Marine Drugs: Implication and Future Studies

Functional Metagenomics as a Tool to Tap into Natural Diversity of Valuable Biotechnological Compounds

The marine ecosystem covers more than 70% of the world's surface, and oceans represent a source of varied types of organisms due to the diversified environment. Consequently, the marine environment is an exceptional depot of novel bioactive natural products, with structural and chemical features generally not found in terrestrial habitats. Here, in particular, microbes represent a vast source of unknown and probably new physiological characteristics. They have evolved during extended evolutionary processes of physiological adaptations under various environmental conditions and selection pressures. However, to date, the biodiversity of marine microbes and the versatility of their bioactive compounds and metabolites have not been fully explored. Thus, metagenomic tools are required to exploit the untapped marine microbial diversity and their bioactive compounds. This chapter focuses on function-based marine metagenomics to screen for bioactive molecules of value for biotechnology. Functional metagenomic strategies are described, including sampling in the marine environment, constructing marine metagenomic large-insert libraries, and examples on function-based screens for quorum quenching and anti-biofilm activities.

Strategies for managing marine disease

The incidence of emerging infectious diseases (EIDs) has increased in wildlife populations in recent years and is expected to continue to increase with global environmental change. Marine diseases are relatively understudied compared with terrestrial diseases but warrant parallel attention as they can disrupt ecosystems, cause economic loss, and threaten human livelihoods. Although there are many existing tools to combat the direct and indirect consequences of EIDs, these management strategies are often insufficient or ineffective in marine habitats compared with their terrestrial counterparts, often due to fundamental differences between marine and terrestrial systems. Here, we first illustrate how the marine environment and marine organism life histories present challenges and opportunities for wildlife disease management. We then assess the application of common disease management strategies to marine versus terrestrial systems to identify those that may be most effective for marine disease outbreak prevention, response, and recovery. Finally, we recommend multiple actions that will enable more successful management of marine wildlife disease emergencies in the future. These include prioritizing marine disease research and understanding its links to climate change, improving marine ecosystem health, forming better monitoring and response networks, developing marine veterinary medicine programs, and enacting policy that addresses marine and other wildlife diseases. Overall, we encourage a more proactive rather than reactive approach to marine wildlife disease management and emphasize that multidisciplinary collaborations are crucial to managing marine wildlife health.

Bioactive Compounds and Nanodelivery Perspectives for Treatment of Cardiovascular Diseases

Bioactive compounds are comprised of small quantities of extra nutritional constituents providing both health benefits and enhanced nutritional value, based on their ability to modulate one or more metabolic processes. Plant-based diets are being thoroughly researched for their cardiovascular properties and effectiveness against cancer. Flavonoids, phytoestrogens, phenolic compounds, and carotenoids are some of the bioactive compounds that aim to work in prevention and treating the cardiovascular disease in a systemic manner, including hypertension, atherosclerosis, and heart failure. Their antioxidant and anti-inflammatory properties are the most important characteristics that make them favorable candidates for CVDs treatment. However, their low water solubility and stability results in low bioavailability, limited accessibility, and poor absorption. The oral delivery of bioactive compounds is constrained due to physiological barriers such as the pH, mucus layer, gastrointestinal enzymes, epithelium, etc. The present review aims to revise the main bioactive compounds with a significant role in CVDs in terms of preventive, diagnostic, and treatment measures. The advantages of nanoformulations and novel multifunctional nanomaterials development are described in order to overcome multiple obstacles, including the physiological ones, by summarizing the most recent preclinical data and clinical trials reported in the literature. Nanotechnologies will open a new window in the area of CVDs with the opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues.

Box Jellyfish (Cnidaria, Cubozoa) Extract Increases Neuron's Connection: A Possible Neuroprotector Effect

Neurodegenerative diseases are one of the major causes of death worldwide, characterized by neurite atrophy, neuron apoptosis, and synapse loss. No effective treatment has been indicated for such diseases so far, and the search for new drugs is being increased in the last years. Animal venoms' secretion/venom can be an alternative for the discovery of new molecules, which could be the prototype for a new treatment. Here, we present the biochemical characterization and activity of the extract from the box jellyfish Chiropsalmus quadrumanus (Cq) on neurites. The Cq methanolic extract was obtained and incubated to human SH-SY5Y neurons, and neurite parameters were evaluated. The extract was tested in other cell types to check its cytotoxicity and was submitted to biochemical analysis by mass spectrometry in order to check its composition. We could verify that the Cq extract increased neurite outgrowth length and branching junctions, amplifying the contact between SH-SY5Y neurons, without affecting cell body and viability. The extract action was selective for neurons, as it did not cause any effects on other cell types, such as tumor line, nontumor line, and red blood cells. Moreover, mass spectrometry analysis revealed that there are no proteins but several low molecular mass compounds and peptides. Three peptides, characterized as cryptides, and 14 low molecular mass compounds were found to be related to cytoskeleton reorganization, cell membrane expansion, and antioxidant/neuroprotective activity, which act together to increase neuritogenesis. After this evaluation, we conclude that the Cq extract is a promising tool for neuronal connection recovery, an essential condition for the treatment of neurodegenerative diseases.

