Efecto antiinflamatorio de la enoxolona en un modelo exvivo de mucosa gingival humana / Antiinflammatory effect of enoxolone in an exvivo model of human gingival mucosa

Introducción. Este estudio tenía por finalidad precisar las modalidades de utilización y el mecanismo de acción antiinflamatoria de la enoxolona contenida en un dentífrico y en una solución bucal. Material y método. Por medio de un modelo de encía humana mantenida con sobrevida, se pudo inducir una reacción inflamatoria mediante la aplicación de mediadores proinflamatorios (SP y LPS) y realizar, en doble ciego contra placebo, una evaluación de los parámetros histológicos y bioquímicos (IL8) de la inflamación previa aplicación del dentífrico. Para la solución bucal, la evaluación bioquímica se realizó por dosificación del IL 1. Resultados. El dentífrico generó una disminución significativa del edema, de la dilatación de los capilares y de la excreción del IL8. La solución generó una disminución de la excreción del IL l. Discusión. La enoxolona ejerce un efecto antiinflamatorio, cualquiera sea el vehículo utilizado.

[Anti-inflammatory and repair activity of two toothpastes in an ex-vivo human gingival mucosa model]. / Comparaison de l'effet anti-inflammatoire et réparateur de deux dentifrices sur un modèle expérimental de muqueuse gingivale humaine.

INTRODUCTION: Our aim was to compare the anti-inflammatory activity of two toothpastes, one including enoxolone 1%, the other including plant extracts and sodium bicarbonate. MATERIAL AND METHODS: Gingival fragments were kept alive ex-vivo. Inflammation, inflammatory mediators (SP and LPS) were applied to culture medium on contact with corium to induce inflammation. The effect of both toothpastes was assessed with histological and biochemical parameters (inflammatory cytokine IL8) of inflammation on the synthesis of collagen and cellular viability. RESULTS: Both toothpaste "A" including enoxolone at 1% and "P" including plant extracts and sodium bicarbonate were effective on edema and vasodilatation. "A" acted on IL8 synthesis, unlike "P". Both toothpastes boosted collagen synthesis by fibroblasts. The percentage of cellular viability for "A" was superior to the currently admitted standard (80%), unlike to "P". DISCUSSION: The mechanisms of action of each toothpaste seem to be different. "A" modulates pro-inflammatory cytokine IL8 expression, unlike "P". The toothpaste "A" seems to be better tolerated.

[Anti-inflammatory effect of enoxolone in an ex-vivo human gingival mucosa model]. / Effet anti-inflammatoire de l'enoxolone dans un modèle ex-vivo de muqueuse gingivale humaine.

INTRODUCTION: Our aim was to assess the modalities of use and the anti-inflammatory activity of enoxolone included in toothpaste and in a mouthwash solution. MATERIAL AND METHODS: We used gingival fragments kept alive during 3 days at 37 degrees C. To induce inflammation, inflammatory mediators (SP and LPS) were applied to culture medium on contact with corium. The toothpaste versus placebo was applied on epithelium, in double blind. Histological analysis was then performed on hematoxylin and eosin stained slides. Edema was evaluated with semi-quantitative scores. Vasodilatation was studied by counting the percentage of dilated vessels according to scores and the surface of these dilated vessels by morphometrical image analysis. An inflammatory cytokine, IL8, was measured in culture supernatants. Dosing IL1alpha tested the mouth solution. RESULTS: The toothpaste induced a significant decrease of edema, vasodilatation, and IL8 excretion. The enoxolone solution induced a decrease of IL1alpha. DISCUSSION: Enoxolone demonstrated an anti-inflammatory property whatever the carrier was.

[Wound healing effect of Eludril in a model of human gingival mucosa]. / L'effet cicatrisant d'Eludril sur un modèle de muqueuse gingivale humaine.

INTRODUCTION: The aim of this study was to evaluate and to compare the potential for wound healing of the buccal mucosa with the use of two mouth rinses; one containing 0.10% chlorhexidine with alcohol, the second containing 0.12% chlorhexidine without alcohol. MATERIAL AND METHOD: Using a model of human buccal mucosa kept alive ex vivo, an immunohistochemical assessment of the mitotic potential of epithelial cells and a biochemical evaluation of the capacity of the fibroblasts of the gingival mucosa to synthesize collagen was performed. RESULTS: A mouth rinse containing 0.10% chlorhexidine with alcohol (Eludril) did not alter the potential for epithelial proliferation and for collagen synthesis within the gingival chorion grown in survival conditions. The results revealed a significant difference between the two mouth rinses for each of the parameters studied. The most favourable results were obtained with the mouth rinse containing alcohol. DISCUSSION: The presence of alcohol in a mouth rinse containing 0.10% chlorhexidine has no deleterious effects on healing capacity. On the contrary, it helps stimulate wound healing. The combination of chlorhexidine plus alcohol is superior for healing, chlorhexidine alone does not show any significant difference compared with the control.

