Anti-inflammatory activities of some brown marine algae in LPS-stimulated RAW 264.7 cells

Comparative evaluation of the antihyperglycemic effects of three extracts of sea mustard (Undaria pinnatifida): In vitro and in vivo studies

Undaria pinnatifida (UP) contains multiple bioactive substances, such as polyphenols, polysaccharides, and amino acids, which are associated with various biological properties. This study aimed to evaluate the antihyperglycemic effects of three extracts obtained from UP. UP was extracted under three different conditions: a low-temperature water extract at 50 °C (UPLW), a high-temperature water extract at 90 °C (UPHW), and a 70 % ethanol extract (UPE). Nontargeted chemical profiling using high-performance liquid chromatography-triple/time-of-flight mass spectrometry (HPLC-Triple TOF-MS/MS) was conducted on the three UP extracts. Subsequently, α-glucosidase inhibitory (AGI) activity, glucose uptake, and the mRNA expression of sodium/glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2) were evaluated in Caco-2 cell monolayers. Furthermore, an oral carbohydrate tolerance test was performed on C57BL/6 mice. The mice were orally administered UP at 300 mg/kg body weight (B.W.), and the blood glucose level and area under the curve (AUC) were measured. Compared with glucose, UPLW, UPHW and UPE significantly inhibited both glucose uptake and the mRNA expression of SGLT1 and GLUT2 in Caco-2 cell monolayers. After glucose, maltose, and sucrose loading, the blood glucose levels and AUC of the UPLW group were significantly lower than those of the control group. These findings suggest that UPLW has antihyperglycemic effects by regulating glucose uptake through glucose transporters and can be expected to alleviate postprandial hyperglycemia. Therefore, UPLW may have potential as a functional food ingredient for alleviating postprandial hyperglycemia.

Modulation of MAPK/NF-κB Pathway and NLRP3 Inflammasome by Secondary Metabolites from Red Algae: A Mechanistic Study

The pharmacological properties of seaweeds are diverse. No studies have been conducted on the protective effect of Galaxaura oblongata (GOE) against lippopolysaccharide (LPS)-induced inflammation in the brain. This study is divided into three phases, the first of which is the initial phase. In vitro study includes antioxidant, radical scavenging, and anti-inflammatory activities, including cyclooxygenase-1 (COX1), COX2, NO, acetylcholine inhibition, sphingosine kinase 1, tumor necrosis factor α (TNF-α), and interleukin-6, as well as antioxidant and radical-scavenging activities, including 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid. Using LPS-induced acute inflammation, the second phase was conducted in vivo. Antioxidant and anti-inflammatory assays were performed to investigate the protective role of GOE. In addition to the phytochemical analysis, the bioactive content of GOE was also investigated. In vitro results demonstrated the potential of GOE as an antioxidant, anti-inflammatory, and neuroprotective agent. A study using LPS as an induced lung injury and neuroinflammation model confirmed the in vitro results. The GOE significantly reduced inflammatory, oxidative, and neurodegenerative biomarkers based on histopathological and immuno-histochemistry results. Based on computational drug design, four target proteins were approved: nuclear factor κB, mitogen-activated protein kinases, TNF-α, and NLRP3. Using polyphenolic compounds in GOE as ligands demonstrated good alignment and affinity against the three proteins. Finally, the current study offers a new approach to developing drug leads considering GOE's protective and curative roles.

Analysis of the Chemical, Antioxidant, and Anti-Inflammatory Properties of Pink Pepper (Schinus molle L.)

