Quantificação de substâncias do fator de hidratação natural (NMF) do estrato córneo ex vivo em função do fototipo e idade / Ex vivo quantification of natural hydration factor (NMF) substances in the stratum corneum as a function of phototype and age

A hidratação cutânea ocorre, em parte, pelos componentes do Fator de Hidratação Natural (NMF), originados da degradação da filagrina, sendo alguns exemplos o ácido pirrolidona-carboxílico (PCA), o ácido urocânico (UCA) e a histidina (His). Estes estão presentes no estrato córneo (EC). O objetivo deste projeto de pesquisa foi determinar, por cromatografia líquida de alta eficiência (CLAE), o PCA, o UCA e a His no estrato córneo de participantes obtido por tape stripping em função do fototipo e idade do participante da pesquisa. Participantes foram selecionados em função da idade acima de 18 anos, ambos os gêneros e fototipo da pele entre I a VI, de acordo com a classificação de Fitzpatrick. As amostras do EC foram obtidas do antebraço volar por tape stripping e irradiadas artificialmente. A cromatografia líquida de alta eficiência (CLAE) foi eficaz para separação e quantificação adequada das substâncias químicas His, PCA e os isômeros de UCA (trans-UCA e cis-UCA) no estrato córneo dos participantes. O método apresentou-se seletivo e ausente de interferentes, ademais, possuiu linearidade e limites de detecção e quantificação compatíveis com os objetivos dessa investigação. No fototipo I, os níveis de His foram menores em comparação aos demais grupos. Ademais, os níveis dessa mesma substância não apresentaram diferença entre as faixas etárias. Em função da irradiação das amostras, o montante de His aumentou em todos os fototipos. Os níveis de PCA apresentaram-se menores após a irradiação em todos os fototipos de pele. Ainda, as concentrações do PCA foram mais elevadas na faixa etária de 46 a 55 anos de idade. Os níveis de concentração do isômero cis-UCA foram maiores nos participantes com fototipo III, após a irradiação UV. Os níveis de concentração do isômero trans-UCA diminuíram após a irradiação, de forma proporcional à formação de cis-UCA em todos os fototipos. A faixa etária de 46-55 anos de idade obteve níveis significativamente menores de trans-UCA e cis-UCA

Cutaneous hydration occurs, in part, by the components of the Natural Hydration Factor (MFN), originating from the degradation of filagrina, some examples being pyrrolidone-carboxylic acid (PCA), urocanic acid (UCA) and histidine (His). These are present in the stratum corneum (SC). The objective of this research project was to determine, by high efficiency liquid chromatography (HPLC), the PCA, UCA and His in the stratum corneum of participants obtained by tape stripping due to the phototype and age of the research participant. Participants were selected according to age above 18 years, both genders and skin phototype between I and VI, according to Fitzpatrick's classification. The SC samples were obtained from the volar forearm by tape stripping and artificially irradiated. High efficiency liquid chromatography (HPLC) was effective for the separation and proper quantification of the chemicals His, PCA and UCA isomers (trans-UCA and cis-UCA) in the stratum corneum of the participants. The method was selective and absent from interfering, in addition, it had linearity and limits of detection and quantification compatible with the objectives of this investigation. In phototype I, His levels were lower compared to the other groups. Moreover, the levels of this same substance showed no difference between age groups. Due to the irradiation of the samples, the amount of His increased in all phototypes. PCA levels were lower after irradiation in all skin phototypes. Furthermore, PCA concentrations were higher in the age group from 46 to 55 years of age. The concentration levels of the cis-UCA isomer were higher in participants with phototype III after UV irradiation. The concentration levels of the trans-UCA isomer decreased after irradiation, proportionally to the formation of cis-UCA in all phototypes. The age group 46-55 years of age obtained significantly lower levels of trans-UCA and cis-UCA

Inhibitory effects of epigallocatechin gallate on compound 48/80-inducedmast cell activation and passive cutaneous anaphylaxis

Epigallocatechin gallate (EGCG) is a principle phenolic antioxidant found in a variety of plants, including green and black tea. The anti-allergic effect of EGCG is unknown. The purpose of this study is to investigate the effects of EGCG on compound 48/80-induced mast cell activation and passive cutaneous anaphylaxis. For this, the influences of EGCG on the compound 48/80-induced cutaneous reaction were measured in vivo and the effects of EGCG on the compound 48/80-induced mast cell activations were examined in vitro. Results are below: as 1) EGCG significantly inhibited compound 48/80-induced passive cutaneous anaphylaxis, 2) the compound 48/80-induced degranulation, calcium influx and histamine release of rat peritoneal mast cells (RPMCs) were significantly inhibited by the pretreatment with EGCG, and 3) the compound 48/80-mediated inhibition of cAMP level in RPMCs was significantly increased by the pretreatment with EGCG. These results suggested that EGCG, the most abundant polyphenol in green tea, inhibits the compound 48/80-induced mast cell activation and the increase of vascular permeability, and potentially serve as effective therapeutic tools for allergic diseases.

