the treatment of various cancers; nevertheless, the associated hepatotoxicity has limited its clinical application. The aim of this investigation is to test the impact of betaine supplementation on cisplatin-induced hepatotoxicity. METHODS: Animals were allocated into four groups; normal control group (control betaine group (250 mg/kg/day, po for twenty six days), cisplatin group (single injection of 7 mg/kg, ip) and betaine + cisplatin group (received betaine for twenty one days before cisplatin injection and daily after cisplatin for five days). RESULTS: Cisplatin-induced liver injury was confirmed by increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Cisplatin elevated lipid peroxides, and reduced the concentrations of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase and superoxide dismutase (SOD) in hepatic tissues. Cisplatin increased the inflammatory mediators; nitrite and tumor necrosis factor-α (TNF- α) in hepatic tissues. Increased gene expressions of the apoptotic marker, caspase-3 and nuclear factor-kappa B (NF-κB) were observed in hepatic tissues of cisplatin-treated rats. All these changes were further confirmed by histopathological findings in cisplatin group. Pre-treatment with betaine reduced serum aminotransferases (ALT and AST), and lowered hepatic concentrations of lipid peroxides, nitrite and TNF-α while increased SOD, GSH, catalase, and GSH-Px concentrations. Moreover, the histological and immunohistochemical changes were improved. CONCLUSION: The suppression of NF-κß-mediated inflammation, oxidative stress, and caspase-3 induced apoptosis are possible mechanisms to the observed hepatoprotective effect of betaine.

Effects of dietary level of tannic acid and protein on internal organ weights and biochemical blood parameters of rats.

Tannic acid (TA) is a polyphenolic compound with a health-promoting potential for humans. It is hypothesised that TA effects on the relative weight of internal organs and biochemical blood indices are modified by dietary protein level in rats. The study involved 72 rats divided into 12 groups fed diets with 10 or 18% of crude protein (CP) and supplemented with 0, 0.25, 0.5, 1, 1.5 or 2% of TA. After 3 weeks of feeding, the relative weight of the caecum was greater in rats fed TA diets, while feeding diets with 10% of CP increased the relative weight of the stomach, small intestine and caecum, but decreased that of kidneys and spleen. Albumin concentration was higher in rats fed 0.25% and 0.5% TA diets than in rats given the 2% TA diets. The 2% TA diets reduced creatine kinase (CK) activity compared to non-supplemented diets and those with 0.5, 1 and 1.5% of TA. Rats fed the 10% CP diets had a higher activity of alkaline phosphatase, amylase, and γ-glutamyltransferase as well as the concentration of iron and cholesterol, but lower that of urea and uric acid. The interaction affected only cholinesterase activity. In conclusion, TA induced caecal hypertrophy and could act as a cardioprotective agent, as demonstrated by reduced CK activity, but these effects were not modified by dietary protein level.

Effects of ciprofloxacin on fetal rat liver during pregnancy and protective effects of quercetin.

Urinary tract infections are common in pregnant women and ciprofloxacin frequently is used as a broad spectrum antibiotic. It has been suggested that ciprofloxacin causes liver damage in fetuses. Quercetin is a flavonoid with antioxidant properties. We investigated the efficacy of quercetin treatment for preventing fetal liver damage caused by ciprofloxacin. Pregnant rats were divided into four groups: untreated control group (C), 20 mg/kg quercetin for 21 days group (Q), 20 mg/kg twice/day ciprofloxacin for 10 days group (CP), and 20 mg/kg, ciprofloxacin + quercetin for 21 days group (CP + Q). Fetal livers were removed on day 21 of gestation to measure antioxidants and for histological observation. Malondialdehyde (MDA) and glutathione (GSH) levels, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were measured in tissue samples. GSH-Px, SOD and CAT activities were significantly lower in the CP group compared to group C. A significant increase in MDA was observed in the CP group compared to group C. There was no significant difference in GSH levels in any group. MDA levels were lower and CAT, SOD and GSH-Px enzyme activities were higher in the CP + Q group compared to group CP. Liver samples of the CP group exhibited central vein dilation, portal vein congestion, pyknotic nuclei and cytoplasmic vacuolization in some hepatocytes. Histological changes were less prominent in the rats treated with quercetin. Use of ciprofloxacin during pregnancy caused oxidative damage in fetal liver tissue. Oxidative stress was ameliorated by quercetin. Quercetin supports the antioxidant defense mechanism and it is beneficial for treating fetal liver damage caused by ciprofloxacin.

