Effect of Topical Application of Black Seed Oil on Imiquimod-Induced Psoriasis-like Lesions in the Thin Skin of Adult Male Albino Rats

Dermaceutical Utilization of Nigella sativa Seeds: Applications and Opportunities

Skin diseases have recently become a major concern among people of all ages due to their highly visible symptoms and persistent and difficult treatment, which significantly impact their quality of life. Nigella sativa seeds, also known as "black seeds" or "kalonji," are one of the most commonly used herbal medicines due to their wide range of biological and pharmacological activities. It contains a wide range of bioactive constituents found in both fixed and essential oils. It has been used for hundreds of years as an alternative ethnomedicine to treat a wide range of skin conditions. N. sativa's dermatological applications in skin diseases are attributed to its potent antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory properties, making it an intriguing skincare candidate. Several studies unravelled positive results associated with N. sativa on skin diseases. As N. sativa is the most studied medicinal plant, several preclinical and clinical studies have been conducted to establish its use in the treatment of various skin diseases. Thymoquinone has anti-inflammatory, antioxidant, and antibacterial properties, which mainly contributed to the treatment of skin diseases. In this context, the present review explores all the available studies on the association of N. sativa and its effect on treating skin diseases in light of recent studies and patents supporting its therapeutic applications.

Volatile Oil Containing Plants as Phytopharmaceuticals to Treat Psoriasis: A Review

INTRODUCTION

Psoriasis is a chronic skin condition caused by an autoimmune response that accelerates the life cycle of skin cells, resulting in the characteristic symptoms of scaling, inflammation, and itching.

METHODS

Palliative treatment options for psoriasis often prioritize the use of volatile oils. These oils contain monoterpenes, sesquiterpenes, and phenylpropanoids that are intricately linked to the molecular cascades involved in the pathogenesis and symptoms of psoriasis. To evaluate the antipsoriatic efficacy of volatile oils and their components, we conducted a systematic review of scientific studies. Our literature search encompassed various online databases, including PubMed, BIREME, SCIELO, Open Grey, Scopus, and ScienceDirect. The selected studies included experimental in vitro/in vivo assessments as well as clinical studies that examined the potential of volatile oils and their extracts as antipsoriatic agents. We excluded conference proceedings, case reports, editorials, and abstracts. Ultimately, we identified and evaluated a total of 12 studies for inclusion in our analysis.

RESULTS

The data collected, compiled, and analyzed strongly support the interaction between volatile oils and their constituents with the key molecular pathways involved in the pathogenesis of psoriasis and the development of its symptoms. Volatile oils play a significant role in the palliative treatment of psoriasis, while their chemical constituents have the potential to reduce the symptoms and recurrence of this condition.

CONCLUSION

The current review highlights that the constituents found in volatile oils offer distinct chemical frameworks that can be regarded as promising starting points for the exploration and development of innovative antipsoriatic agents.

Novel anti-psoriatic nanostructured lipid carriers for the cutaneous delivery of luteolin: A comprehensive in-vitro and in-vivo evaluation

Psoriasis is a prevalent laborious inflammation in skin with alternate phases of remission and relapses. The current study sought to develop nanostructured lipid carriers (NLCs) having enhanced skin deposition as well as augmented anti-inflammatory potential, to repurpose the use of luteolin (Lut), a flavonoid, in the treatment of psoriasis. NLCs were prepared using different oils having reported anti-inflammatory activity and evaluated in terms of size, surface charge, entrapment efficiency, stability upon storage, in-vitro anti-inflammatory potential, surface morphology, in-vitro release profile and release kinetics, and ex-vivo skin deposition. In-vivo animal studies were conducted on the optimized formula using imiquimod-induced psoriasis rat model. The prepared NLCs were nanosized ranging from 202 to 538 nm, negatively charged with values having the range of -13.10 to -19.26 mV with high entrapment efficiency values ranging from 84.21 to 96.53% and high in-vitro anti-inflammatory potential compared to the blank and control formulations. Furthermore, NLCs demonstrated adequate storage stability demonstrated by slightly significant change in their colloidal properties. The prepared nanoparticles exhibited sustained drug release up to 24 h and succeeded in enhancing the skin deposition of Lut by 3.4-fold higher in stratum corneum, epidermis and dermis compared to Lut suspension with minimum transdermal delivery. In-vivo assessment of psoriasis was carried out morphologically, histopathologically and biochemically and results revealed significant augmentation of the anti-psoriatic efficacy of Lut upon its encapsulation in NLCs compared to free Lut suspension. The developed system proved to be an influential drug delivery system providing potent anti-psoriatic therapy, paving the way for futuristic clinical investigations.

