Bupropion in psoriasis and atopic dermatitis: decreased tumor necrosis factor-alpha?

Sirt1/Nrf2/TNFα; TLR4/Myd88/NF-κB signaling pathways are involved in mediating hepatoprotective effect of bupropion in rat model of myocardial infarction

BACKGROUND

The aim of the current study is to identify the possible protective effect of bupropion (BUP) on liver injury in rat model of myocardial infarction (MI). BUP was administered in the presence and absence of MI.

MATERIALS AND METHODS

Thirty-two Wistar adult male rats were randomly arranged into four groups: control, BUP (30 mg/kg/day, intraperitoneal) for 28 days, isoproterenol (ISO) was injected subcutaneous (85mg/kg) in the 26th and 27th days and BUP/ISO groups. Cardiac and hepatic enzymes were measured, also Hepatic oxidative stress indicators, as well as inflammatory and apoptotic biomarkers, were evaluated. Cardiac and hepatic histopathological examination and hepatic nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) immunohistochemical study were also detected.

RESULTS

ISO significantly increased cardiac and hepatic enzymes, hepatic oxidative stress, inflammatory, apoptotic, with a histopathological picture of cardiac and hepatic damage and high hepatic NF-κB immunoexpression were detected. BUP significantly normalised the upraised oxidative, inflammatory, and apoptotic parameters, with an impressive improvement in the histopathological picture and a reduction in hepatic NF-κB immunoexpression.

CONCLUSION

BUP protects against liver injury on top of MI in rat model via modulation of Sirtuin type 1 (Sirt1)/Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/tumor necrosis factor α (TNFα); Toll-like receptor 4 (TLR4)/Hepatic myeloid differentiation primary response 88(Myd88)/NF-κB signaling pathways.

Atopic dermatitis in psychodermatology: a concise review for dermatologists

Atopic Dermatitis (AD) is a chronic disease of the skin with significant pruritus and phases of exacerbation and remission. The hallmarks of AD are changes in the epithelial barrier and chronic inflammation. This condition is associated with an increased risk of developing mental disorders such as depression, anxiety, and suicidal ideation. It has been proposed that psychological stress may impact on immunological factors with an up-regulation of mediating neuropeptides at the level of central nervous system and secondary involvement of endocrine glands, peripheral nervous system, and immune resident skin cells. This article provides a concise review for dermatologists on the psychodermatology of AD, in order to highlight the putative common pathways between the dermatologic and mental health issues in this illness.

Bupropion Ameliorates Acetic Acid-Induced Colitis in Rat: the Involvement of the TLR4/NF-kB Signaling Pathway

Inflammatory bowel disease composed of ulcerative colitis and Crohn's disease is a disorder that may involve entire gastrointestinal tract. Its pathogenesis is mainly an immune-mediated inflammation. Recently, it has been indicated that bupropion possesses anti-inflammatory properties; hence, the objective of this experiment is the investigation of the anti-inflammatory influence of bupropion on colonic lesions that emerged following the intrarectal administration of acetic acid. Thirty-six male Wistar rats were allocated randomly into six groups, including control, acetic acid, dexamethasone (2 mg/kg), and bupropion (40, 80, and 160 mg/kg). Colitis was induced by intrarectal administration of acetic acid in all study groups except control group, and animals were treated by oral administration of dexamethasone and bupropion. While macroscopic and microscopic lesions were observed after colitis induction, administration of dexamethasone and bupropion 160 mg/kg led to the remarkable improvement in lesions. In addition, the expression of TLR4 and NF-ĸB was decreased after colitis induction; however, treatment with dexamethasone (2 mg/kg) and bupropion (160 mg/kg) resulted in a significant decrease in their expression. Regarding biochemical factors, following colitis induction, TNF-α level and MPO activity were increased; nevertheless, dexamethasone (2 mg/kg) and bupropion (160 mg/kg) decreased the TNF-α and MPO activity. In conclusion, bupropion exerts anti-inflammatory influence through suppressing the TLR4 and NF-ĸB expression in the rat model of acute colitis.