Antioxidant and wound healing activity of Lavandula aspic L. ointment.

Lavandula aspic L. is a strongly aromatic shrub plant of the Lamiaceae family and traditionally used in herbal medicine for the treatment of several skin disorders, including wounds, burns, and ulcers. The present study aimed to investigate the composition and in vitro antioxidant activity of lavender essential oil. In addition, it aimed to evaluate the excision wound healing activity and antioxidant property of a Lavandula aspic L. essential oil formulated in ointment using a rat model. The rats were divided into five groups of six animals each. The test groups were topically treated with the vehicle, lavender ointment (4%) and a reference drug, while the control group was left untreated. Wound healing efficiency was determined by monitoring morphological and biochemical parameters and skin histological analysis. Wound contraction and protein synthesis were also determined. Antioxidant activity was assessed by the determination of MDA rates and antioxidant enzymes (GPx, catalase and superoxide dismutase). The treatment with lavender ointment was noted to significantly enhance wound contraction rate (98%) and protein synthesis. Overall, the results provided strong support for the effective wound healing activity of lavender ointment, making it a promising candidate for future application as a therapeutic agent in tissue repairing processes associated with skin injuries.

Blood lipids affect rat islet blood flow regulation through ß3-adrenoceptors.

Pancreatic islet blood perfusion varies according to the needs for insulin secretion. We examined the effects of blood lipids on pancreatic islet blood flow in anesthetized rats. Acute administration of Intralipid to anesthetized rats increased both triglycerides and free fatty acids, associated with a simultaneous increase in total pancreatic and islet blood flow. A preceding abdominal vagotomy markedly potentiated this and led acutely to a 10-fold increase in islet blood flow associated with a similar increase in serum insulin concentrations. The islet blood flow and serum insulin response could be largely prevented by pretreatment with propranolol and the selective ß3-adrenergic inhibitor SR-59230A. The nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester prevented the blood flow increase but was less effective in reducing serum insulin. Increased islet blood flow after Intralipid administration was also seen in islet and whole pancreas transplanted rats, i.e., models with different degrees of chronic islet denervation, but the effect was not as pronounced. In isolated vascularly perfused single islets Intralipid dilated islet arterioles, but this was not affected by SR-59230A. Both the sympathetic and parasympathetic nervous system are important for the coordination of islet blood flow and insulin release during hyperlipidemia, with a previously unknown role for ß3-adrenoceptors.

Simultaneous UPLC-MS/MS analysis of native catechins and procyanidins and their microbial metabolites in intestinal contents and tissues of male Wistar Furth inbred rats.

Procyanidins have been extensively investigated for their potential health protective activities. However, the potential bioactivities of procyanidins are limited by their poor bioavailability. The majority of the ingested dose remains unabsorbed and reaches the colon where extensive microbial metabolism occurs. Most existing analytical methods measure either native compounds (catechins and procyanidins), or their microbial metabolites. The objectives of this study were to develop a high-throughput extraction and UPLC-MS/MS method for simultaneous measurement of both native procyanidins and their metabolites, facilitating high-throughput analysis of native and metabolite profiles in various regions of the colon. The present UPLC-MS/MS method facilitates simultaneous resolution and detection of authentic standards of 14 native catechin monomers and procyanidins, as well as 24 microbial metabolites. Detection and resolution of an additional 3 procyanidin dimers and 10 metabolites for which standards were not available was achieved. Elution and adequate resolution of both native compounds and metabolites were achieved within 10min. The intraday repeatability for native compounds was between 1.1 and 16.5%, and the interday repeatability for native compounds was between 2.2 and 25%. Intraday and interday repeatability for metabolites was between 0.6 and 24.1% and 1 and 23.9%, respectively. Observed lower limits of quantification for native compounds were ∼9-350fmol on-column, and for the microbial metabolites were ∼0.8-12,000fmol on-column. Observed lower limits of detection for native compounds were ∼4.5-190fmol on-column, and for metabolites were 0.304-6020fmol on-column. For native monomers and procyanidins, extraction recoveries ranged from 38 to 102%. Extraction recoveries for the 9 microbial metabolites tested ranged from 41 to 95%. Data from tissue analysis of rats gavaged with grape seed extract indicate fairly high accumulation of native compounds, primarily monomers and dimers, in the cecum and colon. Metabolite data indicate the progressive nature of microbial metabolism as the digesta moves through the lower GI tract. This method facilitates the high-throughput, sensitive, and simultaneous analysis of both native compounds and their microbial metabolites in biological samples and provides a more efficient means of extraction and analysis than previous methods.

