Tumor necrosis factor-alpha in hepatitis B: potential role for bupropion

Buspirone Ameliorates Colon Inflammation in TNBS-Induced Rat Acute Colitis: The Involvement of TLR4/NF-kB Pathway

Inflammatory bowel disease (IBD) is an inflammatory situation involving the whole digestive system. This illness includes ulcerative colitis and Crohn's disease. According to scientific research, the immune system plays an essential part in developing this disease. Recently, buspirone has been discovered to have anti-inflammatory properties. As a result, this research aims to see if buspirone provides anti-inflammatory effects in a rat model of TNBS-induced colitis. Control, TNBS, dexamethasone (2 mg/kg), and buspirone (5, 10, and 20 mg/kg) were randomly given to six groups of 36 male Wistar rats. Colitis was induced by intrarectal instillation of TNBS in all research groups except the control group, and rats were meliorated with dexamethasone and buspirone. Macroscopic and microscopic lesions appeared after colitis induction, while therapy with dexamethasone and buspirone significantly improved the lesions. TLR4 and pNF-κB expression were also enhanced during colitis induction. On the other hand, the administration of dexamethasone or buspirone resulted in a considerable reduction in their expression. Tissue TNF-α and MPO activity were enhanced after induction of colitis in terms of biochemical variables; however, administration of dexamethasone or buspirone reduced TNF-α and MPO activity. Eventually, in an animal model of severe colitis, buspirone displayed anti-inflammatory characteristics via lowering the TLR4/NF-ĸB signaling pathway's activity in an animal model of acute colitis.

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.

Anti-inflammatory effect of amitriptyline in a rat model of acetic acid-induced colitis: the involvement of the TLR4/NF-kB signaling pathway

Inflammatory bowel disease (IBD) consists of ulcerative colitis and Crohn's disease, which affects gastrointestinal tract. The immune-mediated inflammation is mostly considered as the pathogenesis of IBD. It has been demonstrated that amitriptyline exerts anti-inflammatory influence; therefore, the aim of the current experiment is to evaluate the anti-inflammatory impact of amitriptyline on intestinal disorders following acetic acid-induced colitis in rats. Thirty male Wistar rats were randomly divided into five groups, including sham, control, dexamethasone (2 mg/kg), and amitriptyline (10 and 20 mg/kg). Intrarectal administration of acetic acid was applied to colitis induction in all study groups except for sham group. Animals were treated by oral administration of dexamethasone or amitriptyline. While macroscopic and microscopic lesions appeared after colitis induction treatment with dexamethasone and amitriptyline 10 and 20 mg/kg significantly improved lesions. Moreover, Toll-like receptor 4 (TLR4) and nuclear factor binding kappa light-chain (NF-ĸB expression), tumor necrosis factor-alpha (TNF-α) level, and myeloperoxidase (MPO) activity were increased after colitis induction, whereas treatment with dexamethasone (2 mg/kg) or amitriptyline (10 and 20 mg/kg) caused a noticeable decrease in the TLR4 and pNF-ĸB expression, TNF-α level, and MPO activity. In conclusion, amitriptyline plays an anti-inflammatory role through the suppression of TLR4/pNF-ĸB signaling pathway in the rat model of acute colitis.

Bupropion monotherapy alters neurotrophic and inflammatory markers in patients of major depressive disorder

BACKGROUND

Emerging hypotheses in the pathophysiology of major depressive disorder (MDD) indicate the role of neurotrophic factors and inflammation. This study assessed the association between therapeutic response of bupropion and serum brain-derived neurotrophic factor (BDNF) and tumour necrosis factor-α (TNF-α) levels in patients with MDD.

METHODS

Thirty patients (aged 18 to 60 years) with MDD diagnosed by DSM-5 criteria, with Hamilton Depression Rating scale (HAM-D) score ≥ 20 were included in the study. Patients were given bupropion sustained release (SR) in the doses of 150 mg once daily. All patients were followed up for 12 weeks.

RESULTS

HAM-D score at the start of the treatment was 25.57 ± 1.85 which significantly reduced to 10.8 ± 4.24 at 12 weeks of treatment. The serum BDNF level increased significantly (p < 0.05) from 2.42 ± 0.19 ng/ml to 2.97 ± 0.10 ng/ml and the levels of serum TNF-α reduced significantly (p < 0.05) from 4.45 ± 0.95 pg/ml to 2.11 ± 0.84 pg/ml at 12 weeks of treatment, in responders to treatment.

CONCLUSION

The results of our study suggest that bupropion SR monotherapy is effective and well tolerated in MDD patients with moderate to severe depression, and its therapeutic efficacy is accompanied by an increase in serum BDNF levels and a decrease in serum TNF-α levels.