Disruption of the cholinergic anti-inflammatory response by R5-tropic HIV-1 protein gp120JRFL

Despite current pharmacological intervention strategies, patients with HIV still suffer from chronic inflammation. The nicotinic acetylcholine receptors (nAChRs) are widely distributed throughout the nervous and immune systems. In macrophages, activation of alpha7-nAChR (α7-nAChR) controls inflammatory processes through the cholinergic anti-inflammatory response (CAR). Given that this innate immune response controls inflammation and α7-nAChR plays a critical role in the regulation of systemic inflammation, we investigated the effects of an R5-tropic HIV soluble component, gp120JRFL, on the CAR functioning. We previously demonstrated that X4-tropic HIV-1 gp120IIIB disrupts the CAR as well as inducing upregulation of the α7-nAChR in vitro in monocyte-derived macrophages (MDMs), which correlates with the upregulation observed in monocytes, T-lymphocytes, and MDMs recovered from HIV-infected people. We demonstrate here using imaging and molecular assays that the R5-tropic HIV-1 glycoprotein gp120JRFL upregulates the α7-nAChR in MDMs dependent on CD4 and/or CCR5 activation. This upregulation was also dependent on MEK1 since its inhibition attenuates the upregulation of α7-nAChR induced by gp120JRFL and was concomitant with an increase in basal calcium levels, which did not result in apoptosis. Moreover, the CAR was determined to be disrupted, since α7-nAChR activation in MDMs did not reduce the production of the proinflammatory cytokines IL-6, GRO-α, or I-309. Furthermore, a partial antagonist of α7-nAChR, bupropion, rescued IL-6 but not GRO-α or I-309 production. Together, these results demonstrate that gp120JRFL disrupts the CAR in MDMs. Other medications targeting the α7-nAChR need to be tested to reactivate the CAR to ameliorate inflammation in HIV-infected subjects.

Bupropion in dermatology: A brief update

There is currently an interest in evaluating the role that antidepressants may play in the treatment of primary cutaneous disorders. It has been proposed that antidepressants could have anti-inflammatory effects, but the clinical relevance of this effect has not been adequately established. In the case of bupropion, evidence for its specific use in dermatologic conditions currently come only from a pilot study and a case report. While this level of evidence is unlikely to be sufficient to guide clinical practice, the authors of this brief update hope to sort the available information to serve as a guide and provide a structure for future research.

Nicotinic Acetylcholine Receptors in HIV: Possible Roles During HAND and Inflammation

Infection with the human immunodeficiency virus (HIV) remains a threat to global health. Since its discovery, many efforts have been directed at understanding the mechanisms and consequences of infection. Although there have been substantial advances since the advent of antiretroviral therapy, there are still complications that significantly compromise the health of infected patients, particularly, chronic inflammation and HIV-associated neurocognitive disorders (HAND). In this review, a new perspective is addressed in the field of HIV, where the alpha7 nicotinic acetylcholine receptor (α7-nAChR) is the protagonist. We comprehensively discuss the available evidence implicating α7-nAChRs in the context of HIV and provide possible explanations about its role in HAND and inflammation in both the central nervous system and the periphery.

The α7-nicotinic receptor is upregulated in immune cells from HIV-seropositive women: consequences to the cholinergic anti-inflammatory response

Antiretroviral therapy partially restores the immune system and markedly increases life expectancy of HIV-infected patients. However, antiretroviral therapy does not restore full health. These patients suffer from poorly understood chronic inflammation that causes a number of AIDS and non-AIDS complications. Here we show that chronic inflammation in HIV+ patients may be due to the disruption of the cholinergic anti-inflammatory pathway by HIV envelope protein gp120_IIIB. Our results demonstrate that HIV gp120_IIIB induces α7 nicotinic acetylcholine receptor (α7) upregulation and a paradoxical proinflammatory phenotype in macrophages, as activation of the upregulated α7 is no longer capable of inhibiting the release of proinflammatory cytokines. Our results demonstrate that disruption of the cholinergic-mediated anti-inflammatory response can result from an HIV protein. Collectively, these findings suggest that HIV tampering with a natural strategy to control inflammation could contribute to a crucial, unresolved problem of HIV infection: chronic inflammation.