Antidiabetic effect of Ficus racemosa Linn. stem bark in high-fat diet and low-dose streptozotocin-induced type 2 diabetic rats: a mechanistic study.

The present study was designed to investigate the effects of the ethanol extract of Ficus racemosa (FRE) on biochemical parameters in type 2-like diabetes, induced by a combination of standardised high-fat diet and low-dose streptozotocin (25mgkg(-1), i.p.) in rats. To elucidate the mode of action of FRE, its effects on a battery of targets involved in glucose homeostasis was evaluated. FRE (200 and 400mgkg(-1), p.o.), in a dose-dependent manner, altered the biochemical parameters and significantly improved glucose tolerance and HDL-c levels. In different bioassays, FRE showed inhibition of PTP-1B (IC50 12.1µg/mL) and DPP-IV (42.5%). FRE exhibited 82.6% binding to PPAR-γ. Furthermore FRE exhibited stimulation of glucose uptake by skeletal muscles (hemi-diaphragm). Bergenin was quantified in bioactive-FRE by high-performance liquid chromatography (0.15%w/w). This is the first report demonstrating the effectiveness of F. racemosa stem bark in type 2 diabetes and targets involved in it.

Donor simvastatin treatment abolishes rat cardiac allograft ischemia/reperfusion injury and chronic rejection through microvascular protection.

BACKGROUND: Ischemia/reperfusion injury may have deleterious short- and long-term consequences for cardiac allografts. The underlying mechanisms involve microvascular dysfunction that may culminate in primary graft failure or untreatable chronic rejection. METHODS AND RESULTS: Here, we report that rat cardiac allograft ischemia/reperfusion injury resulted in profound microvascular dysfunction that was prevented by donor treatment with peroral single-dose simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase and Rho GTPase inhibitor, 2 hours before graft procurement. During allograft preservation, donor simvastatin treatment inhibited microvascular endothelial cell and pericyte RhoA/Rho-associated protein kinase activation and endothelial cell-endothelial cell gap formation; decreased intragraft mRNA levels of hypoxia-inducible factor-1α, inducible nitric oxide synthase, and endothelin-1; and increased heme oxygenase-1. Donor, but not recipient, simvastatin treatment prevented ischemia/reperfusion injury-induced vascular leakage, leukocyte infiltration, the no-reflow phenomenon, and myocardial injury. The beneficial effects of simvastatin on vascular stability and the no-reflow phenomenon were abolished by concomitant nitric oxide synthase inhibition with N-nitro-l-arginine methyl ester and RhoA activation by geranylgeranyl pyrophosphate supplementation, respectively. In the chronic rejection model, donor simvastatin treatment inhibited cardiac allograft inflammation, transforming growth factor-ß1 signaling, and myocardial fibrosis. In vitro, simvastatin inhibited transforming growth factor-ß1-induced microvascular endothelial-to-mesenchymal transition. CONCLUSIONS: Our results demonstrate that donor simvastatin treatment prevents microvascular endothelial cell and pericyte dysfunction, ischemia/reperfusion injury, and chronic rejection and suggest a novel, clinically feasible strategy to protect cardiac allografts.

Anti-inflammatory and analgesic activity of protocatechuic acid in rats and mice.

