Repeated doses of captopril induce airway hyperresponsiveness by modulating the TRPV1 receptor in rats.

Although TRPV1 receptors play an essential role in the adverse effects on the airways following captopril treatment, there is no available evidence of their involvement in treatment regimens involving repeated doses of captopril. Comparing the difference in these two treatment regimens is essential since captopril is a continuous-use medication. Thus, this study explored the role of the transient receptor potential vanilloid 1 (TRPV1) in the effects of captopril on rat airways using two treatment regimens. Airway resistance, bronchoalveolar lavage (BAL), and histological and immunohistochemical analyses were conducted in rats administered with single or repeated doses of captopril. This study showed that the hyperresponsiveness to bradykinin and capsaicin in captopril-treated rats was acute. Treatment with the selective B2 antagonist, HOE140 reduced bradykinin hyperresponsiveness and abolished capsaicin exacerbation in single-dose captopril-treated rats. Likewise, degeneration of TRPV1-positive neurones also reduced hyperresponsiveness to bradykinin. Single-dose captopril treatment increased leukocyte infiltration in the BAL when compared with the vehicle and this increase was reduced by TRPV1-positive neurone degeneration. However, when compared with the vehicle treatment, animals treated with repeated doses of captopril showed an increase in leukocyte influx as early as 1 h after the last captopril treatment, but this effect disappeared after 24 h. Additionally, an increase in TRPV1 expression occurred only in animals who received repeated captopril doses and the degeneration of TRPV1-positive neurones attenuated TRPV1 upregulation. In conclusion, these data strongly indicate that a treatment regimen involving multiple doses of captopril not only enhances sensitisation but also upregulates TRPV1 expression. Consequently, targeting TRPV1 could serve as a promising strategy to reduce the negative impact of captopril on the airways.

Role of kinin receptors in skin pigmentation.

Previous studies have shown that all kinin system is constitutively expressed in the normal and inflamed skin, with a potential role in both physiological and pathological processes. However, the understanding regarding the involvement of the kinin system in skin pigmentation and pigmentation disorders remains incomplete. In this context, the present study was designed to determine the role of kinins in the Monobenzone (MBZ)-induced vitiligo-like model. Our findings showed that MBZ induces higher local skin depigmentation in kinin receptors knockout mice (KOB1R, KOB2R and KOB1B2R) than in wild type (WT). Remarkably, lower levels of melanin content and reduced ROS generation were detected in KOB1R and KOB2R mice treated with MBZ. In addition, both KOB1R and KOB2R show increased dermal cell infiltrate in vitiligo-like skin, when compared to WT-MBZ. Additionally, lack of B1R was associated with greater skin accumulation of IL-4, IL-6, and IL-17 by MBZ, while KOB1B2R presented lower levels of TNF and IL-1. Of note, the absence of both kinin B1 and B2 receptors demonstrates a protective effect by preventing the increase in polymorphonuclear and mononuclear cell infiltrations, as well as inflammatory cytokine levels induced by MBZ. In addition, in vitro assays confirm that B1R and B2R agonists increase intracellular melanin synthesis, while bradykinin significantly enhanced extracellular melanin levels and proliferation of B16F10 cells. Our findings highlight that the lack of kinin receptors caused more severe depigmentation in the skin, as well as genetic deletion of both B1/B2 receptors seems to be linked with changes in levels of constitutive melanin levels, suggesting the involvement of kinin system in crucial skin pigmentation pathways.

Anti-proliferative and anti-inflammatory effects of the application of baclofen cream, a GABAB receptor agonist, on skin inflammation in mice.

