Allopurinol in dermatology

Anti-inflammatory and uric acid lowering effects of Euodiae fructus on hyperuricemia and gout mice

The metabolic disease hyperuricemia (HUA) is caused by presence of excessive serum uric acid (UA), which leads to an increased risk of chronic kidney disease and gout. As a widely used traditional Chinese medicine, Euodiae fructus (ER) has strong anti-inflammatory and analgesic effects, however, its therapeutic effects on HUA and gout have not been investigated. To investigate the potential effects and underlying mechanisms, the effect of ER on proinflammatory cytokines and NLRP3 inflammasome activation was studied in mouse bone marrow macrophages. Moreover, a mouse model of HUA and gouty arthritis was established by coadministration of potassium oxonate (PO) and monosodium urate crystals to mice fed a high-fat diet (HFD) for 37 consecutive days. Oral administration of ER aqueous extract was given 1 hour later after the injection of PO for 10 days. Our study showed that ER is a powerful NLRP3 inhibitor in mouse macrophages. Most importantly, ER (0.75 g/kg) treatment substantially decreased the ankle joint thickness ratio, serum UA, creatinine and blood urea nitrogen levels (p < 0.05). Additionally, ER (0.75 g/kg) dramatically reversed the increases in renal urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) as well as the decreases in organic anion transporter 1 (OAT1) and ATP binding cassette subfamily G member 2 (ABCG2) levels (p < 0.05). Moreover, ER (0.75 g/kg) markedly ameliorated the production of the serum inflammatory cytokines IL-1β and TNF-α (p < 0.01), and improved the activation of NLRP3 inflammasome signaling in the kidneys. Taken together, these data indicate that ER, a powerful and specific NLRP3 inhibitor, has multiple anti-HUA, anti-gout and anti-inflammatory effects. Our investigation is designed to experimentally support the conventional use of ER-containing classical herbal formulas in the treatment of HUA-related disorders and may add a new dimension to the clinical application of ER.

Stevens-Johnson Syndrome From Combined Allopurinol and Angiotensin-Converting Enzyme Inhibitors: A Narrative Review

Stevens-Johnson syndrome (SJS) is a severe and potentially debilitating skin reaction frequently related to medication use. Allopurinol and angiotensin-converting enzyme (ACE) inhibitors are commonly prescribed medications for prevalent health conditions worldwide, and their interaction associated with SJS warrants further investigation. A comprehensive literature search was performed to investigate cases as studies related to SJS occurring in patients with concomitant use of allopurinol and ACE inhibitors. We identified case reports and studies detailing hypersensitivity reactions, including SJS, attributed to a combination of allopurinol and ACE inhibitors. Despite the drug-drug interactions or lack thereof seen in patient populations, there is no definitive evidence of a pharmacokinetic interaction between allopurinol and ACE inhibitors. We were only able to find one case report specifically detailing SJS in a patient on combined ACE inhibitors and allopurinol. While the exact mechanism of the interaction is unclear, those reported cases of severe hypersensitivity reactions suggest a previous history of impaired renal function as a predisposing factor in the development of SJS. The potential risk of SJS with coadministration of ACE inhibitors and allopurinol is a drug-drug interaction that physicians should be aware of. This topic requires additional attention to determine if this drug combination should be avoided entirely in certain patients.

Granulomatous tattoo reaction treated with topical allopurinol

Granulomatous reactions to tattoo ink have been frequently associated with exogenous pigment, although sometimes they are the manifestation of a cutaneous or an underlying systemic sarcoidosis. We report a case of a patient with a granulomatous reaction to a black tattoo pigment treated with 3% topical allopurinol for 3 months. We observed complete resolution without any side-effects. Examination and follow-up ruled out sarcoidosis. Oral allopurinol has been proven to be effective for the management of granulomatous reactions to tattoos. Based on the significant improvement we have described in our patient, we recommend new studies to reveal all the potential benefits of the topical use of allopurinol for the treatment of granulomatous reactions to tattoo ink.

