The Role of Flavonoids in Inhibiting Th17 Responses in Inflammatory Arthritis

Targeting IL-17 and its receptors: A feasible way for natural herbal medicines to modulate fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by processive synovial hyperplasia and abnormal proliferation of fibroblast-like synoviocytes (FLSs), and can eventually lead to progressive joint destruction. Increasing evidence has demonstrated that cytokines play pivotal roles in the pathogenesis of RA. In particular, the production of interleukin (IL)-17 by T helper 17 (Th17) cells is closely associated with the development of RA, and inhibition of IL-17/IL-17R could regulate the production of inflammatory factors by FLSs, which may be a feasible way to reduce inflammation and bone destruction in RA. Currently, accumulating evidence suggests that the utilization of natural herbal medicines is advantageous in the management of RA. In our present paper, a comprehensive reference search was conducted of the classic Materia Medica books, literature, online databases, academic search engines, and MS. or Ph. D theses. In conclusion, natural herbal medicines with antirheumatic activities that modulate FLSs by targeting IL-17/IL-17R were summarized. Furthermore, we also discuss the limitations and potential research directions for the future development of natural herbal medicines as candidate drugs for RA management in the clinic.

Association between flavonoid intake and rheumatoid arthritis among US adults

Basic research shows that flavonoids have anti-inflammatory effects that influence rheumatoid arthritis (RA) in rats. Investigating potential dietary interventions for RA helps prevent the onset and progression of the disease. Clinical evidence on the association of flavonoid and subclass intake with RA is lacking. Using three survey cycles of 2007-2008, 2009-2010, and 2017-2018 from the National Health and Nutrition Survey and the United States Department of Agriculture's Food and Nutrient Database for Dietary Studies (FNDDS), we analyzed 7,419 American adults (≥20 years old). The values of flavonoid and subclass intake were calculated using FNDDS. The status questions for self-reported RA were from the NHANES codebook. Weighted analyses, revealed that among the 7,419 participants included in this study (mean age of 44.69 years [standard error, 0.40] and 3,584 [48.31%] were female), 408 met the classification criteria for RA. According to the multivariable logistic regression model, compared with the risk of RA in the first quartile (Q1), the risks of RA in the second quartile (Q2), the third quartile (Q3) and the fourth quartile (Q4) were lower (Q2: OR=0.55, 95% CI: 0.38-0.80; Q3: OR=0.66, 95% CI: 0.44-0.97; Q4: OR=0.64, 95% CI: 0.46-0.89; trend: P=.03). The association between total flavonoids and RA remained significant after full consideration of confounding factors. With regard to the subclasses of flavonoids, high flavanones intake was associated with low RA prevalence in Model 3 (Q3: OR= 0.60, 95% CI:0.39-0.92; Q4: OR = 0.56, 95% CI: 0.32-0.99, trend: P=.02), but no such association was found in the other subclasses. Total flavonoids intake protected against RA, and the risk of developing RA decreased significantly with increasing intake of total flavonoids. Total flavonoids and flavanones were significantly associated with reduced RA risk for the American adult population. We highlighted the importance of employing diverse methodologies to assess the health effects of flavonoids.

Assessment of oral toxicity of Moringa oleifera Lam aqueous extract and its effect on gout induced in a murine model

Background and Aim

Although widely employed in traditional remedies globally, the safety and efficacy of Moringa oleifera remain inadequately documented through scientific research. This study evaluated the oral toxicity of M. oleifera leaf aqueous extract (MoAE) and its impact on gout-induced rats.

Materials and Methods

2000 mg/kg was given in a single dose during the acute oral toxicity test, while 100 mg/kg, 250 mg/kg, and 500 mg/kg were given daily for 28 days in the repeated dose toxicity test. 100 mg/kg, 250 mg/kg, and 500 mg/kg MoAE doses were administered during the assessment of its impact on gout caused by monosodium urate. In the hyperuricemia model induced by oxonic acid, serum uric acid levels were assessed and pain response was measured through acetic acid-induced writhing.

