Résumé
Abstract The histological structure and biochemistry of the skin is affected by solar radiation having adverse effects ranging from sunburns, premature aging that includes wrinkles, spots, dryness, and loss of collagen to cancer development. The skin has defense mechanisms to prevent damage caused by radiation, but when radiation exposure is excessive these mechanisms are not strong enough to protect the skin. The use of sunscreen is the most common practice of photo- protection. The active ingredients of these cosmetic protective formulations are generally from synthetic origin and have presented several drawbacks at the level of photo-stability, systemic absorption and can generate contact and photo-contact dermatitis. This review illustrates skin solar radiation problems, common sunscreen ingredients limitation and mentions how algae can be an alternative according to studies that have evaluated the photo-protective potential of extracts and compounds isolated by different techniques.
Sujets)
Peau/anatomopathologie , Produits antisolaires/administration et posologie , Radiation Solaire , Algue marine/classification , Maladies de la peau , Collagène/administration et posologie , Exposition aux rayonnements/prévention et contrôle , Absorption physiologique/effets des médicaments et des substances chimiquesRésumé
OBJECTIVE:To study on the phlorotannins in Ecklonia kurome. METHODS:Silica gel column chromatography and Sephadex LH-20 column chromatography were conducted for isolation and identification of phlorotannins,and the compound structures were analyzed and identified based on physicochemical properties and spectral data. RESULTS:Totally 7 phlorotannins were isolated from E. kurome,namely Phloroglucinol(1),Eckol(2),Fucodiphloroethol G(3),Phlorofucofuroeckol A(4),1-(3′, 5′-dihydro-xyphenoxy)-7-(2″,4″,6-trihydro-xyphenoxy)-2,4,9-trihydroxydibenzo-1,4-dioxin(5),Dieckol(6)and 6,6′-bieckol (7). CONCLUSIONS:Compound 5 and 7 are isolated from E. kurome for the first time,and the study has laid a foundation for its quality evaluation.
Résumé
Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotannins extracts (CPEs) obtained from Sargassum hemiphyllum (SH) and fractionated according to the molecular weights. When CPEs were administrated at a dose of 30 mg/kg to Kunming mice pre-treated with carbon tetrachloride (CCl4), the levels of oxidative stress indicators in the liver, kidney and brain were significantly reduced in vivo. All the components of various molecular weight fractions of CPEs exhibited greater scavenging capacities in clearing hydroxyl free radical and superoxide anion than the positive controls gallic acid, vitamin C and vitamin E. Particularly, the components greater than 30 kD obtained from ethyl acetate phase showed the highest antioxidant capacities. These results indicated that SH is a potential source for extracting phlorotannins, the algal antioxidant compounds.
Sujets)
Animaux , Mâle , Souris , Antioxydants , Pharmacologie , Acide ascorbique , Pharmacologie , Encéphale , Métabolisme , Anatomopathologie , Tétrachloro-méthane , Toxicité , Intoxication au tétrachlorure de carbone , Traitement médicamenteux , Métabolisme , Anatomopathologie , Fractionnement chimique , Méthodes , Acide gallique , Pharmacologie , Radical hydroxyle , Métabolisme , Rein , Métabolisme , Anatomopathologie , Extraction liquide-liquide , Méthodes , Foie , Métabolisme , Anatomopathologie , Lignées consanguines de souris , Oxydoréduction , Stress oxydatif , Phaeophyceae , Chimie , Sargassum , Chimie , Superoxydes , Métabolisme , Tanins , Pharmacologie , Vitamine E , PharmacologieRésumé
Marine algae have been utilized in food as well as medicine products for a variety of purposes. The purpose of this study was to determine whether an ethanol extract of Polyopes affinis (P.affinis) can inhibit the pathogenesis of T helper 2 (Th2)-mediated allergen-induced airway inflammation in a murine model of asthma. Mice that were sensitized and challenged with ovalbumin (OVA) evidenced typical asthmatic reactions such as the following: an increase in the number of eosinophils in the bronchoalveolar lavage (BAL) fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways as well as the narrowing of the airway luminal; the development of airway hyperresponsiveness (AHR); the presence of pulmonary Th2 cytokines; and the presence of allergenspecific immunoglobulin E (IgE) in the serum. The successive intraperitoneal administration of P. affinis ethanolic extracts before the last airway OVA-challenge resulted in a significant inhibition of all asthmatic reactions. These data suggest that P. affinis ethanolic extracts possess therapeutic potential for the treatment of pulmonary allergic disorders such as allergic asthma.
Résumé
Objective To investigate the anticoagulant activities of phlorotannins STP-1 and STP-2 from Sargassum thunbeergii Kuntze.Methods Coagulation time(CT)and bleeding time(BT)of mice were determined by in-vivo experiment to test the effect of phlorotannins by capillary method and cutting tail method respectively.Furthermore,activated partial thromboplastin time(APTT),prothrombin time(PT)and thrombin time(TT)were measured to evaluate the in-vitro anticoagulant activity of phlorotannins on New Zealand rabbits.Results Phlorotannins STP-1 had a significant effect on the prolongation of CT,BT,APTT,PT and TT,especially at the dosage of 1.0 mg/mL.Conclusion Phlorotannins STP-1 has both in-vivo and in-vitro anticoagulant activity.