Anti-Inflammatory Concentrate Enriched with Substituted Oligofucans Derived from Brown Seaweed Turbinaria conoides (J. Agardh) Kützing and Its Safety Assessment on Wistar Rats

Novel Furanyl-Substituted Isochromanyl Class of Anti-Inflammatory Turbinochromanone from Brown Seaweed Turbinaria conoides

Organic extract of the brown seaweed Turbinaria conoides (Sargassaceae) was chromatographically fractionated to yield an undescribed furanyl-substituted isochromanyl metabolite, named as turbinochromanone, which was characterized as methyl 4-[(3S)-8-{[(3R)-4-ethyl-2,3-dihydrofuran-3-yl]methyl}-1-oxo-3,4-dihydro-1H-2-benzopyran-3-yl]butanoate. The isochromanyl derivative possessed comparable attenuation potential against 5-lipoxygenase (IC₅₀ 3.70 μM) with standard 5-lipoxygenase inhibitor drug zileuton (IC₅₀ 2.41 μM). Noticeably, the index of anti-inflammatory selectivity of turbinochromanone (∼1.7) was considerably greater than that exhibited by the standard agent diclofenac (1.06). Antioxidant properties of turbinochromanone against oxidants (IC₅₀ ∼24 μM) further supported its potential anti-inflammatory property. Greater electronic properties (topological polar surface area of 61.8) along with comparatively lesser docking parameters of the studied compound with aminoacyl residues of targeted enzymes (cyclooxygenase-2 and 5-lipoxygenase) (binding energy of -11.05 and -9.40 kcal mol^-1 , respectively) recognized its prospective anti-inflammatory potential. In an aim to develop seaweed-based natural anti-inflammatory leads, the present study isolated turbinochromanone as promising 5-lipoxygenase and cyclooxygenase-2 inhibitor, which could be used for pharmaceutical and biotechnological applications.

Conoidecyclics A-C from marine macroalga Turbinaria conoides: Newly described natural macrolides with prospective bioactive properties

Intertidal marine brown alga Turbinaria conoides (J.Agardh) Kützing (family Sargassaceae) is considered as one of the largely abundant species, available in the coastal zones of the Indian subcontinent. Bioactivity-guided chromatographic fractionation of the organic extract of T. conoides resulted in three previously undescribed macrocyclic lactone homologues, named as conoidecyclics A-C. Conoidecyclic A displayed greater attenuation potential against cyclooxygenase-2 (IC50 1.75 mM) and 5-lipoxygenase (IC50 4.24 mM) in comparison with other analogues. Conoidecyclic A exhibited higher attenuation potential against 5-lipoxygenase than that displayed by an anti-inflammatory agent, ibuprofen (IC50 4.51 mM). The higher selectivity index of conoidecyclic A (1.79) recognized its selective attenuation potential against the inducible cyclooxygenase-2 enzyme. Inhibition potential of conoidecyclic A against angiotensin converting enzyme-I (IC50 1.23 mM) and protein tyrosine phosphatase-1B (IC50 1.39 mM) were non-competitive, as deduced by kinetic studies. In-silico molecular modeling study of conoidecyclic A with the allosteric sites of the targeted enzymes exhibited least binding energy of -14.51 to -11.27 kcal mol-1 compared to those exhibited by other studied macrolide homologues. Reaction kinetic studies of conoidecyclic A coupled with lesser apparent Vmax inferred that it could efficiently bind with the allosteric site of targeted enzymes in a non-competitive manner to diminish the reaction velocity resulting in enzyme inhibition. Drug-likeness and predictive pharmacokinetic parameters of conoidecyclic A exhibited an acceptable oral bioavailability. These reports inferred that conoidecyclic A encompassing pentacosa macrocyclic moiety could be a promising therapeutic lead to inhibit the enzymes related to the development and progression of pathological conditions leading to inflammation, hypertension and type-2 diabetes.

Evaluation of the protein and bioactive compound bioaccessibility/bioavailability and cytotoxicity of the extracts obtained from aquaculture and fisheries by-products

Bioavailability, bioaccessibility, bioactivity and cytotoxicity define if a bioactive compound obtained from aquaculture and associated by-products can be assimilated and used for the body in a safe and efficient way. Four models are used to evaluate the bioavailability: in vitro (simulated gastrointestinal digestion using intestinal epithelial Caco-2 cell cultures); ex vivo (gastrointestinal organs or organoids in laboratory conditions); in situ (intestinal perfusion in animals) and in vivo (animal studies and human studies). In vitro models are very effective, predicting in vivo actions since they evaluate multiple conditions regardless physiological effects. However, in vivo systems are essential for the validation of the results. The use of a combined model between human digestion and cell culture-based models would solve these difficulties, allowing valid conclusions. These studies must be completed with the evaluation of cytotoxicity and oxidative stress markers, providing most accurate results regarding the adverse effect on the body. These methods would test the effect of food structure, food composition, dietary factors and the effect of food processing on bioavailability. Further studies should be carried out to establish a standardized method and achieve a balance between the use of in vivo and in vitro systems.

Marine Polysaccharides in Pharmaceutical Applications: Fucoidan and Chitosan as Key Players in the Drug Delivery Match Field

The use of marine-origin polysaccharides has increased in recent research because they are abundant, cheap, biocompatible, and biodegradable. These features motivate their application in nanotechnology as drug delivery systems; in tissue engineering, cancer therapy, or wound dressing; in biosensors; and even water treatment. Given the physicochemical and bioactive properties of fucoidan and chitosan, a wide range of nanostructures has been developed with these polysaccharides per se and in combination. This review provides an outline of these marine polysaccharides, including their sources, chemical structure, biological properties, and nanomedicine applications; their combination as nanoparticles with descriptions of the most commonly used production methods; and their physicochemical and biological properties applied to the design of nanoparticles to deliver several classes of compounds. A final section gives a brief overview of some biomedical applications of fucoidan and chitosan for tissue engineering and wound healing.