Anti-inflammatory and analgesic activity of protocatechuic acid (PCA), a natural product, was evaluated in different rat models (viz., carrageenan-induced paw oedema, cotton pellet-induced granuloma and Freund's adjuvant arthritis) of inflammation and chemical and heat induced mouse models of pain. Treatment with PCA inhibited significantly different biological parameters like hind paw oedema, granuloma exudates formation and arthritis index in carrageenan oedema, cotton pellet granuloma and Freund's adjuvant arthritis, respectively. The biochemical changes viz., glutathione, superoxide dismutase, catalase, lipid peroxidation and NO in oedematous or in liver tissues and serum alanine aminotransferase and lactic dehydrogenase occurred during different types of inflammation were either significantly restored or inhibited with PCA pretreatment. Present experimental findings demonstrate promising anti-inflammatory and analgesic activity of PCA which is comparable with that of standard drugs used.

Does intraabdominal use of Ankaferd Blood Stopper cause increased intraperitoneal adhesions?

BACKGROUND: The aim of this study was to investigate whether intraabdominal Ankaferd Blood Stopper (ABS) causes increased intraabdominal adhesion formation and to determine any side effects of ABS in vivo. METHODS: The present experimental study was designed to examine the effects of Ankaferd solution on peritoneal adhesion formation in a rat model of cecal abrasion. Intraperitoneal adhesions were assessed macroscopically and histopathologically on the 10th postoperative day. The possible adverse affects of ABS on liver and lung tissues were analyzed histopathologically, and blood chemistry was also evaluated. RESULTS: Our study revealed that ABS reduced intraperitoneal adhesion formation in an experimental rat model. The blood chemistry was not disturbed due to ABS administration. Intraperitoneal administration of ABS led to some minor changes in the lungs and serosal surfaces of the intestines, with minor architectural changes in the liver that were not considered as toxic. Further studies with various application doses and routes with more detailed cellular analysis are thus warranted to clarify the possible pleiotropic and adverse effects of this new agent away from hemostasis. CONCLUSION: There was less intraperitoneal adhesion formation in the ABS group than in the control group and saline group. Intraperitoneal administration of ABS has no toxic effects on blood chemistry or the lungs, kidneys and the liver, but it has some minor adverse effects.

Antifertility activity of leaves of Plumbago zeylanica Linn. in female albino rats.

OBJECTIVES: To evaluate the antifertility properties of extracts of leaves of Plumbago zeylanica Linn. (Plumbaginaceae). METHODS: The effects of petroleum ether, chloroform, acetone, ethanol and aqueous extracts of the leaves of P. zeylanica on the estrous cycle of rats were studied at two dose levels, namely, 200 and 400 mg/kg. The effective extracts were assessed with regard to their oestrogenic activity in the same species. RESULTS: The acetone and ethanol extracts were most effective in interrupting the estrous cycle of the rats (p < 0.05). The animals exhibited a prolonged diestrous stage of the estrous cycle corresponding to a temporary inhibition of ovulation. The antiovulatory activity was reversible on discontinuation of treatment. Both extracts showed significant oestrogenic and anti-oestrogenic activity (p < 0.05). CONCLUSIONS: The acetone and ethanolic extracts of leaves of P. zeylanica have an antifertility activity.

Reversal of high pancreatic islet and white adipose tissue blood flow in type 2 diabetic GK rats by administration of the beta3-adrenoceptor inhibitor SR-59230A.

Previous studies have shown that the Goto-Kakizaki (GK) rat, a nonobese type 2 diabetes model, has an increased white adipose tissue (WAT) and islet blood flow when compared with control rats. The aim of the study was to examine if these increased blood flow values in GK rats could be affected by the beta(3)-adrenoceptor antagonist SR-59230A. We measured organ blood flow with a microsphere technique 10 min after administration of SR-59230A (1 mg/kg body wt), or the corresponding volume of 0.9% NaCl solution (1 ml/kg body wt) in rats anaesthetized with thiobutabarbital. The GK rat had an increased blood flow in all intra-abdominal adipose tissue depots except for the sternal fat pad compared with Wistar-Furth (WF) rats. However, no differences were seen in the blood perfusion of subcutaneous white or brown adipose tissue. The blood flow was also increased in both the pancreas and in the islets in the GK rat compared with WF rats. SR-59230A treatment affected neither WAT nor pancreatic blood flow in WF rats. In GK rats, on the other hand, SR-59230A decreased both WAT and islet blood flow values to values similar to those seen in control WF rats. The whole pancreatic blood flow was not affected by SR-59230A administration in GK rats. Interestingly, the brown adipose tissue blood flow in GK rats increased after SR-59230A administration. These results suggest that beta(3)-adrenoceptors are involved in regulation of blood flow both in islet and in adipose tissue.