Previous studies have demonstrated the role of γ-aminobutyric acid type B (GABAB) receptors in skin-related conditions and pain. However, most studies have focused on the main effects of GABAB on the central nervous system. Therefore, this study has aimed to determine the potential topical anti-inflammatory and anti-proliferative effects of baclofen cream in an inflammatory skin disease model. The effects of the baclofen cream were evaluated using acute and chronic models of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mouse ears. Histological and immunohistochemical evaluations were performed using an ear oedema assay. The effect of baclofen on keratinocyte proliferation was assessed in PAM212, the murine keratinocyte cell line. The results demonstrate that a single topical application of 5% baclofen, 7.5% baclofen, and 1% dexamethasone each inhibited acute TPA-induced ear oedema (58.94 ± 6.14%, 47.73 ± 11.26%, and 87.33 ± 4.59%, respectively). These results were confirmed by histological analysis. In the chronic model, baclofen (5%) and dexamethasone (1%) each inhibited ear oedema and the maximum inhibitory effect was reached at the end of the experiment (9th day of TPA application) with a percentage inhibition of 54.60 ± 6.15% for baclofen and 71.68 ± 3.45% for dexamethasone, when compared to the vehicle. These results were confirmed by histological analysis. Baclofen and dexamethasone also reduced proliferating cell nuclear antigen expression by 62.01 ± 6.65% and 70.42 ± 6.11%, respectively. However, baclofen did not inhibit keratinocyte proliferation in PAM212 cells. In conclusion, these results demonstrate that baclofen exhibits notable topical antiproliferative and anti-inflammatory properties and could be a potential therapeutic alternative for treating inflammatory and proliferative skin diseases.

miRNA-203b-3p Induces Acute and Chronic Pruritus through 5-HTR2B and TRPV4.

Growing evidence indicates that transient receptor potential (TRP) channels contribute to different forms of pruritus. However, the endogenous mediators that cause itch through transient receptor potential channels signaling are poorly understood. In this study, we show that genetic deletion or pharmacological antagonism of TRPV4 attenuated itch in a mouse model of psoriasis induced by topical application of imiquimod. Human psoriatic lesions showed increased expression of several microRNAs, including the miR-203b-3p, which induced a calcium ion response in rodent dorsal root ganglion neurons and scratching behavior in mice through 5-HTR2B activation and the protein kinase C‒dependent phosphorylation of TRPV4. Computer simulation revealed that the miR-203b-3p core sequence (GUUAAGAA) that causes 5-HTR2B/TRPV4-dependent itch targets the extracellular side of 5-HTR2B by interacting with a portion of the receptor pocket consistent with its activation. Overall, we reveal the unconventional pathophysiological role of an extracellular microRNA that can behave as an itch promoter through 5-HTR2B and TRPV4.

Hspa8 and ICAM-1 as damage-induced mediators of γδ T cell activation.

Tissue-resident γδ T cells form the first line of defense at barrier surfaces where they survey host tissue for signs of stress or damage. Following recognition of injury, γδ T cells play a crucial role in the wound-healing response through the production of growth factors and cytokines that promote proliferation in surrounding epithelial cells. To initiate this response, γδ T cells require interactions with a variety of epithelial-expressed costimulatory molecules in addition to primary signaling through their TCR. In the epidermis these signals include the coxsackie and adenovirus receptor (CAR), histocompatibility antigen 60c (H60c), and plexin B2, which interact with γδ T cell-expressed junctional adhesion molecule-like protein (JAML), NKG2D, and CD100, respectively. Here we identify heat shock protein family A member 8 (Hspa8) and ICAM-1 as two additional keratinocyte-expressed costimulatory molecules for epidermal resident γδ T cells (termed DETC). These molecules were rapidly up-regulated in the epidermis following wounding in both mouse and human tissue. Both Hspa8 and ICAM-1 had a costimulatory effect on DETC, inducing proliferation, CD25 up-regulation, and IL-2 production. We also provide evidence that DETC can be activated through the potential ICAM-1 and Hspa8 receptors LFA-1 and CD316. Finally, knockdown of Hspa8 in keratinocytes reduced their ability to activate DETC in culture and ICAM-1-/- mice exhibited impaired rates of healing in skin-organ culture suggesting a role for these proteins in the DETC-mediated damage response. Together with previous work on CAR, H60c, and plexin B2, these results add to a picture of a complex keratinocyte wound signature that is required for efficient DETC activation.

