Tadafumi Tamura

Pharmacological studies of diacerein in animal models of inflammation, arthritis and bone resorption.

Diacerein has proved to be effective in the treatment of osteoarthritis. We investigated the effects of diacerein in animal models of carrageenin-, zymosan-, or dextran-induced paw edema and adjuvant-induced arthritis and in ovariectomized rats. In acute inflammatory models, unlike classical nonsteroidal anti-inflammatory drugs such as naproxen and ibuprofen, diacerein inhibited the rat paw edema induced by various agents. In the adjuvant-induced arthritic rats, diacerein at 100 mg/kg/day significantly suppressed the paw edema and the increase in serum mucoprotein. Addition of 3 mg/kg/day naproxen to each diacerein (3, 10, 30 mg/kg/day) dose resulted in significantly greater anti-inflammatory activity than with naproxen alone. In the ovariectomized rats, diacerein (10, 100 mg/kg/day) also significantly prevented bone loss and reduced the serum alkaline phosphatase and decreased the excretion of urinary hydroxyproline. In addition, rhein (10, 30 microM) inhibited calcium release from mouse calvaria induced by interleukin-1 beta, prostaglandin E(2) and parathyroid hormone 1-34 human fragment. These findings indicate that diacerein is a novel anti-inflammatory drug with pharmacological properties different from those of classical nonsteroidal anti-inflammatory drugs and support the clinical investigation of the use of combination therapy with diacerein and nonsteroidal anti-inflammatory drugs in patients with not only osteoarthritis but also rheumatoid arthritis.

Diacerein suppresses the increase in plasma nitric oxide in rat adjuvant-induced arthritis.

We investigated the effects of rhein, an active metabolite of diacerein, on the interleukin-1alpha-stimulated production of nitric oxide (NO) in rabbit articular chondrocytes, and the effects of diacerein on NO production in rat adjuvant-induced arthritis. At doses of 10 and 30 microM, rhein significantly inhibited the interleukin-1alpha-stimulated NO production in chondrocytes. In the rat adjuvant-induced arthritis model, diacerein was administered for 21 days, starting at the time of adjuvant injection. Paw swelling and plasma NO level were measured in order to assess the effect of diacerein on arthritis and NO biosynthesis in the whole body. At doses of 30 and 100 mg/kg/day, diacerein significantly suppressed the development of adjuvant-induced arthritis and the increase in plasma NO. These results suggest that the inhibitory effect of diacerein on rat adjuvant-induced arthritis is partly related to its reduction of the NO production induced by adjuvant-induced arthritis.

Effects of Diacerein on Indomethacin-Induced Gastric Ulceration

We investigated the effect of diacerein, an antiosteoarthritic agent, and its metabolite, rhein, on the production of reactive oxygen species (ROS) from neutrophils as well as the protective effect of diacerein on indomethacin-induced gastric ulceration and its protection mechanism. Rhein inhibited the ROS production from N-formyl-methionyl-leucyl-phenylalanine or phorbol-12-myristate-13-acetate-activated human peripheral neutrophils. Indomethacin-induced gastric ulceration was significantly inhibited by oxygen radical scavengers and 16,16-dimethyl-prostaglandin E2 (dmPGE2) but not by allopurinol. Diacerein inhibited indomethacin-induced gastric ulceration in a dose-dependent manner. Diacerein did not affect the gastric mucosal PGE2 content. In addition, diacerein inhibited HCl + ethanol-induced gastric ulceration. These data indicate that the inhibitory effect of diacerein on indomethacin-induced gastric ulceration could be mediated not by the augmentation of gastric mucosal PGE2 production but by the suppression of ROS production based on its inhibition of neutrophil activation.

Olopatadine Hydrochloride Improves Dermatitis Score and Inhibits Scratch Behavior in NC/Nga Mice

Background: Control of itch is an important issue in the treatment of atopic dermatitis (AD). Itch is mediated by a variety of pruritogens, including histamine, and promoted by neurite outgrowth in the epidermis of AD patients, probably due to the release of nerve growth factor. Objectives: We investigated the effects of orally administered olopatadine hydrochloride (olopatadine) on itching, itching mediators, and neuritogenic action in a mouse model. Materials and Methods: NC/Nga mice were treated topically with Dermatophagoides farinae body (Dfb) extract twice weekly for 4 weeks to induce AD-like lesions. They were concomitantly given oral olopatadine, distilled deionized water, or topical tacrolimus during the last 2 weeks. Results: Olopatadine significantly suppressed scratching, improved the dermatitis score, inhibited neurite outgrowth, and decreased the elevated inflammatory markers, growth factors and histamine content in the lesional skin, and serum concentration of Dfb-specific IgE. Notably, olopatadine treatment increased semaphorin 3A expression in the epidermis. Conclusions: Our study confirms the pleiotropic effects of olopatadine, i.e. inhibition of inflammation and neurite extension into the epidermis.

