Bioactive Marine Drugs and Marine Biomaterials for Brain Diseases

Marine invertebrates produce a plethora of bioactive compounds, which serve as inspiration for marine biotechnology, particularly in drug discovery programs and biomaterials development. This review aims to summarize the potential of drugs derived from marine invertebrates in the field of neuroscience. Therefore, some examples of neuroprotective drugs and neurotoxins will be discussed. Their role in neuroscience research and development of new therapies targeting the central nervous system will be addressed, with particular focus on neuroinflammation and neurodegeneration. In addition, the neuronal growth promoted by marine drugs, as well as the recent advances in neural tissue engineering, will be highlighted.     

Bioactive Compounds from Macroalgae in the New Millennium: Implications for Neurodegenerative Diseases

Marine environment has proven to be a rich source of structurally diverse and complex compounds exhibiting numerous interesting biological effects. Macroalgae are currently being explored as novel and sustainable sources of bioactive compounds for both pharmaceutical and nutraceutical applications. Given the increasing prevalence of different forms of dementia, researchers have been focusing their attention on the discovery and development of new compounds from macroalgae for potential application in neuroprotection. Neuroprotection involves multiple and complex mechanisms, which are deeply related. Therefore, compounds exerting neuroprotective effects through different pathways could present viable approaches in the management of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. In fact, several studies had already provided promising insights into the neuroprotective effects of a series of compounds isolated from different macroalgae species. This review will focus on compounds from macroalgae that exhibit neuroprotective effects and their potential application to treat and/or prevent neurodegenerative diseases.     

Quinone and Hydroquinone Metabolites from the Ascidians of the Genus Aplidium

Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the ¹³C-NMR spectral data of these compounds is also presented.     

Molecular evaluation of the incidence of Ehrlichia canis, Anaplasma platys and Babesia spp. in dogs from Ribeirão Preto, Brazil

Canine monocytic ehrlichiosis caused by Ehrlichia canis is endemic in many regions of Brazil. Since thrombocytopenia is a common finding in infected dogs, many clinicians tend to use it as an indication for antibiotic treatment. Polymerase chain reaction (PCR) and nested PCR were used to study the presence of E. canis, Anaplasma platys and Babesia spp. in thrombocytopenic and non-thrombocytopenic dogs from Ribeirão Preto, Brazil. Despite the high prevalence of E. canis infection among thrombocytopenic dogs, 46.7% of the thrombocytopenic dogs studied were either infected with Babesia spp. or A. platys or not infected with any of the three pathogens. There was a high incidence (25.4%) of E. canis infection in non-thrombocytopenic dogs. Although infection with E. canis should be considered in thrombocytopenic dogs, the final diagnosis needs to be confirmed by complementary tests such as blood smears and PCR to avoid the unnecessary use of antibiotics.     

Disseminated Mycobacterium avium subsp. avium infection in a Captive Richardson's Ground Squirrel (Spermophilus richardsonii)

Although mycobacteria have been isolated from rodents, overt mycobacteriosis is rare in any rodent species. A pet adult male Richardson's ground squirrel (Spermophilus richardsonii) died after a short course of alopecia, anorexia, and weight loss. Necropsy and subsequent histopathological examination of tissue samples revealed disseminated granulomatous inflammation involving the lungs, lymph nodes, liver, intestine, adrenal gland, spleen, pleura, and peritoneum. Ziehl-Neelsen stain revealed high numbers of acid-fast bacilli within the cytoplasm of macrophages and multinucleated giant cells. Polymerase chain reaction performed on paraffin-embedded tissues was positive for Mycobacterium avium subsp. avium and negative for M. bovis-tuberculosis complex. Three females housed with this squirrel remained clinically healthy, and mycobacterial cultures of pooled feces from these animals were negative. To the authors' knowledge, this is the second report of disseminated mycobacteriosis in squirrels involving M. avium subsp. avium, with both cases described recently in the Iberian Peninsula.