Imiquimod-induced pruritus in female wild-type and knockin Wistar rats: underscoring behavioral scratching in a rat model for antipruritic treatments

OBJECTIVES

Animal models of skin disease are used to evaluate therapeutics to alleviate disease. One common clinical dermatological complaint is pruritus (itch), but there is a lack of standardization in the characterization of pre-clinical models and scratching behavior, a key itch endpoint, is often neglected. One such model is the widely used imiquimod (IMQ) mouse model of psoriasis. However, it lacks characterized behavioral attributes like scratching, nor has widely expanded to other species like rats. Given these important attributes, this study was designed to broaden the characterization beyond the expected IMQ-induced psoriasis-like skin inflammatory skin changes and to validate the role of a potential therapeutic agent for pruritus in our genetic rat model. The study included female Wistar rats and genetically modified knockin (humanized proteinase-activated receptor 2 (F2RL1) female rats, with the widely used C57BL/6 J mice as a methodology control for typical IMQ dosing.

RESULTS

We demonstrate that the IMQ model can be reproduced in rats, including their genetically modified derivatives, and how scratching can be used as a key behavioral endpoint. We systemically delivered an anti-PAR2 antibody (P24E1102) which reversed scratching bouts-validating this behavioral methodology and have shown its feasibility and value in identifying effective antipruritic drugs.

Quality-by-Design Approach for Investigating the Efficacy of Tacrolimus and Hyaluronic Acid-Loaded Ethosomal Gel in Dermal Management of Psoriasis: In Vitro, Ex Vivo, and In Vivo Evaluation

Psoriasis is an auto-immune condition with high keratinocyte hyperproliferation due to lower p53 and p22 levels. Tacrolimus, an immune suppressor, is considered one of the most effective drugs in suppressing psoriasis. Systematic administration of tacrolimus often leads to challenging side effects, namely increased infection risk, renal toxicity, neurological symptoms such as tremors and headaches, gastrointestinal disturbances, hypertension, skin-related problems, etc. To address this, a nanocarrier-based formulation of tacrolimus along with inclusion of hyaluronic acid was developed. The optimization and formulation of ethosomes via the ethanol injection technique were done based on the Box-Behnken experimental design. The results revealed hyaluronic acid-based tacrolimus ethosomes (HA-TAC-ETH) had nanometric vesicle size (315.7 ± 2.2 nm), polydispersity index (PDI) (0.472 ± 0.07), and high entrapment efficiency (88.3 ± 2.52%). The findings of drug release and skin permeation showed sustained drug release with increased dermal flux and enhancement ratio. The effectiveness of HA-TAC-ETH was confirmed in an imiquimod (5%)-prompted psoriasis model. The skin irritation score and Psoriasis Area and Severity Index (PASI) score indicated that HA-TAC-ETH gel has validated a decline in the entire factors (erythema, edema, and thickness) in the imiquimod-induced psoriasis model in contrast with TAC-ETH gel and TAC ointment. The fabricated HA-TAC-ETH opt gel proved to be safe and effective in in vivo studies and could be employed to treat psoriasis further.

Diosmin nanocrystal gel alleviates imiquimod-induced psoriasis in rats via modulating TLR7,8/NF-κB/micro RNA-31, AKT/mTOR/P70S6K milieu, and Tregs/Th17 balance