Comparative study of the anti-aging effect of retinaldehyde alone or associated with pretocopheryl in a surviving human skin model submitted to ultraviolet A and B irradiation.

In the past few years, the cellular effects of ultraviolet (UV) irradiation induced on skin have become increasingly recognized. Indeed, it is now well known that UV irradiation induces structural and cellular changes in all the compartments of skin tissue. Our aim was to study the anti-aging efficacy of a cosmetic cream containing 0.05% retinaldehyde associated with an antioxidant such as pretocopheryl in comparison with a cream containing only 0.05% retinaldehyde. For this purpose, an ex vivo technique using human skin was used to approximate in vivo metabolic conditions. In this model, human skin was maintained alive by organ culture for 14 days and skin aging was simulated with UV irradiation. Creams were applied to the surface of the epidermis and were compared with nontreated skin. After 14 days, free radical modulation was analyzed by hydroperoxide dosage. Epidermal (laminin) and dermal changes (elastic fibers and collagen) were studied by a histological method. Moreover, to examine collagen synthesis, tritiated proline was added to the culture medium and its incorporation in the newly synthesized collagen was evaluated by Webster's method. The formula containing 0.05% retinaldehyde and pretocopheryl significantly decreased UV-generated free radicals. Repair of laminin, elastic fiber and collagen network was significant and the results were better than those obtained with retinaldehyde alone. An increase of collagen synthesis was also shown with the two creams.

Efficacy of sunscreens containing pre-tocopheryl in a surviving human skin model submitted to UVA and B radiation.

The aim of the present study was to evaluate by means of histological and biochemical tools the additive efficacy of pre-tocopheryl during photoprotection using a sunscreen containing mineral sunblock agents 50B-10A (TiO(2), ZnO) and pre-tocopheryl in comparison to a cream containing only mineral sunblock agents 50B-10A. For this purpose, an ex vivo technique and an acetone-impaired human skin model were used in order to approximate in vivo metabolic conditions. Creams were topically applied to the surface of the epidermis and submitted to UV radiations. Then, human skin explants were maintained alive in organ culture for 3 days. Free radical modulation was analysed by hydroperoxide assay. Epidermal (involucrin, cell proliferation, stratum corneum lipids) and dermal changes (elastic fibres and collagen) were studied. Analysis of ex vivo surviving skin samples impaired by UV irradiations and treated with the mineral sunscreen 50B-10A showed a significant decrease in hydroperoxide production and an improvement in the elastic fibre and collagen network in the dermis. Adding pre-tocopheryl to this formula induced an increase in involucrin and epidermal lipids such as squalenes and ceramides. Altogether, these results confirm the efficacy of the combination of a mineral sunscreen and pre-tocopheryl in photoprotection and free radical protection.

[Sodium fluoride controlled release system for intra buccal use]. / Système intra buccal delibèration contrôlée de fluorurede sodium.

Hydroxyapatite which has the same elemental chemical composition as natural bone and teeth is one of the promising raw material for the design of drug controlled release system in intrabuccal use. It is stable and biocompatible and widely used in orthopedics and odontology. So, in order to improve the administration of drugs for intrabuccal use, we have developped a fluoride controlled release delivering system. We have formulated tablets of 160 to 200 mg to be fixed on the vestibular face of a molar or a premolar and permitting to reach high enough local concentrations for desirable therapeutic effect. The tablets have a granular matrix composed of hydroxyapatite and fillers, ethylcellulose and/or Eudragit. For all tablets, the pharmacotechnical values support the pharmacopoeia norms. On fragments of tissue maintained in culture, the sodium fluoride is released at constant rate. The release profiles observed are predictable. No disintegration of tablets have been observed during release studies and after. Histological analyses performed after release studies showed the biocompatibility qualities of the tablets.

[Contribution of Parodium gel in an experimental model of human gingival inflammation]. / Intérêt du gel parodium dans un modèle d'inflammation expérimentale de la muqueuse gingivale humaine maintenue en survie.