Antiallergic/antiasthmatic effect of novel antiallergic hexapeptide-95/220 in various experimental models.

The effects of newly synthesized antiallergic hexapeptide 95/220 was investigated on various allergic and asthmatic test models. This newly developed peptide was found to be more potent than clinically used drug disodium cromoglycate (DSCG). Hexapeptide 95/220 inhibited immediate hypersensitivity reactions such as passive cutaneous anaphylaxis (PCA) and mast cell degranulation in rats, antigen-induced bronchoconstriction in actively sensitized guinea pigs in dose dependent manner like DSCG. Antigen-induced contraction of guinea pig ileum was also markedly inhibited by this newly developed hexapeptide in the same fashion as ketotifen and DSCG did but at comparatively lower dose. Egg albumin-induced histamine release was also blocked by this hexapeptide from chopped lung tissues of sensitized guinea pigs. These results suggest that hexapeptide' 95/220 has potent inhibitory effect on immediate hypersensitivity reactions thereby inhibiting mediator release from mast cell. Moreover, this newly synthesized peptide is orally active and effective at lower doses as compared to standard drugs.

Evaluation of E-721B, an indigenous herbal combination in experimental models of immediate hypersensitivity.

E-721B, an indigenous herbal combination was investigated for its usefulness in immediate hypersensitivity using different animal models. The drug inhibited the mast cell degranulation induced both by antigen and compound 48/80, the Schultz-Dale response in sensitized guinea pig ileum smooth muscle preparation and the production of precipitating antibodies in 50% of tested rats. It also inhibited the mast cell degranulation in passively sensitized rats indicating its suppressive action on production of reaginic antibody (IgE). However, the drug did not inhibit the 48 hours passive cutaneous anaphylaxis reaction in rats, indicating that a single dose of the drug does not have cromoglycate like properties. All the above results indicate the inhibitory effect of E-721B on immediate hypersensitive reactions such as asthma.

Antiallergic activity of alkyl substituted pyrazolo[3, 4-d]pyrimidine (compound 88-765).

Compound 88-765 (4-amino-6-methylthio-1-(2', 2'-diethoxyethyl)-1 H-pyrazolo[3, 4-d]pyrimidine) has shown potent antiallergic activity in experimental models. The compound inhibited the passive cutaneous anaphylaxis (PCA) reaction in rats in dose-dependent manner (5-100 mg/kg, po) by 47 to 87%. In mice it inhibited PCA by 78% at 50 mg/kg, po. It also inhibited mast cell degranulation of normal and passively sensitised rats induced by compound 48/80 and egg albumin, respectively. These effects of Compound 88-765 were comparable with that of disodium cromoglycate (DSCG). The results suggest that compound 88-765 possesses potent antiallergic activity.

Anti-anaphylactic and anti-inflammatory effects of ternatin, a flavonoid isolated from Egletes viscosa Less

Ternatin, a tetramethoxy flavone isolated from Egletes viscosa Less (Compositae), was tested for its efficacy in modulating mouse passive cutaneous anaphylaxis (PCA) and rat carrageenan-induced pleurisy. Ternatin (12.5, 25 and 50 mg/kg, ip) caused a dose-dependent inhibition of IgG antibody-mediated 1.5-h homologous PCA as well as IgE antibody-mediated 48-h homologous PCA in 2-month old mice (N = 5 per group). The inhibitory activity of ternatin was more potent on IgE-mediated PCA (47-79%) than on IgG (45-59%). In the rat carrageenan pleurisy test, ternatin (25 and 50 mg/kg, ip) reduced the response to carrageenan at 5 h both by decreasing exudate volume (33-40%) and leukocyte number (60%) in 5-6-month old rats (N = 6 per group). In contrast, indomethacin (2 mg/kg, po), a known cyclooxygenase inhibitor, showed greater potency in the inhibition of exudate volume (57%) and leukocyte number (77%). These results show that ternatin has both anti-inflammatory and anti-anaphylactic properties and suggest that it may be a useful alternative to anti-allergic drugs of the disodium cromoglycate (DSCG) type for use in bronchial asthma

Modulation of humoral immune responses by Tinospora malabarica in experimental animals.

Effect of alkaloidal fraction of aqueous extract of T. malabarica (Tm) was studied on humoral antibody responses in rats and guineapigs. The anti-SRBC haemagglutination titre was found to be enhanced in rats pretreated with Tm (2.5 mg/kg). Passive cutaneous anaphylaxis (PCA) in rats was also increased in Tm treated group. In vitro experiments with sensitized rat peritoneal mast cells showed a significant decrease in antigen-induced various spasmogens on isolated guineapig ileum.