Diosmin is a flavonoid with promising anti-inflammatory and antioxidant properties. However, it has difficult physicochemical characteristics since its solubility demands a pH level of 12, which has an impact on the drug's bioavailability. The aim of this work is the development and characterization of diosmin nanocrystals using anti-solvent precipitation technique to be used for topical treatment of psoriasis. Results revealed that diosmin nanocrystals stabilized with hydroxypropyl methylcellulose (HPMC E15) in ratio (diosmin:polymer; 1:1) reached the desired particle size (276.9 ± 16.49 nm); provided promising colloidal properties and possessed high drug release profile. Additionally, in-vivo assessment was carried out to evaluate and compare the activities of diosmin nanocrystal gel using three different doses and diosmin powder gel in alleviating imiquimod-induced psoriasis in rats and investigating their possible anti-inflammatory mechanisms. Herein, 125 mg of 5% imiquimod cream (IMQ) was applied topically for 5 consecutive days on the shaved backs of rats to induce psoriasis. Diosmin nanocrystal gel especially in the highest dose used offered the best anti-inflammatory effect. This was confirmed by causing the most statistically significant reduction in the psoriasis area severity index (PASI) score and the serum inflammatory cytokines levels. Furthermore, it was capable of maintaining the balance between T helper (Th17) and T regulatory (Treg) cells. Moreover, it tackled TLR7/8/NF-κB, miRNA-31, AKT/mTOR/P70S6K and elevated the TNFAIP3/A20 (a negative regulator of NF-κB) expression in psoriatic skin tissues. This highlights the role of diosmin nanocrystal gel in tackling imiquimod-induced psoriasis in rats, and thus it could be a novel promising therapy for psoriasis.

Can Essential Oils/Botanical Agents Smart-Nanoformulations Be the Winning Cards against Psoriasis?

Although psoriasis remains one of the most devastating inflammatory disorders due to its huge negative impact on patients’ quality of life, new “green” treatment approaches still need to be fully explored. The purpose of this review article is to focus on the utilization of different essential oils and active constituents of herbal botanical origin for the treatment of psoriasis that proved efficacious via both in vitro and in vivo models. The applications of nanotechnology-based formulations which displayed great potential in augmenting the permeation and delivery of these agents is also addressed. Numerous studies have been found which assessed the potential activity of natural botanical agents to overcome psoriasis. Nano-architecture delivery is applied in order to maximize the benefits of their activity, improve properties, and increase patient compliance. This field of natural innovative formulations can be a promising tool to optimize remediation of psoriasis while minimizing adverse effects.

Curcumin and ustekinumab cotherapy alleviates induced psoriasis in rats through their antioxidant, anti-inflammatory, and antiproliferative effects

INTRODUCTION

Psoriasis is a chronic multifactorial inflammatory disease that affects 3% of people worldwide. Ustekinumab is a selective anti-IL-12/23 biologic that alleviates psoriasis, and curcumin is a natural, effective dietary turmeric extract applied to treat numerous diseases through its antioxidant and anti-inflammatory effects.

OBJECTIVE

The current study evaluated the therapeutic effects of curcumin and ustekinumab cotherapy (CUC) on imiquimod (IQ)-induced psoriasis in a rat model.

MATERIALS AND METHODS

Twenty rats were divided into four groups, G1 (control group), G2 (IQ-treated group), G3 (IQ + ustekinumab), and G4 (IQ + CUC). Clinical, histopathological (HP), immunohistochemical (IHC), antioxidant, and biochemical investigations evaluated the efficacy of these drugs for treating IQ induced-psoriasis.

RESULTS

Rats of G2 exhibited clinical signs of psoriatic skin lesions (erythema, scaling, and skin thickening) with epidermal changes (acanthosis and parakeratosis). Additionally, the biochemical analysis revealed significant (p < 0.05) reductions in the levels of antioxidant biomarkers (SOD, GPx, and CAT) with significant (p < 0.05) elevations in psoriasis-related cytokines (TNF-α, IL-17A, IL-12P40, and IL-23). In contrast, CUC alleviated the psoriatic changes in G4 better than ustekinumab monotherapy in G3.

CONCLUSIONS

Ustekinumab inhibits the inflammatory cytokines IL-12P40 and IL-23, while curcumin has antioxidant effects (increasing SOD, GPx, and CAT levels) with anti-inflammatory effects (decreasing the proinflammatory cytokine TNF-α and IL-17). Therefore, CUC could be an excellent cost-effective regimen that can improve the treatment of psoriasis by the synergistic effects of CUC.HighlightsIQ-induces psoriasis by elevating TNF-α, IL-17A, IL-12, and IL-23 and decreasing GPx, SOD, and CATUstekinumab exhibits anti-inflammatory effects by inhibiting IL-12 and IL-23Curcumin inhibits TNF-α and IL-17A, and increases GPx, SOD, and CAT levelsCUC mitigates psoriasis by synergistic antioxidant and anti-inflammatory effectsCUC inhibits TNF-α, IL-17A, IL-12, and IL-23 and increases GPx, SOD, and CAT levels.