Study on anti-inflammatory and immunomodulatory effects of fluoxetine in rat models of inflammation

The aim of the present study was to evaluate the anti-inflammatory effect of fluoxetine in carrageenan- and lipoplysaccharide-induced models of inflammation by investigating the changes in serum levels of pro-inflammatory cytokine TNF-α and anti-inflammatory cytokines IL-10 and TGF-β after single and repeated administration of the drug. To study the effect of a single and repeated dose fluoxetine on carrageenan-induced paw edema male Wistar rats were divided into five groups (n = 8): control group; positive control group; and three experimental groups treated with 5, 10, and 20 mg/kg bodyweight (bw) fluoxetine, respectively. To study the effect of a single and repeated dose of fluoxetine on serum cytokine levels, the animals were divided in four groups (n = 8): two control groups treated with saline and two experimental groups treated with fluoxetine 20 mg/kg bw. Carrageenan and LPS were injected immediately after fluoxetine or saline injection. Serum cytokine concentrations were tested by enzyme immunoassay. In single administration only the highest dose used inhibited carrageenan-induced inflammation. Edema inhibition was seen with 10 and 20 mg/kg bw fluoxetine after repeated administration. At 24 h a statistically significant effect on inhibition of carrageenan edema was found only in rats treated with 20 mg/kg bw fluoxetine In carrageenan-induced inflammation, fluoxetine significantly increased Il-10 and decreased TNF-α after repeated administration. Surprisingly, in single-dose treated animals an increase in TNF-α values upon fluoxetine administration was observed in this model of inflammation. In LPS-induced inflammation, fluoxetine significantly decreased TNF-α after single and repeated treatment. Fluoxetine has anti-inflammatory and immunomodulatory effect in the carrageenan-induced model of exudative inflammation. In LPS-induced inflammation it showed an immunomodulatory effect manifested with a decrease in pro-inflammatory cytokine TNF-α.

The antidepressant bupropion exerts alleviating properties in an ovariectomized osteoporotic rat model

AIM

Depression is a risk factor for impaired bone mass and micro-architecture, but several antidepressants were found to increase the incidence of osteoporotic fractures. In the present study we used ovariectomized (OVX) rats as a model of osteoporosis to investigate the effects of the antidepressant bupropion on the femoral bones.

METHODS

OVX animals were treated with bupropion (30, 60 mg·kg(-1)·d(-1)) for six weeks. Bone turnover biomarkers (urinary DPD/Cr ratio, serum BALP, OC, TRAcP 5b, CTX and sRANKL levels) and inflammatory cytokines (TNF-α, IL-1β and IL-6) were determined using ELISA. Inductively coupled plasma mass spectroscopy (ICP-MS) was used to determine the femoral bone mineral concentrations. The cortical and trabecular morphometric parameters of femoral bones were determined using micro-CT scan and histopathology.

RESULTS

In OVX rats, the levels of bone turnover biomarkers and inflammatory cytokines were significantly elevated and femoral bone Ca(2+) and PO4(3-) concentrations were significantly reduced. Moreover, cortical and trabecular morphometric parameters and histopathology of femoral bones were severely altered by ovariectomy. Bupropion dose-dependently inhibited the increases in bone turnover biomarkers and inflammatory cytokines. OVX rats treated with the high dose of bupropion showed normal mineral concentrations in femoral bones. The altered morphometric parameters and histopathology of femoral bones were markedly attenuated by the treatment.

CONCLUSION

Bupropion exerts osteo-protective action in OVX rats through suppressing osteoclastogenesis-inducing factors and inflammation, which stabilize the osteoclasts and decrease bone matrix degradation or resorption.

Part Two: Evaluation of N-methylbupropion as a Potential Bupropion Prodrug

N-methylbupropion was selected as a potential prodrug from our in vitro screening of analogues of bupropion described in the preceding paper. This study describes in vivo pharmacokinetics of N-methylbupropion in the guinea-pig animal model, which is reported to best predict human metabolism of bupropion. The suitability of the guinea pig was established by studying N-demethylation of N-methylbupropion using S9 liver fractions. An LC-MS method was developed and validated to measure N-methylbupropion, bupropion and their metabolites in plasma and brain tissue. In separate studies, the prodrug was delivered by intraperitoneal injection (IP) to assess hepatic metabolism and then by oral gavage (PO) to assess the contribution from intestinal enzymes. Bupropion was administered in parallel. The pharmacokinetic profile of bupropion and N-methylbupropion were not comparable when dosed by intraperitoneal injection but when dosed orally, N-methylbupropion showed a comparable bupropion and metabolite PK plasma profile to bupropion. Plasma and brain levels of N-methylbupropion show that it is extensively metabolized to bupropion and its metabolites, and N-methyl-threo-hydrobupropion. This data coupled to the reduced DAT and NET system in vitro activity described in paper 1 would suggest that the N-methyl derivative of bupropion may have potential as an oral prodrug of bupropion in humans.

