The antiviral effect of mollusk mucus on measles virus

Molluscan Compounds Provide Drug Leads for the Treatment and Prevention of Respiratory Disease

Respiratory diseases place an immense burden on global health and there is a compelling need for the discovery of new compounds for therapeutic development. Here, we identify research priorities by critically reviewing pre-clinical and clinical studies using extracts and compounds derived from molluscs, as well as traditional molluscan medicines, used in the treatment of respiratory diseases. We reviewed 97 biomedical articles demonstrating the anti-inflammatory, antimicrobial, anticancer, and immunomodulatory properties of >320 molluscan extracts/compounds with direct relevance to respiratory disease, in addition to others with promising bioactivities yet to be tested in the respiratory context. Of pertinent interest are compounds demonstrating biofilm inhibition/disruption and antiviral activity, as well as synergism with approved antimicrobial and chemotherapeutic agents. At least 100 traditional medicines, incorporating over 300 different mollusc species, have been used to treat respiratory-related illness in cultures worldwide for thousands of years. These medicines provide useful clues for the discovery of bioactive components that likely underpin their continued use. There is particular incentive for investigations into anti-inflammatory compounds, given the extensive application of molluscan traditional medicines for symptoms of inflammation, and shells, which are the principal molluscan product used in these preparations. Overall, there is a need to target research toward specific respiratory disease-related hypotheses, purify bioactive compounds and elucidate their chemical structures, and develop an evidence base for the integration of quality-controlled traditional medicines.

Bioactivity of compounds secreted by symbiont bacteria of Nudibranchs from Indonesia

The aims of this work are to isolate bacterial symbionts from nudibranchs and subsequently to determine anti-Methicillin resistant Staphylococcus aureus (MRSA), cytotoxicity and anti-Herpes simplex virus type 1 (HSV-1) activities of bio compounds. A total of 15 species of nudibranchs were collected from Karimunjawa and five species from Bali, respectively. A total of 245 bacteria isolates were obtained. The anti-MRSA activity screening activity indicated two active bacteria. Ethyl acetate extracts from supernatants, indicating extracelullar compounds, showed an inhibition zone against MRSA at concentrations of 500–1,000 µg/ml. DNA sequence analysis showed that the strain KJB-07 from Phyllidia coelestis was closely related to Pseudoalteromonas rubra, whereas the strain NP31-01 isolated from Phyllidia varicosa was closely related to Virgibacillus salarius. The extract of Pseudoalteromonas rubra was cytotoxic to Vero cells at a concentration of 75 µg/ml. The extract of V. salarius presented no cytotoxicity at concentrations of 5–1,000 µg/ml. No anti HSV-1 was observed for both isolated bacteria. This is the first study describing research on anti-MRSA, cytotoxicity and anti HSV-1 activity of bacterial symbionts from the viscera of nudibranch. Compounds produced by Pseudoalteromonas rubra and V. salarius, had potential anti-MRSA activity. However, only extracts from Pseudoalteromonas rubra showed cytotoxic effects on Vero cells. Three compounds were identified by LC/MS after purification from culture supernatant.

Polyunsaturated fatty acids from Phyllocaulis boraceiensis mucus block the replication of influenza virus

Influenza viruses cause worldwide outbreaks and pandemics in humans and animals every year with considerable morbidity and mortality. The molecular diversity of secondary metabolites extracted from mollusks is a good alternative for the discovery of novel bioactive compounds with unique structures and diverse biological activities. Phyllocaulis boraceiensis is a hermaphroditic slug that exudes mucus, in which was detected hydroxy polyunsaturated fatty acids that exhibited potent antiviral activity against measles virus. The objective of this study was to evaluate this property against Influenza viruses. Cell viability and toxicity of the mucus were evaluated on Madin-Darby canine kidney (MDCK) cells by MTT assay. Antiviral activity from mucus against influenza viruses was carried out by determination of the virus infection dose and by immunofluorescence assays. The crude mucus and its fractions exhibited low cytotoxicity on MDCK cells. A significant inhibition of viral replication, reduced by the order of eight times, was observed in influenza-induced cytopathic effect. In immunofluorescence assay was observed a decrease of more than 80% of the viral load on infected MDCK cell treated with mucus and its fractions. The viral glycoproteins hemagglutinin and neuraminidase located on the surface of the virus are crucial for the replications and infectivity of the influenza virus. Some authors demonstrated that lipids, such as, polyunsaturated fatty acids exhibited multiple roles in antiviral innate and adaptive responses, control of inflammation, and in the development of antiviral therapeutics. As corroborated by other studies, hydroxy polyunsaturated fatty acids interfered with the binding of influenza virus on host cell receptor and reduced viral titers. The results obtained indicated that polyunsaturated fatty acids from P. boraceiensis crude mucus and fractions 39 exerted antiviral activity against influenza virus.

Antimicrobial properties of terrestrial snail and slug mucus

Snail and slug mucus is a viscous-elastic substance secreted by specific glands with adhesive and lubricants properties that allows them to adhere tenaciously to many different surfaces. It has been used since ancient times for care and human health and it is still very important in traditional and folkloristic medicine. Recently, mucus from snail and slugs and its protein and components have been subjected to some investigations on their antibacterial, antiviral and antifungal activity due to extensive traditional uses and for a future application in medicine. Antimicrobial activities of crude mucus, and its components, against different microorganism have been reported, showing antimicrobial activities that lead their potential employment in several fields as natural additives. The purpose of this Review is to summarize the results of antimicrobial studies of snail and slug mucus and its compounds from the first scientific applications to the isolation of the single components in order to better understand its application and propose an employment in future studies as a natural antimicrobial agent.