Preeclamptic programming unevenly perturbs inflammatory and renal vasodilatory outcomes of endotoxemia in rat offspring: modulation by losartan and pioglitazone.

Introduction: Preeclampsia (PE) enhances the vulnerability of adult offspring to serious illnesses. The current study investigated whether preeclamptic fetal programming impacts hemodynamic and renal vasodilatory disturbances in endotoxic adult offspring and whether these interactions are influenced by antenatal therapy with pioglitazone and/or losartan. Methods: PE was induced by oral administration of L-NAME (50 mg/kg/day) for the last 7 days of pregnancy. Adult offspring was treated with lipopolysaccharides (LPS, 5 mg/kg) followed 4-h later by hemodynamic and renovascular studies. Results: Tail-cuff measurements showed that LPS decreased systolic blood pressure (SBP) in male, but not female, offspring of PE dams. Moreover, PE or LPS reduced vasodilations elicited by acetylcholine (ACh, 0.01-7.29 nmol) or N-ethylcarboxamidoadenosine (NECA, 1.6-100 nmol) in perfused kidneys of male rats only. The latter effects disappeared in LPS/PE preparations, suggesting a postconditioning action for LPS against renal manifestation of PE. Likewise, elevations caused by LPS in serum creatinine and inflammatory cytokines (TNFα and IL-1ß) as well as in renal protein expression of monocyte chemoattractant protein-1 (MCP-1) and AT1 receptors were attenuated by the dual PE/LPS challenge. Gestational pioglitazone or losartan reversed the attenuated ACh/NECA vasodilations in male rats but failed to modify LPS hypotension or inflammation. The combined gestational pioglitazone/losartan therapy improved ACh/NECA vasodilations and eliminated the rises in serum IL-1ß and renal MCP-1 and AT1 receptor expressions. Conclusion: Preeclamptic fetal programming of endotoxic hemodynamic and renal manifestations in adult offspring depends on animal sex and specific biological activity and are reprogrammed by antenatal pioglitazone/losartan therapy.

The renin-angiotensin system modulates endotoxic postconditioning of exacerbated renal vasoconstriction in preeclamptic offspring.

We recently reported exacerbated endotoxic signs of neuroinflammation and autonomic defects in offspring of preeclamptic (PE) dams. Here, we investigated whether PE programming similarly modifies hemodynamic and renal vasoconstrictor responsiveness to endotoxemia in PE offspring and whether this interaction is modulated by gestational angiotensin 1-7 (Ang1-7). Preeclampsia was induced by gestational treatment with L-NAME. Adult offspring was challenged with lipopolysaccharides (LPS, 5 mg/kg) and systolic blood pressure (SBP) and renal vasoconstrictions were assessed 4 h later. Male, but not female, offspring of PE rats exhibited SBP elevations that were blunted by LPS. Renal vasoconstrictions induced by angiotensin II (Ang II), but not phenylephrine, were intensified in perfused kidneys of either sex. LPS blunted the heightened Ang II responses in male, but not female, kidneys. While renal expressions of AT1-receptors and angiotensin converting enzyme (ACE) were increased in PE offspring of both sexes, ACE2 was upregulated in female offspring only. These molecular effects were diminished by LPS in male offspring. Gestational Ang1-7 caused sex-unrelated attenuation of phenylephrine vasoconstrictions and preferentially downregulated Ang II responses and AT1-receptor and nuclear factor-kB (NFkB) expressions in females. Together, endotoxemia and Ang1-7 offset in sexually-related manners imbalances in renal vasoconstriction and AT1/ACE/ACE2 signaling in PE offspring.

Dysregulated ACE/Ang II/Ang1-7 signaling provokes cardiovascular and inflammatory sequelae of endotoxemia in weaning preeclamptic rats.