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.

Bupropion: pharmacology and therapeutic applications

A total of 17 years after its introduction, bupropion remains a safe and effective antidepressant, suitable for first-line use. Bupropion undergoes metabolic transformation to an active metabolite, 4-hydroxybupropion, through hepatic cytochrome P450-2B6 (CYP2B6) and has inhibitory effects on cytochrome P450-2D6 (CYP2D6), thus raising concern for clinically-relevant drug interactions. Common side effects are nervousness and insomnia. Nausea appears slightly less common than with the SSRI drugs and sexual dysfunction is probably the least of any antidepressant. Bupropion is relatively safe in overdose with seizures being the predominant concern. The mechanism of action of bupropion is still uncertain but may be related to inhibition of presynaptic dopamine and norepinephrine reuptake transporters. The activity of vesicular monoamine transporter-2, the transporter pumping dopamine, norepinephrine and serotonin from the cytosol into presynaptic vesicles, is increased by bupropion and may be a component of its mechanism of action. Bupropion is approved for use in major depression and seasonal affective disorder and has demonstrated comparable efficacy to other antidepressants in clinical trials. Bupropion is also useful in augmenting a partial response to selective serotonin reuptake inhibitor antidepressants, although bupropion should not be combined with monoamine oxidase inhibitors. It may be less likely to provoke mania than antidepressants with prominent serotonergic effects. Bupropion is effective in helping people quit tobacco smoking. Anecdotal reports indicate bupropion may lower inflammatory mediators such as tumor necrosis factor-alpha, may lower fatigue in cancer and may help reduce concentration problems.

Psychoneuroimmunology of psychological stress and atopic dermatitis: pathophysiologic and therapeutic updates

Atopic dermatitis is a chronic inflammatory skin disease characterized by impaired epidermal barrier function, inflammatory infiltration, extensive pruritus and a clinical course defined by symptomatic flares and remissions. The mechanisms of disease exacerbation are still poorly understood. Clinical occurrence of atopic dermatitis is often associated with psychological stress. In response to stress, upregulation of neuropeptide mediators in the brain, endocrine organs, and peripheral nervous system directly affect immune and resident cells in the skin. Lesional and non-lesional skin of patients with atopic dermatitis demonstrates increased mast cells and mast cell-nerve fiber contacts. In the setting of stress, sensory nerves release neuromediators that regulate inflammatory and immune responses, as well as barrier function. Progress towards elucidating these neuroimmune connections will refine our understanding of how emotional stress influences atopic dermatitis. Moreover, psychopharmacologic agents that modulate neuronal receptors or the amplification circuits of inflammation are attractive options for the treatment of not only atopic dermatitis, but also other stress-mediated inflammatory skin diseases.

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.

Evidence of a mechanism by which etanercept increased TNF-alpha in multiple myeloma: new insights into the biology of TNF-alpha giving new treatment opportunities--the role of bupropion

Etanercept is a commercially available pharmaceutical protein approved for treatment of rheumatoid arthritis, RA. Given subcutaneously, etanercept binds and inactivates soluble tumor necrosis factor-alpha, TNF. Etanercept has a good safety record and is of benefit in lowering pain, inflammation, and joint destruction in RA. RA is mediated by many factors, TNF among them. Malignant myeloma, MM, is a malignant clonal expansion of a post-germinal center B lymphocyte. Since TNF is a necessary growth factor for expansion and maintenance of MM cells, and etanercept binds soluble TNF and is of clinical benefit in RA, etanercept was tried experimentally in MM. Contrary to expectations, etanercept resulted in increased levels of TNF and possibly shortened survival. This paper presents an hypothesis of how this happened. There are two cognate receptors for TNF, termed R1 and R2 and two forms of TNF, soluble and transmembrane. Soluble TNF has greater affinity for TNF-R1 than for TNF-R2. Transmembrane TNF has equal affinity for the two receptors. Since TNF-R2 signaling tends to be more anti-apoptotic and activating of nuclear factor kappa B, NFkB, than is TNF-R1, and TNF-R1 tends to be more pro-apoptotic than is TNF-R2, by inactivating soluble TNF while leaving transmembrane TNF signaling relatively unchanged, etanercept changed the balance in TNF signaling from TNF-R1 towards TNF-R2 weighting. Anti-apoptosis and TNF synthesis would have been up-regulated by that shift. Early data indicates that the common generic antidepressant bupropion may ameliorate Crohn's disease course by down regulating TNF synthesis, maybe it will slow the course of MM as well.

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.