Molecular mechanism of action responsible for carrageenan-induced inflammatory response

Therapeutic potential of (1 → 4)-linked glucuronoglucan from an edible brown mussel Perna indica: A promising candidate for anti-inflammatory and antidyslipidemic nutraceuticals

The brown mussel, Perna indica (Kuriakose & Nair, 1976), family Mytilidae, is harvested along the southwest coast of India for its rich nutritional composition and therapeutic potential. This study highlights the role of PIP-1, a (1 → 4)-linked glucuronoglucan derived from Perna indica composed of repeating pyranose units of β-d-glucose (Glcp) and α-D-glucuronic acid (GlcAp), in alleviating chronic diseases. PIP-1 demonstrated potent anti-inflammatory activity by attenuating 5-lipoxygenase (5-LOX) and cyclooxygenases (COXs) (IC₅₀ ≤ 1.5 mg/mL), with preferential COX-2 selectivity and reduced nitric oxide levels (IC₅₀ 2.9 μg/mL) in lipopolysaccharide-induced macrophages. In vivo models demonstrated that PIP-1, at higher dose, significantly reduced acute paw edema (91 % within 5 h) induced by carrageenan and chronic paw edema (77 % within day 10) induced by formalin. PIP-1 exhibited a potent antihypercholesterolemic effect by inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase (IC₅₀ 0.86 mg/mL) and significantly reduced triglyceride levels by 8-54 % in Caco-2 cells. In vivo studies showed that PIP-1 reduced total cholesterol by 68 % and triglycerides by 25 % in dyslipidemic rats after 48 h of acute study. In chronic studies, reductions of 19 % in total cholesterol and 46 % in triglycerides were observed after 45 days. The therapeutic potential of PIP-1 largely stems from its electronegative groups, which increase its total polar surface area, thereby facilitating receptor interactions through Van der Waals forces and modulating key metabolic pathways. Given its notable anti-inflammatory and antidyslipidemic effects, PIP-1 presents a promising source for developing nutraceutical products designed to alleviate chronic ailments.

Chronic intermittent ethanol produces nociception through endocannabinoid-independent mechanisms in mice

Alcohol use disorder (AUD) affects millions of people and represents a significant health and economic burden. Pain is a frequently under-treated aspect of hyperkatifeia during alcohol withdrawal, yet to date no drugs have received FDA approval for the treatment of this indication in AUD patients. This study aims to evaluate the potential of targeting bioactive lipid signaling pathways as a therapeutic approach for treating alcohol withdrawal-related pain hypersensitivity. We utilized a chronic intermittent ethanol (CIE) vapor exposure model in C57BL/6J mice of both sexes to establish alcohol dependence and demonstrated that CIE produced robust tactile allodynia and thermal hyperalgesia during withdrawal that was independent of prior blood alcohol levels. Next, we evaluated four drugs for their efficacy in reversing tactile allodynia during abstinence from CIE using a cross-over treatment design that included FDA-approved naltrexone as well as commercially available inhibitors targeting the inflammatory lipid signaling enzymes fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), and 15-Lipoxygenase (LOX). None of these compounds produced significant therapeutic benefit in reversing established CIE-induced tactile allodynia, despite attenuating pain-like behaviors at these doses in other chronic pain models. Additionally, we assessed plasma endocannabinoid levels in both sexes during withdrawal. We found that there was an inherent sex difference in the endogenous anti-inflammatory endocannabinoid tone in naive mice and that CIE treatment affected endocannabinoids levels in female mice only. These findings underscore the need to better understand the underlying causes of AUD-induced allodynia and to develop novel therapeutic approaches to mitigate pain hypersensitivity in AUD patients.

Moxifloxacin in HPMC-nanocellulose composite film for the management of ocular inflammation: Effect of carboxymethylated gum on permeation and antimicrobial activity

Moxifloxacin (MFX) is known to decrease inflammation in lung infection by inhibiting interleukin-8 secretion and tumor necrosis factor-alpha production. Carboxymethylated gum combined with hydroxypropyl methylcellulose (HPMC)-nanocellulose (NCC) composite films were developed for the management of ocular inflammation and improved antimicrobial activity of MFX. Carboxymethyl starch (CMS), carboxymethyl tamarind (CMT), or carboxymethyl cellulose (CMC) gum in HPMC-nanocellulose composite film formulation was prepared using solvent casting method for studying ocular anti-inflammatory effect of MFX after ocular application using carrageenan-induced rabbit eye model. Presence of NCC and methylated gum sustained the corneal drug permeation. Improved antimicrobial activity has also been observed due to the combined effect of NCC and methylated gum. Highest zone of inhibition against gram-positive and gram-negative bacteria has been resulted owing to CMT in the film. MTT assay exhibited biocompatibility with human epithelial corneal cells (>84 % and above). A favourable docking score was found with MFX (-6.1 and -6.2 kcal/mol for interleukin and Tumor Necrosis Factor-α, respectively). Ocular inflammation was also diminished within 2 h of using film (CMT), whereas inflammation continued for >3 h of the induced rabbit without film. CMT incorporated film could be used for better management of inflammation associated with bacterial conjunctivitis.

