Sulphated glycosaminoglycan isolated from the edible slipper oyster Magallana bilineata (Röding, 1798) attenuates inflammatory cytokines on lipopolysaccharide-prompted macrophages.

The slipper oyster Magallana bilineata (Ostreidae) is considered as culinary delicacy among marine bivalves, and a sulphated glycosaminoglycan, 4,6-O-SO3-ß-(1→3)-GalNAcp (unit A) and ß-(1→4)-GlcAp (unit B) as principle structural motif containing laterally branched 4-O-SO3-ß-glucopyranose (unit C) (MBP-3) was isolated from this species. Nuclear magnetic resonance (NMR), Fourier transform infra-red (FTIR), and mass spectroscopy techniques were used to characterise MBP-3. MBP-3 exhibited anti-inflammatory activities against inflammatory 5-lipoxygenase (IC50 0.11 mg mL-1) and cyclooxygenase-2 (IC50 0.12 mg mL-1) enzymes. MBP-3 (at 100 µg mL-1) showed effective downregulation against pro-inflammatory cytokines generation, namely interleukins-6, 1ß, (IL-6, 1ß) (1-1.7 pg mL-1) and tumour necrosis factor-α (TNF-α) (4 pg mL-1) along with substantial downregulation of ROS production in lipopolysaccharide (LPS)-inflamed cells. MBP-3 blocked the mRNA of NF-κB, cyclooxygenase-2 (COX-2), and other cytokines, in lipopolysaccharide-induced macrophages. The potential to constrain inflammatory cytokine production revealed its application to develop functional food to attenuate inflammation-associated disorders.

Antibacterial and wound healing potential of topical formulation of marine symbiotic Bacillus.

The inevitability to develop novel antimicrobial agents has considerably increased because of mounting alarms concerning multidrug-resistant microbial strains. The present study evaluated an antibacterial and wound healing topical formulation prepared with the ethyl acetate extract of marine symbiotic Bacillus amyloliquefaciens MTCC 12716 as the basic ingredient and the grafted macroalgal polysaccharide as the gel base with an appropriate proportion of natural stabilizing agents. The formulation exhibited potent antibacterial activities against clinical isolates of Staphylococcus aureus (18 mm inhibition zone) and Pseudomonas aeruginosa (19 mm) causing infection when compared with commercially available antimicrobial cream clindamycin. The in-vitro results indicated that the organic extract of B. amyloliquefaciens MTCC 12716 at its MIC and the formulation sealed the wound by 78 and 94%, respectively, at 48 h in the scratch-induced L929 cells, compared to 84% exhibited by clindamycin. The topical formulation of marine symbiotic Bacillus induced greater than 80% viability of the normal fibroblasts compared to 78% exhibited by clindamycin, when administered at a dose of 25 µg mL-1. The studied antibacterial formulation could accelerate the wound healing by prompting the migration of fibroblasts towards the artificially created wound resulting in rapid wound closure, and at an even higher concentration of formulation, it displayed no cytotoxicity on L929 cells. The stability studies showed that the formulation maintained its physicochemical characteristics and minimal growth (<10 cfu g-1) of bacteria on the plates throughout the time period of 18 months at 30 °C and 65% relative humidity. This study has established the antibacterial and wound healing potential of a topical formulation of marine symbiotic B. amyloliquefaciens.

Biomedical potential of ß-chitosan from cuttlebone of cephalopods.