Glycated chitosan as a new non-toxic immunological stimulant.

Chitosan is capable of stimulating immune responses. However, because chitosan is not water soluble, it has limited biological applications. By attaching galactose molecules to the chitosan molecules, a new water-soluble compound, glycated chitosan (GC), was synthesized. GC was designed for immune stimulations in combination with phototherapies in the treatment of metastatic tumors. To investigate the possible toxicity of GC, cultures of normal and tumor cells were incubated with GC of different concentrations and the cell viabilities were determined. For in vivo studies, GC solution was fed or injected to animals and its toxicity was determined through observations of animals and histological examinations of vital organs. No toxic effects of GC were observed in cultured cells or in animal studies. In addition, the immunological effect of GC was investigated through its stimulation of TNFalpha secretion by macrophages in vitro. In vivo studies showed enhancement of the survival of laser immunotherapy-treated rats bearing metastatic mammary tumors. Our in vitro and in vivo results indicated that GC was a strong immunological stimulant. Its non-toxic nature and immunological activity make GC a potential immunoadjuvant for treatment of metastatic tumors.

Deficient BH4 production via de novo and salvage pathways regulates NO responses to cytokines in adult cardiac myocytes.

Adult rat cardiac myocytes typically display a phenotypic response to cytokines manifested by low or no increases in nitric oxide (NO) production via inducible NO synthase (iNOS) that distinguishes them from other cell types. To better characterize this response, we examined the expression of tetrahydrobiopterin (BH4)-synthesizing and arginine-utilizing genes in cytokine-stimulated adult cardiac myocytes. Intracellular BH4 and 7,8-dihydrobiopterin (BH2) and NO production were quantified. Cytokines induced GTP cyclohydrolase and its feedback regulatory protein but with deficient levels of BH4 synthesis. Despite the induction of iNOS protein, cytokine-stimulated adult cardiac myocytes produced little or no increase in NO versus unstimulated cells. Western blot analysis under nonreducing conditions revealed the presence of iNOS monomers. Supplementation with sepiapterin (a precursor of BH4) increased BH4 as well as BH2, but this did not enhance NO levels or eliminate iNOS monomers. Similar findings were confirmed in vivo after treatment of rat cardiac allograft recipients with sepiapterin. It was found that expression of dihydrofolate reductase, required for full activity of the salvage pathway, was not detected in adult cardiac myocytes. Thus, adult cardiac myocytes have a limited capacity to synthesize BH4 after cytokine stimulation. The mechanisms involve posttranslational factors impairing de novo and salvage pathways. These conditions are unable to support active iNOS protein dimers necessary for NO production. These findings raise significant new questions about the prevailing understanding of how cytokines, via iNOS, cause cardiac dysfunction and injury in vivo during cardiac inflammatory disease states since cardiac myocytes are not a major source of high NO production.

Preconditioning with ozone abrogates acute rejection and prolongs cardiac allograft survival in rats.