INTRODUCTION: Our aim was to evaluate the effect of a gingival gel containing chlorhexidine and Rheum Palmatum extract on gingival fragments stimulated by SP (substance P) and lipopolysaccharides (LPS). MATERIALS AND METHODS: Gingival fragments were maintained in survival for 3 days at 37 degrees C. To induce inflammation, SP and LPS were applied to the culture medium in contact with the corium. The gingival gel was applied on epithelium. Histological analysis was then performed on hematoxylin and eosin stained slides. Edema was evaluated with semi-quantitative scores. Vasodilation was studied by counting the percent of dilated vessels according to scores and the surface of these dilated vessels by morphometrical image analysis. An inflammatory cytokine, IL8, was measured in culture supernatants. Immunohistochemical expression of metalloproteinase type 9 (MMP9) implicated in inflammatory processes, was also studied (% of positive cells). RESULTS: Edema, vasodilation and IL8 were significantly increased after application of SP and LPS. Application of gingival gel showed a significant decrease of these parameters. A significant decrease of MMP9 on fibroblasts and mononuclear cells was observed after use of gingival gel.

Inhibitory effect of oatmeal extract oligomer on vasoactive intestinal peptide-induced inflammation in surviving human skin.

The aim of this study was to evaluate the antiinflammatory effect of oatmeal extract oligomer on skin fragments stimulated by a neuromediator, vasoactive intestinal peptide (VIP). Skin fragments (from plastic surgery) were maintained in survival conditions for 6 h. To induce inflammation, VIP was placed in contact with dermis by culture medium. Histological analysis was then performed on hematoxylin- and eosin-stained slides. Edema was evaluated with semiquantitative scores. Vasodilation was studied by quantifying the percentage of dilated vessels according to scores and by measuring their surface by morphometrical image analysis. TNF-alpha dosage was made on culture supernatants. Vasodilation was significantly increased after application of VIP. After treatment with oatmeal extract oligomer, the mean surface of dilated vessels and edema were significantly decreased compared with VIP-treated skin. Moreover, treatment with this extract decreased TNF-alpha.

Histochemical and biochemical modifications induced by experimental irradiation of human skin maintained in survival conditions and modulation by application of an emulsion containing trolamine.

Radiotherapy continues to cause skin disorders. In this article, with the aid of our human skin model maintained in ex vivo survival conditions for 15 days, we describe the modifications caused by irradiation and their modulation by a trolamine-containing emulsion (Biafine). Normal human skin fragments were maintained in organ culture. One ionizing radiation session with 5 Gy was applied. Skin parameters were evaluated 24 h after the radiation session and were compared with a nonirradiated skin fragment: vascular modifications (histology), edema, epithelial proliferation, interleukin (IL)-1alpha and IL-6. Another series of skin fragments was maintained in survival conditions for 15 days after the radiation session to evaluate collagen neosynthesis by fibroblasts and any vascular changes (CD34). After irradiation the basal cell proliferation was reduced by approximately 50%. Extensive vasodilation occurred with altered capillary permeability accompanied by decreased CD34 transmembrane protein expression. Collagen synthesis and IL-1 secretion were increased. Biafine significantly reduced capillary alterations, restored CD34 expression as well as epithelial cell proliferation and significantly decreased collagen synthesis and IL-1 expression. With this ex vivo human skin model we confirmed the main modifications induced by radiotherapy as previously described in animal models: decreased basal cell proliferation and endothelial cell alterations and increased collagen synthesis by fibroblasts, probably under the influence of IL-1. The effect of Biafine emulsion on these histological and biochemical parameters may support its clinical efficacy.

Palmar erythema: cutaneous marker of neoplasms.

BACKGROUND: Acral erythema on the palms is observed in several conditions. However, the relationship with malignant tumors has only been reported exceptionally. It should be noted that tumors produce angiogenic mediators. OBJECTIVE: These mediators might promote palmar erythema (PE), and the aim of the present study was to investigate the vasodilation of palmar skin capillaries and angiogenesis, mainly with tumors of the central nervous system. METHODS: In a prospective study of 107 patients affected by brain tumors, we assessed PE clinically and the rate of dilated vessels histologically. We also evaluated the mean surface of the lumen of capillaries on skin biopsies and brain tumors. RESULTS: 6.5% of the patients had an important erythema and 18.5% had slight and/or localized PE. In the skin biopsies, the rate of dilated vessels and the mean surface of the lumen of capillaries were higher than in normal skin. Moreover, the intensity of palmar redness was related to the increase in these vascular changes in the histopathological slices of brain tumors. The intensity also depended on the type of tumor and on its growth. CONCLUSION: The results of the present study strongly suggest that acral erythema is associated with malignant tumors and that the intensity of erythema and the vascular changes of brain tumors are related, probably due to angiogenic factors.

Topical retinaldehyde treatment in oral lichen planus and leukoplakia.