Role of nitric oxide, bradykinin B2 receptor, and TRPV1 in the airway alterations caused by simvastatin in rats.

Dry cough has been reported in patients receiving statin therapy. However, the underlying mechanism or other possible alterations in the airways induced by statins remain unknown. Thus, the aim of this study was to evaluate whether simvastatin promotes alterations in airways, such as bronchoconstriction and plasma extravasation, as well as the mechanism involved in these events. Using methods to detect alterations in airway resistance and plasma extravasation, we demonstrated that simvastatin [20 mg/kg, intravenous (i.v.)] caused plasma extravasation in the trachea (79.8 + 14.8 µg/g/tissue) and bronchi (73.3 + 8.8 µg/g/tissue) of rats, compared to the vehicle (34.2 + 3.6 µg/g/tissue and 29.3 + 5.3 µg/g/tissue, respectively). NG-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg, intraperitoneal), a nitric oxide (NO) synthase inhibitor, Icatibant [HOE 140, 10 nmol/50 µl, intratracheal (i.t.)], a bradykinin B2 antagonist, and capsazepine (100 nmol/50 µl, i.t.), a TRPV1 antagonist, attenuated simvastatin-induced plasma extravasation. Simvastatin (5, 10 and 20 mg/kg) did not cause bronchoconstriction per se, but exacerbated the bronchoconstrictive response to bradykinin (30 nmol/kg, i.v.), a B2 agonist (0.7 + 0.1 ml/H2O), or capsaicin (30 nmol/kg, i.v.), a TRPV1 agonist (0.8 + 0.1 ml/H2O), compared to the vehicle (0.1 + 0.04 ml/H2O and 0.04 + 0.01 ml/H2O, respectively). The bronchoconstriction elicited by bradykinin (100 nmol/kg, i.v.) in simvastatin non-treated rats was inhibited by L-NAME. The exacerbation of bronchoconstriction induced by bradykinin or capsaicin in simvastatin-treated rats was inhibited by L-NAME, HOE 140 or capsazepine. These results suggest that treatment with simvastatin promotes the release of bradykinin, which, via B2 receptors, releases NO that can then activate the TRPV1 to promote plasma extravasation and bronchoconstriction.

B1 and B2 kinin receptor blockade improves psoriasis-like disease.

BACKGROUND AND PURPOSE: The entire kallikrein-kinin system is present in the skin, and it is thought to exert a relevant role in cutaneous diseases, including psoriasis. The present study was designed to evaluate the relevance of kinin receptors in the development and progression of a model of psoriasis in mice. EXPERIMENTAL APPROACH: The effects of kinin B1 and B2 receptor knockout and of kinin receptor antagonists (SSR240612C or FR173657) were assessed in a model of psoriasis induced by imiquimod in C57BL/6 mice. Severity of psoriasis was assessed by histological and immunohistochemical assays of skin, along with objective scores based on the clinical psoriasis area and severity index. KEY RESULTS: Both kinin receptors were up-regulated following 6 days of imiquimod treatment. Kinin B1 and B2 receptor deficiency and the use of selective antagonists show morphological and histological improvement of the psoriasis hallmarks. This protective effect was associated with a decrease in undifferentiated and proliferating keratinocytes, decreased cellularity (neutrophils, macrophages, and CD4+ T lymphocytes), reduced γδ T cells, and lower accumulation of IL-17. The lack of B2 receptors resulted in reduced CD8+ T cells in the psoriatic skin. Relevantly, blocking kinin receptors reflected the improvement of psoriasis disease in the well-being behaviour of the mice. CONCLUSIONS AND IMPLICATIONS: Kinins exerted critical roles in imiquimod-induced psoriasis. Both B1 and B2 kinin receptors exacerbated the disease, influencing keratinocyte proliferation and immunopathology. Antagonists of one or even both kinin receptors might constitute a new strategy for the clinical treatment of psoriasis.