Weaning preeclamptic (PE) rats exhibit exaggerated endotoxic signs of hypotension and cardiac autonomic neuropathy. Considering the role of renin-angiotensin system (RAS) in maternal programming during PE, we investigated the hypothesis that gestational modulation of offensive (Angiotensin II, Ang II) and defensive (Ang 1-7) components of RAS alleviates cardiovascular hyperresponsiveness of weaning PE mothers to postpartum endotoxemia. PE was induced by treating pregnant rats with the nitric oxide synthase inhibitor L-NAME (50 mg/kg/day) for 7 consecutive days starting from gestational day 14. The PE-associated elevations in gestational systolic blood pressure and proteinuria were reduced after gestational treatment with Ang 1-7 (Ang II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (RAS modulator), or combined losartan/pioglitazone, with the latter therapy being the most effective. In weaning PE rats, the potentiated falls in mean arterial pressure and spectral index of cardiac sympathovagal balance (low frequency/high frequency ratio) caused by i.v. Lipopolysaccharides (LPS, 5 mg/kg) were attenuated by all therapies. Pioglitazone and Ang 1-7 were more effective in reversing increases and decreases in left ventricular contractility and isovolumic relaxation time constant, respectively, seen in endotoxic PE mothers. Immunohistochemically, cardiac Toll-like receptor 4 (TLR-4) expression was increased in endotoxic PE rats, and this effect was abrogated by Ang 1-7 or losartan/pioglitazone. The same treatments blunted the increased cardiac angiotensin converting enzyme (ACE) expression whereas ACE2 expression was altered by none of the intervening therapies. Overall, the mitigation of Ang II/ACE imbalances alleviates the sensitized cardiovascular and inflammatory actions of endotoxemia in weaning PE mothers.

Short-lived sensitization of cardiovascular outcomes of postpartum endotoxemia in preeclamptic rats: Role of medullary solitary tract neuroinflammation.

Preeclampsia (PE) is a pregnancy-related disorder with serious maternal complications. Considering the increased importance of postpartum infection in maternal morbidity and mortality, we investigated whether preeclamptic maternal programming alters cardiovascular consequences of endotoxemia in rats and the role of cardiac and brainstem neuroinflammation in this interaction. Preeclampsia was induced by oral administration of L-NAME (50 mg/kg/day) for 7 days starting from day 14 of conception. Changes in blood pressure, heart rate, and cardiac autonomic function caused by lipopolysaccharide (LPS, 5 mg/kg i.v.) were assessed in mothers at 3 weeks (weaning time) and 9 weeks postnatally. Compared with respective non-PE counterparts, LPS treatment of weaning PE mothers caused significantly greater (i) falls in blood pressure, (ii) rises in heart rate and left ventricular contractility (dP/dtmax), (iii) reductions in time and frequency domain indices of heart rate variability and shifts in cardiac sympathovagal balance (low-frequency/high-frequency ratio, LF/HF) towards parasympathetic dominance, and (iv) attenuation of reflex bradycardic responses measured by the vasoactive method. The intensified LPS effects in weaning PE rats subsided after 9 weeks of delivery. Immunohistochemical studies showed increased protein expression of nuclear factor kappa B (NF-κB) in brainstem neuronal pools of the nucleus of the solitary tract (NTS), but not rostral ventrolateral medulla (RVLM), in endotoxic PE weaning rats compared with non-PE rats. Cardiac NF-κB expression was increased by LPS but this was similarly noted in PE and non-PE rats. Together, preeclamptic maternal programming elicits short-term exacerbation of endotoxic cardiovascular and autonomic derangements due possibly to exaggerated NTS neuroinflammatory insult.

Nicotine uncovers endotoxic-like cardiovascular manifestations in female rats: Estrogen and nitric oxide dependency.

Endotoxic manifestations are diminished in female populations due to immune boosting actions of sex steroids. Considering that tobacco constituents including nicotine inhibit estrogen synthesis, we tested the hypothesis that nicotine exposure unveils cardiovascular anomalies of endotoxemia in female rats. Studies were undertaken in conscious female rats treated with i.v. lipopolysaccharide (LPS, 10 mg/kg) in absence and presence of nicotine. In contrast to no effects for LPS when used alone, dose-related decreases in blood pressure (BP) and serum estrogen were noted in endotoxic rats treated consequently with nicotine (25, 50, or 100 µg/kg i.v.). Signs of cardiac autonomic dysfunction appeared in LPS/nicotine-treated rats such as (i) decreased time-domain indices of heart rate variability (HRV), e.g. standard deviation of R-R intervals (SDNN) and root mean square of successive differences in R-R interval durations (rMSSD), and (ii) reduced total power of the frequency spectrum and shifted cardiac sympathovagal balance toward sympathetic dominance. Nicotine reversed the LPS-evoked modest rises in serum TNFα and IL-1ß while had no effect on associated arterial baroreflex dysfunction, inferring no roles for inflammation or baroreflexes in LPS-nicotine interaction. Estrogen or aminoguanidine (iNOS inhibitor), but not pentoxifylline (TNFα inhibitor), abolished LPS/nicotine hypotension. Together, nicotine acts probably via reducing estrogen availability to uncover nitric oxide-dependent hypotension and autonomic dysregulation in endotoxic female rats.

Ovariectomy provokes inflammatory and cardiovascular effects of endotoxemia in rats: Dissimilar benefits of hormonal supplements.