Short Hexapeptide Optimized from Rice-Derived Peptide 1 Shows Promising Anti-hyperuricemia Activities

Plant-derived peptides are a treasure trove for new-generation anti-hyperuricemia drugs. In the current study, we optimized a short hexapeptide rice-derived peptide 1 (RDP1)-M3 (AAAAGA) according to the anti-hyperuricemia RDP1 peptide identified from rice in our previous research. Results showed that RDP1-M3 exerted better hyperuricemia-alleviating and xanthine oxidase (XOD)-inhibiting potency in mice than RDP1. The biodistribution of RDP1-M3 was also analyzed. RDP1-M3 directly decreased XOD and uric acid levels in vivo and in vitro. In addition, RDP1-M3 reduced the expression of urate transporter 1 and glucose transporter 9, increased the level of organic anion transporter 1, reduced the expression of NOD-like receptor superfamily pyrin 3 inflammasomes, and reduced the levels of interleukin-1β and tumor necrosis factor-α of hyperuricemic mice. Thus, our results indicated that the optimized short hexapeptide RDP1-M3 may be a candidate drug for anti-hyperuricemia.

A theoretical study of allopurinol drug sensing by carbon and boron nitride nanostructures: DFT, QTAIM, RDG, NBO and PCM insights

The application of low-dimensional nanomaterials in clinical practice as efficient sensors has been increasing day by day due to progress in the field of nanoscience. In this research work, we have conducted a theoretical investigation to nominate a potential electrochemical sensor for the allopurinol (APN) drug molecule via studying the fundamental interactions of the drug molecule with two nanocages (carbon nanocage/CNC – C₂₄ and boron nitride nanocage/BNNC – B₁₂N₁₂) and two nanosheets (graphene – C₅₄H₁₈ and boron nitride – B₂₇N₂₇H₁₈) by means of the DFT B3LYP/6-31G(d,p) level of theory in both gas and water phases. The adsorption energies of APN–BNNC conjugated structures are in the range of −20.90 kcal mol⁻¹ to −22.33 kcal mol⁻¹, which indicates that weak chemisorption has occurred. This type of interaction happened due to charge transfer from the APN molecule to BNNC, which was validated and characterized based on the quantum theory of atoms in molecules, natural bond analysis, and reduced density gradient analysis. The highest decreases in energy gap (36.22% in gas and 26.79% in water) and maximum dipole moment (10.48 Debye in gas and 13.88 Debye in water) were perceived for the APN–BNNC conjugated structure, which was also verified via frontier molecular orbital (FMO) and MEP analysis. Also, the highest sensitivity (BNNC > BNNS > CNC > GNS) and favorable short recovery time (in the millisecond range) of BNNC can make it an efficient detector for the APN drug molecule.

The adsorption–desorption behavior of the drug allopurinol on/from the outer surface of a boron nitride nanocage was studied.

Successful treatment of acquired reactive perforating collagenosis with itraconazole

Background

Acquired reactive perforating collagenosis (ARPC) is a rare form of transepithelial elimination in which altered collagen is extruded through the epidermis.

Case presentation

A 23-year-old male presented with cup-like ulcerated lesions on his limbs since 3 months. A series of serological and immunological tests showed no abnormalities. A diagnosis of ARPC was based on skin biopsy findings. The patient was cured using treatment with itraconazole for 8 weeks, in the absence of a fungal infection.

Conclusions

The anti-inflammatory and anti-angiogenic effects of itraconazole can have good therapeutic benefits for ARPC.

