This review focuses on the description of macromolecular gels formed as a result of polymerization, under freezing conditions, from monomer solutions. Materials resulting from this polymerization are known as cryogels and have particular properties, such as porosity of a specific nature. They are attractive in terms of biotechnological applications. The cryogels have interconnected macropores, and their preparation method from aqueous solutions in freezing conditions is a process that combines the crystallization of a solvent with the copolymerization of monomers. Cryogels have recently been used as adsorbents for the efficient separation and purification of biomacromolecules, such as proteins, DNA, cell organelles, viruses and enzymes that are present in solutions. Despite the wide application of cryogels, improvements in their preparation are necessary to minimize problems, such as the formation of hydrogels, instead of cryogels. Hydrogels form due to immediate polymerization after addition of the redox initiator before solvent freezing. The synthesis and use of cryogels as chromatographic supports are also discussed.
22 September 2013 in BioMed Research International
Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2(PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.
This study aimed to chemically characterize the pulps of the tropical fruits araticum (Annona crassiflora), buriti (Mauritia flexuosa), coquinho azedo (Butia capitata), cagaita (Eugenia dysenterica), and cajá (Spondias mombin), with a focus on antioxidant potential and microminerals. Calcium levels in the Araticum pulp are 9.35 mg/100 g and the iron content was 4.78 mg/100 g. In cagaita pulp, the calcium content was 15.35 mg/100 g and magnesium content was 66.00 mg/100 g. The iron content present in coquinho pulp was 11.47 mg/100 g and in cagaita it was 11.53 mg/100 g. The extracts with the highest contents of total phenolic compounds were araticum (433.80 mg GAE/g) and coquinho (173.5 mg GAE/g). Araticum pulp had the highest antioxidant potential because it had the lowest EC50 (0.04 mg/mL). The results presented here demonstrate the great potential of the fruits of the Cerrado in terms of rich mineral nutrients and bioactive compounds.