The dual blocker of FAAH/TRPV1 N-arachidonoylserotonin reverses the behavioral despair induced by stress in rats and modulates the HPA-axis.

In recent years, several studies have explored the involvement of the deregulation of the hypothalamus-pituitary-adrenal (HPA) axis in the pathophysiology of stress-related disorders. HPA hyper-activation as a consequence of acute/chronic stress has been found to play a major role in the neurobiological changes that are responsible for the onset of such states. Currently available medications for depression, one of the most relevant stress-related disorders, present several limitations, including a time lag for treatment response and low rates of efficacy. N-Arachidonoylserotonin (AA-5-HT), a dual blocker at fatty acid amide hydrolase (FAAH, the enzyme responsible for the inactivation of the endocannabinoid anandamide) and transient receptor potential vanilloid type-1 channel (TRPV1), produces anxiolytic-like effects in mice. The present study was designed to assess the capability of AA-5-HT to reverse the behavioral despair following exposure to stress in rats and the role of the HPA-axis. Behavioral tasks were performed, and corticosterone and endocannabinoid (anandamide and 2-arachidonoylglycerol) levels were measured in selected brain areas critically involved in the pathophysiology of stress-related disorders (medial PFC and hippocampus) under basal and stress conditions, and in response to treatment with AA-5-HT. Our data show that AA-5-HT reverses the rat behavioral despair in the forced swim test under stress conditions, and this effect is associated with the normalization of the HPA-axis deregulation that follows stress application and only in part with elevation of anandamide levels. Blockade of FAAH and TRPV1 may thus represent a novel target to design novel therapeutic strategies for the treatment of stress-related disorders.

Dopamine D3 receptor is necessary for ethanol consumption: an approach with buspirone.

Mesolimbic dopamine (DA) controls drug- and alcohol-seeking behavior, but the role of specific DA receptor subtypes is unclear. We tested the hypothesis that D3R gene deletion or the D3R pharmacological blockade inhibits ethanol preference in mice. D3R-deficient mice (D3R(-/-)) and their wild-type (WT) littermates, treated or not with the D3R antagonists SB277011A and U99194A, were tested in a long-term free choice ethanol-drinking (two-bottle choice) and in a binge-like ethanol-drinking paradigm (drinking in the dark, DID). The selectivity of the D3R antagonists was further assessed by molecular modeling. Ethanol intake was negligible in D3R(-/-) and robust in WT both in the two-bottle choice and DID paradigms. Treatment with D3R antagonists inhibited ethanol intake in WT but was ineffective in D3R(-/-) mice. Ethanol intake increased the expression of RACK1 and brain-derived neurotrophic factor (BDNF) in both WT and D3R(-/-); in WT there was also a robust overexpression of D3R. Thus, increased expression of D3R associated with activation of RACK1/BDNF seems to operate as a reinforcing mechanism in voluntary ethanol intake. Indeed, blockade of the BDNF pathway by the TrkB selective antagonist ANA-12 reversed chronic stable ethanol intake and strongly decreased the striatal expression of D3R. Finally, we evaluated buspirone, an approved drug for anxiety disorders endowed with D3R antagonist activity (confirmed by molecular modeling analysis), that resulted effective in inhibiting ethanol intake. Thus, DA signaling via D3R is essential for ethanol-related reward and consumption and may represent a novel therapeutic target for weaning.

Safety profile assessment of buflomedil: an overview of adverse reactions between 1975 and 2011.

PURPOSE: Review all the individualized cases of adverse drug reaction (ADR) potentially related to buflomedil, a vasodilator with the indication for peripheral arterial disease (PAD), marketed in Europe since the 1970s but recently suspended by the European Medicines Agency. METHODS: A review of all available individualised case safety data relating to oral buflomedil from the buflomedil global safety database (provided by the manufacturer of buflomedil), the worldwide published medical literature, toxicology/poison centres and regulatory authorities. RESULTS: The main ADRs reported were in the cardiovascular (CVS) and nervous systems (NS), grouped under four (MedDRA) System Organ Classes (SOCs): (i) Cardiac disorders; (ii) Vascular disorders; (iii) Investigations; (iv) NS disorders. From an initial cumulative number of 1054 case reports, there were 401 cases of intentional overdose (IOD) of which 63 were fatal, and 137 cases of accidental overdose, with two fatalities, and 516 case reports of ADRs under normal conditions of use of the product at normal therapeutic dosage with 11 fatalities. Overdosage (intentional or accidental) represented 50.9% of cases, with 47.6% of patients <40 years of age. The indications for which these young patients were prescribed buflomedil were not reported in most cases. CONCLUSIONS: The main indication of buflomedil is PAD; however, because most cases of IOD occurred in people <40 years of age, where PAD is unlikely, it is possible that buflomedil was prescribed for other indications and/or that it was not directly prescribed to the end user, who rather gained access to the medication prescribed to family members or friends.