Results

In acute oral and 28-day repeated dose tests, no indications of toxicity were detected, while MoAE alleviated ankle joint swelling and reduced serum uric acid concentrations in arthritic rats, causing a significant reduction in acetic acid-induced contortions.

Conclusion

No acute oral toxicity or toxicity in 28-day repeated doses was found for MoAE, while it exhibited antiarthritic, antihyperuricemic, and pain-relieving effects in the murine model.

Unraveling the intricate dance of the Mediterranean diet and gut microbiota in autoimmune resilience

The nutritional habits regulate the gut microbiota and increase risk of an autoimmune disease. Western diet is rich in sugars, meat, and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. In contrast, the Mediterranean Diet (MedDiet) is abundant in ω3 fatty acids, fruits, and vegetables, possessing anti-inflammatory properties that contribute to the restoration of gut eubiosis. Numerous studies have extensively examined the impact of MedDiet and its components on both health and various disease states. Additionally, specific investigations have explored the correlation between MedDiet, microbiota, and the risk of autoimmune diseases. Furthermore, the MedDiet has been linked to a reduced risk of cardiovascular diseases, playing a pivotal role in lowering mortality rates among individuals with autoimmune diseases and comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of disease's activity and progression.

Redox Remodeling by Nutraceuticals for Prevention and Treatment of Acute and Chronic Inflammation

Antioxidant-rich dietary regimens are considered the best practice to maintain health, control inflammation, and prevent inflammatory diseases. Yet, nutraceuticals as food supplements are self-prescribed and purchasable over the counter by healthy individuals for the purpose of beneficial effects on fitness and aging. Hence, the effectiveness, safety, and correct intake of these compounds need to be better explored. Since redox-modulating activity of these compounds appears to be involved in activation and or suppression of immune cells, the preventive use of nutraceuticals is very attractive even for healthy people. This review focuses on redox- and immunomodulating nutraceuticals in the context of diabetes mellitus (DM). In fact, DM is an illustrative disease of latent and predictable inflammatory pathogenetic processes set out and sustained by oxidative stress. DM has been thoroughly investigated through in vitro and in vivo models. Furthermore, human DM is characterized by uncontrolled levels of glucose, a pivotal factor shaping immune responses. Hence, antioxidant nutraceuticals with multifaced activities, including glucose keeping, are described here. A greater number of such multi-player nutraceuticals might be identified using DM animal models and validated in clinical settings on genetic and environmental high-risk individuals.

Time to Deal with Rheumatoid Cachexia: Prevalence, Diagnostic Criteria, Treatment Effects and Evidence for Management

Cachexia is an early result of rheumatoid arthritis (RA) (rheumatoid cachexia, RC), characterised mainly by involuntary loss of fat-free mass. RC is apparent in 1-67% of patients with RA, depending on the diagnostic criteria applied and the method used for the assessment of body composition. RC is associated with increased inflammation and disability, lower health perception, and greater mortality risk. These changes in body composition are driven by the inflammation process, the low levels of physical activity, the underlying testosterone deficiency and hypogonadism, and the pharmacotherapy required for RA. Chronic inflammation enhances resting energy expenditure as a response to stress, inducing an energy deficit, further propelling protein turnover. The use of corticosteroids and tumour necrosis factor α (TNF-α) inhibitors tend to increase fat accumulation, whereas other disease-modifying antirheumatic drugs (DMARDs) appear to induce increments in fat-free mass. The present review presents all information regarding the prevalence of RC, diagnostic criteria, and comorbidities, as well as the effects of pharmacotherapy and medical nutrition therapy on body composition of patients with RA.