Baccharis dracunculifolia (Asteraceae) essential oil displays anti-inflammatory activity in models of skin inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis dracunculifolia (Asteraceae) is a commonly used plant in traditional medicine known as "alecrim-do-campo". Popularly it has been used as an immunostimulant, antibiotic, anti-inflammatory among other applications. So far, only a few studies have investigated the B. dracunculifolia anti-inflammatory effect and none has investigated the effectiveness of essential oil on skin diseases. AIM OF THE STUDY: The study aimed at evaluating the topical anti-inflammatory activity of B. dracunculifolia essential oil (BdEO) in mice models of acute and chronic skin inflammation. MATERIALS AND METHODS: BdEO was obtained from leaves and it was analyzed with Gas Chromatograph. Topical anti-inflammatory activity of BdEO (0.1, 0.3 and 1.0 mg/ear) was evaluated in Arachidonic Acid or TPA-induced acute and chronic skin inflammation in mice. Parameters such edema, cell migration and keratinocytes proliferation were evaluated. In addition, safety and a possible mechanism of action for BdEO essential oil were also investigated. RESULTS: Our results indicate that mainly terpenoids compounds compose BdEO. In addition, topical treatment with BdEO inhibited inflammatory parameters in both acute and chronic models of skin inflammation. This protective effect was associated with reduced edema formation, smaller cellular influx into the inflamed tissue and reduction of keratinocytes hyperproliferation. Although BdEO appears to exert its anti-inflammatory effect through a corticosteroid pathway, no local or systemic side effects were observed. CONCLUSION: Taken together, the present results showed that the essential oil obtained by hydrodistillation from B. dracunculifolia leaf samples exhibit remarkable topical anti-inflammatory properties. Therefore, our study demonstrated evidence for BdEO topical anti-inflammatory efficacy and safety, suggesting that it could be considered for developing of a new phytotherapeutic formulation as treatment for skin diseases.

Expanding the anti-inflammatory potential of Moringa oleifera: topical effect of seed oil on skin inflammation and hyperproliferation.

ETHNOPHARMACOLOGICAL RELEVANCE: Popularly used in India and sub-Hymalaian region, Moringa oleifera (Moringaceae) is associated with healing properties demonstrated in its use as treatment of acute and chronic skin diseases. Our study aimed at investigating the effects of M. oleifera seed oil (MOSO) in animal models for inflammatory and hyperproliferative skin conditions. MATERIALS AND METHODS: MOSO was analyzed using gas chromatography/mass spectrometry. The anti-inflammatory and anti-hyperproliferative effects of treatment with either MOSO or oleic acid (OA), its main constituent, was evaluated. Acute and chronic inflammation was induced by applying 12-O-Tetradecanoylphorbol-13-acetate (TPA) and acute inflammation with either Arachidonic Acid (AA) or Phenol onto the ear of Swiss mice. Systemic activity and the influence of glucocorticoid receptors (GC) was also evaluated. RESULTS: Topical application of MOSO and OA inhibited ear edema caused by TPA, and Phenol. Only MOSO inhibited ear edema induced by AA. Neutrophil migration was also inhibited by treatment with MOSO. Topical application of MOSO, but not OA, significantly reduced chronic skin inflammation and epidermal hypertrophy induced by multiple TPA applications. Pre-treatment with GC antagonist mifepristone reversed the anti-inflammatory effect of MOSO and OA on the TPA model. Repeated administration of MOSO show a similar effect to dexamethasone on thymus weight, though MOSO did not present any influence on skin thickness, as well as in the weight of the spleen, adrenal gland and lymph node. CONCLUSION: The results suggest that MOSO is effective as a treatment for skin diseases that rely on keratinocyte hyperproliferation. OA is also effective in acute inflammation. Both MOSO and OA depend on GC activation for anti-inflammatory effect but do not exhibit the same adverse effects seen in topical treatment with dexamethasone. We hereby evidence the use of MOSO as a topical anti-inflammatory agent in inflammatory skin diseases, thus, expanding its therapeutic potential.