PMMA Safety for Facial Filling: Review of Rates of Granuloma Occurrence and Treatment Methods

PMMA is composed of microspheres suspended in bovine collagen. Once injected in a dermal area, the carrier is absorbed, giving place to collagen that gives volume and maintains the spheres in the place. This process may give origin to exacerbate foreign body reaction and granuloma. The frequency of such complication is not clear. The primary objective was to review and compare the frequencies of granuloma between the published studies. The secondary aim was to compare the therapies and efficacies. The series of cases in which PMMA was used as facial filler were reviewed, and the rate of granulomas was compared; the case report studies describing those complications were also reviewed, and the therapies and outcomes were quantified. The data showed general frequency of PMMA-related complications of 4.9% and granulomas 1.9%; the incidence of granuloma was 1/2075 patients-year, and the time to development ranged from 6 to 180 months. The most used therapies were steroid, surgery or both, with satisfactory results. In conclusion, considering the actual risks and benefits of PMMA, we may affirm that it is a safe filler; doctors and patients must be conscious of potential risks when deciding for its use. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Severe Cutaneous Adverse Drug Reactions Associated with Allopurinol: An Analysis of Spontaneous Reporting System in Southern Italy

Background

Allopurinol can induce severe cutaneous adverse reactions (SCARs), including Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

Aims and Methods

We analyzed the Individual Case Safety Reports (ICSRs) sent from January 2001 until April 2019 to the Campania regional Center of Pharmacovigilance (Southern Italy) that reported allopurinol as suspected, with a focus on those reporting at least one serious cutaneous adverse drug reaction (ADR). This study was aimed to describe the main characteristics of all ADRs associated with allopurinol, analyze the proportion of serious cutaneous ADRs of total ICSRs related to allopurinol and to compare the main features (age, sex, seriousness and outcome) of ICSRs that reported serious cutaneous ADRs with those that did not.

Results

The Campania regional Center of Pharmacovigilance received 108 ICSRs that reported allopurinol as suspected. ADRs occurred more frequently in the elderly (median age: 71 years) and female patients (53.7%). Fifty-seven percent of all ADRs were classified as serious and 58% had a favorable outcome. Fifty-six ICSRs reported at least one serious cutaneous ADR; among these ICSRs, 37 cases of SCARs were found [DRESS syndrome (n = 3; 5.4%), SJS (n = 8; 14.3%) and TEN (n = 26; 46.4%)]. Serious cutaneous ADRs commonly occurred in the elderly (median age: 73 years) and female patients (62.5%). They frequently required hospitalization (75%) and had an unfavorable outcome (46%). No statistically significant differences were found between ICSRs that reported serious cutaneous ADRs and ICSRs that did not report serious cutaneous ADRs except for the seriousness degree “Hospitalization or its prolongation” and the outcome degrees “Unfavorable” and “Favorable”.

Conclusion

This study found that 52% (56/108) of all ICSRs having allopurinol as a suspected drug were serious cutaneous ADRs. Serious cutaneous ADRs associated with allopurinol frequently required hospitalization or prolonged hospitalization, and almost half had an unfavorable outcome.

Diabetes Impedes the Epigenetic Switch of Macrophages into Repair Mode

In this issue of Immunity, Kimball et al. (2019) show that restoring expression of the chromatin modifying enzyme Setdb2 in macrophages rescues impaired wound healing associated with type 2 diabetes. Their findings reveal epigenetic regulation as central to the resolution of macrophage-mediated inflammation in tissue repair and have therapeutic implications for the treatment of diabetic wounds.

Freeze-Dried Self-Nanoemulsifying Self-Nanosuspension (SNESNS): a New Approach for the Preparation of a Highly Drug-Loaded Dosage Form

Febuxostat suffers from relatively low bioavailability owing to the poor drug solubility and hepatic first-pass effect. This study aimed to prepare highly drug-loaded self-nanoemulsifying self-nanosuspension systems (SNESNS). SNESNS were designed to improve febuxostat's oral bioavailability by enhancing its solubility. Different oil and surfactant/co-surfactant mixtures were used for the preparation of SNESNS. The prepared SNESNS were estimated for their particle size, in vitro drug release and transmission electron microscopy (TEM). Results revealed that the oil mixture of Capryol™ 90:Miglyol^® 812 (1:1 w/w) with surfactant/co-surfactant mixture of Cremophor^® RH 40/Transcutol^® HP loaded with drug in 4-fold greater concentration than its saturated solubility resulted in the formation of SNESNS by dilution under the effect of magnetic stirring. SNESNS were freeze-dried using trehalose as a cryoprotectant. TEM images and the bimodal particle size curve confirmed the formation of the biphasic nanosystems after dilution (nanoemulsion and nanosuspension). Higher C_max and AUC_0-48 values compared to those of the market product Feburic^® tablets confirmed the success of the SNESNS as a promising carrier for drugs suffering from poor water solubility like febuxostat.