The aim of this exploratory study was to assess the efficacy of a natural metabolite of vitamin A, retinaldehyde 0.1%, vehicled in a gel in 17 patients with oral lichen planus and in 13 patients with oral leukoplakia, twice daily for 2 months. Our investigation was clinical, histological, immunohistochemical through the expression of markers of cell terminal differentiation and biochemical by using two-dimensional gel electrophoresis of cytokeratins (CK). In addition, the activity of retinaldehyde was studied ex vivo on surviving buccal mucosa. Retinaldehyde gel 0.1% showed good clinical efficacy, resulting in 6% disappearance and 82% improvement of the lesions in lichen planus and 17% disappearance and 75% improvement in leukoplakia. This was confirmed with immunohistochemistry, which revealed down-regulation of filaggrin and CK-10 as markers of terminal differentiation in both diseases. The effects of retinaldehyde in these two diseases were further demonstrated in the ex vivo surviving mucosal model, resulting in histological disappearance of keratinization in 80% of the lichen planus fragments and 40% of the leukoplakia fragments, associated with down-regulation of filaggrin and CK-10.

Inhibitory effect of Avene spring water on vasoactive intestinal peptide-induced inflammation in surviving human skin.

The aim of this study was to evaluate the antiinflammatory effect of Avene spring water on skin fragments stimulated by a neuromediator, vasoactive intestinal peptide (VIP). Skin fragments (from plastic surgery) were maintained for 6 h. To induce inflammation, VIP was applied on contact with the dermis by culture medium. Cellulose patches containing Avene spring water were applied over the epidermis at the same time. Histological analysis was then performed on hematoxylin and eosin stained slides. Edema was evaluated with semiquantitative scores. Vasodilation was studied by calculating the percentage of dilated vessels according to scores and by measuring the surface of these dilated vessels by morphometrical image analysis. Tumor necrosis factor (TNF)-alpha dosage was made on culture supernatants. Edema was significantly increased after application of VIP compared with untreated skin. Treatment with cellulose patches containing Avene spring water showed decreased edema in comparison with cellulose patches containing distilled water. Vasodilation was significantly increased after application of VIP. After treatment with Avene spring water, the percentage and the surface of dilated vessels were significantly decreased. Moreover, treatment with cellulose patches containing Avene spring water showed a decrease in TNF-alpha compared with skins treated with VIP.

Repair of UVA-induced elastic fiber and collagen damage by 0.05% retinaldehyde cream in an ex vivo human skin model.

BACKGROUND: Cellular effects of UV exposure are implicated in cutaneous aging. UV radiations induce structural and cellular changes in all the compartments of skin. AIM: To study the antiaging efficacy of a cream containing 0.05% retinaldehyde with an ex vivo technique using human skin in order to approximate in vivo metabolic conditions. METHODS: Human skin explants were maintained alive in organ culture for 18 days and subjected to UVA exposure, thus simulating skin photoaging. Retinaldehyde cream was then applied to the surface of the epidermis for 2 weeks and the results were compared with those of nontreated skin explants. Dermal repair was analyzed histologically with quantification of collagen and elastic fibers, and biochemically by the measure of newly synthesized collagen as shown by adding tritiated proline to the culture medium. RESULTS: UVA exposure induced significant alterations of collagen and elastic fibers as shown by morphometric analysis. In all UVA-exposed and then retinaldehyde-treated skin specimens, collagen and elastic fibers were restored to the level of nonexposed skin. UVA exposure induced a decrease in collagen synthesis, whereas in retinaldehyde-treated UVA-exposed skin the synthesis was similar to that of unexposed skin. CONCLUSION: It has been shown that retinaldehyde has many of the properties of tretinoin in its biological and beneficial effects on photoaging. We have verified some of these previous observations, especially on dermal connective tissue, by obtaining significant repair of elastic fibers and collagen alteration induced by UVA exposure.

Neurogenic modifications induced by substance P in an organ culture of human skin.

Neurogenic inflammation of the skin observed after topical application of an irritant substance or environmental stimulation induces vascular changes and the production of inflammatory mediators. Substance P (SP) is one of the main neuropeptides which trigger an inflammatory response in the skin. So, with the aim to develop an alternative method to study neurogenic inflammation of the skin, we used an organ culture of human skin. SP was added onto epidermis or directly to culture medium in an attempt to reproduce ex vivo the effects described in vivo. Even disconnected from systemic blood circulation, in skin fragments in culture, we observed dose-dependent edema, vasodilation and extravasation of lymphocytes and mast cells through the microvascular wall. Moreover, the release of proinflammatory mediators interleukin 1alpha and tumor necrosis factor alpha was evidenced.