Effects of the COOH-terminal tripeptide alpha-MSH(11-13) on corneal epithelial wound healing: role of nitric oxide.

It is known that alpha-melanocyte stimulating hormone (alpha-MSH) may exert anti-inflammatory effects and facilitate reparative processes in different tissues. The effective message sequence of alpha-MSH resides in the COOH-terminal tripeptide alpha-MSH(11-13). This study was undertaken to investigate the effects of topical administration of the COOH-terminal tripeptide sequence of alpha-MSH (alpha-MSH(11-13), KPV) on corneal epithelial wound healing in rabbits and the possible role of nitric oxide (NO) in these effects. The whole corneal epithelium was denuded in both eyes by mechanical abrasion. The area of the corneal epithelial defect was stained with fluorescein, photographed, and then measured before the treatment and every 12 h by a computerized software. The mean epithelial wound area and the mean percent of epithelial defect remaining at each follow-up control were compared between experimental groups. Rabbits were topically treated with KPV 1, 5 or 10 mg/ml (30 microl), two drops four times in a day, for 4 days, starting immediately after corneal abrasion, while control animals received topical phosphate-buffered saline as vehicle. In order to study the role of NO in corneal repair processes, the NO donor, sodium nitroprusside (SP, 10 mg/ml, 30 microl) was administered in both eyes, two drops four times in a day, for 4 days. The effects of KPV or SP were challenged by pre-treatment with the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME, 10 mg/ml, 30 microl) 30 min prior to KPV or SP instillation. The mean percent epithelial defect remaining each time was significantly smaller in animals treated with KPV or SP in comparison to controls. Sixty hours later, eight out of eight (100%) corneas treated with KPV or SP were completely re-epithelized (P<0.05) while none of the corneas treated with placebo were re-epithelized. Pre-treatment with L-NAME inhibited the facilitating effect of KPV on corneal epithelial wound healing process and totally prevented the effect of SP. Rabbit corneal epithelial cells (RCE) in culture were exposed for 1, 6 and 24 h to different KPV concentrations (0.1, 1 and 10 microM) in medium containing 15% foetal bovine serum (FBS). Cell viability was stimulated by 1 and 10 microM concentrations of the substance. Thus, KPV may facilitate corneal epithelial wound healing in rabbits with a mechanism that may involve NO disposition in corneal tissue. However, it is not known whether this mechanism is likely to depend on a direct stimulating repairing activity shared by the entire molecule of alpha-MSH.

Possible involvement of nitric oxide in morphine-induced miosis and reduction of intraocular pressure in rabbits.

The role of mu3 opioid receptors in morphine-induced intraocular pressure (IOP) lowering effect and miosis was evaluated in conscious, dark-adapted New Zealand white (NZW) rabbits using a masked-design study. IOP and pupil diameter (PD) measurements were taken at just before and 0.5, 1, 2, 4, 6 h after monolateral instillation of morphine (10, 50 and 100 microg/30 microl) as compared to vehicle administered in the contralateral eye. Morphine-induced ocular effects were challenged by a pre-treatment with the non-selective opioid receptor antagonist, naloxone (100 microg/30 microl), the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME, 1%, 30 microl), or the non-selective mu3 opioid receptor inhibitor, reduced L-glutathione (GSH, 1%, 30 microl). Morphine induced a dose-dependent decrease in IOP and PD. Pre-treatment with naloxone totally prevented morphine-induced decrease in IOP and miosis. Ocular administration of L-NAME or GSH alone failed to affect IOP or PD of NZW rabbits. However, pre-treatment with either drugs significantly reduced, but not totally prevented ocular effects of morphine. These results suggest that biochemical mechanisms related to nitric oxide release are involved, at least in part, in morphine effects on the eye. Since the mu3 opioid receptor subtype is able to release nitric oxide and is sensitive to inactivation by GSH, it may be possible that mu3 opioid receptors are involved in morphine-induced miosis and reduction in IOP.

Oral Echinacea purpurea extract in low-grade, steroid-dependent, autoimmune idiopathic uveitis: a pilot study.