Marine microorganisms as an untapped source of bioactive compounds

The search for novel biologically active molecules has extended to the screening of organisms associated with less explored environments. In this sense, Oceans, which cover nearly the 67% of the globe, are interesting ecosystems characterized by a high biodiversity that is worth being explored. As such, marine microorganisms are highly interesting as promising sources of new bioactive compounds of potential value to humans. Some of these microorganisms are able to survive in extreme marine environments and, as a result, they produce complex molecules with unique biological interesting properties for a wide variety of industrial and biotechnological applications. Thus, different marine microorganisms (fungi, myxomycetes, bacteria, and microalgae) producing compounds with antioxidant, antibacterial, apoptotic, antitumoral and antiviral activities have been already isolated. This review compiles and discusses the discovery of bioactive molecules from marine microorganisms reported from 2018 onwards. Moreover, it highlights the huge potential of marine microorganisms for obtaining highly valuable bioactive compounds.

Characterization of (2E,6E)-3,7,11-Trimethyldodeca-2,6,10-Trien-1-Ol with Antioxidant and Antimicrobial Potentials from <i>Euclea Crispa</i> (Thunb.) Leaves

(2E,6E)-3,7,11-Trimethyldodeca-2,6,10-trien-1-ol or farnesol is a natural isoprenoid possessing a range of beneficial biological activities as anti-candidiasis, anti-tumor and anti-hyperglycaemia. The present study, for the first time, isolated and identified farnesol from Euclea crispa leaves’ extract, subsequently, validated its antioxidant and antimicrobial potentials. The isolated compound was confirmed by spectroscopic techniques including ultraviolet-visible (UV/Vis), fourier-transform infrared (FTIR), and 1H and 13C magnetic resonance (NMR) spectroscopies. By in vitro investigations, farnesol exhibited a considerable antioxidant activity with IC50 values of 113.79, 109.59, and 116.65 µg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and nitric oxide radical scavenging assays, respectively. Additionally, farnesol performed a potent reducing power capacity which was in line with ascorbic acid, an outstanding antioxidant. By the disc-diffusion assay, farnesol exposed the superior antimicrobial activity against various disease-causing microorganisms. Significantly, at the concentration of 50 µg/mL, the compound effectively inhibited the growth of Escherichia coli and Aspergillus niger with inhibition zones of 12 and 11 mm, respectively. Findings from this research suggest that E. crispa leaf is a potential source of farnesol, a powerful antioxidant and antimicrobial agent.

Natural products against cancer: Review on phytochemicals from marine sources in preventing cancer

Marine natural products have as of now been acknowledged as the most important source of bioactive substances and drug leads. Marine flora and fauna, such as algae, bacteria, sponges, fungi, seaweeds, corals, diatoms, ascidian etc. are important resources from oceans, accounting for more than 90% of the total oceanic biomass. They are taxonomically different with huge productive and are pharmacologically active novel chemical signatures and bid a tremendous opportunity for discovery of new anti-cancer molecules. The water bodies a rich source of potent molecules which improve existence suitability and serve as chemical shield against microbes and little or huge creatures. These molecules have exhibited a range of biological properties antioxidant, antibacterial, antitumour etc. In spite of huge resources enriched with exciting chemicals, the marine floras and faunas are largely unexplored for their anticancer properties. In recent past, numerous marine anticancer compounds have been isolated, characterized, identified and are under trials for human use. In this write up we have tried to compile about marine-derived compounds anticancer biological activities of diverse flora and fauna and their underlying mechanisms and the generous raise in these compounds examined for malignant growth treatment in the course of the most recent quite a long while.

Prediction of skin anti-aging clinical benefits of an association of ingredients from marine and maritime origins: Ex vivo evaluation using a label-free quantitative proteomic and customized data processing approach

BACKGROUND

The application of ingredients from marine and maritime origins is increasingly common in skin care products, driven by consumer expectations for natural ingredients. However, these ingredients are typically studied for a few isolated in vitro activities.

OBJECTIVES

The purpose of this study was to carry out a comprehensive evaluation of the activity on the skin of an association of ingredients from marine and maritime origins using label-free quantitative proteomic analysis, in order to predict the clinical benefits if used in a skin care product.