Molecular and histopathological profiling of imiquimod induced dermatosis in Swiss Wistar rats: contribution to the rat model for novel anti-psoriasis treatments

Imiquimod (IMQ) induced human-like psoriasis in mice has been shown to be effective in testing and development of novel treatments. The IMQ psoriasis model has become widely used animal model, however, it is not completely characterized in different rat strains. We aimed to evaluate IMQ and betamethasone treatment for induction and reversal of psoriatic lesions on macroscopic, histological, genetic as well as cytokines and chemokines activation levels. Wistar rats were treated topically with IMQ. Adopted Psoriasis Area Severity Index (PASI) was calculated at the baseline, after the IMQ-symptoms induction and after betamethasone-symptoms reversal. Systematic effects were studied on cytokines and chemokines levels in plasma. Skin biopsy was taken to assess histological symptoms and selected inflammatory cytokines and receptors genes expression levels. Reversal of skin lesions, after betamethasone treatment, was significant (p = 0.03). Histological differences between untreated and IMQ-treated skin were significant for some markers (p < 0.05) though not significantly decreased by betamethasone treatment. Fourteen genes were significantly up-regulated after the IMQ and four genes were down-regulated after skin lesions reversal by betamethasone. This work provides new insights on biological effects of imiquimod induced psoriasis and its reversal by betamethasone treatment in Wistar rats. It also contributes to general knowledge of the rat model usage for testing of novel anti-psoriasis drugs.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Desmoglein-4 Deficiency Exacerbates Psoriasiform Dermatitis in Rats While Psoriasis Patients Displayed a Decreased Gene Expression of DSG4

Desmogleins are involved in cell adhesion conferring structural skin integrity. However, their role in inflammation has been barely studied, and whether desmoglein-4 modulates psoriasis lesions is completely unknown. In this study, we assessed the impact of desmoglein-4 deficiency on the severity of imiquimod (IMQ)-induced skin inflammation and psoriasiform lesions. To this end, desmoglein-4-/- Oncins France Colony A (OFA) with Sprague-Dawley (SD) genetic background were used. Additionally, human RNA-Seq datasets from psoriasis (PSO), atopic dermatitis (AD), and a healthy cohort were analyzed to obtain a desmosome gene expression overview. OFA rats displayed an intense skin inflammation while SD showed only mild inflammatory changes after IMQ treatment. We found that IMQ treatment increased CD3+ T cells in skin from both OFA and SD, being higher in desmoglein-4-deficient rats. In-depth transcriptomic analysis determined that PSO displayed twofold less DSG4 expression than healthy samples while both, PSO and AD showed more than three-fold change expression of DSG3 and DSC2 genes. Although underlying mechanisms are still unknown, these results suggest that the lack of desmoglein-4 may contribute to immune-mediated skin disease progression, promoting leukocyte recruitment to skin. Although further research is needed, targeting desmoglein-4 could have a potential impact on designing new biomarkers for skin diseases.

A review of Nigella sativa plant-based therapy in dermatology

Nigella sativa (N. sativa) is a widely used medicinal herb with a rich cultural and religious history in Unani, Ayurveda, Chinese, and Arabic medicine. N. sativa contains many natural bioactive agents including alkaloids, saponins, alpha-hederin, and thymoquinone that contribute to its broad range of benefits as a diuretic, bronchodilator, antihypertensive, antidiabetic, and analgesic. In addition, N. sativa possesses antimicrobial, anti-inflammatory, and antineoplastic effects, making it an interesting potential therapy for the treatment of dermatological conditions. This article reviews the current literature surrounding the pharmacological effects of N. sativa for the treatment of acne vulgaris, melanoma, vitiligo, atopic dermatitis, plaque psoriasis, and wound healing.

