Modulation of macrophage transcript and secretion profiles by Sargassum Serratifolium extract is associated with the suppression of muscle atrophy

Recent research has emphasized the role of macrophage-secreted factors on skeletal muscle metabolism. We studied Sargassum Serratifolium ethanol extract (ESS) in countering lipopolysaccharide (LPS)-induced changes in the macrophage transcriptome and their impact on skeletal muscle. Macrophage-conditioned medium (MCM) from LPS-treated macrophages (LPS-MCM) and ESS-treated macrophages (ESS-MCM) affected C2C12 myotube cells. LPS-MCM upregulated muscle atrophy genes and reduced glucose uptake, while ESS-MCM reversed these effects. RNA sequencing revealed changes in the immune system and cytokine transport pathways in ESS-treated macrophages. Protein analysis in ESS-MCM showed reduced levels of key muscle atrophy-related proteins, TNF-α, IL-6, IL-1, and GDF-15. These proteins play crucial roles in muscle function. These findings highlight the intricate relationship between the macrophage transcriptome and their secreted factors in either impairing or enhancing skeletal muscle function. ESS treatment has the potential to reduce macrophage-derived cytokines, preserving skeletal muscle function.

The Beneficial Roles of Sargassum spp. in Skin Disorders

As the body's largest organ, the skin is located at the internal and external environment interface, serving as a line of defense against various harmful stressors. Recently, marine-derived physiologically active ingredients have attracted considerable attention in the cosmeceutical industry due to their beneficial effects on skin health. Sargassum, a genus of brown macroalgae, has traditionally been consumed as food and medicine in several countries and is rich in bioactive compounds such as meroterpenoids, sulfated polysaccharides, fucoidan, fucoxanthin, flavonoids, and terpenoids. Sargassum spp. have various beneficial effects on skin disorders. They help with atopic dermatitis by improving skin barrier protection and reducing inflammation. Several species show potential in treating acne by inhibiting bacterial growth and reducing inflammation. Some species, such as Sargassum horneri, demonstrate antiallergic effects by modulating mast cell activity. Certain Sargassum species exhibit anticancer activity by inhibiting tumor growth and promoting apoptosis, and some species help with wound healing by promoting angiogenesis and reducing oxidative stress. Overall, Sargassum spp. demonstrate potential for treating and managing various skin conditions. Therefore, the bioactive compounds of Sargassum spp. may be natural ingredients with a wide range of functional properties for preventing and treating skin disorders. The present review focused on the various biological effects of Sargassum extracts and derived compounds on skin disorders.

Combination Therapy for Bacterial Pathogens: Naturally Derived Antimicrobial Drugs Augmented with Ulva lactuca Extract

BACKGROUND

With the growing incidence of microbial pathogenesis, several alternative strategies have been developed. The number of treatments using naturally (e.g., plants, algae, fungi, bacteria, and animals) derived compounds has increased. Importantly, marine-derived products have become a promising and effective approach to combat the antibiotic resistance properties developed by bacterial pathogens. Furthermore, augmenting the sub-inhibitory concentration of the naturally-derived antimicrobial compounds (e.g., hydroxycinnamic acids, terpenes, marine-derived polysaccharides, phenolic compounds) into the naturally derived extracts as a combination therapy to treat the bacterial infection has not been well studied.

OBJECTIVE

The present study was aimed to prepare green algae Ulva lactuca extract and evaluate its antibacterial activity towards Gram-positive and Gram-negative human pathogenic bacteria. Also, revitalize the antibacterial efficiency of the naturally-derived antimicrobial drugs and conventional antibiotics by augmenting their sub-MIC to the U. lactuca extracts.

METHODS

Extraction was done using a different organic solvent, and its antibacterial activity was tested towards Gram-positive and Gram-negative pathogens. The minimum inhibitory concentration (MIC) of U. lactuca extracts has been determined towards pathogenic bacteria using the micro broth dilution method. The viable cell counting method was used to determine the minimum bactericidal concentration (MBC). The fractional inhibitory concentration (FIC) assay was utilized to examine the combinatorial impact of sub-MIC of two antibacterial drugs using the micro broth dilution method. The chemical components of the extract were analyzed by GC-MS analysis.