Vitexin-2-O-rhamnoside improves immunosuppression, oxidative stress, and phosphorylation of PI3K/Akt signal pathway in cyclophosphamide treated mice

Vitexin-2-O-rhamnoside (VR) is an important active substance in hawthorn, which is widely used as a food or functional food raw material; however, its immunomodulatory activities have not been extensively studied. In this study, BALB/c mice immunocompromised by cyclophosphamide (CY) were used as models to explore the effects of VR on the immunity and antioxidant capacity of mice. The results revealed that VR can restore weight to the immunosuppressed mice to varying degrees, improve spleen and thymus injury, and restore peripheral blood levels. Furthermore, it can effectively promote the proliferation of T and B lymphocytes, natural killer (NK) and cytotoxic T lymphocyte (CTL) cell activities, and the secretion and mRNA expression of cytokines IFN-γ, IL-2, IL-6, and IL-12 to 0.36, 0.34, 50.25%, 45.74%, 28.36 pg/mL or 0.68, 31.81 pg/mL or 0.74, 20.40 pg/mL or 0.75, and 19.81 pg/mL or 0.55, respectively. Moreover, it can upregulate the phosphorylation level of PI3K/Akt signaling pathway in mice immunosuppressed by CY, increase the activities of glutathione peroxidase (GSH-Px), chloramphenicol acetyltransferase (CAT), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC), and decrease the level of malondialdehyde (MDA). This study provides a theoretical and experimental basis for the research and development of health products with targeted efficacy, and the development of diversified products in the hawthorn deep-processing industry.

Flavonoids as Potential Anti-Inflammatory Molecules: A Review

Hydroxylated polyphenols, also called flavonoids, are richly present in vegetables, fruits, cereals, nuts, herbs, seeds, stems, and flowers of numerous plants. They possess numerous medicinal properties such as antioxidant, anti-cancer, anti-microbial, neuroprotective, and anti-inflammation. Studies show that flavonoids activate antioxidant pathways that render an anti-inflammatory effect. They inhibit the secretions of enzymes such as lysozymes and β-glucuronidase and inhibit the secretion of arachidonic acid, which reduces inflammatory reactions. Flavonoids such as quercetin, genistein, apigenin, kaempferol, and epigallocatechin 3-gallate modulate the expression and activation of a cytokine such as interleukin-1beta (IL-1β), Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8); regulate the gene expression of many pro-inflammatory molecules such s nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), activator protein-1 (AP-1), intercellular adhesion molecule-1 (ICAM), vascular cell adhesion molecule-1 (VCAM), and E-selectins; and also inhibits inducible nitric oxide (NO) synthase, cyclooxygenase-2, and lipoxygenase, which are pro-inflammatory enzymes. Understanding the anti-inflammatory action of flavonoids provides better treatment options, including coronavirus disease 2019 (COVID-19)-induced inflammation, inflammatory bowel disease, obstructive pulmonary disorder, arthritis, Alzheimer’s disease, cardiovascular disease, atherosclerosis, and cancer. This review highlights the sources, biochemical activities, and role of flavonoids in enhancing human health.

Pinocembrin Reduces Keratinocyte Activation and Ameliorates Imiquimod-Induced Psoriasis-like Dermatitis in BALB/c Mice through the Heme Oxygenase-1/Signal Transducer and Activator of Transcription 3 Pathway

Psoriasis is an autoimmune disease characterized by chronic skin inflammation and excessive keratinocyte proliferation. The itchy, scaly, and erythematous lesions present on psoriatic skin negatively affect patients' quality of life. Pinocembrin is a flavonoid present in propolis, fruits, and vegetables. It exerts neuroprotective effects and was used for treating ischemic stroke in a human clinical trial. However, the effects of pinocembrin on psoriasis have never been examined. In this study, we evaluated the effects of pinocembrin on human HaCaT keratinocytes and BALB/c mice with imiquimod- (IMQ-) induced psoriatic dermatitis. In interferon-γ- (IFN-γ-) activated HaCaT cells, pinocembrin reduced the expression of inflammatory cytokines, namely, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and keratinocyte proliferation markers, namely, keratin (K)16, K17, and Ki-67. The mechanism underlying these inhibitory effects involved the regulation of the heme oxygenase- (HO-) 1/signal transducer and activator of transcription (STAT) 3 pathway. In the IMQ-induced psoriatic dermatitis mouse model, the topical application of pinocembrin significantly ameliorated the Skin Psoriasis Area and Severity Index score, epidermal thickness, inflammation, hyperplasia, hyperkeratosis, and cluster of differentiation (CD) 4⁺ T-cell infiltration. Expression of the inflammatory cytokines and keratinocyte proliferation markers in dorsal skin was significantly decreased in the pinocembrin-treated group. Meanwhile, in lesional skin, the expression of HO-1 was upregulated, but that of phospho-STAT3 (pSTAT3) was downregulated. Collectively, our results indicated the therapeutic potential of pinocembrin. Additional studies are warranted to evaluate its clinical benefits in patients with psoriasis.