Preclinical study of the topical anti-inflammatory activity of Cyperus rotundus L. extract (Cyperaceae) in models of skin inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Cyperus rotundus L. (Cyperaceae) is considered one of the most widely distributed plant species in the world, especially in tropical and subtropical regions. In addition, it is commonly used in India, China and Japan in traditional medicine to treat different diseases, including dermatitis and other skin disorders. AIM OF THE STUDY: To investigate the topical anti-inflammatory activity of C. rotundus rhizome ethanolic extract in models of acute and chronic dermatitis. MATERIALS AND METHODS: Phytochemical analysis was carried out using High-performance liquid chromatography-ultraviolet detection (HPLC/UV) to determine the presence of quercetin and chlorogenic acid in C. rotundus extract. Topical anti-inflammmatory effects of C. rotundus extract were evaluated on arachidonic acid (AA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice. Skin biopsies were collected and submitted to histological and enzymatic analysis to evaluate the C. rotundus effect in leukocyte migration into inflamed tissue. Antiproliferative activity of C. rotundus was confirmed by PCNA immunostained cell analysis. Systemic and possible adverse effects of topical treatment with C. rotundus were evaluated by the skin atrophy and same organ weights. In addition, the glucocorticoid receptor (GR) antagonist mifepristone was used to investigate possible GR-mediated mechanisms of action. RESULTS: The phytochemical analysis show that C. rotundus ethanol extract contains 45 µg/g of chlorogenic acid. Topical treatment with C. rotundus extract reduced ear edema and cellular infiltrate in acute and chronic skin inflammation models. Moreover, mice topically treated with C. rotundus exhibited decrease in TPA-induced keratinocyte hyperproliferation. Relevantly, topical treatment with C. rotundus did not caused skin atrophy or changes in lymphoid organ weight. The anti-inflammatory effect of C. rotundus was not influenced by the GR antagonist. CONCLUSION: The results here demonstrate for the first time the topical anti-inflammatory and antiproliferative efficacy of C. rotundus extract, suggesting that the extract could be a potential new therapeutic tool for the treatment of inflammatory skin disorders.

Corticoid-like anti-inflammatory effect of Vochysia bifalcata Warm.: Preclinical evidence of efficacy and safety.

ETHNOPHARMACOLOGICAL RELEVANCE: Vochysia bifalcata is a Brazilian native tree commonly used for economic purpose in the reforestation and in the manufacture of products. However, the potential usage of other parts of the plant is usually wasted. Besides, other species of Vochysia are well known for its anti-inflammatory action. AIM OF THE STUDY: In this study we evaluate the possible anti-inflammatory activity of the hydroethanolic extract from the leaves of V. bifalcata in models of mice skin inflammation. MATERIALS AND METHODS: Effects of V. bifalcata were evaluated in croton oil-induced acute and chronic skin inflammation. The role of glucocorticoid receptors in the extract effect was assessed by using a glucocorticoid receptor antagonist and by a specific binding assay. Possible adverse effects were evaluated after multiple treatments with the extract in a skin atrophy model. RESULTS: Topical application of V. bifalcata reduced ear edema formation, cell infiltration and interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels. In the chronic model, besides edema formation and cell infiltration, the extract inhibited epidermal hyperproliferation and Proliferating Cell Nuclear Antigen expression. V. bifalcata seems to act by biding to corticoid receptors, however it did not induce corticoid related undesirable effects. CONCLUSION: Hydroethanolic extract from leaves of V. bifalcata could be an interesting tool in the search for new anti-inflammatory and antiproliferative agents for the treatment of skin disorders.

Role of TRPA1 receptors in skin inflammation induced by volatile chemical irritants in mice.