Toxicological analysis and anti-inflammatory and antioxidant evaluations of extract, fractions and secoxyloganin obtained from Guettarda viburnoides Cham. & Schltdl. in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Guettarda viburnoides, "veludinho do campo," is traditionally used for the treatment of pain and inflammatory conditions in humans; however, only one scientific study has reported this effect in an ear inflammatory model. Therefore, it is necessary to explore other in vivo models and the chemical composition of this medicinal plant.

AIM OF THE STUDY

A chemical investigation of methanolic extract of G. viburnoides (MEGV) (leaves) led to the isolation of secoxyloganin (GV-1). In addition, the preclinical safety of MEGV (in acute and subacute toxicological models, gavage = p.o.), antioxidants of MEGV, ethyl acetate (EAFGV) and hydromethanolic (HMFGV) fractions were tested using free radical scavenging and lipid peroxidation methodologies, and the anti-inflammatory effects of MEGV, HMFGV and GV-1 (p.o.) were evaluated on carrageenan and complete Freund's adjuvant (CFA) models of inflammation in mice.

MATERIALS AND METHODS

MEGV was obtained from air-dried leaves by maceration with methanol at room temperature. MEGV was then purified by liquid-liquid partitioning, to obtain the EAFGV and HMFGV fractions. Purification of HMFGV afforded GV-1. The quantification of total phenols, flavonoids, flavonols, and condensed tannins was subsequently performed for MEGV. The antioxidant activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and oxidation of β-carotene were evaluated in MEGV and its fractions. The anti-inflammatory activity of MEGV (3, 30, and 100 mg/kg, p.o.) was assayed in carrageenan-induced models, followed by assessments of MEGV (100 mg/kg, p.o.), HMFGV (3 and 30 mg/kg, p.o.) and GV-1 (3 mg/kg, p.o.) in CFA-induced models in mice (including paw oedema, mechanical allodynia and cold sensitivity). Acute (14 days of MEGV, 2000 mg/kg, p.o.) and subacute (28 days, MEGV 30, 100, and 300 mg/kg, p.o.) toxicity was assessed in female Swiss mice.

RESULTS

The major compound was secoxyloganin (GV-1). The oral acute toxicity test of MEGV revealed no evidence of toxicity, indicating low toxicity according to the Organization for Economic Cooperation and Development (OECD) guidelines. In the subacute toxicity group, no clinical signs of toxicity or changes in body weight, water consumption, food consumption, or organ weight or morphology were observed after 28 days of gavage with MEGV (30, 100, and 300 mg/kg) compared with those in the control group. MEGV, EAFGV, and HMFGV showed significant free-radical scavenging and lipid peroxidation activities, with IC50 values ≤ 26.38 ± 4.56 μg/mL. In in vivo anti-inflammatory assays, MEGV (3, 30 and 100 mg/kg) reduced carrageenan-induced oedema (2 and 4 h) and hyperalgesia (3 and 4 h). In the CFA model, MEGV (100 mg/kg), HMFGV (30 mg/kg) and GV-1 (3 mg/kg) reduced inflammation (at 3, 4 and 24 h) in all parameters (oedema, mechanical allodynia and cold sensitivity).

CONCLUSION

This study revealed that G. viburnoides has antioxidant and anti-inflammatory properties, and no toxicity was detected after acute or subacute gavage with MEGV, validating its traditional use in the treatment of inflammatory conditions.

Chronic intermittent ethanol produces nociception through endocannabinoid-independent mechanisms in mice

Alcohol use disorder (AUD) affects millions of people and represents a significant health and economic burden. Pain represents a frequently under-treated aspect of hyperkatifeia during alcohol withdrawal, yet to date no drugs have received FDA approval for the treatment of this indication in AUD patients. This study aims to evaluate the potential of targeting bioactive lipid signaling pathways as a therapeutic approach for treating alcohol withdrawal-related pain. We utilized a chronic intermittent ethanol (CIE) vapor exposure model in C57BL/6J mice of both sexes to establish alcohol dependence, and demonstrated that CIE mice developed robust tactile allodynia and thermal hyperalgesia during withdrawal that was independent of prior blood alcohol levels. Next, we evaluated four drugs for their efficacy in reversing tactile allodynia during abstinence from CIE using a cross-over treatment design that included FDA-approved naltrexone as well as commercially available inhibitors targeting inflammatory lipid signaling enzymes including fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), and 15-Lipoxygenase (LOX). None of these compounds produced significant therapeutic benefit in reversing established CIE-induced tactile allodynia, despite attenuating pain-like behaviors at these doses in other chronic pain models. Additionally, we assessed plasma endocannabinoid levels in both sexes during withdrawal. We found that there is an inherent sex difference in the endogenous anti-inflammatory endocannabinoid tone in naive mice and CIE treatment affected endocannabinoids levels in female mice only. These findings underscore the need to better understand the driving causes of AUD induced pain and to develop novel therapeutic approaches to mitigate pain in AUD patients.