Polymeric ß-chitosan allomorph characterized by parallel arrangement of linear polysaccharide comprised of ß-(1 â†’ 4)-linked-D-glucosamine and N-acetyl-D-glucosamine was isolated and characterized from the gladius of Indian Ocean Squid (Uroteuthis duvaucelii) and spineless cuttlefish (Sepiella inermis). The ß-chitosan from U. duvaucelii displayed considerably greater attenuation potential against hydroxymethylglutaryl coenzyme-A reductase, dipeptidyl peptidase-4, I converting enzyme, and 5-lipoxygenase (IC50 0.15-0.53 mg mL-1) than those exhibited by α-chitosan of comparable molecular weight. Comparatively lesser conformational rigidity of ß-chitin could result in its greater susceptibility to deacetylation (86-87%) contrasted to the α-allomorph (~83%), consequently delivering enhanced functionalities than those exhibited by α-chitosan. Porous ß-chitosan scaffolds displayed an average pore size of lesser than 50 µm, and its binding capacity was significantly higher than that exhibited by α-chitosan (p < 0.05). Potential pharmacological activities reinforced by lesser binding affinities and intermolecular energy of ß-chitosan with the target enzymes recognized its prospective biomedical applications.

Euryfuranyl compounds from edible species of cuttlefish as potential anti-inflammatory leads attenuating NF-κB signaling cascade in lipopolysaccharide-activated macrophages.

Nuclear factor-kappa B is an inducible transcription element, which was considered as an important regulator of immune functions, and plays a critical role to induce inflammatory reactions. In this study, we have demonstrated the anti-inflammatory potentials of previously undescribed (4 â†’ 13)-abeo-euryfuranyls (1-2) from the spineless cuttlefish Sepiella inermis in lipopolysaccharide-stimulated macrophages. The euryfuranyl bearing (4 â†’ 13)-abeo-euryfuranyl-2-ene-6-hydroxymethyl-propanoate framework (compound 1) displayed prominent inhibitory effects against pro-inflammatory cyclooxygenase-2 (IC50 0.36 mM) and 5-lipoxygenase (IC50 0.70 mM). Additionally, it suppressed the generation of inducible nitric oxide synthase along with cyclooxygenase-2 and 5-lipoxygenase in lipopolysaccharide-stimulated macrophages. The euryfuranyl analogue (1) down-regulated the mRNA expression of cyclooxygenase-2 and nuclear factor-κB signaling pathway in lipopolysaccharide-activated macrophage cells by hindering the degradation of inhibitor-κB proteins, and transfer of the subunit NF-κB p65 to the nucleus from the cytosol. These results demonstrated that the euryfuranyl analogue could be explored as a promising anti-inflammatory therapeutic lead attenuating nuclear factor-κB signaling cascade.

Antioxidative oxygenated terpenoids with bioactivities against pro-inflammatory inducible enzymes from Indian squid, Uroteuthis (Photololigo) duvaucelii.

Cephalopod squid, Uroteuthis (Photololigo) duvaucelii is consumed as culinary delicacy along the southwest part of Asian continent. Ethyl acetate:methanol extract of U. duvaucelii was chromatographically fractionated to yield C19 furano-norditerpenoid (1) along with irregular C15 sesquiterpenoid (2) and C20 diterpenoid compounds (3). In vitro anti-inflammatory and antioxidant analyses were utilised to evaluate their bio-potentials. The C19 furano-norditerpenoid was reported for significantly effective 2,2-diphenyl-1-picrylhydrazyl radical inhibition (IC50 0.60 mg/mL) than other compounds and α-tocopherol (IC50 ≥ 0.64 mg/mL). The 2,2'-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid inhibition and ferrous ion chelating potentials were higher for compounds 1 and 2 (IC50 ∼ 0.69 and ∼0.84 mg/mL, respectively) compared to α-tocopherol (IC50 0.76-0.95 mg/mL). The studied compounds displayed comparable inhibitory activities with synthetic ibuprofen against pro-inflammatory inducible 5-lipoxygenase (IC50 ∼ 0.92 mg/mL). The lower hydrophobicity and steric variables were directly correlated with their antioxidative and anti-inflammatory properties. The studied compounds could be utilised as natural antioxidants and anti-inflammatory functional food ingredients.

Polygalactan from bivalve Crassostrea madrasensis attenuates nuclear factor-κB activation and cytokine production in lipopolysaccharide-activated macrophage.