Contact dermatitis is a very common inflammatory reaction in the skin, causing not only aesthetic problems but also loss functionality at work. The molecular mechanisms of contact dermatitis induced by chemical irritants are still unclear. Considering that transient receptor potential channels (TRP) may induce neurogenic inflammation and the exacerbation of inflammatory responses, here we investigated the role of transient receptor potential channel ankyrin type-1 (TRPA1) in skin inflammation evoked by chemical irritants. Ear oedema and nociceptive responses elicited by the topical application of xylene and toluene were measured in Swiss mice, wild type and TRPA1 knockout (Trpa1-/-) C57BL/6 mice. Histological analyses were performed in mice subjected to the ear oedema assay. Topical application of xylene and toluene in the mouse ear induced an edematogenic response (0.113 ±â€¯0.008 mm and 0.067 ±â€¯0.011 mm), compared to vehicle (0.008 ±â€¯0.008 mm), assessed by ear thickness measurements and histological analyses. These responses were prevented by topical pretreatment with a selective TRPA1 antagonist, HC-030031 (% inhibition: xylene 36.8 ±â€¯9.4% and toluene 50.7 ±â€¯11.0%), and by the genetic deletion of TRPA1 ((% inhibition: xylene 66.6 ±â€¯16.7% and toluene 75 ±â€¯0%). In addition, the topical application of xylene and toluene to the mouse paw elicited nociceptive responses, which were significantly reduced by oral treatment with HC-030031 ((% of inhibition: 84.9 ±â€¯1.3% and 27.1 ±â€¯8.0%, respectively); nociceptive responses were almost completely abolished in Trpa1-/-mice. Our data suggest that the activation of TRPA1 could be involved in some of the symptoms of irritant-mediated contact dermatitis, such as oedema, pain and neurogenic inflammation.

Chemical composition, antioxidant and anti-inflammatory activities of the essential oils from male and female specimens of Baccharis punctulata (Asteraceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis punctulata (Asteraceae), popularly known as "Chíllka saru saru" in Bolivia, has been used by rural communities in Bustillo Province of the Potosi Department for treatment of asthma, luxations and contusions. AIM OF THE STUDY: To analyze the chemical composition of the essential oils obtained from leaves of female (BPF) and male (BPM) specimens and evaluate their anti-inflammatory and antioxidant properties. MATERIAL AND METHODS: Chemical composition analyses of Baccharis punctulata essential oils isolated by hidrodistillation from leaves of male and female specimens were performed by GC-FID-MS. The in vivo anti-inflammatory activity was evaluated using the model of TPA (12-O-tetradecanoylphorbol-13-acetate) induced ear edema, and the polymorphonuclear cell migration was evaluated by mieloperoxidase (MPO) and analyzed histologically. To measure the reactive oxygen species (ROS) in the inflamed tissue, the DCFH-DA fluorescent probe was used. The chemical in vitro antioxidant activity of essential oils was determined using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical assay. RESULTS: The chemical analysis showed high proportion of sesquiterpenes in the volatiles samples obtained from BPM, such as δ-elemene (14.29%), germacrene D (11.29%) and bicyclogermacrene (10.90%), and in the sample from BPF, bicyclogermacrene (42.44%), germacrene D (21.18%) and ß-caryophyllene (14.06%). A statistical difference (p < 0.05) on chemical composition between both essential oils was observed. Topical administration of both BPM and BPF essential oils was able to inhibit the formation of TPA-induced edema in the treated groups. Isolated administration of TPA promoted an increase in MPO enzyme activity, and inhibition of the increase of MPO activity was observed when animals were treated with BFP at concentrations of 0.1 mg/ear (13.69 ±â€¯0.20%), 0.3 mg/ear (22.35 ±â€¯0.11%), and 1.0 mg/ear (44.98 ±â€¯0.27%). Topical treatment with BPM was able to inhibit MPO activity at 22.40 ±â€¯0.29% (0.1 mg/ear), 36.49 ±â€¯0.07% (0.3 mg/ear) and 52.19 ±â€¯0.28% (1.0 mg/ear). The positive control of dexamethasone (DEXA, 0.1 mg/ear) was able to revert the increase in the enzymatic activity of MPO caused by TPA (65.16%). Histological analysis showed that topical application of TPA promoted intense cellular infiltration. This inflammatory parameter was reduced with the topical application of the BPF and BPM oil samples as well as with DEXA. The results observed in the ROS and DPPH tests suggest that both samples were able to reduce the inflammatory cells influx and have in vitro antioxidant properties, respectively. CONCLUSIONS: This study presents, for the first time, the chemical composition of the essential oils obtained from leaves of male and female specimens of Baccharis punctulata, and their anti-inflammatory and antioxidant activities. The results presented by the volatile samples in our biotests support traditional uses of this plant species.