Delphinidin diminishes in vitro interferon-γ and interleukin-17 producing cells in patients with psoriatic disease

The anthocyanidin delphinidin reduces psoriasiform lesions and inflammatory mediators in human cell culture systems. Its role in psoriatic disease has not yet been investigated. We assessed delphinidin's in vitro immunomodulatory effect on ex vivo stimulated peripheral blood mononuclear cells (PBMCs) from 50 individuals [26 with psoriasis, 10 with psoriatic arthritis (PsA) and 14 healthy controls (HCs)]. Cells were either left untreated or stimulated with PMA plus ionomycin in the presence or absence of delphinidin. Intracellular production of interferon-γ (IFNγ), interleukin-17A (IL-17A), and interleukin-10 (IL-10) was measured flow cytometrically. Delphinidin dose-dependently reduced IFNγ⁺ T cells from patients and HCs. The mean IFNγ decrease in CD4⁺ T subpopulations was 42.5 ± 28% for psoriasis patients, 51.8 ± 21.5% for PsA patients and 49 ± 17% for HCs (p < 0.001 for all). Similarly, IFNγ reduction in CD8⁺ T cells was 34 ± 21.6% for psoriasis patients, 47.1 ± 22.8% for PsA and 44.8 ± 14.3% for HCs (P < 0.001 for all). An inhibitory effect of delphinidin was also noted in IFNγ producing NKs and NKTs from psoriasis individuals. Delphinidin also significantly decreased IL-17⁺ CD4⁺ T cells in all tested subjects, with marginal effect on the increase of IL-10-producing T regulatory subsets. In conclusion, delphinidin exerts a profound in vitro anti-inflammatory effect in psoriasis and psoriatic arthritis by inhibiting IFNγ⁺ innate and adaptive cells and T helper (Th) 17 cells. If this effect is also exerted in vivo, delphinidin may be regarded as a nutraceutical with immunosuppressive potential.

A molecular insight of inflammatory cascades in rheumatoid arthritis and anti-arthritic potential of phytoconstituents

Rheumatoid arthritis (RA) is an auto-immune inflammatory disorder of the synovial lining of joints marked by immune cells infiltration and hyperplasia of synovial fibroblasts which results in articular cartilage destruction and bone erosion. The current review will provide comprehensive information and results obtained from the recent research on the phytochemicals which were found to have potential anti-arthritic activity along with the molecular pathway that were targeted to control RA progression. In this review, we have summarized the scientific data from various animal studies about molecular mechanisms, possible side effects, associations with conventional therapies, and the role of complementary and alternative medicines (CAM) for RA such as ayurvedic medicines in arthritis. In the case of RA, phytochemicals have been shown to act through different pathways such as regulation of inflammatory signaling pathways, T cell differentiation, inhibition of angiogenic factors, induction of the apoptosis of fibroblast-like synoviocytes (FLS), inhibition of autophagic pathway by inhibiting High-mobility group box 1 protein (HMGB-1), Akt/ mTOR pathway and HIF-1α mediated Vascular endothelial growth (VEGF) expression. Also, osteoclasts differentiation is inhibited by down-regulating the VEGF expression by decreasing the accumulation of the ARNT (Aryl Hydrocarbon Receptor Nuclear Translocator)-HIF-1α complex Although phytochemicals have shown to exert potential anti-arthritic activity in many animal models and further clinical data is needed to confirm their safety, efficacy, and interactions in humans.

Flavonoid and cannabinoid impact on the ocular surface

PURPOSE OF REVIEW

To evaluate the impact of flavonoids and cannabinoids as anti-inflammatory and antiallergic treatments on the anterior surface of the eye.