A polygalactosamino-glucopyranosyl fucopyranose →4)-ß-GlcAp{(3→1)-α-Fucp}-ß-GalNAcp-(4,6-SO3-)-(1→ isolated from the bivalve Crassostrea madrasensis exhibited prospective anti-inflammatory activity against cyclooxygenase-2 and 5-lipoxygenase (IC50 < 50 µg mL-1) on lipopolysaccharide-induced macrophages. The polygalactan attenuated inducible nitric oxide synthase (IC50 65.7 µg mL-1) in lipopolysaccharide-prompted inflammation leading to the reduction of pro-inflammatory cytokine nitric oxide (236.2 µg mL-1 lysate), nuclear factor-κB, tumor necrosis factor-α, and interleukins (0.19-0.22 units mg-1 protein at 100 µg mL-1) by inhibiting cyclooxygenase-2. The polygalacatan suppressed the mRNA of nuclear factor-κB and cyclooxygenase-2 in lipopolysaccharide-induced macrophages. Western blot experiment revealed that the polygalactan attenuated the migration of nuclear factor-κB-p65 to the nucleus from cytoplasm, and suppressed the phosphorylation of α-subunit of κB inhibitor. Greater selectivity index of sulfated polygalactan (3.93) towards inducible cyclooxygenase-2 as compared with the anti-inflammatory agent ibuprofen (1.11), and the potential to inhibit nuclear factor-κB cascade to generate chemokine production manifested its utilization in the development of functional food attenuating inflammation-related disorders.

Sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan from seafood Amphioctopus neglectus attenuates angiotensin-II prompted cardiac hypertrophy.

Angiotensin converting enzyme (ACE) is a multifunctional enzyme involved in translation of angiotensin-I (AngI) to vasoconstrictor angiotensin-II (AngII). A sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan characterized as poly-[(2-methoxy-ß-arabinopyranosyl)-(1 â†’ 3)-(ß-glucurono)-(1 â†’ 4)-(2-acetamido-2-deoxy-3,6-di-O-sulfonato-ß-glucopyranose)] was purified and reported first time from the edible portion of Amphioctopus neglectus and evaluated for various pharmacological properties. The polysaccharide exhibited potential ACE attenuation property (IC50 0.11 mg mL-1), whereas molecular docking simulations displayed its efficient binding at the ACE active site with lesser inhibitory constant (Ki) of 17.36 nM and binding energy (-10.59 kcal mol-1). The in-vitro analysis showed that the studied polysacharide attenuated AngII prompted cardiac hypertrophy at 50 µg mL-1 in the cardiomyoblast cells, whereas 48% reduction in cellular surface area with extended viability could be correlated with anti-hypertrophic properties of the studied polysaccharide. The sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan purified from A. neglectus could function as a prospective functional lead against the pathophysiological conditions leading to hypertension.

First report of anti-inflammatory chromenyl derivatives from the spineless cuttlefish Sepiella inermis.

The spineless cuttlefish Sepiella inermis encompasses a major share in the marine fisheries sector, and represents as a culinary delicacy in many cultures. Bioactivity-guided fractionation of methanol:ethyl acetate (MeOH:EtOAc, 1:1) extract of the edible parts of the species ensued in identification of two hexahydro chromenyl analogues namely, methyl 7-ethyl-hexahydro-8a-methyl-2H-chromene-4-carboxylate (1) and methyl 1-acetoxy-hexahydro-3-methyl-3-propyl-1H-isochromene-4-carboxylate (2). The isolated metabolites were checked for their radical scavenging and anti-inflammatory potentials by selective in vitro models. The isochromenyl derivative exhibited potential 2,2-diphenyl-1-picryl-hydrazil and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (IC50 < 0.45 mg mL-1) radical-scavenging capacities along with pro-inflammatory cyclooxygenase-2 (COX-2) (IC50 0.75 mg mL-1) and 5-lipoxygenase (5-LOX) (IC50 0.77 mg mL-1) inhibitory activities. The titled compounds displayed the selectivity indices (IC50 anti-COX-1/IC50 anti-COX-2) greater than 1.25, in comparison with synthetic anti-inflammatory drug ibuprofen (0.44), which attributed to their greater selectivity towards inducible pro-inflammatory enzyme COX-2.