Modulation of PI3K/AKT signaling and DFT modeling via selected pharmaceutical compounds attenuates carrageenan-induced inflammation and oxidative stress in rats

The main goal of the current study is to estimate the in vivo anti-inflammatory/antioxidant ability of four selected pharmaceutical compounds: bisoprolol (Biso), piracetam (Pirc), clopidogrel (Clop), and cinnarizine (Cinna). Indomethacin (Indo) was used as a reference drug to perform a realistic comparison between the four compounds and the Indo in vivo through tracking PI3K/AKT signaling and computational chemistry via density functional theory (DFT) modeling to analyze the electrostatic potential across the molecule and provide insight into the regions for receptor binding of the studied compounds. To achieve the safe dose of these compounds, cytotoxicity was performed against isolated adipose tissue-derived mesenchymal stem cells (ADMSCs) using MTT assay. In vivo determination of anti-inflammatory/antioxidant biochemical and genetic parameters of the tested compounds against rats' paw carrageenan (Carg)-induced inflammation was assessed. The data showed that there was no significant different in cell viability of ADMSCs until dose 10 µg/ml, so we used this concentration for in vivo experiments. Carg high significantly increased the volume of the paw edema at 120 min and 180 min compared to the control group (p < 0.01). Cinna (10 mg/kg), relatively similar to Indo, was the most anti-inflammatory compound among others, followed by Clop and Pirc, where they decreased the volume of the paw edema significantly (p < 0.01) at 120 min and 180 min compared to the Carg-group. Microscopic examination confirmed the above results indicating that paw tissue of Carg-group shows edema formation and massive inflammation compared with control. In comparison to the control group, Carg high significantly increased the malondialdehyde (MDA) levels (p < 0.01), whereas, at the concentration 10 mg/kg of the tested compounds, the MDA concentrations significantly reduced, especially the Clop, Cinna, and Indo-treated groups. On the contrary, total antioxidant capacity (TAC) and 5-lipoxygenase (5-LOP) concentrations were significantly decreased in Carg-group (p < 0.01) compared with control. Cyclooxygenase-2 (COX-2), phosphoinositide 3-kinase (PI3k), and protein kinase B (AKT) gene expressions were high and significantly upregulated in Carg-group compared to control, while the tested compounds downregulated their expressions compared to the Carg-group. Moreover, COX-2, interleukins (IL-10/IL-6/IL-4), PI3k, and AKT protein concentrations were high and significantly increased in Carg-group compared to control, however the tested compounds were high and significantly decreased their concentrations compared to the Carg-group. DFT modeling aligned with the biochemical data and indicated that Cinna emerges as the most reactive drug with high polarizability (302.741 a.u.), a relative small FMOs energy gap (ΔE 5.002 eV), relative low molecular hardness (2.501 eV), relative high softness (0.400 eV-1), and distinct nucleophilic/electrophilic interaction sites, indicating strong specific interactions with biological receptor. In conclusion, this study revealed the ability of Cinna to potentially suppress inflammation in in vivo Carg-induced rat paw inflammation model through inhibition of PI3K/AKT signaling and DFT modeling mediated by oxidative stress and inflammatory mediators.

Carrageenan and TLR4 Crosstalk: A Comprehensive Review of Inflammatory Responses in Animal Models

Carrageenan, a naturally occurring polysaccharide derived from red seaweed, has been utilized extensively in the food industry as a stabilizer, thickener, and emulsifier due to its unique gel-forming properties. This versatile compound exists in various forms, including kappa, iota, and lambda, each with distinct characteristics suitable for different applications. Its widespread use as a food additive has raised concerns regarding its safety, particularly its potential inflammatory effects on the gastrointestinal tract. While carrageenan has been deemed safe for consumption by regulatory agencies in small amounts, studies have suggested its association with intestinal inflammation and gastrointestinal disturbances, particularly in susceptible individuals. Animal models, including rodents and non-human primates, have been employed to investigate the inflammatory response induced by carrageenan ingestion. These models have provided valuable insights into the molecular mechanisms underlying its pro-inflammatory properties. At the molecular level, carrageenan is believed to trigger inflammation by activating toll-like receptor 4 (TLR4) signaling pathways, leading to the production of pro-inflammatory cytokines and the recruitment of immune cells to the site of exposure. Furthermore, carrageenan-induced inflammation may disrupt the intestinal barrier function, facilitating the translocation of luminal antigens and exacerbating immune responses. This review provides a comprehensive examination of the current understanding of carrageenan's role in inflammation, encompassing its diverse applications in the food industry, safety concerns, experimental findings from animal models, and molecular mechanisms underlying its pro-inflammatory effects.