The anti-hyperuricemic effect of four astilbin stereoisomers in Smilax glabra on hyperuricemic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Smilax glabra Roxb. (SG), a Chinese medicinal herb which called "tufuling", is believed to be effective in treating hyperuricemia and gout symptoms. But the active substance and pharmacological mechanism of reducing uric acid remain unknown. This study aimed to obtain the total flavonoids including four astilbin stereoisomers and to examine their effects on reducing uric acid content in hyperuricemic mice.

MATERIALS AND METHODS

The total flavonoids of S. glabra (TFSG) were purified and then analysed by HPLC-PDA-MS. The effect of TFSG on the content of serum uric acid (S_UA), Serum creatinine (S_Cr), blood urea nitrogen (BUN) and the activities of xanthine oxidase (XOD) in hyperuricemic mouse model induced by potassium oxonate were examined. Western blot and PCR method were also used to investigate whether TFSG have effect on renal transport protein organic anion transporter 1 (OAT1), organic cation/carnitine transporter 2 (OCTN2) and their mRNA in hypeuricemic mice.

RESULT

Total flavonoids were obtained from EtOAc soluble portion of S. glabra. Four compounds were identified as neoastilbin, astilbin, neoisoastilbin and isoastilbin, which accounted for 55.6% of total flavonoids. TFSG could significantly reduce the serum uric acid content in hyperuricemic mouse (p < 0.01 or p < 0.05). The activities of hepatic XOD have been reduced in hyperuricemic mouse administered with 125 mg/kg TFSG (p < 0.05). The expressions of renal OAT1, OCTN2 and their mRNA have been up-regulated in hyperuricemic mice administered with TFSG (250, 125 mg/kg) (p < 0.01or p < 0.05). TFSG (62.5 mg/kg) could also elevated the expression of renal OCTN2 (p < 0.05).

CONCLUSION

A novel and simple method for preparative separation of astilbin stereoisomers from S. glabra was developed. It was the first time to obtain total flavonoids (including four marker compounds) of S. glabra, and the total content was up to 55.6%. The results suggested TFSG has significant effect on reducing uric acid in hyperuricemic mice by inhibiting the XOD activities and up-regulating the expression of OAT1, OCTN2 and their mRNA in kidney tissue.

Itraconazole in the Treatment of Nonfungal Cutaneous Diseases: A Review

INTRODUCTION

The anti-inflammatory and pro-kinetic properties of antibiotics have been widely reported. However, the non-antifungal properties of antifungal agents are less well known and less explored in clinical practice. The purpose of this review was to survey the literature on the non-antifungal use of itraconazole in dermatological practice and the possible modes of action of this agent.

METHODS

The PubMed database was searched for relevant articles published up to January 2017. The references in the articles identified by the search were then hand-searched for additional relevant publications.

RESULTS

Itraconazole displays a great diversity of non-antifungal activity and has been used to treat a broad spectrum of diseases. The results of our survey reveal that itraconazole has the potential to be an alternative agent for treating patients with advanced cancer (either alone or in combination with other cytotoxic chemotherapeutic drugs), especially those refractory to traditional treatments. Moreover, itraconazole acts as an anti-angiogenesis agent, induces nail growth, and modulates inflammatory or immune diseases.

CONCLUSION

Oral antifungal agents have many non-antifungal properties. However, the body of evidence on individual agents often remains limited due to the lack of large-scale randomized controlled studies. Although some of the findings published to date seem promising, pharmacological vigilance should be taken for off-label use in real-world practice.