Aliskiren: Preclinical evidence for the treatment of hyperproliferative skin disorders.

Psoriasis is a complex inflammatory and hyperproliferative skin disease. The pathogenesis and mechanisms involved are not completely understood, which makes treatment a difficult issue. Angiotensin II, the most active peptide of the renin-angiotensin system, seems to be involved in processes related to psoriasis pathogenesis, such as inflammation and cell proliferation. The aim of this study was to investigate the influence of renin inhibition on inflammation parameters and keratinocyte proliferation in a mouse model of chronic skin inflammation induced by croton oil. Aliskiren had anti-inflammatory effects by reducing levels of tumor necrosis factor-α and interleukin -6, and by inhibiting myeloperoxidase activity. Aliskiren also showed antiproliferative activity by reducing epidermal hyperplasia and proliferating cell nuclear antigen levels. Aliskiren treatment did not induce alterations in the cardiovascular system, normal skin thickness, and organ weight. These results suggest that aliskiren could be a valuable tool to be incorporated in the treatment of hyperproliferative and inflammatory skin disorders such as psoriasis.

Pre-clinical efficacy assessment of Malva sylvestris on chronic skin inflammation.

In the search for improved quality of life, the treatment of skin diseases like psoriasis (hyperproliferative disease) is valid, since it causes huge social discomfort to the patient. In this context, earlier studies showed that Malva sylvestris L. has anti-inflammatory activity demonstrated by acute animal models of skin inflammation, becoming a promising target for further studies. The present investigation aimed to verify the effect of hydroalcoholic extract of M. sylvestris (HEMS) on the chronic inflammatory and hyperproliferative response caused by multiple applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) on mouse ears. Topical application of HEMS reduced oedema, leukocyte migration (mono- and polymorphonuclear cells) and keratinocyte hyperproliferation, confirmed by histology and proliferating cell nuclear antigen (PCNA) immunostaining. It was found that the anti-inflammatory effects of the extract did not involve the glucocorticoid system, and its incubation with HaCaT keratinocytes caused low toxicity and reduced cell proliferation by apoptosis. Thus, HEMS proved to be effective as an anti-psoriatic therapy, with the ability to prevent keratinocyte hyperproliferation and with low toxicity by topical application.

Systematic review and meta-analysis of the efficacy and safety of amfepramone and mazindol as a monotherapy for the treatment of obese or overweight patients.

The aim of this study was to evaluate efficacy and safety of amfepramone, fenproporex and mazindol as a monotherapy for the treatment of obese or overweight patients. A systematic review of primary studies was conducted, followed by a direct meta-analysis (random effect) and mixed treatment comparison. Medline and other databases were searched. Heterogeneity was explored through I2 associated with a p-value. Of 739 identified publications, 25 were included in the meta-analysis. The global evaluation of Cochrane resulted in 19 studies with a high level of bias and six with unclear risk. Due to the lack of information in primary studies, direct meta-analyses were conducted only for amfepramone and mazindol. Compared to placebo, amfepramone resulted in higher weight loss in the short-term (<180 days; mean difference (MD) -1.281 kg; p<0.05; I2: 0.0%; p=0.379) and long-term (≥180 days; MD -6.518 kg; p<0.05; I2: 0.0%; p=0.719). Only studies with long-term follow up reported efficacy in terms of abdominal circumference and 5-10% weight reduction. These results corroborated the finding that the efficacy of amfepramone is greater than that of placebo. Treatment with mazindol showed greater short-term weight loss than that with placebo (MD -1.721 kg; p<0.05; I2: 0.9%; p=0.388). However, metabolic outcomes were poorly described, preventing a meta-analysis. A mixed treatment comparison corroborated the direct meta-analysis. Considering the high level of risk of bias and the absence of important published outcomes for anti-obesity therapy assessments, this study found that the evaluated drugs showed poor evidence of efficacy in the treatment of overweight and obese patients. Robust safety data were not identified to suggest changes in their regulatory status.