Anti-inflammatory and antiophidic effects of extract of Hymenaea eriogyne benth and structure-activity relationship prediction of the major markers in silico

ETHNOPHARMACOLOGICAL RELEVANCE

Hymenaea eriogyne Benth (Fabaceae) is popularly known as "Jatobá". Despite its use in folk medicine to treat inflammatory disorders, there are no descriptions that show its anti-inflammatory potential.

AIM OF THE STUDY

In this sense, this study aimed to evaluate the anti-inflammatory and antivenom action of bark and leaves extract of H. eriogyne.

MATERIALS AND METHODS

The in vivo anti-inflammatory activity was conducted by carrageenan-induced paw edema and zymosan-induced air pouch models, evaluating the edematogenic effect, leukocyte migration, protein concentration, levels of pro-inflammatory cytokines, malondialdehyde (MDA) and myeloperoxidase (MPO) activity. The antivenom potential was investigated in vitro on the enzymatic action (proteolytic, phospholipase and hyaluronidase) of Bothrops brazili and B. leucurus venom, as well as in vivo on the paw edema model induced by B. leucurus. Furthermore, the influence of its markers (astilbin and rutin) on MPO activity was investigated in silico. For molecular docking, AutodockVina, Biovia Discovery Studio, and Chimera 1.16 software were used.

RESULTS

The extracts and bark and leaves of H. eriogyne revealed a high anti-inflammatory effect, with a reduction in all inflammatory parameters evaluated. The bark extract showed superior results when compared to the leaf extract, suggesting the influence of the astilbin concentration, higher in the bark, on the anti-inflammatory action. In addition, only the H. eriogyne bark extract was able to reduce MDA, indicating an associated antioxidant effect. Regarding the in vitro antivenom action, the extracts (bark and leaves) revealed the ability to inhibit the proteolytic, phospholipase and hyaluronidase action of both bothropic venom, with a greater effect against B. leucurus venom. In vivo, extracts from the bark and leaves of H. eriogyne (50-200 mg/kg) showed antiedematogenic activity, reducing the release of MPO and pro-inflammatory cytokines, indicating the presence of bioactive components useful in controlling the inflammatory process induced by the venom. In the in silico assays, astilbin and rutin showed reversible interactions of 9 possible positions and orientations towards MPO, with affinities of -9.5 and -10.4 kcal/mol and interactions with Phe407, Gln91, His95 and Arg239, important active pockets of MPO. Rutin demonstrated more effective types of interactions with MPO.

CONCLUSION

This approach reveals for the first time the anti-inflammatory action of H. eriogyne bark and leaf extracts in vivo, as well as its antiophidic potential. Moreover, the distinct effect of pharmacogens as antioxidant agents and distinct effect of astilbin and rutin under MPO sheds light on the different anti-inflammatory mechanisms of bioactive compounds present in H. eriogyne extracts, with high potential for the prospection of new pharmacological agents.

Trolox, Ferulic, Sinapic, and Cinnamic Acid Derivatives of Proline and GABA with Antioxidant and/or Anti-Inflammatory Properties

Degenerative conditions, such as neurodegenerative disorders (Alzheimer's disease (AD), Parkinson's disease (PD)) and cardiovascular diseases, are complex, multifactorial disorders whose pathophysiology has not been fully elucidated yet. As a result, the available treatment options cannot eliminate these diseases radically, but only alleviate the symptoms. Both inflammatory processes and oxidation are key factors in the development and evolution of neurodegeneration, while acetylcholinesterase inhibitors are the most used therapeutic options against AD. In this work, following the multi-targeting compound approach, we designed and synthesized a series of proline and gamma-aminobutyric acid (GABA) amides with various acidic moieties that possess an antioxidant and/or anti-inflammatory potency. Proline is the pharmacophore of nootropic drugs (e.g., piracetam) used for memory improvement, while GABA is the main inhibitory neurotransmitter in the central nervous system. The designed molecules were subjected to a preliminary screening of their bioactivity in antioxidant and anti-inflammatory assays, as well as against acetylcholinesterase. Most of the synthesized compounds could inhibit lipid peroxidation (IC50 as low as 8 μΜ) and oxidative protein glycation (inhibition of up to 48%) and reduce the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH). In addition, all of the compounds were moderate inhibitors of lipoxygenase (LOX) (up to 46% at 100 μΜ) and could decrease carrageenan-induced paw edema in rats by up to 55%. Finally, some of the compounds were moderate acetylcholinesterase inhibitors (IC50 as low as 219 μΜ). The results confirmed the design rationale, indicating that the compounds could be further optimized as multi-targeting molecules directed against degenerative conditions.