METHODS

An aqueous gel containing 6.1% of ingredients from marine and maritime origins (amino acid-enriched giant kelp extract, trace element-enriched seawater, dedifferentiated sea fennel cells) was topically applied on human skin explants. The skin explants' proteome was analyzed in a label-free manner by high-performance liquid nano-chromatography coupled with tandem mass spectrometry. A specific data processing pipeline (CORAVALID) providing an objective and comprehensive interpretation of the statistically relevant biological activities processed the results.

RESULTS

Compared to untreated skin explants, 64 proteins were significantly regulated by the gel treatment (q-value ≤ 0.05). Computer data processing revealed an activity of the ingredients on the epidermis and the dermis. These significantly regulated proteins are involved in gene expression, cell survival and metabolism, inflammatory processes, dermal extracellular matrix synthesis, melanogenesis and keratinocyte proliferation, migration, and differentiation.

CONCLUSIONS

These results suggest that the tested ingredients could help to preserve a healthy epidermis and dermis, and possibly to prevent the visible signs of skin aging.

Nonribosomal Peptides from Marine Microbes and Their Antimicrobial and Anticancer Potential

Marine environments are largely unexplored and can be a source of new molecules for the treatment of many diseases such as malaria, cancer, tuberculosis, HIV etc. The Marine environment is one of the untapped bioresource of getting pharmacologically active nonribosomal peptides (NRPs). Bioprospecting of marine microbes have achieved many remarkable milestones in pharmaceutics. Till date, more than 50% of drugs which are in clinical use belong to the nonribosomal peptide or mixed polyketide-nonribosomal peptide families of natural products isolated from marine bacteria, cyanobacteria and fungi. In recent years large numbers of nonribosomal have been discovered from marine microbes using multi-disciplinary approaches. The present review covers the NRPs discovered from marine microbes and their pharmacological potential along with role of genomics, proteomics and bioinformatics in discovery and development of nonribosomal peptides drugs.

Antiangiogenic, wound healing and antioxidant activity of Cladosporium cladosporioides (Endophytic Fungus) isolated from seaweed (Sargassum wightii)

Endophytic fungi from marine seaweeds are the less studied group of organisms with vast medical applications. The aim of the present study was to evaluate antioxidant, antiangiogenic as well as wound healing potential of the endophytic fungus isolated from the seaweed Sargassum wightii. The morphological characters and the rDNA internal transcribed spacer sequence analysis (BLAST search in Gen Bank database) was used for the identification of endophytic fungus. The antioxidant potential of the ethyl acetate extract of endophytic fungus was assessed by, 1,1-diphenyl-2-picryl-hydrazyl radical scavenging method. The fungal extract was also analysed for reducing power, total phenolic and flavonoid content. Antiangiogenic activity of the fungal extract was studied in vitro by inhibition of wound healing scratch assay and in vivo by Chick chorioallantoic membrane assay. The endophytic fungus was identified as Cladosporium cladosporioides (Gen Bank ID - KT384175). The ethyl acetate extract of C. cladosporioides showed a significant antioxidant and angiosuppressive activity. The ESI-LC-MS analysis of the extract revealed the presence of wide range of secondary metabolites. Results suggest that C. cladosporioides extract could be exploited as a potential source for angiogenic modulators.

Alpha-adrenoceptor antagonism by Crassostrea gigas oyster extract inhibits noradrenaline-induced vascular contraction in Wistar rats

OBJECTIVE

Crassostrea gigas oyster extract has been reported to have antioxidant, antihypertensive and lipid-lowering properties that may be useful for treating cardiovascular diseases. This study aimed to evaluate the effect of C. gigas oyster extract on cardiovascular function in tissues from healthy rats.

METHODS

Single-cell microelectrode and isolated thoracic aortic organ bath studies were performed on tissues from 8-week-old healthy Wistar rats, using varying concentrations of C. gigas oyster extract. To elucidate a mechanism of action for the oyster's vasoactive properties, concentration response curves were carried out in the presence of a calcium channel inhibitior (verapamil), a nitric oxide synthase inhibitor (N(G)-nitro-L-arginine methyl ester), a potassium channel inhibitor (4-aminopyridine), in addition to the α-adrenoceptor inhibitor prazosin.

RESULTS

Oyster solution at 7 500 mg/mL inhibited noradrenaline-induced contraction in isolated aortic rings. Cardiac electrophysiology results showed that neither concentration of oyster solution was able to significantly reduce action potential duration at all phases of repolarisation in left ventricular papillary muscles from healthy animals.

CONCLUSION

When administered to healthy vascular tissue, C. gigas oyster extract inhibits contraction induced by noradrenaline. This effect is likely to be mediated through α-adrenoceptor inhibition, and to a lesser extent, calcium modulating activity.

Marine natural products

This review covers the literature published in 2011 for marine natural products, with 870 citations (558 for the period January to December 2011) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1152 for 2011), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.