Synthesis, screening and pharmacokinetic evaluation of potential prodrugs of bupropion. Part one: in vitro development

In general, prodrugs are developed to circumvent deficiencies associated with the absorption, distribution, metabolism, excretion or toxicological (ADMET) profile associated with the active drug. In our study, we select bupropion, a drug with broad pharmacology incorporating dopaminergic, noradrenergic, nicotinic and cytokine modulation properties, but which is rapidly metabolized in vivo. We exploited its carbonyl and secondary amine functionality to facilitate the synthesis of bioprecursor prodrug forms with the sole objective of identifying analogues with enhanced properties over bupropion. A range of analogues were synthesized, ranging from N-methyl, N-benzyl, oximes, enol acetate and ether forms to examples where both functional groups were utilized to form oxadiazine, oxadiazinone, oxazolone and acetylated derivatives. We then developed an in vitro metabolic screen to simulate the human oral delivery route for these analogues. The selection of media in the screens contained a variety of pH, enzymatic and co-factor systems which mimic metabolic in vivo environments that drugs encounter when delivered orally. By coupling our in vitro screening tool to a selective hyphenated technique such as LC-MS, we were able to quickly select potential prodrugs for further in vitro and in vivo development. From the data generated, the N-alkylated bupropion analogues were shown to have the highest potential to act as bioprecursor prodrugs of bupropion.

A new chapter opens in anti-inflammatory treatments: the antidepressant bupropion lowers production of tumor necrosis factor-alpha and interferon-gamma in mice

In a wide range of human diseases of inflammatory nature like Crohn's disease, pathology is mediated in part by pro-inflammatory cytokines like tumor necrosis factor-alpha (TNF) or interferon-gamma. We show here that a commonly used generic antidepressant bupropion, in wide use worldwide to treat depression in humans for a decade now, profoundly lowers levels of TNF, interferon-gamma, and interleukin-1 beta in vivo, in a mouse lipopolysaccharide (LPS) induced inflammation model. Mice challenged with an otherwise lethal dose of LPS were protected by bupropion and levels of the anti-inflammatory cytokine interleukin-10 were increased. Previous data in rodents and humans indicate antidepressant effects of bupropion are mediated by its weak reuptake inhibition of norepinephrine and dopamine. Concordant with this, TNF suppression by bupropion in our mouse LPS model was largely abrogated by beta-adrenergic or dopamine D1 receptor antagonists but not by a D2 antagonist. TNF synthesis is controlled by an inverse relationship with intracellular cyclic adenosine monophosphate (cAMP) and stimulation of either beta-adrenoreceptors or D1 dopaminergic receptors result in increased cAMP but stimulation of D2 receptors lowers cAMP. We conclude that bupropion may suppress TNF synthesis by mediating increased signaling at beta-adrenoreceptors and D1 receptors, resulting in increased cAMP that inhibits TNF synthesis. Bupropion is well tolerated also in non-psychiatric populations and has less risk with long term use than current anti-inflammatory, immunosuppressive or TNF suppressive treatments such as prednisone, azathioprine, infliximab, or methotrexate. New anti-inflammatory treatments are needed. We believe a new chapter in antiinflammatory, TNF lowering treatment of disease has been opened. Bupropion's use for this in humans should be explored.

Bupropion for fatigue and as a tumor necrosis factor-α lowering agent in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic disease which can often be severe, progressive and necessitate liver transplantation. The cause of PBC is not known, and treatments other than liver transplantation are often not effective. Among the more common and troublesome symptoms of PBC is fatigue. The etiology of fatigue in PBC is not well-understood, and there is no known treatment for it. Here, we suggest that for a number of reasons that the safe and commonly used oral antidepressant bupropion might be effective for fatigue in PBC: (1) increased monoaminergic and dopaminergic tone to combat fatigue, (2) treatment of concomitant depression, (3) in general for PBC as a tumor necrosis factor-alpha (TNF) lowering agent, if TNF is eventually found to play a role in PBC pathogenesis.

Bupropion for Blau syndrome

Blau syndrome (BS) is an autosomal dominantly inherited disease characterized by granulomas and arthritis. The gene mutated in BS was recently found to be CARD15. Mutations in this gene also occur in about 20% of patients with Crohn's disease (CD), though with different mutations than in the Crohn's patients. We are not aware of any cure or specific treatment for BS. We have found that bupropion is effective for CD, and we now suggest that bupropion be considered for treatment of BS.