Models in vivo and in vitro for the study of acute and chronic inflammatory activity: A comprehensive review

Inflammatory conditions are among the principal causes of morbidity worldwide, and their treatment continues to be a challenge, given the restricted availability of effective and safe drugs. Thus, the identification of new compounds with biological activity that can be used for the treatment of inflammatory disorders is an essential field in medical and health research, in order to improve the health and quality of life of patients suffering from these diseases. Evaluation of the anti-inflammatory activity of drugs requires the implementation of models that accurately depict the biochemical and/or physiological responses that characterize human inflammation; for this reason, several in vitro and in vivo models have been developed, providing a platform for discovering novel or repurposed compounds. For this reason, in the present review we have selected twelve commonly used models for the evaluation of the anti-inflammatory effect, and extensively describes the difference between in vivo and in vitro models of inflammation, highlighting their advantages and limitations. On the other hand, the inflammatory mechanisms involved in them, the methods employed for their establishment, and the different parameters assessed to determine the anti-inflammatory activity of a given compound are extensively discussed. We expect to provide a comprehensive guide for the improved selection of a suitable model for the preclinical evaluation of plausible anti-inflammatory agents.

Comparative Bioactivities of Chemically Modified Fucoidan and λ-Carrageenan toward Cells Encapsulated in Covalently Cross-Linked Hydrogels

The sulfated marine polysaccharides, fucoidan and λ-carrageenan, are known to possess anti-inflammatory, immunomodulatory, and cellular protective properties. Although they hold considerable promise for tissue engineering constructs, their covalent cross-linking in hydrogels and comparative bioactivities to cells are absent from the literature. Thus, fucoidan and λ-carrageenan were modified with methacrylate groups and were covalently cross-linked with the synthetic polymer poly(vinyl alcohol)-methacrylate (PVA-MA) to form 20 wt % biosynthetic hydrogels. Identical degrees of methacrylation were confirmed by 1H NMR, and covalent conjugation was determined by using a colorimetric 1,9-dimethyl-methylene blue (DMMB) assay. Pancreatic beta cells were encapsulated in the hydrogels, followed by culturing in the 3D environment for a prolonged period of 32 days and evaluation of the cellular functionality by live/dead, adenosine 5'-triphosphate (ATP) level, and insulin secretion. The results confirmed that fucoidan and λ-carrageenan exhibited ∼12% methacrylate substitution, which generated hydrogels with stable conjugation of the polysaccharides with PVA-MA. The cells encapsulated in the PVA-fucoidan hydrogels demonstrated consistently high ATP levels over the culture period. Furthermore, only cells in the PVA-fucoidan hydrogels retained glucose responsiveness, demonstrating comparatively higher insulin secretion in response to glucose. In contrast, cells in the PVA-λ-carrageenan and the PVA control hydrogels lost all glucose responsiveness. The present work confirms the superior effects of chemically modified fucoidan over λ-carrageenan on pancreatic beta cell survival and function in covalently cross-linked hydrogels, thereby illustrating the importance of differential polysaccharide structural features on their biological effects.

The antioxidant, anti-inflammatory and analgesic activity effect of ethyl acetate extract from the flowers of Syringa pubescens Turcz

ETHNOPHARMACOLOGICAL RELEVANCE

Syringa Pubescens Turcz. (SP), a member of the Oleaceae family, is a species of plant known as Syringa. Flowers, as the medicinal part, are commonly used in the treatment of hepatitis and tonsillitis.

AIM OF THE STUDY

The research was the first to assess the antioxidant and anti-inflammatory potential of different parts of SP flowers (SPF) in vitro. The most promising fraction was ethyl acetate fraction of SP flower (SPFEA). The antioxidant, anti-inflammatory and analgesic activities of SPFEA were further studied, and the chemical components were identified.

METHODS

HPLC was used to identify the major components in various fraction of SPF. DPPH and ABTS + radical scavenging assays as well as FRAP test and β-carotene bleaching test were employed to assess the antioxidant potential of SPF fraction in vitro. The inhibitory effect on NO production in LPS-treated RAW264.7 cells and heat-induced protein denaturation test were used to evaluate the anti-inflammatory potential of SPF fraction. Further analysis of the biological activity of SPFEA was performed. Acute toxicity test was conducted to assess the toxicity of SPFEA. The anti-inflammatory effect was assessed by utilizing xylene induced ear edema model, carrageenan-induced foot edema model and peritonitis model in vivo. The analgesic effect of SPFEA was evaluated using hot plate test, tail immersion test, formaldehyde test as well as acetic acid-induced abdominal writhing pain experiment in vivo. In carrageenan induced foot edema model, ELISA kits were employed to measure levels of inflammation factors (NO, TNF-α, IL-6, COX-2, IL-1β) in foot tissue as well as MDA, CAT, SOD, GSH-PX levels in liver tissue.

