Psoriasis treated with ursodeoxycholic acid: three case reports

Primary biliary cirrhosis and psoriasis: a two-sample Mendelian randomization study

Background

Primary biliary cirrhosis (PBC) and psoriasis are frequently observed to co-occur in clinical settings. However, the causal associations and underlying mechanisms between PBC and psoriasis remain poorly defined.

Methods

In this study, we conducted bidirectional MR analysis to explore the causal relationship between PBC and psoriasis using four MR methods: inverse-variance weighted, MR-Egger regression, weighted median, and weighted mode. Sensitivity analyses were carried out, employing different models and testing methods for comparison to assess the influence of heterogeneity and pleiotropy on our findings and to confirm the robustness of these results.

Results

A causal relationship between the risk of PBC and psoriasis was identified, as confirmed by IVW analysis (OR: 1.081, 95%CI: 1.028~1.137, P<0.05). The other three MR methods also produced similar results. However, psoriasis did not have a causal effect on PBC risk (OR: 1.022, 95%CI: 0.935~1.118, P>0.05). The intercept of MR-Egger regression was 0.0013 (P>0.05), indicating that genetic pleiotropy did not influence the results. Additionally, the leave-one-out analysis demonstrated the robustness of our MR findings.

Conclusion

This study reveals a causal relationship between PBC and psoriasis, with PBC increasing the risk of psoriasis, but not the reverse. This potential causal relationship offers a new perspective on the etiology of PBC.

Impact of Gut Bacterial Metabolites on Psoriasis and Psoriatic Arthritis: Current Status and Future Perspectives

There is growing evidence that supports a role of gut dysbiosis in the pathogenesis of psoriasis (Pso). Thus, probiotic supplementation and fecal microbiota transplantation may serve as promising preventive and therapeutic strategies for patients with Pso. One of the basic mechanisms through which the gut microbiota interacts with the host is through bacteria-derived metabolites, usually intermediate or end products produced by microbial metabolism. In this study, we provide an up-to-date review of the most recent literature on microbial-derived metabolites and highlight their roles in the immune system, with a special focus on Pso and one of its most common comorbidities, psoriatic arthritis.

Bile acids improve psoriasiform dermatitis through inhibition of IL-17A expression and CCL20-CCR6 mediated trafficking of T cells

Bile acids (BAs), produced in the liver and further transformed in the gut, are cholesterol-derived molecules involved in essential physiological processes. Recent studies suggest that BAs regulate Th17 cell function, but the underlying mechanism of this action and their therapeutic value in disease models remains unclear. Using an IL-23 minicircle DNA (MC) based murine model of psoriasiform dermatitis (PsD), we showed that oral administration of secondary BAs, including lithocholic acid (LCA), deoxycholic acid (DCA) and 3-oxoLCA, significantly improved PsD without inducing apparent hepatotoxicity. Of the BAs tested, LCA possessed the greatest potency in treating PsD. Intravenous administration of LCA at a much lower dosage (compared to oral treatment) showed a comparable anti-psoriatic effect and markedly suppressed the IL-17A response. Ex vivo experiments revealed that LCA reduced IL-17A production in IL-23-stimulated murine T cells in the absence of BA receptors TGR5 or FXR. Strikingly, BAs inhibited CCL20 expression in keratinocytes, which led to reduced migration of CCR6-expressing Jurkat cells cultured in the conditioned medium of stimulated keratinocytes. Thus, BAs improve PsD with minimal toxicity via direct inhibition of IL-17A production and blockade of CCL20-mediated trafficking, supporting the potential use of BAs in psoriasis.

Ursodeoxycholic Acid May Inhibit Environmental Aging-Associated Hyperpigmentation

Extrinsic aging of the skin caused by ultraviolet (UV) light or particulate matter is often manifested by hyperpigmentation due to increased melanogenesis in senescent skin. Ursodeoxycholic acid (UDCA), which has been commonly used as a health remedy for liver diseases, is known to possess antioxidant properties. This study was done to investigate whether UDCA inhibits cellular aging processes in the cells constituting human skin and it reduces melanin synthesis. ROS, intracellular signals, IL-1α, IL-8, TNF-α, cyclooxygenase (COX)-2, type I collagen, and matrix metalloproteinases (MMPs) levels were measured in human dermal fibroblasts treated with or without UDCA after UV exposure. Melanin levels and mechanistic pathways for melanogenesis were investigated. UDCA decreased ROS, senescence-associated secretory phenotype (SASP), and proinflammatory cytokines induced by UV treatment. UDCA reduced melanogenesis in normal human melanocytes cocultured with skin constituent cells. Our results suggest that UDCA could be a comprehensive agent for the treatment of environmental aging-associated hyperpigmentation disorders.