Role of fibroblast growth factor 8 (FGF8) in animal models of osteoarthritis.

IntroductionFibroblast growth factor 8 (FGF8) is isolated as an androgen-induced growth factor, and has recently been shown to contribute to limb morphogenesis. The aim of the present study was to clarify the role of FGF8 in animal models of osteoarthritis (OA).MethodsThe expression of FGF8 in the partial meniscectomy model of OA in the rabbit knee was examined by immunohistochemistry. The effect of intraperitoneal administration of anti-FGF8 antibody was tested in a model of OA that employed injection of monoiodoacetic acid or FGF8 into the knee joint of rats. The effect of FGF8 was also tested using cultured chondrocytes. Rabbit articular chondrocytes were treated with FGF8 for 48 hours, and the production of matrix metalloproteinase and the degradation of sulfated glycosaminoglycan in the extracellular matrix (ECM) were measured.ResultsThe expression of FGF8 in hyperplastic synovial cells and fibroblasts was induced in the meniscectomized OA model, whereas little or no expression was detected in normal synovium. Injection of FGF8 into rat knee joints induced the degradation of the ECM, which was suppressed by anti-FGF8 antibody. In the monoiodoacetic acid-induced arthritis model, anti-FGF8 antibody reduced ECM release into the synovial cavity. In cultured chondrocytes, FGF8 induced the release of matrix metalloproteinase 3 and prostaglandin E2, and caused degradation of the ECM. The combination of FGF8 and IL-1α accelerated the degradation of the ECM. Anti-FGF8 antibody suppressed the effects of FGF8 on the cells.ConclusionFGF8 is produced by injured synovium and enhances the production of protease and prostaglandin E2 from inflamed synoviocytes. Degradation of the ECM is enhanced by FGF8. FGF8 may therefore participate in the degradation of cartilage and exacerbation of osteoarthritis.

Olopatadine hydrochloride decreases tissue interleukin-31 levels in an atopic dermatitis mouse model.

with clinically significant cardiovascular risk: a Danish 12. nationwide cohort study. J Intern Med 2011: 270: 147-157. 9. Brauchli YB, Jick SS, Meier CR. Psoriasis and the risk of incident diabetes mellitus: a population-based study. Br J Dermatol 2008: 159: 1331-1337. 13. 10. Deanfield JE, Halcox JP, Rabelink TJ. Endothelial function and dysfunction: testing and clinical relevance. Circulation 14. 2007; 115: 1285-1295. 11. Rubinshtein R, Kuvin JT, Soffler M, Lennon RJ, Lavi S, Nelson RE, et al. Assessment of endothelial function 15. by non-invasive peripheral arterial tonometry predicts late cardiovascular adverse events. Eur Heart J 2010: 31: 1142-1148. Haller MJ, Stein J, Shuster J, Theriaque D, Silverstein J, Schatz DA, et al. Peripheral artery tonometry demonstrates altered endothelial function in children with type 1 diabetes. Pediatr Diabetes 2007; 8: 193-198. Benoit S, Hamm H. Childhood psoriasis. Clin Dermatol 2007: 25: 555-562. Jensen PR, Zachariae C, Hansen P, Skov L. Normal endothelial function in patients with mild-to-moderate psoriasis: a case-eontrol study. Acta Derm Venereol 2011: 91: 516-520. Späh F. Inflammation in atherosclerosis and psoriasis: common pathogenic mechanisms and the potential for an integrated treatment approach. Br J Dermatol 2008: 159 Suppl2: 10-17.

Effect of Olopatadine and Other Histamine H1 Receptor Antagonists on the Skin Inflammation Induced by Repeated Topical Application of Oxazolone in Mice

Histamine H1 receptor antagonists have long been prescribed for atopic dermatitis as an adjuvant therapy with topical therapy by local applied steroids. Olopatadine is one of the second-generation histamine H1 receptor antagonists that are treated for allergic disorders. We investigated that the effect of olopatadine on oxazolone-induced chronic contact hypersensitivity response in BALB/c mice compared with other histamine H1 receptor antagonists loratadine, cetirizine and fexofenadine. The chronic contact hypersensitivity induced by repeated application of oxazolone was treated with olopatadine and other histamine H1 receptor antagonists at the effective doses on histamine-induced paw edema in mice. The effects of these drugs in the oxazolone-induced model were quantified by measurements of ear swelling, and levels of cytokines in the lesioned ear. Olopatadine significantly inhibited the ear swelling and the increased production of IL-4, IL-1β, IL-6, GM-CSF and NGF in the lesioned ear. On the other hand, the other histamine H1 receptor antagonists did not significantly suppress the increase in ear thickness. Moreover, they did not affect the production of cytokines in the lesioned ear. These results indicate that olopatadine appears to exert additional biological effects besides its blockade of the histamine H1 receptor.