RESULTS

HPLC results showed that there were significant differences in bioactive substances among different fractions of SPF, and SPFEA was rich in bioacitve components. Compared with other fractions of SPF, SPFEA exhibited better antioxidant and anti-inflammatory abilities. The 3000 mg/kg SPFEA group in mice had no obvious side effects. The xylene-induced ear edema model, carrageenan-induced foot edema and peritonitis models demonstrated that the SPFEA had significant anti-inflammatory effect. Moreover, inflammation factors including NO, TNF-α, IL-6, COX-2, IL-1β were significantly reduced in SPFEA groups in foot tissue induced by carrageenan. Additionally, SPFEA effectively decreased liver tissue oxidative stress levels (MDA, SOD, GSH-PX and CAT). The bioactivities of SPFEA demonstrated a clear dose-dependent relationship. The results of the hot plate test, tail immersion test, formaldehyde test and acetic acid-induced abdominal writhing pain experiments indicated the SPFEA possessed an excellent analgesic effect, and this effect was in dose-dependent manner.

CONCLUSION

The study provides a scientific foundation for understanding the pharmacological action of SPFEA. It has been indicated that SPFEA has excellent antioxidant, analgesic and anti-inflammatory effects.

Polyphenols and extracts from Zingiber roseum (Roxb.) Roscoe leaf mitigate pain, inflammation and pyrexia by inhibiting cyclooxygenase-2: an in vivo and in silico studies

Zingiber roseum (Roxb.) Roscoe, a perennial herb from the Zingiberaceae family, has a long history of traditional use in the treatment of several ailments including pain, inflammation, fever, cough, arthritis, skin diseases, and liver infections. This study sought to confirm the efficacy of Zingiber roseum (Roxb.) Roscoe leaves methanol extract (ZrlME) as reported in traditional usage by evaluating its analgesic, anti-inflammatory, and antipyretic capabilities. In addition, in silico molecular docking of the metabolites identified in ZrlME was studied to verify the experimental outcomes. ZrlME demonstrated strong dose-dependent analgesic efficacy against all analgesic tests. ZrlME (400 mg/kg) showed higher anti-inflammatory activity than the standard in the carrageenan-induced paw edema test model. A significant reduction of rectal temperature (3.97°F↓) was also recorded at the same dose of ZrLME after 24 h of treatment. Seven polyphenolic metabolites were identified and quantified by HPLC-DAD analysis, including 3, 4- dihydroxy benzoic acid, (-) epicatechin, rutin hydrate, p-coumaric acid, trans-ferulic acid, rosmarinic acid, and myricetin. Strong binding affinities (ranges from -5.8 to -8.5 Kcal/mol) between the aforesaid polyphenols and cyclooxygenase-2 were discovered. Moreover, molecular dynamics simulations (MDS) demonstrated that these polyphenols exhibit significant COX-2 inhibitory activity due to their high stability in the COX-2 active site. In computational prediction, the polyphenols were also found to be nontoxic, and a variety of biological activities, such as antioxidant, analgesic, anti-inflammatory, antipyretic, and hepatoprotective, were observed. The results of this study revealed that ZrlME possesses notable analgesic, anti-inflammatory, and antipyretic properties.

Anti-inflammatory potential of a Thai traditional remedy called Prabchompoothaweep in an animal model of acute and sub-acute inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Prabchompoothaweep (PCT) is a Thai remedy which is composed of 23 herbs and has been added onto the National List of Essential Medicines (NLEM) of Thailand. This remedy has been used to treat allergic rhinitis and asthma in Thai traditional medicine for many years. Furthermore, a few studies have reported anti-allergic, anti-malarial, anti-inflammatory and antioxidant activities.

AIM OF THE STUDY

This study aims to evaluate anti-inflammatory activity of PCT extract in an animal model.

MATERIALS AND METHODS

The animal model of acute inflammation was studied over a 24-h period, utilizing the method of carrageenan-induced paw oedema. In addition, sub-acute inflammation was examined over 7 days, using the formalin-induced paw oedema method. The treatment groups received PCT extracts, via the oral route, at 1-h prior to injection and then the sub plantar of the rat right paw was injected with the named substances to generate paw oedema. The paw thickness was measured by vernier caliper at regular intervals after injection. At the end of experiment, the blood and paw tissues were collected for measurement of pro-inflammatory cytokines and histological examination respectively.

