Publications by authors named "Miguel Puertas-Mejia"

Osteosarcoma is a bone cancer primarily affecting teenagers. It has a poor prognosis and diminished quality of life after treatment due to chemotherapy side effects, surgical complications and post-surgical osteoporosis risks. The sulphated polysaccharide fucoidan, derived from brown algae, has been a subject of interest for its potential anti-cancer properties and its impact on bone regeneration.

View Article and Find Full Text PDF

Chemotherapy is a widely used strategy to treat cancer, a disease that causes millions of deaths each year. However, its efficacy is reduced by the overexpression of ABC transporters, which are proteins that expel the drugs used in chemotherapy and involved in the multidrug resistance (MDR). Glycolipids have been identified as potential inhibitors of ABC transporters.

View Article and Find Full Text PDF

The antioxidant and the potential inhibitory capacity of matrix metalloproteinases of the phlorotannin-type polyphenolic and fucoidan-type polysaccharides extracts obtained from the macroalga were evaluated. Through chromatographic and spectroscopic techniques, the corresponding chemical structure of compounds present in the extracts was determined. Antioxidant capacity was evaluated using the methyl linoleate model for the inhibition of lipid peroxidation, and the free radical scavenging capacity was assessed using DPPH, ABTS, OH, O methods.

View Article and Find Full Text PDF

Overexposure to solar radiation has become an increasingly worrying problem due to the damage to the skin caused by ultraviolet radiation (UVR). In previous studies, the potential of an extract enriched with glycosylated flavonoids from the endemic Colombian high-mountain plant as a photoprotector and antioxidant was demonstrated. Therefore, in this work we sought to develop a dermocosmetic formulation with broad-spectrum photoprotection from the hydrolysates and purified polyphenols obtained from this species.

View Article and Find Full Text PDF

Wild mushrooms have gained great importance for being a source of biologically active compounds. In this work, we evaluate the anticancer and antioxidant activity of a water-soluble crude polysaccharide extract isolated from the fruiting bodies of the aff. (GACP).

View Article and Find Full Text PDF

The fruiting bodies of edible mushrooms represent an important source of biologically active polysaccharides. In this study, crude polysaccharides (LECP) were extracted in hot water, and their antioxidant and antiradical activities were investigated. The antioxidant activity of LECP was investigated against reactive species such as 1,1'-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, hydroxyl and superoxide anion radicals, reducing power with EC values of 0.

View Article and Find Full Text PDF

The aim of this study was to develop a new hybrid biomaterial that could photo-stabilize and improve the photoprotective capacity of a extract. Different combinations of lignin/gelatin/natural extract were applied to prepare hybrid biomaterial nanoparticles (NPs), which were then incorporated into an emulsion. The in vitro photoprotection and photostability were evaluated.

View Article and Find Full Text PDF

Most of the plant species found in the high mountain ecosystems of the tropics is unique and exceptional, because they have developed complex adaptations to survive in extreme environmental conditions, such as high levels of UVR and low temperatures of these ecological environments. In an exploratory study carried out on some plants of this ecosystem, we found that one of the most promising species was the Pentacalia pulchella (Kunth) Cuatrec. (Asteraceae) an endemic plant of Colombia, which grows between 2500 and 3500 m.

View Article and Find Full Text PDF

The photoprotective and antioxidant activities of extracts of six species of plants collected in a high mountain ecosystem at 3150 m.a.s.

View Article and Find Full Text PDF

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from and , and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in crude fucoidan compared to crude fucoidan.

View Article and Find Full Text PDF

Synthetic antioxidants are used in the food and pharmaceutical industry, however, there is concern about their safety; this has prompted the search for new antioxidants that are effective, safe and act at low concentrations. The objective of this study is to evaluate the oxygen radical scavenging capacity and clastogenic effect of the Isoespintanol /2-isopropyl-3,6-dimethyl-5-methylphenol) in DNA of human lymphocyte compared with the BHA (Butylated hydroxyanisole). The oxygen radical scavenging ability was evaluated by methods ORACFL and ORACPGR, genotoxicity was determined by comet assay and data analysis was performed using ANOVA and Duncan test.

View Article and Find Full Text PDF

In the quest for new natural agents of photoprotection, we evaluated the photoprotective and antioxidant activity of B. antioquensis leaf extracts as well as its phenolic composition. The methanolic extract treated with activated carbon showed the highest absorption coefficients for UVA-UVB radiation, as well as an antioxidant capacity comparable to butylated hydroxy toluene.

View Article and Find Full Text PDF

Currently, plants have gained widespread interest as a source of natural sunscreen. Specifically, plants from high altitude ecosystems are exposed to high UVR levels; therefore, they must produce an adaptive chemical response. The aim of this study was to evaluate the photo-protection and antioxidant capacity in vitro of nine plants from high altitude ecosystems in Antioquia, Colombia (Sphagnum meridense, Calamagrostis effusa, Lycopodiella alopecuroides, Morella parvifolia, Baccharis antioquensis, Pentacalia pulchella, Castilleja fissifolia, Hesperomeles ferruginea and Hypericum juniperinum).

View Article and Find Full Text PDF

Nine root-nodulating bacterial isolates were obtained from the leguminous shrubs Spartium junceum, Adenocarpus hispanicus, Cytisus purgans, Cytisus laburnuum, Retama sphaerocarpa and Colutea arborescens in areas of Central Spain. A poliphasic approach analyzing phenotypic, symbiotic and genetic properties was used to study their diversity and characterize them in relation to Mediterranean conditions. Stress tolerance assays revealed marked variations in salinity, extreme pH and cadmium tolerance compared with reference strains, with the majority showing salinity, alkalinity and Cd tolerance and three of them growing at acid pH.

View Article and Find Full Text PDF

A method for selective extraction using SPE, electrophoretic separation at basic condition and the identification by using exact masses and fragmentation patterns has been developed in order to know the anthocyanins in dried calyces of Hibiscus sabdariffa L. A detailed and comparative study of several extraction procedures has been carried out to obtain the maximum number of anthocyanidins from the calyces and then a CE-TOF-MS method in positive mode using ESI has been developed for the separation and rapid identification of anthocyanins in H. sabdariffa L.

View Article and Find Full Text PDF