Layered dissolving microneedles as a need-based delivery system to simultaneously alleviate skin and joint lesions in psoriatic arthritis

Psoriatic arthritis (PsA) is a complicated psoriasis comorbidity with manifestations of psoriatic skin and arthritic joints, and tailoring specific treatment strategies for simultaneously delivering different drugs to different action sites in PsA remains challenging. We developed a need-based layered dissolving microneedle (MN) system loading immunosuppressant tacrolimus (TAC) and anti-inflammatory diclofenac (DIC) in different layers of MNs, i.e., TD-MN, which aims to specifically deliver TAC and DIC to skin and articular cavity, achieving simultaneous alleviation of psoriatic skin and arthritic joint lesions in PsA. In vitro and in vivo skin permeation demonstrated that the inter-layer retained TAC within the skin of ∼100 μm, while the tip-layer delivered DIC up to ∼300 μm into the articular cavity. TD-MN not only efficiently decreased the psoriasis area and severity index scores and recovered the thickened epidermis of imiquimod-induced psoriasis but also alleviated carrageenan/kaolin-induced arthritis even better than DIC injection through reducing joint swelling, muscle atrophy, and cartilage destruction. Importantly, TD-MN significantly inhibited the serum TNF-α and IL-17A in psoriatic and arthritic rats. The results support that this approach represents a promising alternative to multi-administration of different drugs for comorbidity, providing a convenient and effective strategy for meeting the requirements of PsA treatment.

Local Usage of Nigella sativa Oil as an Innovative Method to Attenuate Primary Dysmenorrhea: A Randomized Double-blind Clinical Trial

Objectives

We sought to determine the effect of topical application of Nigella sativa (black seed) oil, on the primary dysmenorrhea intensity.

Methods

We conducted a randomized, double-blind clinical trial on 124 female students, 18–22 years old, living in the dormitories of Sabzevar Universities. After a primary assessment, participants were randomly divided into two groups. The first group rubbed two drops of N. sativa oil, and the second group rubbed liquid olive oil, as the placebo. Massage was performed on the fontanel lobe 3, at night, three days before menstruation, for eight consecutive days (about five days after menses). This procedure was repeated for three menstrual cycles. After three cycles, pain severity was measured by the visual analog scale. Data analysis was carried out using the Mann-Whitney U test and analysis of covariance (ANCOVA).

Results

This study was conducted on 124 female students. The mean age of students, mean age of first menarche, body mass index, and pain severity were not significantly different in the two groups (p > 0.050). No adverse effects were observed during the study. The results of ANCOVA showed that pain intensity in N. sativa oil group was significantly decreased compared to that of the placebo group (0.6 score; p < 0.050).

Conclusions

N. sativa could be a promising, safe, and easily available analgesic supplement in women suffering from primary dysmenorrhea.

Integrated serum metabolomics and network pharmacology approach to reveal the potential mechanisms of withanolides from the leaves of Datura metel L. on psoriasis

Psoriasis is a chronic, immune-mediated inflammatory skin disease and highly depends on inflammation and angiogenesis as well as other pathways. Our previous study showed that the withanolides from the leaves of Datura metel L. exhibited significant therapeutically effect on psoriasis, but the mechanisms concerning this effect have not been systematically studied. The purpose of this paper was to investigate the possible mechanism of withanolides for treating psoriasis using an integrated metabolomics and network pharmacology strategy. Untargeted metabolomics profiling of serum with UHPLC/Orbitrap MS and a multivariate data method were performed to discover the potential biomarkers and metabolic pathways. Afterward, the compound-target-pathway network of withanolides for psoriasis was constructed by virtue of network pharmacology. Finally, the crucial pathways were selected by integrating the results of metabolomics and network pharmacology, and then validated by ELISA and western blot analysis. The results showed that withanolides could exert excellent effects on psoriasis through regulating two types of pathways, angiogenesis and inflammation, including sphingolipids metabolism and HIF-1α/VEGF pathway, reflected by inhibiting the production of inflammatory cytokines (IL-1β, IL-6, IL-8, IFN-γ, TNF-α, HIF-1α and VEGF), as well as reducing the protein expressions of HIF-1α and VEGF. Our study successfully explained the polypharmcological mechanisms underlying the efficiency of withanolides from the D. metel L. leaves on treating psoriasis. Meanwhile, it was also valuable for performing a systematical investigation of herb medicines, as well as for efficiently predicting the therapeutic mechanisms of traditional Chinese medicine.