Here, we compared the chemical properties and antioxidant effects of black pepper (Piper nigrum L.) and pink pepper (Schinus molle L.). Additionally, the antioxidant and anti-inflammatory capacities of pink pepper were measured to determine nutraceutical potential. Pink peppers from Brazil (PPB), India (PPI), and Sri Lanka (PPS) had higher Hunter a* (redness) values and lower L* (lightness) and b* (yellowness) values than black pepper from Vietnam (BPV). Fructose and glucose were detected in PPB, PPI, and PPS, but not in BPV. PPB, PPI, and PPS had greater 2,2-diphenyl-1-picrylhydrazyl and 3-ethylbenzothiazoline-6-sulphonic acid radical scavenging stabilities and higher total phenolic contents than BPV. BPV had higher levels of piperine than the pink peppers. Gallic acid, protocatechuic acid, epicatechin, and p-coumaric acid were detected only in the three pink peppers. PPB significantly suppressed lipopolysaccharide-induced reactive oxygen species production with increased Nrf2 translocation from cytosol to nucleus and heme oxygenase-1 expression. PPB and PPS significantly suppressed lipopolysaccharide-induced nitrite production and nitric oxide synthase expression by suppressing phosphorylation of p38 without affecting cell viability. Additionally, PPB and PPS significantly suppressed ultraviolet B-induced cyclooxygenase-2 expression by affecting the phosphorylation of ERK1/2 without cell cytotoxicity. These results suggest that pink pepper is a potential nutraceutical against oxidative and inflammatory stress.

Lipophilic Fraction of Cultivated Bifurcaria bifurcata R. Ross: Detailed Composition and In Vitro Prospection of Current Challenging Bioactive Properties

Macroalgae have been seen as an alternative source of molecules with promising bioactivities to use in the prevention and treatment of current lifestyle diseases. In this vein, the lipophilic fraction of short-term (three weeks) cultivated Bifurcaria bifurcata was characterized in detail by gas chromatography–mass spectrometry (GC-MS). B. bifurcata dichloromethane extract was composed mainly by diterpenes (1892.78 ± 133.97 mg kg⁻¹ dry weight (DW)), followed by fatty acids, both saturated (550.35 ± 15.67 mg kg⁻¹ DW) and unsaturated (397.06 ± 18.44 mg kg⁻¹ DW). Considerable amounts of sterols, namely fucosterol (317.68 ± 26.11 mg kg⁻¹ DW) were also found. In vitro tests demonstrated that the B. bifurcata lipophilic extract show antioxidant, anti-inflammatory and antibacterial activities (against both Gram-positive and Gram-negative bacteria), using low extract concentrations (in the order of µg mL⁻¹). Enhancement of antibiotic activity of drug families of major clinical importance was observed by the use of B. bifurcata extract. This enhancement of antibiotic activity depends on the microbial strain and on the antibiotic. This work represents the first detailed phytochemical study of the lipophilic extract of B. bifurcata and is, therefore, an important contribution for the valorization of B. bifurcata macroalgae, with promising applications in functional foods, nutraceutical, cosmetic and biomedical fields.

Immunostimulatory Activity of Opuntia ficus-indica var. Saboten Cladodes Fermented by Lactobacillus plantarum and Bacillus subtilis in RAW 264.7 Macrophages

To increase the functionality of Opuntia ficus-indica var. saboten cladodes, it was fermented by Lactobacillus plantarum and Bacillus subtilis. Eighty percent methanol extracts were investigated for their effects on nitric oxide (NO) production, cytokine secretion, nuclear factor-κB (NF-κB) activity, and mitogen-activated protein kinase (MAPK) phosphorylation in RAW 264.7 cells. Methanol extracts of L. plantarum culture medium (LPCME) and B. subtilis culture medium (BSCME) did not affect lipopolysaccharide (LPS)-induced NO production but, at 500 μg/mL, increased interferon (IFN)-γ-induced NO production by 55.2 and 66.5 μM, respectively, in RAW 264.7 cells. In RAW 264.7 cells not treated with LPS and IFN-γ, LPCME did not affect NO production, but BSCME increased NO production significantly in a dose-dependent manner. In addition, BSCME induced the expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in RAW 264.7 cells in a dose-dependent manner. BSCME at 500 μg/mL increased TNF-α and IL-1β mRNA levels by 83.8% and 82.2%, respectively. BSCME increased NF-κB-dependent luciferase activity in a dose-dependent manner; 500 μg/mL BSCME increased activity 9.1-fold compared with the control. BSCME induced the phosphorylation of p38, c-JUN NH₂-terminal protein kinase (JNK), and extracellular signal-regulated kinase (ERK) in a dose-dependent manner, but did not affect total ERK levels. In conclusion, BSCME exerted immunostimulatory effects, which were mediated by MAPK phosphorylation and NF-κB activation, resulting in increased TNF-α and IL-1β gene expression in RAW 264.7 macrophages. Therefore, BSCM shows promise for use as an immunostimulatory therapeutic.