RESULTS

In acute inflammation, all doses of PCT extract (250, 500 and 1000 mg/kg p.o.) significantly reduced paw thickness after the first 3 h in a dose-dependent manner and the percentage of inhibition was 38.7%, 47.8% and 49.5% respectively. The pro-inflammatory cytokines, including TNF-α and IL-1β, statistically decreased with all doses of the extracts. However, the histological examination did not reveal significant results due to the short time duration. As regards to sub-acute inflammation, all doses of PCT extract significantly reduced paw thickness with 12.78%, 23.64% and 35.78%, in a dose dependent manner. Also, the pro-inflammatory cytokines (TNF-α and IL-1β) significantly decreased at day 7. Interestingly, the histological examination of paw tissue demonstrated reductions of mononuclear infiltrations of inflammatory cells, this was observed in the group receiving PCT extracts, also in a dose-dependent manner.

CONCLUSION

Therefore, PCT exerted anti-inflammatory activity in an animal model of acute and sub-acute inflammation, suggesting that it could be used as a new source for treatment of inflammatory diseases.

C-type lectin-like receptor-2 (CLEC-2) is a key regulator of kappa-carrageenan-induced tail thrombosis model in mice

Kappa-carrageenan (KCG), which is used to induce thrombosis in laboratory animals for antithrombotic drug screening, can trigger platelet aggregation. However, the cell-surface receptor and related signaling pathways remain unclear. In this study, we investigated the molecular basis of KCG-induced platelet activation using light-transmittance aggregometry, flow cytometry, western blotting, and surface plasmon resonance assays using platelets from platelet receptor-deficient mice and recombinant proteins. KCG-induced tail thrombosis was also evaluated in mice lacking the platelet receptor. We found that KCG induces platelet aggregation with α-granule secretion, activated integrin αIIbβ3, and phosphatidylserine exposure. As this aggregation was significantly inhibited by the Src family kinase inhibitor and spleen tyrosine kinase (Syk) inhibitor, a tyrosine kinase-dependent pathway is required. Platelets exposed to KCG exhibited intracellular tyrosine phosphorylation of Syk, linker activated T cells, and phospholipase C gamma 2. KCG-induced platelet aggregation was abolished in platelets from C-type lectin-like receptor-2 (CLEC-2)-deficient mice, but not in platelets pre-treated with glycoprotein VI-blocking antibody, JAQ1. Surface plasmon resonance assays showed a direct association between murine/human recombinant CLEC-2 and KCG. KCG-induced thrombosis and thrombocytopenia were significantly inhibited in CLEC-2-deficient mice. Our findings show that KCG induces platelet activation via CLEC-2.

Unveiling the Potent Fibrino(geno)lytic, Anticoagulant, and Antithrombotic Effects of Papain, a Cysteine Protease from Carica papaya Latex Using κ-Carrageenan Rat Tail Thrombosis Model

While fibrinolytic enzymes and thrombolytic agents offer assistance in treating cardiovascular diseases, the existing options are associated with a range of adverse effects. In our previous research, we successfully identified ficin, a naturally occurring cysteine protease that possesses unique fibrin and fibrinogenolytic enzymes, making it suitable for both preventing and treating cardiovascular disorders linked to thrombosis. Papain is a prominent cysteine protease derived from the latex of Carica papaya. The potential role of papain in preventing fibrino(geno)lytic, anticoagulant, and antithrombotic activities has not yet been investigated. Therefore, we examined how papain influences fibrinogen and the process of blood coagulation. Papain is highly stable at pH 4-11 and 37-60 °C via azocasein assay. In addition, SDS gel separation electrophoresis, zymography, and fibrin plate assays were used to determine fibrinogen and fibrinolysis activity. Papain has a molecular weight of around 37 kDa, and is highly effective in degrading fibrin, with a molecular weight of over 75 kDa. Furthermore, papain-based hemostatic performance was confirmed in blood coagulation tests, a blood clot lysis assay, and a κ-carrageenan rat tail thrombosis model, highlighting its strong efficacy in blood coagulation. Papain shows dose-dependent blood clot lysis activity, cleaves fibrinogen chains of Aα, Bβ, and γ-bands, and significantly extends prothrombin time (PT) and activated partial thromboplastin time (aPTT). Moreover, the mean length of the infarcted regions in the tails of Sprague-Dawley rats with κ-carrageenan was shorter in rats administered 10 U/kg of papain than in streptokinase-treated rats. Thus, papain, a cysteine protease, has distinct fibrin and fibrinogenolytic properties, suggesting its potential for preventing or treating cardiovascular issues and thrombosis-related diseases.

