Chemical Composition, Antioxidant, and Antimicrobial Activities of Lichen Umbilicaria cylindrica (L.) Delise (Umbilicariaceae).

The phytochemical analysis of methanol and chloroform extracts of Umbilicaria cylindrica was determined by HPLC-UV method. The predominant phenolic compound in both extracts was depsidone, salazinic acid (1). Besides salazinic acid, the tested extracts of U. cylindrica contain norstictic acid (2), methyl-ß-orcinol carboxylate (3), ethyl haematommate (4), atranorin (5), and usnic acid (6), in different amounts and relations. The lichen extracts showed comparable and strong antioxidant activity, exhibited higher DPPH and hydroxyl radical scavengings, chelating activity, and inhibitory activity towards lipid peroxidation. The lichen extracts demonstrated important antimicrobial activity against eight strains with MIC values from 15.62 to 62.50 µg/mL. This is the first report of the detail chemical composition and antioxidant activity of the lichen Umbilicaria cylindrica, and the results suggest that this lichen can be used as a new source of the natural antioxidants and the substances with antimicrobial features.

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand.

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identified by relative retention time and spectral data. This is the first time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic significance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the first time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity.

Osteogenic capacity of diluted platelet-rich plasma in ectopic bone-forming model: Benefits for bone regeneration.

Platelet-rich plasma (PRP) with normal and below-normal physiological concentrations of platelets is designated as diluted PRP (dPRP). The aims of this study are to evaluate whether bone mineral matrix in combination with dPRP possesses osteogenic capacity; and whether the differences in dynamics and osteogenic process pattern depend on different platelet concentrations, to what extent, and also what could be benefits for bone regeneration in clinical practice. Three types of implants were made: BMM-bone mineral matrix alone; dPRP/10-bone mineral matrix mixed with dPRP (concentration of platelets 10 times lower than physiological level) and dPRP/3-bone mineral matrix mixed with dPRP (concentration of platelets 3 times lower than physiological level). A subcutaneous implantation model in Balb/c mice was used. The implants were analyzed using expression analysis of bone-related genes, histochemical, immunohistochemical and histomorphometrical analysis. All types of implants induced creation of necessary preconditions for supporting osteogenic processes, but did not induce visible young bone growth. Implant types dPRP/10 and dPRP/3 showed very similar and significantly better stimulatory effects on osteogenic processes than bone matrix alone. In this study, significant ectopic osteogenic potential of concentration of platelets in PRP that are lower than physiological level in blood plasma in combination with bone mineral matrix was demonstrated. Diluted platelet-rich plasma could be a promising and useful adjuvant therapeutic agent in bone regeneration.

Apatite formation on nanomaterial calcium phosphate/poly-DL-lactide-co-glycolide in simulated body fluid.

UNLABELLED: Simulated body fluid (SBF) is an artificial fluid which has ionic composition and ionic concentration similar to human blood plasma. PURPOSE: This paper compares the interaction between the nanomaterial containing calcium phosphate/poly-dl-lactide-co-glycolide (N-CP/PLGA) and SBF, in order to investigate whether and to what extent inorganic ionic composition of human blood plasma leads to the aforementioned changes in the material. METHODS: N-CP/PLGA was incubated for 1, 2, 3, and 5 weeks in SBF. The surface of the material was analyzed on SEM-EDS and FTIR spectrometer, while SBF was subjected to pH and electrical conductivity measurement. RESULTS: Our results indicate that dissolution of the polymer component of the material N-CP/PLGA and precipitation of the material similar to hydroxyapatite on its surface are based on the morphologic changes seen in this material. CONCLUSIONS: The mechanism of the apatite formation on the bioceramic surface was intensively studied and was considered crucial in designing the new biomaterials. The results obtained in this work indicate that N-CP/PLGA may be a good candidate for application to bone regeneration.

Chemical composition and antioxidant activity of lichen Toninia candida

In the present investigation, methanol, chloroform and petrol ether extracts from the lichen Toninia candida (Weber) Th. Fr, Catillariaceae, were assayed for their antioxidant activity. The phenolic composition of the extracts was determined by HPLC-UV analysis. The predominant phenolic compound in all the extracts was depsidone, norstictic acid. All the tested extracts of T. candida contain, besides norstictic acid, atranorin, stictic, protocetraric and usnic acid, but in different amounts and relations. The lichen extracts showed comparable and strong antioxidant activity, exhibited higher DPPH and hydroxyl radical scavengings, chelating activity and inhibitory activity towards lipid peroxidation. This is the first report of chemical composition and antioxidant antimicrobial activity of the lichen Toninia candida.

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity.