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Background: Parasitic infections affecting the central nervous system (CNS) present high morbidity and mortality rates and affect millions of people worldwide. The most important parasites affecting the CNS are protozoans (Plasmodium sp., Toxoplasma gondii, Trypanosoma brucei), cestodes (Taenia solium) and free-living amoebae (Acantamoeba spp., Balamuthia mandrillaris and Naegleria fowleri). Current therapeutic regimens include the use of traditional chemicals or natural compounds that have very limited access to the CNS, despite their elevated toxicity to the host. Improvements are needed in drug administration and formulations to treat these infections and to allow the drug to cross the blood-brain barrier (BBB). Methods: This work aims to elucidate the recent advancements in the use of nanoparticles as nanoscaled drug delivery systems (NDDS) for treating and controlling the parasitic infections that affect the CNS, addressing not only the nature and composition of the polymer chosen, but also the mechanisms by which these nanoparticles may cross the BBB and reach the infected tissue. Results: There is a strong evidence in the literature demonstrating the potential usefulness of polymeric nanoparticles as functional carriers of drugs to the CNS. Some of them demonstrated the mechanisms by which drugloaded nanoparticles access the CNS and control the infection by using in vivo models, while others only describe the pharmacological ability of these particles to be utilized in in vitro environments. Conclusion: The scarcity of the studies trying to elucidate the compatibility as well as the exact mechanisms by which NDDS might be entering the CNS infected by parasites reveals new possibilities for further exploratory projects. There is an urgent need for new investments and motivations for applying nanotechnology to control parasitic infectious diseases worldwide.

Objeti vo: Verifi car, in vitro, o efeito anti microbiano do pólen e dos extratos alcoólico e aquoso da própolis em suas formas pura e diluídas sobre cepas de referência Streptococcus mutans ATCC 25175, Streptococcus salivarius ATCC 7073, Streptococcus miti s ATCC 903 e Lactobacillus casei ATCC 9595 pela determinação da Diluição Inibitória Máxima (DIM). Método: Uti lizou-se a clorexidina como controle positi vo e água desti lada e álcool de cereais 70% como controles negati vos. Efetuou-se a diluição das soluções de 1:1 até 1:64 dos extratos alcoólico e aquoso da própolis diluídos em álcool 70% e água desti lada, respecti vamente. O pólen foi diluído em álcool, por ser uma substancia apolar, nas concentrações de 5% (quanti dade presente na composição química da própolis) e 50%. Cada linhagem bacteriana foi reati vada em caldo nutriti vo Brain Heart Infusion (BHI) e semeadas as placas com auxílio de swabs, procedendo-se com testes de susceti bilidade, em duplicata, por meio do método da difusão em ágar e técnica do ágar recortado. Em seguida, foram incubadas a 37°C, em microaerofi lia, por 48h. Resultados: Constatou-se que todas as diluições da própolis alcoólica inibiram o crescimento bacteriano enquanto a própolis aquosa mostrou os menores resultados tendo efeito apenas sobre S. miti s na forma pura e nas diluições de 1:1 até 1:4. O pólen a 5% foi efi ciente sobre todas as bactérias, porém o pólen a 50% teve ação apenas sobre S. miti s. Os controles negati vos não apresentaram ati vidade. Conclusão: Apesar da própolis e do pólen apresentarem ati vidade anti microbiana contra as cepas de referência superior à do placebo, esta, porém, foi inferior à da clorexidina. Objecti ve: To evaluate, in vitro, the anti microbial eff ect of pollen and alcoholic and aqueous propolis extracts in their pure and diluted forms against reference strains Streptococcus mutans ATCC 25175, Streptococcus salivarius ATCC 7073, Streptococcus miti s ATCC 903 and Lactobacillus casei ATCC 9595, by determinati on of Maximum Inhibitory Diluti on (MID). Methods: Chlorhexidine was used as a positi ve control and disti lled water and 70% grain alcohol as negati ve controls. The alcoholic and aqueous propolis extracts were subjected to diluti ons from 1:1 to 1:64 in 70% alcohol and disti lled water, respecti vely. For being an apolar substance, pollen was diluted in alcohol at the concentrati ons of 5% (amount present in the chemical compositi on of propolis) and 50%. Each bacterial strain was reacti vated in Brain Heart Infusion (BHI) broth and seeded onto plates with swabs, and the suscepti bility tests were performed in duplicate by the agar diff usion method using the agar well technique. Next, the plates were incubated at 37°C in microaerophilia during 48 hours. Results: All diluti ons of alcoholic propolis extract inhibited the bacterial growth while the aqueous propolis extract showed less effi cient results, being eff ecti ve only against S. miti s in its pure form and in the 1:1 to 1:4 diluti ons. Pollen at 5% was effi cient against all b...

: Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins have been found to be promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.

Background: Plant extracts loaded in nanostructured drug delivery systems (NDDSs) have been reported as an alternative to current therapies for treating parasitic and antimicrobial diseases. Among their advantages, plant extracts in NDSSs increase the stability of the drugs against environmental factors by promoting protection against oxygen, humidity, and light, among other factors; improve the solubility of hydrophobic compounds; enhance the low absorption of the active components of the extracts (i.e., biopharmaceutical classification II), which results in greater bioavailability; and control the release rate of the substances, which is fundamental to improving the therapeutic effectiveness. In this review, we present the most recent data on NDDSs using plant extracts and report results obtained from studies related to in vitro and in vivo biological activities.

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Background: The high surface-to-volume ratio of polymeric nanofibers makes them an effective vehicle for the release of bioactive molecules and compounds such as growth factors, drugs, herbal extracts and gene sequences. Synthetic polymers are commonly used as sensors, reinforcements and energy storage, whereas natural polymers are more prone to mimicking an extracellular matrix. Natural polymers are a renewable resource and classified as an environmentally friendly material, which might be used in different techniques to produce nanofibers for biomedical applications such as tissue engineering, implantable medical devices, antimicrobial barriers and wound dressings, among others. This review sheds some light on the advantages of natural over synthetic polymeric materials for nanofiber production. Also, the most important techniques employed to produce natural nanofibers are presented. Moreover, some pieces of evidence regarding toxicology and cell-interactions using natural nanofibers are discussed. Clearly, the potential extrapolation of such laboratory results into human health application should be addressed cautiously.