Autoimmune/inflammatory syndrome induced by adjuvants-ASIA-related to biomaterials: analysis of 45 cases and comprehensive review of the literature

Systemic autoimmune or granulomatous disorders related to biomaterials of human use have rarely been described. The aim of this study was to report cases of autoimmune/inflammatory syndrome induced by adjuvants (ASIA) related to biomaterial injections and prostheses, mainly silicone, hyaluronic acid, acrylamides and methacrylate compounds in a Spanish patient cohort. This study is a retrospective analysis of clinical, laboratory, histopathological and follow-up data of 45 cases of patients suffering from late-onset, non-infectious inflammatory/autoimmune disorders related to bioimplants. Late onset was defined as 3 months or more post injection. Data were obtained through a further non-systematic but comprehensive review of the literature. Forty-five cases of late-onset adverse reactions related to biomaterial injections or prostheses were reviewed. All cases had systemic complaints that could be categorised as ASIA. In all but four patients, inflammatory features at the implantation site preceded distant or systemic manifestations. Abnormal blood tests were common. Localised inflammatory nodules and panniculitis in 40/45 (88.88%) evolved into a variety of disorders, viz., primary biliary cirrhosis, Sjögren's syndrome, sarcoidosis, human adjuvant disease, vasculitis, inflammatory bowel syndrome and inflammatory polyradiculopathy. Five (11.11%) cases presented primarily with systemic autoimmune disorders. Biomaterials and prostheses can provoke late-onset systemic autoimmune disorders fulfilling ASIA criteria, or present primarily local/regional inflammatory reactions that may eventually evolve into systemic autoimmune and/or granulomatous disorders which fall under ASIA.

Risk factors of allopurinol-induced severe cutaneous adverse reactions in a Thai population

BACKGROUND

Allopurinol is one of the most common causes of severe cutaneous adverse drug reactions (SCARs) including drug reactions with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). This study identified the risk factors associated with the development of allopurinol-induced SCARs in a Thai population.

PATIENTS AND METHODS

Eighty-six allopurinol-induced SCARs (i.e. 19 DRESS and 67 SJS/TEN) and 182 allopurinol-tolerant patients were enrolled in the study. The HLA-B*58:01 allele was determined. Clinical and medicinal data were collected.

RESULTS

Results from multivariate analysis showed that only the HLA-B*58:01 and female sex were identified as risk factors of allopurinol-induced SCARs in this Thai population. Patients who carried the HLA-B*58:01 allele were at a higher risk of allopurinol-induced DRESS [odds ratio (OR)=149.2, 95% confidence interval (CI)=24.0-∞, P<1.00×10]. Similar results were observed in allopurinol-induced SJS/TEN (OR=175.0, 95% CI=44.3-690.9, P=1.69×10). The risk of allopurinol-induced SCARs in women was higher than that in men (OR=4.6, 95% CI=1.4-15.6, P=1.44×10). The overall mortality rate of allopurinol-induced SCARs was 11.39% and a higher mortality rate was observed in elderly women.

CONCLUSION

Among the risk factors identified, the HLA-B*58:01 allele had the greatest impact on the development of both phenotypes of allopurinol-induced SCARs in this studied Thai population. In case HLA-B*58:01 genotyping cannot be accessed, close monitoring of allopurinol usage, especially in elderly women with impaired renal function, is necessary to reduce the mortality rate of these life-threatening SCARs.

Screening, separation, and evaluation of xanthine oxidase inhibitors from Paeonia lactiflora using chromatography combined with a multi-mode microplate reader

Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora (P. lactiflora), and both high-performance counter-current chromatography and medium-pressure liquid chromatography were employed to separate the main constituents. Furthermore, the xanthine oxidase inhibitory activities and the mechanisms of inhibition of the isolated compounds were evaluated using a multi-mode microplate reader by Molecular Devices. As a result, three monoterpene glycosides were separated by combined high-performance counter-current chromatography and medium-pressure liquid chromatography in purities of 90.4, 98.0, and 86.3%, as determined by liquid chromatography. These three compounds were identified as albiflorin, paeoniflorin, and 1-O-β-ᴅ-glucopyranosyl-8-O-benzoylpaeonisuffrone by electrospray ionization tandem mass spectrometry, and albiflorin and paeoniflorin were screened as potential xanthine oxidase inhibitors by ultrafiltration with liquid chromatography. The evaluation results of xanthine oxidase inhibitory activity corresponded with the screening results, as only albiflorin and paeoniflorin exhibited xanthine oxidase inhibitory activity.