The female gender is protected against immunological complications of endotoxemia. Here we investigated whether gonadal hormone depletion by ovariectomy (OVX) uncovers inflammatory and cardiovascular effects of endotoxemia and whether these effects are reversed by hormone replacement therapies. Changes in inflammatory cytokines, blood pressure (BP), left ventricular (LV) function, and cardiac autonomic activity caused by lipopolysaccharide (LPS) in conscious female rats with different hormonal states were determined. In contrast to no effects in sham-operated females, treatment of OVX rats with LPS (i) decreased BP, (ii) increased spectral low-frequency/high-frequency ratio of HRV, denoting enhanced cardiac sympathetic dominance, (iii) attenuated reflex tachycardic responses to sodium nitroprusside, and (iv) increased systolic contractility (dP/dtmax). The developed hypotension was (i) fully eliminated in estrogen (E2)-pretreated OVX rats, (ii) partially counteracted after selective activation of estrogen receptor-α (PPT) or ß (DPN). All estrogenic compounds abrogated LPS enhancement of cardiac sympathetic drive. However, PPT was more successful than E2 or DPN in compromising LPS depression in baroreflex activity and elevation in dP/dtmax. Molecular studies showed that PPT was most effective in attenuating the upregulated myocardial expressions of NF-κB and iNOS in endotoxic OVX rats. Myocardial expression of the defensive HSP70 was comparably increased by all estrogenic products. Except for improved cardiac spectral activity, none of these functional or molecular entities was affected by medroxyprogesterone acetate (MPA). Overall, our data suggest diverse therapeutic advantages for gonadal hormones in the worsened endotoxic complications in rats with surgical menopause, with probably more favorable role for ERα agonism within this context.

Additive counteraction by α7 and α4ß2-nAChRs of the hypotension and cardiac sympathovagal imbalance evoked by endotoxemia in male rats.

The cholinergic antiinflammatory pathway favorably influences end organ damage induced by inflammatory conditions. Here, we hypothesized that α7 and/or α4ß2-nicotinic acetylcholine receptors (nAChRs) protect against cardiovascular and autonomic imbalances induced by endotoxemia in rats. We assessed dose-effect relationships of i.v. nicotine (25, 50, or 100 µg/kg), PHA-543613 (α7-nAChR agonist; 0.2 or 2.0 mg/kg), or 5-iodo-A-85380 (5IA, α4ß2-nAChRs agonist; 0.01 or 0.1 mg/kg) on cardiovascular and inflammatory responses elicited by lipopolysaccharide (LPS, 10 mg/kg i.v.). The two lower doses of nicotine caused dose-dependent attenuation of hypotensive and tachycardic responses of LPS. Nicotine also reversed LPS-evoked reductions in time-domain indices of heart rate variability (HRV) and spectral measure of cardiac sympathovagal balance. Alternatively, hypotensive and tachycardic effects of LPS were (i) partly and dose-dependently reversed after selective activation of α7 (PHA) or α4ß2-nAChRs (5IA), and (ii) completely eliminated after co-treatment with the smaller doses of the two agonists. Further, PHA or 5IA abolished the reducing effect of LPS on time and spectral measures of HRV. Elevations in serum tumor necrosis factor-α (TNF-α) observed in LPS-treated rats were compromised upon co-administration of nicotine, PHA, or 5IA. In conclusion, monomeric α7 or heteromeric α4ß2-nAChRs favorably and additively influence inflammatory and associated cardiovascular anomalies induced by endotoxemia.

Hemin blunts the depressant effect of chronic nicotine on reflex tachycardia via activation of central NOS/PI3K pathway in female rats.

BACKGROUND: Chronic nicotine administration impairs reflex chronotropic responses that follow arterial baroreceptor unloading in female rats with repleted, but not depleted (ovariectomized, OVX), estrogen (E2). This study investigated whether products of nitric oxide synthase (NOS) and/or heme oxygenase (HO) and related soluble guanylate cyclase (sGC)/phosphatidylinositol 3-kinase (PI3K)/mitogen-activated protein kinases (MAPKs) signaling mediate the E2-sensitive depressant effect of nicotine on reflex tachycardia. METHODS: Baroreflex curves relating reflex tachycardic responses to falls in blood pressure (BP) generated by sodium nitroprusside (SNP) were established in conscious female rats and slopes of the curves were taken as measures of baroreflex sensitivity (BRS). RESULTS: Nicotine (2 mg/kg/day ip, 14 days) reduced BRS in OVX rats treated with E2 but not vehicle. Baroreceptor dysfunction in nicotine-treated OVXE2 rats was abolished after iv treatment with hemin (HO inducer) but not l-arginine (NOS substrate) denoting the importance of reduced availability of carbon monoxide, but not NO, in the nicotine effect. The favorable BRS effect of hemin was abolished after intracisternal (ic) administration of L-NAME (NOS inhibitor) or wortmannin (PI3 K inhibitor). Central circuits of MAPKs do not seem to contribute to the baroreflex facilitatory effect of hemin because the latter was preserved after central inhibition of MAPKERK (PD98059), MAPKp38 (SB203580) or MAPKJNK (SP600125). Likewise, sGC inhibition (ODQ) or E2 receptor blockade (ICI182780) failed to alter the hemin effect. CONCLUSION: The activation of central NOS/PI3K signaling following HO upregulation improves the E2-dependent depressant effect of nicotine on reflex tachycardia.