RECENT FINDINGS

Allergic conjunctivitis and dry eye syndrome are common ocular surface diseases that have been treated with traditional pharmacological measures, e.g. corticosteroids, antihistamines. Given the side-effect profiles of these medications and the growing interest in complementary treatment modalities as part of integrative medical interventions, well known flavonoids, such as quercetin and catechin, are under investigation for topical and systemic application methods for relief. As flavonoid derivatives, pycnogenol and epigallocatechin gallate have alleviated dry eye symptoms, including lacrimal gland inflammation, tear secretion, and the stability of the tear film. Research on ocular cannabinoid receptors and response to synthetic cannabinoids are also being considered for therapy of anterior ocular disorders. The expansion of herbal formulations provides a framework for future treatment regimens for ocular surface disorders.

SUMMARY

Flavonoids and cannabinoids show promise as potential complementary treatment for allergic diseases because of their anti-inflammatory and antiallergic properties. Several studies implementing ocular and systemic application of these compounds show potential in becoming adjuvant treatment strategies for improving quality of life while also managing ocular surface disease processes.

Depression and Obesity in Patients With Psoriasis and Psoriatic Arthritis: Is IL-17-Mediated Immune Dysregulation the Connecting Link?

Patients with psoriasis are frequently obese and experience anxiety or suffer from depressive disorders. The immunopathogenesis of psoriasis and indeed psoriatic arthritis is largely based on the pivotal role of IL-17/IL-23 axis, to an extent that currently monoclonal antibodies selectively inhibiting IL-17 or IL-23 are routinely used for the treatment of psoriatic diseases. Emerging data, demonstrating a decisive role for IL-17 and IL-17 producing cell subsets, such as Th17 in the induction and progression of obesity and depression has led authors to suggest that psoriatic disease, obesity and anxiety/depression may indeed be interconnected manifestation of a state of immunedysregulation, the linked being IL-17 and its related cells. We discuss this hypothetical link in depth taking into account the beneficial effects anti-IL17 and anti-IL-17 receptor inhibitors in treating psoriatic disease and the on-going debate as to whether these biologics may exert a direct or indirect effect in ameliorating concomitant obesity and depressive disorders, which are frequently noted in the same patient.

From Suppressor T cells to Regulatory T cells: How the Journey That Began with the Discovery of the Toxic Effects of TCDD Led to Better Understanding of the Role of AhR in Immunoregulation

Aryl hydrocarbon receptor (AhR) was identified in the early 1970s as a receptor for the ubiquitous environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin), which is a member of halogenated aromatic hydrocarbons (HAHs). TCDD was found to be highly toxic to the immune system, causing thymic involution and suppression of a variety of T and B cell responses. The fact that environmental chemicals cause immunosuppression led to the emergence of a new field, immunotoxicology. While studies carried out in early 1980s demonstrated that TCDD induces suppressor T cells that attenuate the immune response to antigens, further studies on these cells were abandoned due to a lack of specific markers to identify such cells. Thus, it was not until 2001 when FoxP3 was identified as a master regulator of Regulatory T cells (Tregs) that the effect of AhR activation on immunoregulation was rekindled. The more recent research on AhR has led to the emergence of AhR as not only an environmental sensor but also as a key regulator of immune response, especially the differentiation of Tregs vs. Th17 cells, by a variety of endogenous, microbial, dietary, and environmental ligands. This review not only discusses how the role of AhR emerged from it being an environmental sensor to become a key immunoregulator, but also confers the identification of new AhR ligands, which are providing novel insights into the mechanisms of Treg vs. Th17 differentiation. Lastly, we discuss how AhR ligands can trigger epigenetic pathways, which may provide new opportunities to regulate inflammation and treat autoimmune diseases.

