leukotriene-b4 and Erythema

Topics: Animals; Anti-Inflammatory Agents; Arachidonic Acids; Capillary Permeability; Edema; Eicosanoic Acids; Erythema; Fever; Humans; Hyperalgesia; Inflammation; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Muscle, Smooth, Vascular; Pain; Prostaglandin Antagonists; Prostaglandins; SRS-A

Licochalcone A (LicA), a major phenolic constituent of the licorice species Glycyrrhiza inflata, has recently been reported to have anti-inflammatory as well as anti-microbial effects. These anti-inflammatory properties might be exploited for topical applications of LicA. We conducted prospective randomized vehicle-controlled clinical trials to assess the anti-irritative efficacy of cosmetic formulations containing LicA in a post-shaving skin irritation model and on UV-induced erythema formation. The clinical trials were accompanied by a series of in vitro experiments to characterize anti-inflammatory properties of LicA on several dermatologically relevant cell types. Topical LicA causes a highly significant reduction in erythema relative to the vehicle control in both the shave- and UV-induced erythema tests, demonstrating the anti-irritative properties of LicA. Furthermore, LicA is a potent inhibitor of pro-inflammatory in vitro responses, including N-formyl-MET-LEU-PHE (fMLP)- or zymosan-induced oxidative burst of granulocytes, UVB-induced PGE(2) release by keratinocytes, lipopolysaccharide (LPS)-induced PGE(2) release by adult dermal fibroblasts, fMLP-induced LTB(4) release by granulocytes, and LPS-induced IL-6/TNF-alpha secretion by monocyte-derived dendritic cells. The reported data suggest therapeutic skin care benefits from LicA when applied to sensitive or irritated skin.

Topics: Administration, Topical; Adult; Anti-Inflammatory Agents; Cells, Cultured; Chalcones; Dinoprostone; Erythema; Granulocytes; Humans; Interleukin-6; Keratinocytes; Leukotriene B4; Middle Aged; Plant Extracts; Prospective Studies; Respiratory Burst; Tumor Necrosis Factor-alpha; Ultraviolet Rays; Zymosan

When the potent chemoattractant leukotriene B4 (LTB4) is applied topically to human skin it causes delayed onset, long-lasting leukocyte accumulation and erythema. We investigated the role of prostaglandins in the increase in local blood flow by applying LTB4 topically to the forearm skin of 22 healthy male volunteers and measuring the effect of the anti-inflammatory compounds tenidap, naproxen and indomethacin. Local microvascular blood flow responses were measured by laser Döppler flow probe and planimetry. LTB4 induced dose-dependent increases in blood flow which were maximal at 48 hr and lasted 4 days. Laser Döppler flow (% flux) at 48 hr was 2.7 +/- 0.1, 20.6 +/- 3.1, 28.7 +/- 2.4 and 30.2 +/- 2.3% in control and 3, 10, 30 ng/site LTB4, respectively (mean +/- S.E.M.). In eight subjects the intradermal injection of indomethacin, at a dose (3 x 10(-9) mol/site) that inhibited significantly the increased flow induced by intradermally injected arachidonic acid (1 x 10(-9) mol/site, n = 6), had no effect on the increased skin blood flow response induced by LTB4 (10 ng/site) at 48 hr. Blood flow in vehicle-injected LTB4 sites was 810 +/- 150% above basal and 819 +/- 149% in sites injected with indomethacin. In 20 subjects, the effect of the anti-inflammatory drugs naproxen and tenidap given orally on the skin blood flow responses to LTB4 were compared in a double-blind crossover design. The 1085 +/- 98% increase in local blood flow induced by 30 ng of LTB4 at 48 hr was unaltered at the end of the treatment periods with either naproxen or tenidap, where blood flow in the LTB4-treated sites was increased 1018 +/- 131% and 1034 +/- 130%, respectively. Because the vasodilator response to exogenous LTB4 was not altered by nonsteroidal anti-inflammatory drugs either injected locally or taken orally, we suggest that endogenous prostaglandins are not involved in this response.

