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1.
Braz. J. Pharm. Sci. (Online) ; 56: e17560, 2020. tab, graf
Article Dans Anglais | LILACS | ID: biblio-1285514

Résumé

Urea's thermal instability and burning on sensitive skin can cause problems for cosmetic formulations. To overcome these drawbacks, urea was incorporated into ordered mesoporous silica (SBA-15). SBA-15 was synthesized using tetraethyl orthosilicate and Pluronic® P123 in an acid medium. Urea (20 wt.%) was incorporated into calcined SBA-15 by the incipient wetness impregnation method. Several techniques were used to characterize the samples. Skin hydration and transepidermal water loss were measured using Corneometer® CM 825 PC and Tewameter® 300 TM. Results showed that the structural properties of SBA-15Urea were similar to pure SBA-15, indicating that SBA-15 remained structured even after urea incorporation. Nitrogen physisorption data showed the volume and surface area of the pores in SBA-15Urea were much lower than those in SBA-15, demonstrating that urea was deposited inside the mesopores. In vivo moisturization studies revealed that SBA-15Urea was not able to reduce transepidermal water loss compared to the other products and control, while forming a non-occlusive surface film on the skin. We conclude that incorporation of urea in the pores of the inorganic SBA-15 matrix is a promising approach to enhancing its stability and providing a prolonged moisturizing effect.


Sujets)
Urée/analyse , Silice/administration et posologie , Peau/effets des médicaments et des substances chimiques , Traitement par apport liquidien/effets indésirables
2.
Mem. Inst. Oswaldo Cruz ; 102(6): 769-772, Sept. 2007. graf
Article Dans Anglais | LILACS | ID: lil-463483

Résumé

Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 mug/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 mumols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 mug/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.


Sujets)
Animaux , Souris , Antibiotiques antituberculeux/pharmacologie , Dilleniaceae/composition chimique , Macrophages/microbiologie , Mycobacterium tuberculosis/effets des médicaments et des substances chimiques , Antibiotiques antituberculeux/isolement et purification , Peroxyde d'hydrogène/métabolisme , Tests de sensibilité microbienne , Macrophages/métabolisme , Monoxyde d'azote/biosynthèse , Extraits de plantes/pharmacologie , Facteur de nécrose tumorale alpha/biosynthèse
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