Oral treatments with a flavonoid-enriched fraction from Cecropia hololeuca and with rutin reduce articular pain and inflammation in murine zymosan-induced arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia Loefl. species (Urticaceae) are widely spread across the rainforest in tropical and subtropical regions of Central and South America. Inhabitants of different regions of Brazil employ leaves, fruits and sprouts of Cecropia hololeuca Miq. mainly as anti-inflammatory, anti-asthmatic, expectorant, fever suppressant, and against cough.

AIM OF THE STUDY

To evaluate the antinociceptive and anti-inflammatory activities of an aqueous leaf extract of C. hololeuca in a murine model of zymosan-induced arthritis (ZIA) and characterize compounds contributing to these effects.

MATERIALS AND METHODS

The crude aqueous extract of C. hololeuca (CAE) was obtained by infusion, screened for antinociceptive and anti-inflammatory activities, and fractionated (solvent partition; RP-2 and Sephadex G-25 column chromatography), yielding fractions that were chemically and pharmacologically investigated. TLC, HPLC-DAD, HPLC-DAD-ESI-MS/MS and NMR analyses were peformed. The antinociceptive activity was assessed by means of acetic acid-induced writhing, hot-plate and rota-rod tests. ZIA was used to evaluate the anti-arthritic activity of oral treatment with CAE, butanolic (BF) and aqueous fraction (AF), as well as the fractions obtained from BF (F2, F2-A and F2-B). Rutin, a flavonoid found in C. hololeuca, was also tested. Mechanical hypernociception, joint edema, local neutrophil recruitment and articular TNF-α quantification were performed to measure the severity of arthritis and identify the anti-inflammatory potential of C. hololeuca.

RESULTS

CAE (0.03-1 g/kg, p.o.) showed a dose-related inhibitory effect on acetic acid-induced writhing test, but did not change the pain latency in the hotplate test, nor the first fall time on the rota-rod test. In addition, CAE (1 g/kg, p.o.) inhibited by 65% the mechanical hypernociception, 46% the joint edema, 54% the neutrophil recruitment and 53% the articular TNF-α concentration levels in ZIA. BF (0.4 g/kg, p.o.), AF (0.6 g/kg), F2 (0.1 g/kg) and F2-A (0.045 g/kg), but not F2-B (0.055 g/kg), inhibited the mechanical hypernociception, joint edema and neutrophil recruitment in ZIA. Rutin (0.001-0.03 g/kg, p.o.) produced dose-related inhibitory effects in the mechanical hypernociception, joint edema and neutrophil recruitment, and at 0.03 g/kg also inhibited articular TNF-α synthesis after intra-articular zymosan injection. Isoorientin, isovitexin, rutin and isoquercitrin were identified in the most active fraction (F2-A), along with luteolin and apigenin derivatives, tentatively identified as isoorientin-2″-O-glucoside and isovitexin-2″-O-glucoside.

CONCLUSION

This study corroborates the popular use by oral route of aqueous preparations of C. hololeuca against joint inflammatory disorders, such as rheumatoid arthritis. Our results demonstrated for the first time that oral administration of rutin shows antinociceptive and anti-inflammatory effects in ZIA, indicating that this flavonoid is one of the immunomodulatory compounds involved in the anti-arthritic activity of C. hololeuca.

Interferon gamma/interleukin-4 modulation, anti-inflammatory and antioxidant effects of hesperidin in complete Freund's adjuvant (CFA)-induced arthritis model of rats

BACKGROUND

This study sought to assess the effect of hesperidin on serum inflammatory cytokines and oxidative damage in liver of complete Freund's adjuvant (CFA)-induced arthritic rats.

METHOD

Fifty-six adult female Wistar rats (220-250 g) were acclimatized for two weeks. Intraplantar injection of CFA was done for the induction of arthritis and confirmed on the 14th day prior to oral administration of 40 and 80 mg/kg of hesperidin or dexamethasone for 45 days.