Heme oxygenase byproducts variably influences myocardial and autonomic dysfunctions induced by the cyclosporine/diclofenac regimen in female rats.

We recently reported that exposure to cyclosporine (CSA) plus diclofenac causes hypertension and impairs left ventricular (LV) and cardiac autonomic functions in female rats. Here, we tested the hypothesis that these effects could be mitigated by facilitated heme oxygenase (HO) signaling. Experiments were performed in female rats to assess the effects of 10-day treatment with CSA (25 mg/kg/day)/diclofenac (1 mg/kg/day) regimen on cardiovascular functions in absence and presence of maneuvers that upregulate HO or its enzymatic products. The CSA/diclofenac-induced hypertension and impairment in cardiac sympathovagal balance (i.e. reduced low-frequency/high-frequency spectral ratio) were blunted upon concurrent treatment with hemin (HO-1 inducer), tricarbonyldichlororuthenium (II) dimer (CORM-2, carbon monoxide-releasing molecule), or bilirubin. While none of the latter treatments affected the CSA/diclofenac-evoked decrease in isovolumic relaxation constant (Tau, a measure of diastolic function), the increased LV contractility (dP/dtmax) and attenuated reflex bradycardia in CSA/diclofenac-treated rats was abolished by bilirubin only. Paradoxically, the CSA/diclofenac-evoked attenuation in reflex tachycardia was improved in presence of hemin or CORM-2, but not bilirubin. The favorable hemin effects were abrogated after inhibition of HO (ZnPP) or nitric oxide synthase (NOS, l-NAME). These finding highlights NOS-dependent modulatory roles for HO and its enzymatic products in improving the worsened cardiovascular profile in CSA/diclofenac-treated female rats.

Gonadal hormone receptors underlie the resistance of female rats to inflammatory and cardiovascular complications of endotoxemia.

The male gender is more vulnerable to immunological complications of sepsis. Here, we tested the hypotheses that female rats are protected against endotoxemia-evoked hypotension and cardiac autonomic dysfunction, and that gonadal hormone receptors account for such protection. Changes in blood pressure, heart rate, and cardiac sympathovagal balance caused by i.v. lipopolysaccharide (LPS) were determined. In male rats, LPS elevated serum TNFα together with falls in blood pressure and rises in heart rate. The spectral index of cardiac sympathovagal balance (low-frequency/high-frequency ratio, LF/HF) was reduced by LPS, suggesting an enhanced parasympathetic dominance. Remarkably, none of these LPS effects was evident in female rats. We also report that pretreatment of female rats with fulvestrant (nonselective estrogen receptor blocker), PHTPP (estrogen receptor ß blocker), or mifepristone (progesterone receptor blocker) uncovered clear inflammatory (increased serum TNFα), hypotensive and tachycardic responses to LPS. However, these female rats, contrary to their male counterparts, exhibited increases in LF/HF ratio. On the other hand, LPS failed to modify inflammatory or cardiovascular states in rats pretreated with MPP (estrogen receptor α blocker). In females treated with formestane (aromatase inhibitor), LPS increased LF/HF ratio but had no effect on blood pressure. In male rats, the hypotensive and cardiac autonomic effects of LPS were (i) eliminated after treatment with estrogen, and (ii) intensified and inhibited, respectively, in flutamide (androgen receptor blocker)-pretreated rats. These findings highlight important roles for female gonadal hormones and functional estrogen receptor ß and progesterone receptors in offsetting inflammatory and cardiovascular derangements caused by endotoxemia in female rats.

Hybrid polymeric matrices for oral modified release of Desvenlafaxine succinate tablets.