NAFLD and Extra-Hepatic Comorbidities: Current Evidence on a Multi-Organ Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its incidence is definitely increasing. NAFLD is a metabolic disease with extensive multi-organ involvement, whose extra-hepatic manifestations include type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, chronic kidney disease, osteoporosis, and polycystic ovarian syndrome. Recently, further evidence has given attention to pathological correlations not strictly related to metabolic disease, also incorporating in this broad spectrum of systemic involvement hypothyroidism, psoriasis, male sexual dysfunction, periodontitis, and urolithiasis. The most common cause of mortality in NAFLD is represented by cardiovascular disease, followed by liver-related complications. Therefore, clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations, in order to provide appropriate multidisciplinary assessments and rigorous surveillance. This review evaluates the current evidence regarding extra-hepatic associations of NAFLD, focusing on the pathogenic hypothesis and the clinical implications.

How lifestyle factors and their associated pathogenetic mechanisms impact psoriasis

BACKGROUNDS AND AIMS

Psoriasis is a skin disorder affecting approximately 2-3% of the global population. While research has revealed a strong genetic component, there are few studies exploring the extent to which lifestyle factors influence psoriasis pathogenesis. The aim of this review was to describe the role of lifestyle factors as both a potential cause and treatment for psoriasis. The review also examines the underlying mechanisms through which these lifestyle factors may operate.

METHODS

This narrative review aims to incorporate current knowledge relating to both lifestyle and pathogenetic factors that contribute to and alleviate psoriasis presentation. Studies reporting the effect of an inflammatory diet and potential dietary benefits are reported, as well as insights into the effects of stress, smoking and alcohol, insulin resistance and exercise.

RESULTS

Poor nutrition and low Omega 3 fatty acid intake, likely combined with fat malabsorption caused by gut dysbiosis and systemic inflammation, are associated with psoriasis. The data strongly suggest that improvements to disease severity can be made through dietary and lifestyle interventions and increased physical activity. Less conclusive, although worthy of mention, is the beneficial effect of bile acid supplementation.

CONCLUSIONS

Lifestyle interventions are a promising treatment for psoriasis and its associated co-morbidities. However, gaps and inadequacies exist within the literature, e.g. methodology, absence of a unified scoring system, lack of controlled clinical data and lack of studies without simultaneous usage of biologics or alternative therapies. Future directions should focus on high quality cohort studies and clinical trials.

Is psoriasis a bowel disease? Successful treatment with bile acids and bioflavonoids suggests it is

The gut is the largest lymphoid organ in the body. The human microbiome is composed of trillions of bacteria. The DNA of these bacteria dwarfs the human genome. Diet and ethanol can cause rapid shifts in the number and types of bacteria in the gut. The psoriatic microbiome is similar to that seen in alcoholics; there is a decrease in bacterial diversity and overgrowth of bacteria in the small bowel. Psoriatics often have liver disease and deficiencies in bile acids. Psoriasis is a disease characterized by a leaky gut. All of the comorbidities of this disease are due to systemic endotoxemia. Bacterial peptidoglycans absorbed from the gut have direct toxic effects on the liver and skin. Their absorption, as well as endotoxin absorption, must be eliminated to treat psoriasis successfully. Endotoxin absorption is markedly increased by ethanol and peppers. Bioflavonoids, such as quercetin and citrus bioflavonoids, prevent this absorption. Bile acids, given orally, break up endotoxin in the intestinal lumen. Pathogens, including Helicobacter pylori and Streptococcus pyogenes, must be eliminated with antimicrobial therapy for any treatment to work. A complete protocol for curing psoriasis is provided.

Risk of non-alcoholic fatty liver disease in patients with psoriasis: a systematic review and meta-analysis

BACKGROUND

Psoriasis has been linked to an increased risk of metabolic syndrome (MetS). Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of MetS, is now the commonest liver disease worldwide and can evolve into cirrhosis in a subgroup of patients. Psoriasis has been reported to be associated to NAFLD.

AIM

The aim of this study was to evaluate the strength of the association between psoriasis and NAFLD.