Datura Metel L. Ameliorates Imiquimod-Induced Psoriasis-Like Dermatitis and Inhibits Inflammatory Cytokines Production through TLR7/8-MyD88-NF-κB-NLRP3 Inflammasome Pathway

Background: Psoriasis is a chronic, immune-mediated inflammatory skin disease, and the inflammatory response plays an important role in its development and progression. Datura metel L. is a traditional Chinese medicine that exhibited a significant therapeutic effect on psoriasis in our previous study due to its remarkable anti-inflammatory effect. Meanwhile, the mechanism underlying its effects on psoriasis is still unclear. Methods: An imiquimod-induced psoriasis-like dermatitis mouse model was constructed to evaluate the protective effect of the effective part of Datura metel L. (EPD), which was verified by evaluations of the Psoriasis Area and Severity Index (PASI) score. Hematoxylin and eosin (H&E) staining, immunohistochemical examination, enzyme-linked immunosorbent assay (ELISA), and Western blot were used to measure the inflammatory cytokines and the protein expression associated with the Toll-like receptor 7– myeloid differentiation primary response gene 88–nuclear Factor-κB–nucleotide-binding oligomerization domain (Nod)-like receptor family pyrin domain-containing 3 (TLR7/8–MyD88–NF-κB–NLRP3) inflammasome pathway. Results: EPD significantly decreased the PASI, reduced epidermal thickness, and decreased the proliferation and differentiation of epidermal cells in psoriasis-like dermatitis C57BL/6 mice induced by imiquimod (IMQ). Furthermore, EPD reduced the infiltration of CD3+ cells to psoriatic lesions, as well as ameliorated the elevations of intercellular adhesion molecule 1 (ICAM-1) and inhibited the production of imiquimod-induced inflammatory cytokines, including IL-1β, IL-2, IL-6, IL-10, IL-12, IL-17, IL-22, IL-23, tumor necrosis factor-α (TNF-α), monocyte chemotactic protein 1 (MCP-1), and interferon-γ (IFN-γ). Besides, EPD decreased the imiquimod-induced expression levels of TLR7, TLR8, TRAF6, MyD88, p-IKKα, p-IKBα, p-NF-κB, NLRP3, apoptosis-associated speck-like protein contained a caspase recruitment domain (ASC), cysteinyl aspartate specific proteinase 1 (caspase-1), and IL-1β. Conclusion: This study demonstrated that EPD exhibited a protective effect on an imiquimod-induced psoriasis mice model by inhibiting the inflammatory response, which might be ascribed to the inhibition of the TLR7/8–MyD88–NF-κb–NLRP3 inflammasome pathway.

LC/MS/MS analyses of open-flow microperfusion samples quantify eicosanoids in a rat model of skin inflammation

Eicosanoids are lipid-mediator molecules with key roles in inflammatory skin diseases, such as psoriasis. Eicosanoids are released close to the source of inflammation, where they elicit local pleiotropic effects and dysregulations. Monitoring inflammatory mediators directly in skin lesions could provide new insights and therapeutic possibilities. Here, we analyzed dermal interstitial fluid samples obtained by dermal open-flow microperfusion in a rat model of skin inflammation. We developed a solid-phase extraction ultra-HPLC/MS/MS method to reliably and precisely analyze small-volume samples and quantified 11 eicosanoids [thromboxane B2, prostaglandin (PG) E2, PGD2, PGF2α, leukotriene B4, 15-HETE, 12-HETE, 5-HETE, 12-hydroxyeicosapentaenoic acid, 13-HODE, and 17-hydroxydocosahexaenoic acid]. Our method achieved a median intraday precision of approximately 5% and interday precision of approximately 8%. All calibration curves showed excellent linearity between 0.01 and 50 ng/ml (R2 > 0.980). In the rat model, eicosanoids were significantly increased in imiquimod-treated inflamed skin sites compared with untreated control sites. Oral treatment with an anti-inflammatory glucocorticoid decreased eicosanoid concentrations. These results show that a combination of tissue-specific sampling with LC/MS analytics is well suited for analyzing small sample volumes from minimally invasive sampling methods such as open-flow microperfusion or microdialysis to study local inflammation and the effect of treatments in skin diseases.