Purpose: Desvenlafaxine succinate (DSV) is a water soluble anti-depressant drug, which is rapidly absorbed after oral administration exaggerating its side effects. The current work aimed to prepare controllable release DSV matrix to reduce DSV side effects related to its initial burst. Methods: Fifteen DSV matrix formulations were prepared using different polymers, polymer/drug ratios and matrix excipients and characterized using Differential Scanning Calorimetry (DSC), infrared (IR) spectroscopy, water uptake and in vitro DSV release. The release kinetics were calculated to determine the drug release mechanism. Ex-vivo DSV absorption via rat intestinal mucosal cells and the calculation of the apparent permeability coefficient (Papp) were performed using everted sac technique. Results: Maltodextrin was the best matrix excipient (F7 and F10) showing acceptable decrease in the initial burst compared to the innovator. The addition of negatively charged polymers sodium carboxy methyl cellulose (SCMC) or sodium alginate resulted in an interaction that was proved by DSC and IR findings. This interaction slowed DSV release. F10 showed an excellent absorption of more than 80% of DSV after 4 h and the highest similarity factor with the innovator (84.7). Conclusion: A controllable release pattern of DSV was achieved using Methocel, Maltodextrin and SCMC. The obtained results could be used as a platform to control the release of cationic water soluble drugs that suffer from side effects associated with their initial burst after oral administration.

Role of NADPHox/Rho-kinase signaling in the cyclosporine-NSAIDs interactions on blood pressure and baroreflexes in female rats.

AIMS: The hypertensive effect of the immunosuppressant drug cyclosporine (CSA) is paralleled, and probably triggered, by impaired arterial baroreceptor sensitivity (BRS). Here we asked if these effects of CSA are influenced by co-administration of nonsteroidal antiinflammatory drugs (NSAIDs) and if the oxidative NADPH-oxidase (NADPHox)/Rho-kinase (ROCK) pathway mediates this interaction. MATERIALS AND METHODS: Female rats were treated for 10days with CSA (25mg/kg/day), diclofenac (DIC, COX-1/COX-2 inhibitor, 1mg/kg/day), celecoxib (COX-2 inhibitor, 10mg/kg/day), or their combinations. Baroreflex curves relating changes in heart rate (HR) to increases or decreases in blood pressure (BP) evoked by phenylephrine (PE) and sodium nitroprusside (SNP), respectively, were constructed and slopes of the curves were taken as measures of BRS. KEY FINDINGS: Compared with control rats, CSA increased BP and reduced reflex chronotropic responses as indicated by the significantly smaller BRSPE and BRSSNP values. Similar effects were observed in rats treated with diclofenac alone or combined with CSA. Whereas CSA hypertension was maintained after selective COX-2 inhibition by celecoxib, the concomitant BRS reductions were largely eliminated. NADPHox inhibition by diphenyleneiodonium (DPI) blunted the CSA/DIC-evoked increases and decreases in BP and BRSPE, respectively. By contrast, fasudil (ROCK inhibitor) had no effect on CSA/DIC hypertension but reversed the associated reductions in both BRSPE and BRSSNP. SIGNIFICANCE: Depending on the nature of the cardiovascular response, NADPHox and ROCK contribute variably to the worsened cardiovascular profile in CSA/DIC-treated rats. Further, celecoxib rather than diclofenac could be a better choice as an add-on therapy to CSA in autoimmune arthritic conditions.

Modulation by NADPH oxidase of the chronic cardiovascular and autonomic interaction between cyclosporine and NSAIDs in female rats.

Cyclosporine (CSA) and nonsteroidal antiinflammatory drugs (NSAIDs) are used together to manage arthritic disorders with an immune component. Previous reports showed contrasting effects for NSAIDs on CSA nephrotoxicity and acute elevations in blood pressure. Both effects were ameliorated or exaggerated after selective cyclooxygenase-2 (COX2) and nonselective COX inhibition, respectively. Here we investigated: (i) the interaction of CSA with NSAIDs possessing variable COX1/COX2 selectivities on hemodynamic, left ventricular (LV) and cardiac autonomic and histologic profiles, and (ii) role of NADPH-oxidase (NOX)/Rho-kinase (ROCK) pathway in the interaction. Female rats were pre-instrumented with femoral catheters and treated for 10 days with CSA (25mg/kg/day), diclofenac (nonselective NSAIDs, 1mg/kg/day), celecoxib (COX2 inhibitor, 10mg/kg/day), or their combinations. CSA-mediated hypertension was maintained upon co-administration of either NSAID whereas the concomitant reductions in time- and frequency-domain indices of heart rate variability (HRV) were accentuated in presence of diclofenac but not celecoxib. The isovolumic relaxation time (Τau), a measure of diastolic function, was reduced by all regimens whereas LV contractility (dP/dtmax) remained unaffected. The CSA/diclofenac regimen, but not individual treatments, increased cardiac NOX2 expression and caused more cardiac structural damage. The inhibition of NOX by diphenyleneiodonium reversed CSA/diclofenac-evoked increases in MAP, decreases in HRV and Tau, cardiac structural damage, and increased NOX2 expression. No such effects were observed after ROCK inhibition by fasudil, despite concomitant decreases in NOX2 expression. In conclusion, CSA/diclofenac-treated female rats exhibit exacerbated hemodynamic, autonomic, LV, and histopathologic disturbances via ROCK-independent NOX2 upregulation.

