Antimicrobial lipids from the hemolymph of brachyuran crabs

Antimicrobial Lipids from Plants and Marine Organisms: An Overview of the Current State-of-the-Art and Future Prospects

In the actual post-antibiotic era, novel ways of rethinking antimicrobial research approaches are more urgent than ever. Natural compounds with antimicrobial activity such as fatty acids and monoacylglycerols have been investigated for decades. Additionally, the interest in other lipid classes as antimicrobial agents is rising. This review provides an overview on the research about plant and marine lipids with potential antimicrobial activity, the methods for obtaining and analyzing these compounds, with emphasis on lipidomics, and future perspectives for bioprospection and applications for antimicrobial lipids. Lipid extracts or lipids isolated from higher plants, algae or marine invertebrates are promising molecules to inactivate a wide spectrum of microorganisms. These lipids include a variety of chemical structures. Present and future challenges in the research of antimicrobial lipids from natural origin are related to the investment and optimization of the analytical workflow based on lipidomics tools, complementary to the bioassay-guided fractionation, to identify the active compound(s). Also, further work is needed regarding the study of their mechanism of action, the structure-activity relationship, the synergistic effect with conventional antibiotics, and the eventual development of resistance to lipids, which, as far as is known, is unlikely.

Antiviral effect of the egg wax of Amblyomma cajennense (Acari: Ixodidae)

The control of viral infections, especially those caused by influenza viruses, is of great interest in Public Health. Bio prospection has shown the presence of active principles in the hemolymph of arthropods, and in the salivary gland of ticks, and some of these are of interest for the development of new pharmacological drugs. Ticks lay their eggs in the environment, and to protect them from desiccation and microbial attack they involve the eggs in a waxy layer produced by an organ known as Gené's Organ. In this study, the eggs wax from tick Amblyomma cajennense (Fabricius) was extracted using ice cold phosphate buffer. The antiviral activity was evaluated with picornavirus and influenza virus. In both cases egg wax was able to inhibit virus replication. For influenza virus, an amount as small as 12 μg/mL of crude egg wax suspension neutralized 128 UHA (hemaglutinant unit) of H(1)N(1) influenza virus. With picornavirus, egg wax led to a 256-fold reduction in virus production by L929 cells. Egg wax was not cytotoxic to VERO, MDCK and L929 cell, being observed that the cell morphology was preserved with concentration as high as 2 mg/mL. In addition no genotoxic effect was observed for Vero cells, suggesting a very interesting potential antiviral activity.

Control of Clinical Pathogens by the Haemolymph of Paratelphusa hydrodromous, a Freshwater Crab

In the present study, effort has been made to find the antimicrobial activity of haemolymph collected from freshwater crab, Paratelphusa hydrodromous. The haemolymph collected was tested for antimicrobial assay by disc diffusion method against clinical pathogens. Five bacterial species, namely, Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and five fungal strains, namely and Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Rhizopus sp., and Mucor sp., were selected for the study. The result shows a strong response of haemolymph against the clinical pathogens which confirms the immune mechanism of the freshwater crab.