Allopurinol-Induced Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome: A Cause of Acalculous Cholecystitis?

Acalculous cholecystitis (AC) is an inflammation of the gallbladder in the absence of gallstones. There are many risk factors associated with AC. However, this report implicates allopurinol as an inciting agent for a severe systemic drug reaction, i.e., the drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome complicated by AC. We report a Chinese woman who presented on two occasions with a diffuse maculopapular rash, elevated liver enzymes, and upper abdominal pain attributable to acute AC, the second episode of which developed after the reintroduction of allopurinol treatment for gout. The AC complicated the DRESS syndrome during the course of her hospitalization.

A comparative study of efficacy and safety of febuxostat and allopurinol in pyrazinamide-induced hyperuricemic tubercular patients

OBJECTIVES

To compare the efficacy and safety of febuxostat and allopurinol in pyrazinamide (PZA)-induced hyperuricemia in patients taking antitubercular therapy (ATT).

METHODS

This randomized controlled study was conducted at a tertiary care teaching institute of Rajasthan in all the sputum-positive tubercular patients aged between 18 and 65 years of either sex. Serum uric acid level was monitored at 0^th, 2^nd, 4^th, 6^th, and 8^th week of ATT. Patients whose uric acid level was found to be increased at 2^nd week were finally recruited in the study. Ninety patients who developed hyperuricemia due to ATT were divided randomly into three groups (Group A - febuxostat, Group B - allopurinol, and Group C - control) of thirty patients each. Mean serum uric acid levels were calculated at all the weeks in all the groups, and serum uric acid levels were compared by applying student's t-test and ANOVA.

RESULTS

Mean serum uric acid level decreased from 10.698 mg/dl (at 2^nd week) to 7.846 mg/dl (at 8^th week) in Group A and from 11.34 mg/dl (at 2^nd week) to 7.280 mg/dl (at 8^th week) in Group B. Numbers of adverse events encountered across both the treatment groups were same with both the drugs.

CONCLUSION

Allopurinol and febuxostat were equally efficacious in lowering PZA induced raised serum uric acid level in tubercular patients, and it was possible to continue ATT without withdrawing PZA.

Hypouricemic effect of allopurinol are improved by Pallidifloside D based on the uric acid metabolism enzymes PRPS, HGPRT and PRPPAT

Allopurinol is a commonly used medication to treat hyperuricemia and its complications. Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to enhanced hypouricemic effect of allopurinol based on uric acid metabolism enzyme XOD. In this study, we evaluated whether Pallidifloside D (5mg/kg) enhanced hypouricemic effect of allopurinol (5mg/kg) related to others uric acid metabolism enzymes such as PRPS, HGPRT and PRPPAT. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly up-regulated HGPRT mRNA expression and down-regulated the mRNA expression of PRPS and PRPPAT in PC12 cells (all P<0.01). These results strongly suggest that hypouricemic effect of allopurinol are improved by Pallidifloside D via numerous mechanisms and our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.

Oxidative stress in psoriasis and potential therapeutic use of antioxidants

The pathophysiology of psoriasis is complex and dynamic. Recently, the involvement of oxidative stress in the pathogenesis of psoriasis has been proposed. Oxidative stress is an imbalance between oxidants and antioxidants in favor of the oxidants, leading to a disruption of redox signaling and control and/or molecular damage. In this article, the published studies on the role of oxidative stress in psoriasis pathogenesis are reviewed, focusing on the impacts of oxidative stress on dendritic cells, T lymphocytes, and keratinocytes, on angiogenesis and on inflammatory signaling (mitogen-activated protein kinase, nuclear factor-κB, and Janus kinase/signal transducer and activator of transcription). As there is compelling evidence that oxidative stress is involved in the pathogenesis of psoriasis, the possibility of using this information to develop novel strategies for treatment of patients with psoriasis is of considerable interest. In this article, we also review the published studies on treating psoriasis with antioxidants and drugs with antioxidant activity.