Opposite Modulatory Effects of Selective and Non-Selective Cyclooxygenase Inhibition on Cardiovascular and Autonomic Consequences of Cyclosporine in Female Rats.

Non-steroidal anti-inflammatory drugs (NSAIDs) and the immunosuppressant drug cyclosporine (CSA) are concurrently administered in arthritis. Here, we investigated whether diclofenac (non-selective inhibitor of cyclooxygenase-1 and 2, COX-1/COX-2), celecoxib (selective COX-2 inhibitor) or SC560 (selective COX-1 inhibitor) interact variably with haemodynamic effects of CSA in conscious female rats. Changes caused by CSA (10 mg/kg i.v.) in blood pressure (BP), heart rate (HR), HR variability (HRV) and myocardial contractility were assessed in the absence and presence of individual NSAIDs (10 mg/kg each). Compared with vehicle values, CSA caused immediate and sustained (i) increases in BP and decreases in pulse pressure index (PPI) and HR, (ii) elevations in left ventricular (LV) contractility (dP/dtmax ) and isovolumic relaxation constant (Τau) and (iii) increases in the time- and frequency-domain indices of HRV and shifted the cardiac sympathovagal balance towards parasympathetic dominance. CSA hypertension was abolished in rats pre-treated with celecoxib and intensified in the presence of diclofenac or SC560. Alternatively, the CSA-evoked decreases in PPI, increases in HRV indices and cardiac parasympathetic dominance were blunted by celecoxib in contrast to no effect for diclofenac or SC560. Similarly, celecoxib, but not other NSAIDs, eliminated the elevated LV contractility (dP/dtmax ) and isovolumic relaxation constant (Τau, τ), which reflect cardiac systolic and diastolic function, respectively, that accompanied the CSA-induced pressure load. The data underscore the preferential capacity of selective COX-2 inhibition by celecoxib to mitigate CSA hypertension and consequent alterations in cardiac performance and autonomic balance. By contrast, CSA effects are preserved or even exacerbated after COX-1 inhibition.

A Multi-layered Particulate System for Desvenlafaxine Succinate Oral Customized Release.

BACKGROUND: With its reported side effects Desvenlafaxine succinate (DSV) is a good candidate to prepare prolonged release system. Such prolonged release could decrease the rapid DSV absorption after oral administration and reduce its exaggerated side effects. METHODS: A prolonged release Desvenlafaxine succinate (DSV) multilayered system was prepared by ionotropic gelation using sodium alginate (SA) and calcium chloride as a cross-linker. DSV was incorporated simultaneously during the gelation stage and the formed beads were evaluated for shape and particle size. Thirteen formulation variables including pH, DSV: polymer ratio, cross-linker concentration and curing time were optimized for optimal drug entrapment. The optimized formula was evaluated ex vivo using the everted sac technique to predict DSV absorption through intestinal mucosal cells, follow the permeation and calculate its apparent permeability coefficient. RESULTS: The optimum formulation variables were: pH (8-9), DSV: SA ratio (2:1), cross-linker concentration (5%w/v) and 30 min curing time. Multilayered beads coating using chitosan and SA was compared with uncoated beads or the innovator for DSV release. Coating of the beads greatly retarded DSV release with a release profile similar to that of the innovator. An optimized formula (T13) coated with 0.04% w/v of each of chitosan and SA was selected. The developed system gave rise to a prolonged release pattern with high similarity factor with the innovator. CONCLUSION: The results of the current work can be applied to prepare controlled release systems of similar drugs that have intense side effects associated with their initial burst after oral administration.

Histopathological and ultra-structural characterization of local neuromuscular damage induced by repeated phosphatidylcholine/deoxycholate injection.

