Sargassum filipendula, a Source of Bioactive Compounds with Antioxidant and Matrix Metalloproteinases Inhibition Activities In Vitro with Potential Dermocosmetic Application.

The antioxidant and the potential inhibitory capacity of matrix metalloproteinases of the phlorotannin-type polyphenolic and fucoidan-type polysaccharides extracts obtained from the macroalga S. filipendula were evaluated. Through chromatographic and spectroscopic techniques, the corresponding chemical structure of compounds present in the extracts was determined. Antioxidant capacity was evaluated using the methyl linoleate model for the inhibition of lipid peroxidation, and the free radical scavenging capacity was assessed using DPPH, ABTS, •OH, O2•- methods. The matrix metalloproteinase inhibition potential was measured by collagenase and elastase inhibition tests, using epigallocatechin gallate as a positive control. The extracts exhibited a high scavenging capacity of radical species evaluated and inhibition of diene conjugate formation and thiobarbituric acid reactive substances. The results showed that the crude extracts presented dose-dependent collagenase and elastase inhibition, with IC50 values between 0.04 and 1.61 mg/mL. The structure of the residues of the polysaccharide was identified mainly as (1→3)-sulfated (1→3) α-l-fucopyranose at carbon 4 and residues of ß-d-glucopyranose, α-d-Mannopyranose, and ß-d-Galactopyranose, while in the polyphenol extract the presence of phloroglucinol was identified and the presence of eckol, bifuhalol, and trifuhalol was suggested. Our results allow us to infer that S. filipendula is a potential source of bioactive ingredients with antioxidant and anti-aging activity.

Heavy Metal Tolerance of Microorganisms Isolated from Coastal Marine Sediments and Their Lead Removal Potential.

In this study, 338 microorganisms, comprising 271 bacteria and 67 fungi, were isolated from sediment samples collected from underexplored Pacific and Caribbean regions of Colombia. Screening trials were conducted on selected strains (n = 276) to assess their tolerance to cadmium (Cd2+), lead (Pb2+), and zinc (Zn2+), leading to the identification of six bacteria capable of withstanding 750 mg·L-1 of each heavy metal ion. Three promising microorganisms, identified as Enterobacter sp. INV PRT213, Pseudomonas sp. INV PRT215, and Stenotrophomonas sp. INV PRT216 were selected for lead removal experiments using LB broth medium supplemented with 400 mg·L-1 Pb2+. Among these, Pseudomonas sp. INV PRT215 exhibited significant potential, removing 49% of initial Pb2+ after 240 min of exposure (16.7 g wet biomass·L-1, pH 5, 30 °C). Infrared spectra of Pb-exposed biomass showed changes in functional groups, including carbonyl groups of amides, carboxylate, phosphate, hydroxyl, and amine groups, compared to the not-exposed control. These changes suggested interactions between the metal and functional groups in the biomass. The findings of this study highlight the potential of microorganisms derived from coastal marine environments as promising candidates for future applications in bioremediation of polluted environments contaminated with heavy metals.