Granulomatous reaction to red tattoo pigment treated with allopurinol

Granulomatous reactions to tattoo ink are most commonly associated with mercury sulfide, a component of red pigments. Treatment options show limited results. Allopurinol, an inhibitor of xanthine oxidase, has been reported as a successful alternative treatment to granulomatous disorders, such as sarcoidosis and granulomatous reactions to fillers and tattoos. We report a case of granulomatous reaction to red tattoo pigment treated with allopurinol for 6 months. Good clinical improvement could be noticed during this time. Two months after we stopped the treatment, the lesion recurred. Allopurinol emerges as an important drug for the management of granulomatous reactions caused by tattoo pigments. Based on the significant clinical improvement noticed during its use, we recommend new studies to elucidate all the potential benefits of the use of allopurinol for the treatment of granulomatous reactions to tattoo ink.

Pallidifloside D from Smilax riparia enhanced allopurinol effects in hyperuricemia mice

Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to be effective in hyperuricemic control. Allopurinol is a commonly used medication to treat hyperuricemia and its complications. In this study, we evaluated whether Pallidifloside D could enhance allopurinol's effects by decreasing the serum uric acid level in a hyperuricemic mouse model induced by potassium oxonate. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly decreased the serum uric acid level and increased the urine uric acid level (both P<0.05), leading to the normalized serum and urine uric acid concentrations. Data on serum, urine creatinine and BUN supported these observations. Our results showed that the synergistic effects of allopurinol combined with Pallidifloside D were linked to the inhibition of both serum and hepatic xanthine oxidase (XOD), the down-regulation of renal mURAT1 and mGLUT9, and the up-regulation of mOAT1. Our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.

Practical method for the rapid screening of xanthine oxidase inhibitors in herbal extracts by high-performance liquid chromatography based on on-line precolumn enzymatic reaction

A high-performance liquid chromatography method with on-line precolumn enzymatic reaction for the screening of xanthine oxidase inhibitors in natural extracts was developed. In this method, the enzymatic reaction occurred at the capillary inlet during a predetermined waiting period, after which the reaction product, uric acid, was separated and detected by liquid chromatography using ultraviolet absorption at 295 nm. Enzyme inhibition can be read out directly from the reduced peak area of uric acid in comparison to a reference chromatogram obtained in the absence of any inhibitor. In the present study, the availability of on-line precolumn enzymatic reaction with ultraviolet detection was firstly evaluated by determining the inhibitory mechanism and IC50 values of allopurinol, a commercially available positive drug. Then, the newly developed method was applied to screening of ten natural extracts from traditional Chinese medicine and as a result, the extract of Epimedium sagittatum (Sieb. et Zucc.) Maxim was found to be most positive for xanthine oxidase inhibition. The results obtained were compared with those obtained by offline enzyme assay and the effectiveness of the present method was confirmed. A rapid, low-cost, and fully automated method for xanthine oxidase inhibitor screening was proposed.

Anti-hyperuricemia effects of allopurinol are improved by Smilax riparia, a traditional Chinese herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

The roots and rhizomes of Smilax riparia are called "Niu-Wei-Cai" in traditional Chinese medicine (TCM). This botanical has been used in treating the symptoms of gout and other hyperuricemic-related conditions in TCM. Allopurinol is a commonly used medication to treat hyperuricemia and its complications. In this study, we evaluated whether Smilax riparia could enhance allopurinol׳s effects by decreasing the serum uric acid level in a hyperuricemic mouse model induced by potassium oxonate.