Phosphatidylcholine/deoxycholate (PC/DC) combination is frequently used for injection lipolysis in body contouring and size reduction of subcutaneous lipomas. Nonetheless, studies that assess possible injurious effects of PC/DC combination on tissues at injection sites are inadequate. The current work attempts to evaluate the effects of repeated PC/DC injection on skeletal muscles and neural tissues at the injection site. For this purpose, female Wistar rats were randomly assigned into 2 groups, 10 rats each, and injected percutaneously via either normal saline (control group) or PC/DC (treated group) in the groin area for 4 consecutive days. Biopsies were harvested on the 4(th) day for histopathological studies. The results of the present work demonstrated that repeated injection of PC/DC caused neural damage and intense inflammation at the injection site leading to skeletal muscle degeneration, necrosis and fibrosis. Electron microscopic examination of the neural tissues in the injected area showed intra-neural fibroblasts, deposition of intra-neural collagen fibers and marked myelin degeneration. In addition, PC/DC injection caused thickening of intra-neural blood vessel walls and evident endo-neural mast cells. The current data highlight the attendant risk of neuromuscular injury associated with repeated PC/DC injection during the treatment of undesirable fat deposits and lipomas.

Green synthesis of silver nanoparticles using cranberry powder aqueous extract: characterization and antimicrobial properties.

BACKGROUND: The growing threat of microbial resistance against traditional antibiotics has prompted the development of several antimicrobial nanoparticles (NPs), including silver NPs (AgNPs). In this article, a simple and eco-friendly method for the synthesis of AgNPs using the cranberry powder aqueous extract is reported. MATERIALS AND METHODS: Cranberry powder aqueous extracts (0.2%, 0.5%, and 0.8% w/v) were allowed to interact for 24 hours with a silver nitrate solution (10 mM) at 30°C at a ratio of 1:10. The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy and their concentrations were determined using atomic absorption spectroscopy. The prepared NPs were evaluated by transmission electron microscopy, measurement of ζ-potential, and Fourier-transform infrared spectroscopy. The in vitro antimicrobial properties of AgNPs were then investigated against several microbial strains. Finally, in vivo appraisal of both wound-healing and antimicrobial properties of either plain AgNPs (prepared using 0.2% extract) or AgNP-Pluronic F-127 gel was conducted in a rat model after induction of a Staphylococcus aureus ATCC 6538P wound infection. RESULTS: The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy, where a surface-plasmon resonance absorption peak was observed between 432 and 438 nm. Both size and concentration of the formed AgNPs increased with increasing concentration of the extracts. The developed NPs were stable, almost spherical, and polydisperse, with a size range of 1.4-8.6 nm. The negative ζ-potential values, as well as Fourier-transform infrared spectroscopy analysis, indicated the presence of a capping agent adsorbed onto the surface of the particles. In vitro antimicrobial evaluation revealed a size-dependent activity of the AgNPs against the tested organisms. Finally, AgNPs prepared using 0.2% extract exhibited a substantial in vivo healing potential for full-thickness excision wounds in rats. CONCLUSION: AgNPs were successfully synthesized from a silver nitrate solution through a simple green route, using cranberry powder aqueous extract as a reducing as well as capping agent.

The estrogen-dependent baroreflex dysfunction caused by nicotine in female rats is mediated via NOS/HO inhibition: Role of sGC/PI3K/MAPKERK.

We have previously reported that estrogen (E2) exacerbates the depressant effect of chronic nicotine on arterial baroreceptor activity in female rats. Here, we tested the hypothesis that this nicotine effect is modulated by nitric oxide synthase (NOS) and/or heme oxygenase (HO) and their downstream soluble guanylate cyclase (sGC)/phosphatidylinositol 3-kinase (PI3K)/mitogen-activated protein kinases (MAPKs) signaling. We investigated the effects of (i) inhibition or facilitation of NOS or HO on the interaction of nicotine (2mg/kg/day i.p., 2 weeks) with reflex bradycardic responses to phenylephrine in ovariectomized (OVX) rats treated with E2 or vehicle, and (ii) central pharmacologic inhibition of sGC, PI3K, or MAPKs on the interaction. The data showed that the attenuation by nicotine of reflex bradycardia in OVXE2 rats was abolished after treatment with hemin (HO inducer) or l-arginine (NOS substrate). The hemin or l-arginine effect disappeared after inhibition of NOS (Nω-Nitro-l-arginine methyl ester hydrochloride, L-NAME) and HO (zinc protoporphyrin IX, ZnPP), respectively, denoting the interaction between the two enzymatic pathways. E2-receptor blockade (ICI 182,780) reduced baroreflexes in OVXE2 rats but had no effect on baroreflex improvement induced by hemin or l-arginine. Moreover, baroreflex enhancement by hemin was eliminated following intracisternal (i.c.) administration of wortmannin, ODQ, or PD98059 (inhibitors of PI3K, sGC, and extracellular signal-regulated kinases, MAPKERK, respectively). In contrast, the hemin effect was preserved after inhibition of MAPKp38 (SB203580) or MAPKJNK (SP600125). Overall, NOS/HO interruption underlies baroreflex dysfunction caused by nicotine in female rats and the facilitation of NOS/HO-coupled sGC/PI3K/MAPKERK signaling might rectify the nicotine effect.