Topics: Administration, Oral; Administration, Topical; Adult; Arachidonic Acid; Dose-Response Relationship, Drug; Erythema; Humans; Indoles; Indomethacin; Leukotriene B4; Male; Microcirculation; Naproxen; Oxindoles; Regional Blood Flow; Skin; Vasodilation

Important roles of neutrophils as well as lymphocytes against invasive fungi has been suggested. Leukotriene B4 (LTB4) is a potent chemoattractant for neutrophils and its topical application to human skin has already been performed without serious side effects, forming intraepidermal neutrophil abscesses. Thus topical LTB4 therapy for tinea was attempted in a randomized, placebo-controlled study. LTB4 (100-900 ng depending on the area of each lesion) was applied to a whole lesion once a week until, as a rule, complete clearing was observed but maximum for 2 weeks (vesiculobullous type lesions), 5 weeks (patches with or without raised borders) or 7 weeks (macerated lesions between toes). As a result, 16 of 18 lesions treated with LTB4 were cleared either completely (13) or partially (3). In contrast, only 2 of 18 lesions treated with vehicle (50% ethanol) were cleared partially. Statistical analysis with chi 2 test revealed a significant efficacy of LTB4 over vehicle. Topical LTB4 will be used as a powerful antifungal regimen. LTB4 has not been used for infectious diseases before.

Topics: Administration, Topical; Adult; Aged; Erythema; Female; Humans; Leukotriene B4; Male; Middle Aged; Pruritus; Random Allocation; Tinea; Tinea Pedis

Cytosolic phospholipase A2 (cPLA2) catalyzes the selective release of arachidonic acid from the sn-2 position of phospholipids and is believed to play a key cellular role in the generation of arachidonic acid. BMS-229724 (4-[4-[2-[2-[bis(4-chlorophenyl)methoxy]ethyl-sulfonyl]ethoxy]phenyl]-1,1,1-trifluoro-2-butanone) was found to be a selective inhibitor of cPLA2 (IC50 = 2.8 microM) in that it did not inhibit secreted phospholipase A2 in vitro, nor phospholipase C and phospholipase D in cells. The compound was active in inhibiting arachidonate and eicosanoid production in U937 cells, neutrophils, platelets, monocytes, and mast cells. With a synthetic covesicle substrate system, the dose-dependent inhibition could be defined by kinetic equations describing competitive inhibition at the lipid/water interface. The apparent equilibrium dissociation constant for the inhibitor bound to the enzyme at the interface (K(I)*(app)) was determined to be 1. 10(-5) mol% versus an apparent dissociation constant for the arachidonate-containing phospholipid of 0.35 mol%. The unit of concentration in the interface is mole fraction (or mol%), which is related to the surface concentration of substrate, rather than bulk concentration that has units of molarity. Thus, BMS-229724 represents a novel inhibitor of cPLA2, which partitions into the phospholipid bilayer and competes with phospholipid substrate for the active site. This potent inhibition of the enzyme translated into anti-inflammatory activity when applied topically (5%, w/v) to a phorbol ester-induced chronic inflammation model in mouse ears, inhibiting edema and neutrophil infiltration, as well as prostaglandin and leukotriene levels in the skin. In hairless guinea pigs, BMS-229724 was active orally (10 mg/kg) in a UVB-induced skin erythema model in hairless guinea pigs.

Topics: Administration, Oral; Administration, Topical; Animals; Anti-Inflammatory Agents; Carcinogens; Chlorobenzenes; Dinoprostone; Dose-Response Relationship, Drug; Erythema; Female; Guinea Pigs; Humans; Inflammation; Leukotriene B4; Male; Mice; Neutrophils; Phorbol Esters; Phospholipases A; Phospholipases A2; Phospholipids; Platelet Activating Factor; Rats; Rats, Sprague-Dawley; Skin; Sulfones

Topics: Adult; Aged; Arachidonate 5-Lipoxygenase; Calcimycin; Eicosapentaenoic Acid; Erythema; Female; Glucuronidase; Humans; In Vitro Techniques; Kinetics; Leukotriene B4; Male; Middle Aged; Neutrophils; Psoriasis; Skin