METHODS

A systematic review of the literature was conducted in six databases (Medline, CINAHL, Scopus, LILACS, Cochrane Library and EMBASE). Data from studies assessing frequency of NAFLD in psoriatic and non-psoriatic patients were extracted and meta-analysed using the Mantel-Haenszel method. Subgroups analysis of patients with psoriatic arthritis and moderate to severe psoriasis was also performed.

RESULTS

Seven case-control studies were included, all of them of low or moderate quality. Psoriatic patients exhibited an increased risk of NAFLD compared to non-psoriatic controls (six studies; n = 267,761 patients; odds ratio (OR): 2.15, 95% CI: 1.57-2.94). The association remained significant (OR: 2.07, 95% CI: 1.62-2.64) when only high/moderate quality studies were analysed (three studies; n = 3345 patients). The risk of NAFLD was significantly greater in patients with psoriatic arthritis (three studies; n = 505 patients; OR: 2.25, 95% IC: 1.37-3.71) and in patients with moderate to severe psoriasis compared to those with mild psoriasis (two studies; 51,930 patients, OR: 2.07, 95% CI: 1.59-2.71).

LIMITATIONS

Data quality and heterogeneity may restrict the interpretation of the pooled risk estimates.

CONCLUSION

Case-control studies support an association between psoriasis and NAFLD. Screening of NAFLD in this group of patients may be warranted.

The immunomodulatory role of bile acids

Enzymatic oxidation of cholesterol generates numerous distinct bile acids which function both as detergents that facilitate the digestion and absorption of dietary lipids and as hormones that activate five distinct receptors. Activation of these receptors alters gene expression in multiple tissues, leading to changes not only in bile acid metabolism but also in glucose homeostasis, lipid and lipoprotein metabolism, energy expenditure, intestinal motility, bacterial growth, inflammation, and in the liver-gut axis. This review focuses on the present knowledge regarding the physiologic and pathologic role of bile acids and their immunomodulatory role, with particular attention to bacterial lipopolysaccharides (endotoxins) and bile acid and immunological disorders. The specific role that bile acids play in the regulation of innate immunity, various systemic inflammations, inflammatory bowel diseases, allergy, psoriasis, cholestasis, obesity, metabolic syndrome, alcoholic liver disease, and colon cancer will be reviewed.

The Unexpected Uses of Urso- and Tauroursodeoxycholic Acid in the Treatment of Non-liver Diseases

Tauroursodeoxycholic acid (TUDCA) is the taurine conjugate of ursodeoxycholic acid (UDCA), a US Food and Drug Administration–approved hydrophilic bile acid for the treatment of certain cholestatic liver diseases. There is a growing body of research on the mechanism(s) of TUDCA and its potential therapeutic effect on a wide variety of non-liver diseases. Both UDCA and TUDCA are potent inhibitors of apoptosis, in part by interfering with the upstream mitochondrial pathway of cell death, inhibiting oxygen-radical production, reducing endoplasmic reticulum (ER) stress, and stabilizing the unfolded protein response (UPR). Several studies have demonstrated that TUDCA serves as an anti-apoptotic agent for a number of neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disease. In addition, TUDCA plays an important role in protecting against cell death in certain retinal disorders, such as retinitis pigmentosa. It has been shown to reduce ER stress associated with elevated glucose levels in diabetes by inhibiting caspase activation, up-regulating the UPR, and inhibiting reactive oxygen species. Obesity, stroke, acute myocardial infarction, spinal cord injury, and a long list of acute and chronic non-liver diseases associated with apoptosis are all potential therapeutic targets for T/UDCA. A growing number of pre-clinical and clinical studies underscore the potential benefit of this simple, naturally occurring bile acid, which has been used in Chinese medicine for more than 3000 years.

Psoriasis and non-alcoholic fatty liver disease

Several recent studies have found an increased prevalence of non-alcoholic fatty liver disease within psoriasis patients. The exact pathophysiological mechanisms behind these observations are unclear, but are likely related to the high prevalence of obesity and metabolic syndrome within this patient population. Chronic inflammation, mediated by either proinflammatory adipokines or skin-derived cytokines, may contribute to fatty liver disease development by increasing insulin resistance which in turn promotes hepatic lipid accumulation. These same adipokines in addition to hepatic cytokines may act on the skin to influence psoriasis disease severity.