Co-administration of α-lipoic acid and cyclosporine aggravates colon ulceration of acetic acid-induced ulcerative colitis via facilitation of NO/COX-2/miR-210 cascade.

In this work, α-lipoic acid and cyclosporine demonstrated significant protection against acetic acid-induced ulcerative colitis in rats. We proposed that α-lipoic acid and cyclosporine co-administration might modulate their individual effects. Induction of ulcerative colitis in rats was performed by intra-rectal acetic acid (5% v/v) administration for 3 consecutive days. Effects of individual or combined used of α-lipoic acid (35 mg/kg ip) or cyclosporine (5mg/kg sc) for 6 days starting 2 days prior to acetic acid were assessed. Acetic acid caused colon ulceration, bloody diarrhea and weight loss. Histologically, there was mucosal atrophy and inflammatory cells infiltration in submucosa, associated with depletion of colon reduced glutathione, superoxide dismutase and catalase activities and elevated colon malondialdehyde, serum C-reactive protein (C-RP) and tumor necrosis factor-α (TNF-α). Colon gene expression of cyclooxygenase-2 and miR-210 was also elevated. These devastating effects of acetic acid were abolished upon concurrent administration of α-lipoic acid. Alternatively, cyclosporine caused partial protection against acetic acid-induced ulcerative colitis. Cyclosporine did not restore colon reduced glutathione, catalase activity, serum C-RP or TNF-α. Unexpectedly, co-administration of α-lipoic acid and cyclosporine aggravated colon ulceration. Concomitant use of α-lipoic acid and cyclosporine significantly increased nitric oxide production, cyclooxygenase-2 and miR-210 gene expression compared to all other studied groups. The current findings suggest that facilitation of nitric oxide/cyclooxygenase-2/miR-210 cascade constitutes, at least partially, the cellular mechanism by which concurrent use of α-lipoic acid and cyclosporine aggravates colon damage. Collectively, the present work highlights the probable risk of using α-lipoic acid/cyclosporine combination in ulcerative colitis patients.

Pioglitazone ameliorates methotrexate-induced renal endothelial dysfunction via amending detrimental changes in some antioxidant parameters, systemic cytokines and Fas production.

Methotrexate (MTX) is widely used in treatment of cancers and autoimmune diseases. However, nephrotoxicity is one of its most important side effects. The peroxisome proliferator-activated receptor gamma agonist, pioglitazone, is known to exert antiinflammatory and reno-protective effects in various kidney injuries. The purpose of this study was to investigate the potential involvement of endothelial damage in MTX-induced renal injury and to elaborate the possible protective effect of pioglitazone against MTX-induced endothelial impairment. Compared with saline-treated rats, treatment with MTX (7mg/kg for 3days) caused significant elevations in serum levels of urea and creatinine, increased renal nitrate/nitrite level and impaired renovascular responsiveness of isolated perfused kidney to endothelium-dependent vasodilations induced by acetylcholine (0.01-2.43nmol) and isoprenaline (1µmol). These effects were abolished by concurrent treatment with pioglitazone (2.5mg/kg, for 5days starting 2days before MTX). Alternatively, MTX treatment did not affect endothelium-independent renovascular relaxation induced by sodium nitroprusside (0.001-10µmole). The possibility that alterations in renal antioxidants, circulating cytokine and apoptotic factor (Fas) levels contributed to MTX-pioglitazone interaction was assessed. Pioglitazone treatment abrogated renal oxidative stress (decreased reduced glutathione and catalase activity and increased malondialdehyde), elevated serum cytokine (interleukin-6, interleukin-10, tumor necrosis factor-alpha and transforming growth factor-beta1) and Fas induced by MTX. Histologically, MTX caused defused tubular cells swelling and vacuolization associated with endothelial damage in renal arterioles. These effects disappeared upon co-treated with pioglitazone. Collectively, pioglitazone abolished MTX-induced endothelium dysfunction and nephrotoxicity via ameliorating oxidative stress and rectifying cytokines and Fas abnormalities caused by MTX.