RESULTS

Among all the extracts, n-hexane extract was found to show effective antibacterial activity towards tested pathogens with the lowest MIC and MBC value. Furthermore, the n-hexane extracts have also been used to enhance the efficacy of the naturally-derived (derived from plants and marine organisms) compounds and conventional antibiotics at their sub-inhibitory concentrations. Most of the tested antibiotics and natural drugs at their sub-MIC were found to exhibit synergistic and additive antibacterial activity towards the tested bacterial pathogens.

CONCLUSIONS

The augmenting of U. lactuca n-hexane extracts resulted in synergistic and additive bactericidal effects on Gram-positive and Gram-negative human pathogenic bacteria. The present study shows a new alternative strategy to revitalize the antimicrobial activity of naturally derived compounds for treating human bacterial pathogens.

Pharmacological and natural products diversity of the brown algae genus Sargassum

Sargassum (F. Sargassaceae) is an important seaweed excessively distributed in tropical and subtropical regions.

α-Glucosidase and Protein Tyrosine Phosphatase 1B Inhibitory Activity of Plastoquinones from Marine Brown Alga Sargassum serratifolium

Sargassum serratifolium C. Agardh (Phaeophyceae, Fucales) is a marine brown alga that belongs to the family Sargassaceae. It is widely distributed throughout coastal areas of Korea and Japan. S. serratifolium has been found to contain high concentrations of plastoquinones, which have strong anti-cancer, anti-inflammatory, antioxidant, and neuroprotective activity. This study aims to investigate the anti-diabetic activity of S. serratifolium and its major constituents through inhibition of protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, and ONOO--mediated albumin nitration. S. serratifolium ethanolic extract and fractions exhibited broad PTP1B and α-glucosidase inhibitory activity (IC50, 1.83~7.04 and 3.16~24.16 µg/mL for PTP1B and α-glucosidase, respectively). In an attempt to identify bioactive compounds, three plastoquinones (sargahydroquinoic acid, sargachromenol and sargaquinoic acid) were isolated from the active n-hexane fraction of S. serratifolium. All three plastoquinones exhibited dose-dependent inhibitory activity against PTP1B in the IC50 range of 5.14-14.15 µM, while sargachromenol and sargaquinoic acid showed dose-dependent inhibitory activity against α-glucosidase (IC50 42.41 ± 3.09 and 96.17 ± 3.48 µM, respectively). In the kinetic study of PTP1B enzyme inhibition, sargahydroquinoic acid and sargaquinoic acid led to mixed-type inhibition, whereas sargachromenol displayed noncompetitive-type inhibition. Moreover, plastoquinones dose-dependently inhibited ONOO--mediated albumin nitration. Docking simulations of these plastoquinones demonstrated negative binding energies and close proximity to residues in the binding pocket of PTP1B and α-glucosidase, indicating that these plastoquinones have high affinity and tight binding capacity towards the active site of the enzymes. These results demonstrate that S. serratifolium and its major plastoquinones may have the potential as functional food ingredients for the prevention and treatment of type 2 diabetes.

BACE1 inhibitory activity and molecular docking analysis of meroterpenoids from Sargassum serratifolium

A wide range of pharmacological properties of Sargassum spp. extracts and isolated components have been recognized. Although individual meroterpenoids of Sargassum species have been reported to possess strong activity against Alzheimer's disease (AD), the active compounds of Sargassum serratifolium have not been fully explored. Therefore, we evaluated the anti-AD activity of S. serratifolium extract through enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1). Three meroterpenoids (sargahydroquinoic acid (1), sargachromenol (2) and sargaquinoic acid (3)) were isolated from S. serratifolium. These compounds showed moderate AChE inhibitory activity, but exhibited potent inhibitory activity against BChE and BACE1 (15.1, 9.4, and 10.4µM for BChE; 4.3, 6.9, and 12.5µM for BACE1, respectively). Kinetic study and molecular docking simulation of these compounds demonstrated that 1 and 3 interacted with both catalytic aspartyl residues and allosteric sites of BACE1, whereas 2 interacted with the allosteric site of BACE1. The results of the present study demonstrate that meroterpenoids from S. serratifolium might be beneficial in the treatment of AD.

Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria

The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 μg/mL). Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC) indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (∑FIC) values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.