Olopatadine Ameliorates Rat Experimental Cutaneous Inflammation by Improving Skin Barrier Function

Olopatadine hydrochloride (olopatadine) is an antiallergic agent with histamine H1 receptor antagonistic action. We investigated the possible efficacies of olopatadine on the chronic inflammatory dermatitis and the impaired skin barrier functions induced by repeated application of oxazolone in rats. Oxazolone-sensitized rats were challenged with oxazolone applied to the ear every 3 days. Olopatadine was orally administered once daily (1 and 3 mg/kg/day). The effects of the drug were quantified by measurements of ear thickness, levels of cytokines in the lesioned ear and the number of scratching episodes. As parameters of skin barrier function, transepidermal water loss (TEWL) and hyaluronic acid (HA) levels in the lesioned ear were measured. The effect of olopatadine on the production of HA by cultured dermal fibroblasts was also measured. Repeated topical application of oxazolone to rat ears induced local inflammation that was exemplified by swelling. In inflamed ears, the amount of IFNγ increased at both the protein and mRNA level, but IL-4 levels changed minimally. Olopatadine significantly decreased ear swelling and the number of scratching episodes. The drug also significantly inhibited the increase of IFNγ and nerve growth factor production in inflamed ears. Olopatadine significantly inhibited the increase in TEWL and the decrease in HA in lesioned ears. Furthermore, the drug stimulated the production of HA by cultured dermal fibroblasts. These results suggest that olopatadine suppressed inflammation and scratching not only by inhibiting cytokine production, but also by repairing skin barrier function.

Olopatadine suppresses the migration of THP-1 monocytes induced by S100A12 protein.

Olopatadine hydrochloride (olopatadine) is an antiallergic drug with histamine H1 receptor antagonistic activity. Recently, olopatadine has been shown to bind to S100A12 which is a member of the S100 family of calcium-binding proteins, and exerts multiple proinflammatory activities including chemotaxis for monocytes and neutrophils. In this study, we examined the possibility that the interaction of olopatadine with S100A12 inhibits the proinflammatory effects of S100A12. Pretreatment of olopatadine with S100A12 reduced migration of THP-1, a monocyte cell line, induced by S100A12 alone, but did not affect recombinant human regulated upon activation, normal T cell expressed and secreted (RANTES)-induced migration. Amlexanox, which also binds to S100A12, inhibited the THP-1 migration induced by S100A12. However, ketotifen, another histamine H1 receptor antagonist, had little effect on the activity of S100A12. These results suggest that olopatadine has a new mechanism of action, that is, suppression of the function of S100A12, in addition to histamine H1 receptor antagonistic activity.

Olopatadine ophthalmic solution suppresses substance P release in the conjunctivitis models

Background Olopatadine hydrochloride ophthalmic solutions are treated for allergic conjunctival diseases that are a selective histamine H1 receptor antagonist and an inhibitor of the release of mediators including histamine from the human mast cells. Substance P (SP) levels are increased in tears of patients with allergic conjunctivitis. However, little is known about the regulation of SP release by anti-allergic ophthalmic solutions. Objective We investigated that the effect of olopatadine hydrochloride ophthalmic solutions (olopatadine 0.1% and olopatadine 0.2%) on rat conjunctivitis models compared with other anti-allergic ophthalmic solutions. Methods Conjunctivitis was induced by subconjunctival injection of histamine or intravenous injection of ovalbumin in rats passively sensitized with anti-ovalbumin anti-serum. The releases of SP were determined in the conjunctiva and tears using rat antigen-induced conjunctivitis models. Results Olopatadine 0.1% and 0.2% significantly inhibited the increased conjunctival dye leaked in the histamine- or antigen-induced hyperpermeability. The inhibitory effects by olopatadine were more potent than by other tested anti-allergic ophthalmic solutions. Moreover, olopatadine significantly inhibited the release of SP from the conjunctiva. Conclusion These results indicate that olopatadine ophthalmic solutions appear to exert additional SP release inhibition besides dual-action such as selective histamine H1 receptor antagonistic action and mast cell stabilization action.