15-Hydroxyeicosatetraenoic acid (15-HETE), a 15-lipoxygenase product of arachidonic acid, inhibits leukotriene B4 (LTB4)-induced chemotaxis of polymorphonuclear leukocytes (PMNs) in vitro. In this study the effects of intradermal injections of LTB4 were determined in the absence or presence of 15-HETE. For comparison intradermal injections of purified human complement split product C5a were performed in the absence or presence of 15-HETE. The skin response was evaluated by measuring the diameter of the wheal, the area of the flare and by intensity of the erythema (erythema index). LTB4 and C5a were injected at the concentration of 200 ng/ml. At this concentration the maximal skin response of LTB4 and C5a were equivalent. In contrast to C5a reaction, which resolved within 1 h, LTB4-induced skin response lasted up to 18 h. In all subjects the skin response was significantly decreased when LTB4 was injected together with 300 ng of 15-HETE. The decrease of wheal, flare, and erythema index averaged 81.9%, 56.6%, 53.6%, respectively, when all parameters were obtained at the maximal skin response. In contrast, the C5a-induced skin response was not affected by addition of 15-HETE, even when the final dose of 15-HETE was increased 10 times to 3 micrograms. The LTB4-induced reaction could last up to 18 h after injection. After the addition of 300 ng of 15-HETE the skin response resolved after 1 h. The present results demonstrate that 15-HETE is a specific inhibitor of the LTB4-induced skin response and brings additional evidence in support of the ability of 15-HETE to regulate the proinflammatory effects of LTB4 in vivo.

Topics: Adult; Complement C5a; Erythema; Female; Humans; Hydroxyeicosatetraenoic Acids; Intradermal Tests; Leukotriene B4; Male; Middle Aged; Skin

The arachidonate lipoxygenase products 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) and 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid (leukotriene B4, LTB4) are potent leucocyte chemoattractants in vitro and in vivo. Both 12-HETE and LTB4-like material are found in increased amounts in lesional skin in psoriasis. Epicutaneous administration of 12(R,S)-HETE and LTB4 in normal skin evokes neutrophil and mononuclear dermal infiltrates accompanied by collections of neutrophils in the epidermis. Similar appearances result from the application of LTB4 to uninvolved skin in psoriasis. We have now investigated the effects of single and multiple epicutaneous applications of 12(R,S)-HETE and LTB4, both alone and in combination, in normal human skin and in clinically uninvolved skin of patients with psoriasis. As in the case of LTB4, erythematous responses to 12(R,S)-HETE were similar in normal skin and in psoriasis. Similar neutrophil polymorphonuclear responses were evoked by topical application of 50 ng LTB4 and 20 micrograms 12(R,S)-HETE. Application of the combination of 12(R,S)-HETE and LTB4 evoked only a partially additive erythematous response, and no evidence of an additive neutrophilotactic response was detected histologically. Multiple applications resulted in tolerance both clinically and histologically. Cross tolerance to 12(R,S)-HETE and LTB4 occurred in the majority of subjects. These results suggest that both 12(R,S)-HETE and LTB4 may be important in the production and control of the magnitude of the inflammatory events in psoriasis.

Topics: Dose-Response Relationship, Drug; Erythema; Humans; Hydroxyeicosatetraenoic Acids; Immune Tolerance; Leukotriene B4; Neutrophils; Psoriasis; Skin

Topics: Arachidonic Acids; Erythema; Histamine; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxygenase; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Skin; SRS-A; Ultraviolet Rays

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Eicosanoic Acids; Erythema; Female; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotriene B4; Male; Photosensitivity Disorders; Skin; Ultraviolet Rays

Intradermal injections of 1-50 pmol leukotriene B4, C4, D4 and E4, (LTB4, LTC4, LTD4 and LTE4) were performed in healthy subjects and patients with recurrent urticaria. A wheal and erythema were seen 15 minutes after injection and were most marked after LTC4 and LTD4. LTE4 also produced a wheal whereas the reaction to LTB4 did not significantly differ from the saline control. When mixed with histamine no potentiation of the wheals was noted and no significant difference in reaction was observed between the healthy controls and those with urticaria.

Topics: Drug Hypersensitivity; Erythema; Histamine; Humans; Intradermal Tests; Leukotriene B4; Leukotriene E4; Male; Skin; SRS-A; Urticaria