Acute cardiac allograft rejection remains a major cause of morbidity and mortality after heart transplantation and predisposes for the development of graft vasculopathy. The aim of this study was to investigate the immunomodulatory effect of preconditioning of the donor and recipient with medical ozone (O(3)/O(2)) on acute allograft rejection. Minimizing the initial ischemia-reperfusion injury may result in a reduction of graft vasculopathy and ameliorate long-term outcomes after cardiac transplantation. Lewis rats were challenged with Wistar-Furth cardiac allograft. In donor and recipient animals a medical ozone (O(3)/O(2))-pneumoperitoneum was induced by single (1x) or repetitive (5x) insufflation (concentration: 50 microg/mL, 80 mL/kg body weight) of medical ozone intraperitoneally. Without immunomodulatory therapy (n = 11) cardiac allograft survival was 5.9 +/- 0.9 days. Preconditioning with medical ozone alone (single bolus as well as repetitive administration, n = 7) of the donor and recipient animals prolonged cardiac allograft survival significantly to 7.6 +/- 1.4 days (P < .05), without any adjunctive immunosuppressive therapy. In this pilot study, the intraperitoneal administration of ozone in donor and recipient animals protected from ischemia-reperfusion injury, reduced the immunogenicity of the graft, and prolonged cardiac allograft survival. Further studies are warranted to elucidate the underlying mechanisms and--more important--to investigate the effect on the development of graft vasculopathy, the major obstacle to long-term graft and patient survivals.

Inhibitory effects of ginger oil on spontaneous and PGF2alpha-induced contraction of rat myometrium.

Solvent extracts of ginger, the rhizome of Zingiber officinale Roscoe (Zingiberaceae), have been extensively studied for their pharmacological activities in smooth muscles. However, the effects of ginger essential oil on smooth muscle contractility have not been elucidated. The aims of the study were to investigate the effects of ginger oil on rat myometrial contractility. We particularly examined the effects on phasic contractions arising either spontaneously or with PGF (2) (alpha) stimulation. Ginger oil was obtained by hydrodistillation and its constituents analyzed using gas chromatography and mass spectrometry. Rats were humanely killed by asphyxiation with CO (2), and longitudinal uterine smooth muscles were isolated. Isometric force was measured and the effects of ginger oil studied. It was found that citral was the main constituent of ginger oil (24 %). Ginger oil inhibited spontaneous contractions with an IC (50) of 50 microL/100 mL (10 - 150 microL/100 mL). The PGF (2) (alpha)-induced contractions were also significantly reduced by ginger oil. Increases in external calcium concentration completely reversed the relaxant effects of ginger oil. This was the case for both spontaneous and PGF (2) (alpha)-induced contractions. The effects of ginger oil were indistinguishable from those of pure citral. In conclusion, ginger oil is a potent inhibitor of phasic activity in rat uterus, irrespective of how it was produced. Our data suggest that the effects are largely due to citral, and could be via inhibition of L-type Ca channels.

Long-term effects of oral vitamin C supplementation on the endothelial dysfunction in the iris microvessels of diabetic rats.

The current study was aimed to investigate effects of long-term supplementation of vitamin C on the iris microcirculation in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in male Wistar-Furth rats by intravenous injection of STZ (55 mg/kg b.w.). The rats were divided into three groups: control rats (CON), STZ-induced diabetic rats (STZ), and STZ rats supplemented with vitamin C (STZ-vitC). For supplementation of vitamin C, ascorbic acid (1 g/l) was added into the drinking water. The experiments were performed at different periods (8, 12, 24 and 36 weeks) after injection of STZ. Blood glucose, tissue lipid peroxidation and plasma vitamin C were measured. To examine the endothelial function, leukocyte adhesion to the venular endothelium was evaluated in the iris post-capillaries by means of counting the number of leukocytes labeled with rhodamine 6G. Blood flow perfusion in the iris was monitored using a laser Doppler flow meter. In the STZ rats, hyperglycemia was induced with an increase in HbA(1c) and lipid peroxidation but with a decrease in the plasma vitamin C level which improved by vitamin C supplementation. The number of adherent leukocytes increased significantly, associated with reduction in the iris blood flow perfusion, at 8, 12, 24 and 36 weeks after injection of STZ. In the STZ-vitC rats, the iris blood flow perfusion was significantly increased in comparison with the STZ rats, while the leukocyte adhesion was decreased at 24 and 36 weeks. The statistical analysis shows that the leukocyte adhesion decreased with increase in the iris blood flow perfusion in STZ and STZ-vitC rats. In conclusion, vitamin supplementation suppressed leukocyte adhesion and thus endothelial dysfunction, associated with increase in iris blood flow perfusion in diabetes. The antioxidant vitamin C may be a therapeutic agent for preventing diabetic retinopathy.