First report of chromenyl derivatives from spineless marine cuttlefish Sepiella inermis: Prospective antihyperglycemic agents attenuate serine protease dipeptidyl peptidase-IV.

Spineless marine cuttlefish Sepiella inermis has been considered as a popular dietary cephalopod species in Asian and Mediterranean coasts. Bioassay-directed purification of organic extract of S. inermis ensued in the characterization of two chromenyl derivatives. The studied compounds exhibited significantly greater antioxidant potencies (IC50  ≤ 0.5 mg/ml) when compared with α-tocopherol. The substituted 1H-isochromenyloxy-11-hydroxyethyl pentanoate isoform (compound 1) efficiently inhibited the carbolytic enzymes along with key regulator of insulin secretion dipeptidyl peptidase-IV (IC50 0.16 mg/ml). The molecular docking simulations displayed optimum binding affinity of the compound 1 (-10.01 kcal/mol) with dipeptidyl peptidase-IV and lesser inhibition constant (Ki 46.41 nM), which along with its permissible hydrophobic-hydrophilic balance (log Pow  ~ 2) appeared to play significant roles in its greater antihyperglycemic activity compared to other studied chromenyl isoform. The greater antioxidant and antidiabetic properties of compound 1 could be utilized as an important natural lead against hyperglycemic-related disorders. PRACTICAL APPLICATIONS: The edible spineless marine cuttlefish Sepiella inermis are ubiquitously available in Asian and Mediterranean coasts. The sequential chromatographic purification of the organic extract of S. inermis led to the identification of two pure chromenyl chemotypes. The metabolites with substituted 1H-isochromenyloxy-11-hydroxyethyl pentanoate isoform (compound 1) displayed potential antioxidative and antihyperglycemic activities compared to the chemotype (2) bearing 3H-isochromen-5-yl moiety. The attenuating potential of chromenyl chemotype 1 against carbohydrate hydrolyzing enzymes and insulin secretion regulator attributed towards its efficiency as an important natural lead against postprandial hyperglycemia and incretin hormone regulation to maintain glucose homeostasis in the biological system. The chromenyl metabolites isolated from S. inermis could be utilized as a functional food ingredient in the nutraceutical formulations against hyperglycemic-related disorders.

Macrocyclic lactones from seafood Amphioctopus neglectus: Newly described natural leads to attenuate angiotensin-II induced cardiac hypertrophy.

Amphioctopus neglectus (Family: Octopodidae) is recognised as culinary delicacy in many cultures and a common sea food item on the Mediterranean and Asian coasts. Bioassay-directed fractionation of ethyl acetate/methanol extract of A. neglectus ensued in the characterisation of four previously undescribed macrocyclic lactones (1-4). These compounds exhibited potential radical-scavenging capacities (IC50 0.95-1.73 mM) along with anti-hypertensive activities (IC50 1.12-2.34 mM) against angiotensin converting enzyme (ACE). The optimum binding affinity of compound 2 (-9.84 kcal mol-1) bearing furo[1,4,8]trioxacyclohexadecine-12,19-dione moiety with ACE, along with its permissible hydrophobic-hydrophilic balance, manifested towards its greater anti-hypertensive activity compared to other analogues. The compound 2, with lesser values of the inhibitory constant (Ki = 1.0 mM) towards ACE, was found to bind more effectively to the enzyme in a non-competitive manner, and could describe the greater inhibitory ramifications than those displayed by other compounds (Ki >1.1 mM). The ex-vivo studies revealed that compound 2 imparted protective effects against angiotensin-II induced cardiac hypertrophy at 25 µg mL-1 on H9C2 cell lines, wherein about 34 percent decrease in cell area with increase in viability could be attributed to anti-hypertrophic effects of the compound administrated. These results confirmed that the protective effect of the isolated macrocyclic lactones is mediated by enhancement of anti-oxidant defense systems, which subsequently attenuates the hypertensive related disorders.