AIM: The aim of to test efficacy and safety of Echinacea purpurea (echinacea) extract in the control of low-grade uveitis. METHODS: Fifty-one (51) patients with low-grade, steroid dependent, autoimmune uveitis were recruited; posterior uveitis was excluded. The start therapy was represented by topical desamethazone for anterior uveitis and oral prednisone, rapidly tapered, for anterior uveitis with inflammatory scores equal to +2 and in all cases of intermediate uveitis. Best-corrected visual acuity (BCVA) decrease or improvement was defined as a reduction or increase of 2 or more letters seen from the initial BCVA; ETDRS chart was used. Thirty-two (32) patients (21 with anterior uveitis and 11 with intermediate uveitis) received Echinacea (150 mg twice/day) as add-on therapy, whereas 20 patients (10 with anterior uveitis and 9 with intermediate uveitis) were treated with the conventional steroid therapy alone. RESULTS: Thirty-one (31) patients showed anterior uveitis and 20 intermediate uveitis. The follow-up duration was 9 months. At the last follow-up, 19/21 patients with anterior uveitis and 9/11 with intermediate uveitis treated with echinacea presented uveitis settled, with a steroid-off time of 209 and 146 days, respectively. BCVA was stable or improved in 19/21 of anterior uveitis and 9/11 of intermediate uveitis. No adverse reactions supposed to be resulting from commercial-grade echinacea were recorded. Patients who did not receive echinacea required a longer treatment period with steroids with a steroid-off time of 121 and 87 days. CONCLUSIONS: Systemic echinacea appears safe and effective in the control of low-grade autoimmune idiopathic uveitis.

Effects of hyaluronan on free-radical formation, corneal endothelium damage, and inflammation parameters after phacoemulsification in rabbits.

Free-radical formation may play a role in postoperative complications of phacoemulsification (e.g., corneal endothelium damage from mechanical injury). The present experiments were aimed at investigating whether different molecular weight ranges (2000-2600, 2600-3200, or 3200-3800 kDa) of hyaluronan may influence free radical formation, corneal endothelium damage, and inflammation parameters after phacoemulsification in the rabbit eye. The viscoelastic substance was injected in the anterior chamber of rabbits' eyes before phacoemulsification, at a 2.5% concentration. The formation of free radicals was determined by adding luminol to the irrigation media and measuring the chemoluminescence in eyes. The corneal endothelial damage was evaluated by measuring the corneal central thickness by pachimetry. The inflammation parameters were measured by calculation in aqueous humor of peak levels of leukocytes and prostaglandin E(2) (PGE(2)) and evaluation in uveal tissue of myeloperoxidase activity. Hyaluronan decreased by about 58-60% free-radical formation during phacoemulsification, reduced by about 76-80% modifications in mean corneal thickness and by about 54-61% the corneal endothelial cell loss in all molecular weight ranges used. No difference was found among various molecular weight ranges. The highest molecular weight range showed to be more potent than the lowest range for reduced number of inflammation cells and level of PGE(2) in aqueous humor. Thus, hyaluronan reduces free-radical formation, exerts protection on the corneal endothelium and exerts anti-inflammation properties after phacoemulsification in rabbits. The latter effect seems to depend on the molecular weight of the substance.

Hyaluronan-induced stimulation of corneal wound healing is a pure pharmacological effect.

The aim of this study was to evaluate whether corneal reparative activity of hyaluronan is a concentration-dependent phenomenon. Corneal blocks from rabbit eyes were cultured for 20 hours with hyaluronan in different concentrations and molecular weight ranges. In another experiment, the corneal epithelium was denuded and hyaluronan was administered as eye drops. Distances of epithelial migration increased over exposed stroma proportionally to concentration, when hyaluronan was added with a molecular weight of 800-1,400 kD. Maximum effect was observed with 0.2% hyaluronan concentration. No difference was seen when corneal blocks were cultured with hyaluronan 0.2% in different molecular weight ranges (800-1,400, 1,400-2,000, and 2,000-2,600 kD). When hyaluronan (molecular weight, 800-1,400 kD) eye drops were administered after corneal epithelial denudation in rabbits, it was found to have faster wound reparation. This effect was concentration-dependent. The 2 highest concentrations (0.2% and 0.4%) were not different for the time needed to complete wound healing. In conclusion, hyaluronan-induced stimulation of corneal wound healing fulfills standards for being considered as a pharmacological effect.