Diethylpropion and mazindol: An end to the discussion?

Antiobesity pharmacotherapy remains the main point of disagreement among both scientists and regulators. This is probably due to small sample sizes, high levels of heterogeneity, and low methodological quality. For many years, Brazil was one of the largest consumers of appetite suppressants worldwide, with evidence of irrational use of this drug class. Therefore, the country was the scene of a debate that divided the Brazilian Health Surveillance Agency (Anvisa - Agência Nacional de Vigilância Sanitária) and medical societies over the maintenance record of diethylpropion, mazindol and fenproporex. In this context, this commentary presents new arguments to contribute to the discussion, as well as recommendations for future studies.

Systematic review and meta-analysis of the efficacy and safety of amfepramone and mazindol as a monotherapy for the treatment of obese or overweight patients

The aim of this study was to evaluate efficacy and safety of amfepramone, fenproporex and mazindol as a monotherapy for the treatment of obese or overweight patients. A systematic review of primary studies was conducted, followed by a direct meta-analysis (random effect) and mixed treatment comparison. Medline and other databases were searched. Heterogeneity was explored through I2 associated with a p-value. Of 739 identified publications, 25 were included in the meta-analysis. The global evaluation of Cochrane resulted in 19 studies with a high level of bias and six with unclear risk. Due to the lack of information in primary studies, direct meta-analyses were conducted only for amfepramone and mazindol. Compared to placebo, amfepramone resulted in higher weight loss in the short-term (<180 days; mean difference (MD) -1.281 kg; p<0.05; I2: 0.0%; p=0.379) and long-term (≥180 days; MD -6.518 kg; p<0.05; I2: 0.0%; p=0.719). Only studies with long-term follow up reported efficacy in terms of abdominal circumference and 5-10% weight reduction. These results corroborated the finding that the efficacy of amfepramone is greater than that of placebo. Treatment with mazindol showed greater short-term weight loss than that with placebo (MD -1.721 kg; p<0.05; I2: 0.9%; p=0.388). However, metabolic outcomes were poorly described, preventing a meta-analysis. A mixed treatment comparison corroborated the direct meta-analysis. Considering the high level of risk of bias and the absence of important published outcomes for anti-obesity therapy assessments, this study found that the evaluated drugs showed poor evidence of efficacy in the treatment of overweight and obese patients. Robust safety data were not identified to suggest changes in their regulatory status.

Photodynamic effect of meso-(aryl)porphyrins and meso-(1-methyl-4-pyridinium)porphyrins on HaCaT keratinocytes.

Sixteen porphyrins, including neutral, anionic and cationic meso-(aryl)porphyrins and meso-(1-methyl-4-pyridinium)porphyrins were herein evaluated in terms of their photosensitizing properties against HaCaT keratinocytes. After an initial screening, the cationic porphyrins were studied in more details, by both determining their log POW and performing PDT assays in lower porphyrin concentrations. Porphyrins presenting two or more adjacent positively charged groups, directly linked to the macrocycle meso positions, appeared to be the most effective photosensitizers. The present study also included the dicationic 5,10-diphenyl-15,20-di(1-methylpyridinium-4-yl)porphyrin (14b), which has previously shown promising results on a psoriasis-like in vivo model. Overall results indicated that the beneficial effect related to porphyrins on psoriasis can be related to the decreasing of keratinocyte viability. Furthermore, some of the cationic porphyrins studied appeared as candidates to be utilized as photosensitizers for psoriasis treatment.