MATERIALS AND METHODS

We examined the effects of allopurinol (5mg/kg) administration alone or in combination with Smilax riparia saponins (SRS, 500 mg/kg) on the serum uric acid (SUA), serum creatinine (SCr) and blood urea nitrogen (BUN) levels in a hyperuricemic mouse model. The effects of allopurinol alone or those of allopurinol plus SRS on the XOD activities were measured. Western blot analysis was used to measure the levels of mURAT1, mGLUT9 and mOTA1 in the mice.

RESULTS

Compared with allopurinol alone, the combination of allopurinol and SRS significantly decreased the serum uric acid level and increased the urine uric acid level (both P<0.05), leading to the normalized serum and urine uric acid concentrations. Data on serum and urine creatinine and BUN supported these observations. The attenuation of hyperuricemia-induced renal dysfunction was linked to the inhibition of both serum and hepatic xanthine oxidase (XOD), the down-regulation of renal mURAT1 and mGLUT9, and the up-regulation of mOAT1.

CONCLUSION

The anti-hyperuricemia effects of allopurinol are improved by Smilax riparia co-administration. The results were supported by the measurement of uric acid, creatinine, BUN, XOD, mURAT1, mGLUT9 and mOAT1. Our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.

Fixed drug eruption due to allopurinol: positive oral provocation

A fixed drug eruption (FDE) is characterized by the presence of a solitary or multiple, pruritic, well-circumscribed, erythematous plaques. These lesions have tendency to recur at same sites and heal with residual hyperpigmenation. With repeated attacks, the size and/or number of the lesions may increase. So far, more than 100 drugs have been implicated in causing FDEs, including ibuprofen, sulfonamide, naproxen, and tetracylines. FDE caused by allopurinol has been rarely reported in the literature, but there has been no confirmed case based on oral provocation test. Herein, we report a case of FDE in which the lesions recurred whenever allopurinol was administered for the treatment of gout. A 64-year-old male experienced repeated episodes of well-demarcated dusky erythematous patches on the whole body for 2 months. He took allopurinol intermittently for amelioration of his gout symptom, but denied other medication history. Pruritic erythematous edema developed on the previous lesions 12 hours after oral provocation of 200 mg of allopurinol.

Amelioration of diabetes-induced cavernosal fibrosis by antioxidant and anti-transforming growth factor-β1 therapies in inducible nitric oxide synthase-deficient mice

OBJECTIVE

•  To investigate whether sustained long-term separate treatments of diabetic inducible nitric oxide synthase knockout (iNOSKo) mice with allopurinol, an antioxidant inhibiting xanthine oxidoreductase, decorin, a transforming growth factor-β1 (TGFβ1) -binding antagonist, and molsidomine, a long-life nitric oxide donor, prevent the processes of diabetes-induced cavernosal fibrosis.

MATERIALS AND METHODS

•  Eight week old male iNOS knock out (iNOSKo) mice were made diabetic by injecting 150 mg/kg B.W Streptozotocin (1P) with were either left untreated or treated with the oral antioxidant allopurinol (40 mg/kg/day), or decoin (50 mg, 1P, twice), as an anti-TGFβ1 agent (n = 8/group). •  Glycemia and oxidative stress markers were determined in blood and urine. •  Paraffin-embedded tissue sections from the penile shaft were subjected to Masson trichrome staining for the smooth muscle (smc)/collagen ratio, and imunostaining for smc content, profibrotic factors, oxidative stress, cell replication and cell death markers followed by quantitative image analysis.

RESULTS

•  Eight-week treatment with either allopurinol or decorin counteracted the decrease in smooth muscle cells and the increase in apoptosis and local oxidative stress within the corpora tissue. •  Decorin but not allopurinol increased the smooth muscle cell/collagen ratio, whereas allopurinol but not decorin inhibited systemic oxidative stress. •  Molsidomine was effective in reducing both local and systemic oxidative stress, but did not prevent corporal fibrosis.

CONCLUSION

•  Both allopurinol and decorin appear as promising approaches either as a single or a combined pharmacological modality for protecting the diabetic corpora from undergoing apoptosis and fibrosis although their functional effects still need to be defined.