Nutraceutical and Medicinal Importance of Marine Molluscs

Marine molluscs are of enormous scientific interest due to their astonishing diversity in terms of their size, shape, habitat, behaviour, and ecological roles. The phylum Mollusca is the second most common animal phylum, with 100,000 to 200,000 species, and marine molluscs are among the most notable class of marine organisms. This work aimed to show the importance of marine molluscs as a potential source of nutraceuticals as well as natural medicinal drugs. In this review, the main classes of marine molluscs, their chemical ecology, and the different techniques used for the extraction of bioactive compounds have been presented. We pointed out their nutraceutical importance such as their proteins, peptides, polysaccharides, lipids, polyphenolic compounds pigments, marine enzymes, minerals, and vitamins. Their pharmacological activities include antimicrobial, anticancer, antioxidant, anti-inflammatory, and analgesic activities. Moreover, certain molluscs like abalones and mussels contain unique compounds with potential medicinal applications, ranging from wound healing to anti-cancer effects. Understanding the nutritional and therapeutic value of marine molluscs highlights their significance in both pharmaceutical and dietary realms, paving the way for further research and utilization in human health

Potentiation effect of mallotojaponin B on chloramphenicol and mode of action of combinations against Methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus, the causative agent of many infectious diseases has developed resistance to many antibiotics, even chloramphenicol which was the essential antibiotic recommended for the treatment of bacterial infection. Thus, other alternatives to fight against S. aureus infections are necessary; and combinatory therapy of antibiotics with natural compounds is one of the approaches. This study evaluated the activity of the combination of mallotojaponin B and chloramphenicol against Methicillin-resistant Staphylococcus aureus (MRSA). Antibacterial activities were evaluated by broth microdilution and the checkerboard methods. Modes of action as time-kill kinetic, Nucleotide leakage, inhibition and eradication of biofilm, and loss of salt tolerance were evaluated. Cytotoxicity was evaluated on Vero and Raw cell lines. Mallotojaponin B showed good activity against MRSA with a MIC value of 12.5 μg/mL. MRSA showed high resistance to chloramphenicol (MIC = 250 μg/mL). The combination produced a synergistic effect with a mean FICI of 0.393. This combination was bactericidal, inducing nucleotide leakage, inhibiting biofilm formation, and eradicating biofilm formed by MRSA. The synergic combination was non-cytotoxic to Vero and Raw cell lines. Thus, the combination of mallotojaponin B and chloramphenicol could be a potential alternative to design a new drug against MRSA infections

Fig 7 -

(A and B). Biomass of biofilms produced by MRSA ATCC 33591 in different cultures medium after 24 and 48hrs of incubation. MHB: Muller Hinton Broth; MHB 1%: Muller Hinton Broth with Glucose 1%; MHB 2%: Muller Hinton Broth with Glucose 2%; TSG 1%: Tryptic Soy with Glucose 1%; TSG2%: Tryptic Soy with Glucose 2%; BHI: Brain Heart Infusion; BHI 1%: Brain Heart Infusion with Glucose 1%; BHI 2%: Brain Heart Infusion with Glucose 2%. Histograms with the same letters are not significantly different (p ˃0.05), while those carrying the same Greek alphabet are not significantly different for the same medium.</p

Variation in the number of <i>S</i>. <i>aureus</i> colonies as a function of extract and NaCl concentration.

MIC: Minimum Inhibitory Concentration; PC: positive control; NC: negative control; Comb: Combination; Comb 1: 0.781 μg/ml of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol; For each salt concentration, histograms carrying the same letters are not significantly different (p˃0.05); while for each test sample, histograms with same Greek alphabets are not significantly different, Waller Duncan test.</p

Biofilms eradication percentage of mallotojaponin B at different concentrations and combinations.

PC: Ciprofloxacin; Comb: Combination; Comb 1: 0.781 μg/mL of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol; MIC: Minimum Inhibitory Concentration; NC: Negative Control. Histograms with the same letters are not significantly different at p ≤0.05.</p

Effect of the mallotojaponin B and the different combinations on nucleotide leakage MRSA ATCC 33591.

MIC: Minimum Inhibitory Concentration; PC: positive control (TritonX); NC: negative control; Comb: combination; Comb 1: 0.781 μg/mL of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol.</p

Percentage of inhibition of biofilm of MRSA ATCC 33591 in MHB 2%.

CP: Ciprofloxacin; Comb: Combination; Comb 1: 0.781 μg/mL of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol; MIC: Minimum Inhibitory Concentration; NC: Negative Control. Histograms with the same letters are not significantly different (p˃0.05).</p

Growth curves of MRSA following exposure to various concentrations of mallotojaponin B and synergistic combinations.

MIC: Minimum Inhibitory Concentration; PC: positive control (Ciprofloxacin); NC: negative control; Comb: combination; Comb 1: 0.781 μg/mL of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol.</p

Fractional Minimum inhibitory concentration indices (FICI) of different combinations of mallotojaponin B and chloramphenicol vis-à-vis MRSA ATCC 33591.

Fractional Minimum inhibitory concentration indices (FICI) of different combinations of mallotojaponin B and chloramphenicol vis-à-vis MRSA ATCC 33591.</p