RESULT

The result showed that treatment with both doses of hesperidin and dexamethasone in the joint of arthritic rats significantly (p < .05) diminished paw swelling/edema and arthritis score as well as enhanced latency in thermal hyperalgesia test. In addition, hesperidin treatment in arthritis rats showed significant (p < .01) improvement in red blood cells and platelets counts as well as hemoglobin and hematocrit compared to the arthritis control rat group. Furthermore, hesperidin treatment significantly (p < .05) reduced serum interferon gamma (IFN-γ) and interleukin-4 (IL-4) levels in arthritic rat. In addition, treatment with hesperidin significantly (p < .05) decreased the liver of thiobarbituric acid reactive species and reactive oxygen species levels but raised the levels of total and non-protein thiols of rat induced with CFA. The reduced activities of liver δ-aminolevulinate dehydratase, catalase, glutathione-S transferase in arthritic rats were significantly (p < .05) increased with hesperidin treatment in arthritic rats. This study suggests that hesperidin demonstrated an anti-arthritic effect via modulation of serum IFN-γ and IL-4 levels as well as protection against oxidative damage.

CONCLUSION

Hence, hesperidin could be a potential immune-modulatory, anti-inflammatory and anti-oxidant agent.

Black Raspberries and Protocatechuic Acid Mitigate DNFB-Induced Contact Hypersensitivity by Down-Regulating Dendritic Cell Activation and Inhibiting Mediators of Effector Responses

Contact hypersensitivity (CHS) is the most common occupational dermatological disease. Dendritic cells (DCs) mediate the sensitization stage of CHS, while T-cells facilitate the effector mechanisms that drive CHS. Black raspberry (Rubus occidentalis, BRB) and BRB phytochemicals possess immunomodulatory properties, but their dietary effects on CHS are unknown. We examined the effects of diets containing BRB and protocatechuic acid (PCA, a constituent of BRB and an anthocyanin metabolite produced largely by gut microbes), on CHS, using a model induced by 2,4-dinitrofluorobenze (DNFB). Mice were fed control diet or diets supplemented with BRB or PCA. In vitro bone-marrow derived DCs and RAW264.7 macrophages were treated with BRB extract and PCA. Mice fed BRB or PCA supplemented diets displayed decreased DNFB-induced ear swelling, marked by decreased splenic DC accumulation. BRB extract diminished DC maturation associated with reduced Cd80 expression and Interleukin (IL)-12 secretion, and PCA reduced IL-12. Dietary supplementation with BRB and PCA induced differential decreases in IL-12-driven CHS mediators, including Interferon (IFN)-γ and IL-17 production by T-cells. BRB extracts and PCA directly attenuated CHS-promoting macrophage activity mediated by nitric oxide and IL-12. Our results demonstrate that BRB and PCA mitigate CHS pathology, providing a rationale for CHS alleviation via dietary supplementation with BRB or BRB derived anthocyanins.

Synthesis and characterization of a polyurethane carrier used for a prolonged transmembrane transfer of a chili pepper extract

Purpose

Red chili peppers have been highly valued in gastronomy and traditional medicine since ancient times; it seems that it is not just an ingredient for food but also a good remedy for various medical conditions such as increased blood pressure and high levels of serum triglycerides and cholesterol, myocardial infarction, arthritis, and migraines. The objective of this study is the characterization of a new carrier used for encapsulated extract.

Methods

Chili pepper extract was obtained and was physically entrapped inside polyurethane microparticles in order to diminish the irritative potential of this extract. The particles were evaluated by Zetasizer measurements, small-angle neutron scattering and thermal analysis, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy; the encapsulation efficacy and the drug release profile were assessed by UV-Vis spectroscopy. Bioevaluations on mice skin were performed to predict the irritative potential of the samples.

Results

Two different types of samples were compared: hollow polyurethane microparticles vs polyurethane particles containing the natural extract. The sizes of the particles were very similar, but the sample containing the extract presents three particle populations (the polydispersity index increases from 0.3 to 0.6 from one sample to another). The zeta-potential measurements and SEM images indicate a medium tendency to form clusters, while the UV-Vis study revealed an almost 70% encapsulation efficacy.

Conclusion

The results suggest that encapsulation of a chili pepper extract inside polyurethane microparticles leads to a non-irritative product with a prolonged release: ~30% of encapsulated extract is released within the first 8 days and a maximum 45% is reached in 2 weeks.