Galgravin Isolated from Piper kadsura Ameliorates Lipopolysaccharide (LPS)-Induced Endotoxemia in Mice

Sepsis results from uncontrolled inflammation, characterized by cytokine storm and immunoparalysis. To assess whether galgravin, a natural lignan isolated from Piper kadsura, can be used to treat sepsis, models of bacterial lipopolysaccharide (LPS)-activated macrophages and LPS-induced endotoxemia mice were used. Galgravin suppressed NF-κB activation in LPS-activated RAW 264.7 macrophages without causing significant cytotoxicity, in which proinflammatory molecules like TNF-α, IL-6, iNOS, and COX-2 were downregulated. In addition, the expression of TNF-α and IL-6 was also suppressed by galgravin in LPS-activated murine bone marrow-derived macrophages. Moreover, galgravin significantly downregulated the mRNA expression of TNF-α, IL-6, and iNOS in the lungs and decreased TNF-α and IL-6 in the serum and IL-6 in the bronchoalveolar lavage fluid of LPS-challenged mice. The COX-2 expression in tissues, including the lung, liver, and kidney, as well as the lung alveolar hemorrhage, was also reduced by galgravin. The present study reveals the anti-inflammatory effects of galgravin in mouse models and implies its potential application in inflammation diseases.

In Vitro and In Vivo Anti-Inflammatory Effects of Cannabidiol Isolated from Novel Hemp (Cannabis sativa L.) Cultivar Pink Pepper

Cannabis sativa L. contains more than 80 cannabinoids, among which cannabidiol (CBD) is the main neuroactive component. We aimed to investigate the anti-inflammatory efficacy of CBD in vitro and in vivo isolated from "Pink pepper", a novel hemp cultivar, by repeating the method of selecting and cultivating individuals with the highest CBD content. We investigated the effects of CBD on inflammatory markers elevated by lipopolysaccharide (LPS) treatment in RAW 264.7 mouse macrophage cells through Western blot and RT-PCR. In addition, we confirmed these effects through the ELISA of inflamed paw tissue of a λ-carrageenan-induced mouse edema model that received an oral administration of CBD. CBD inhibited the LPS-induced phosphorylation of NF-κB and MAPK in RAW 264.7 and exhibited anti-inflammatory effects by participating in these pathways. In our in vivo study, we confirmed that CBD also inhibited the inflammatory mediators of proteins extracted from edematous mouse paw tissue. These results show that CBD isolated from "Pink pepper" exhibits potent anti-inflammatory effects. These anti-inflammatory effects of CBD have pharmacological and physiological significance, highlighting the industrial value of this novel cultivar.

IL-33/ST2 signaling in pain and itch: Cellular and molecular mechanisms and therapeutic potentials

Pain is a cardinal feature of many diseases. Chronic pain poses heavy burdens to the suffering patients, both physically and mentally. However, current mainstream medications for chronic pain, including opioids, antidepressants and non-steroid anti-inflammatory drugs are sometimes inefficient for chronic pain management and may cause side effects that limit long term usage. IL-33 belongs to IL-1 cytokine family and it exerts biological activities through binding to its specific receptor ST2. IL-33/ST2 signaling is very important in both innate and adaptive immunity. Emerging evidence indicates IL-33/ST2 signaling regulates pain in both immune and somatosensory systems through promoting neuro-immune or neuron-glia crosstalk, neuroinflammation and neuronal hyperexcitability. Some very latest studies indicate a vital part of IL-33/ST2 in mediating chronic itch. This work aims to overview the existing knowledge regarding the mechanisms of IL-33/ST2 involvement in pain and itch conditions, considering their potential similarities. We also summarized some key findings obtained from clinical studies. The targeting of IL-33/ST2 signaling holds promise for the development of novel therapeutic modalities in the management of pain and itch.

Inflammatory Orofacial Pain Activates Peptidergic Neurons and Upregulates the Oxytocin Receptor Expression in Trigeminal Ganglion

The majority of orofacial pain is caused by musculoskeletal and neuropathological diseases related to inflammatory processes that lead even to transcriptional alterations in the trigeminal ganglion (TG) neurons. The hypothalamic nonapeptide oxytocin has been reported to modulate nociception via binding and activating its receptor in primary sensory neurons. The purpose of this study was to analyze the gene expression of the oxytocin receptor (OTR), c-Fos, an indicator of neuronal activity, and α-calcitonin gene-related peptide (αCGRP), a characteristic neurotransmitter of the peptidergic trigeminal primary afferents in an animal model of inflammation-induced orofacial pain. Carrageenan was unilaterally injected into the vibrissal pads of male and female adult Wistar rats. RT-qPCR was performed to analyze the levels of mRNA expression in TGs 24 h after injection. The gene expression analysis revealed higher fold changes regarding the c-Fos (mean ± S.E: ♀: 3.9 ± 0.19; ♂: 3.55 ± 0.18) and αCGRP (♀: 2.84 ± 0.13; ♂: 3.39 ± 0.47) expression levels of mRNA, and a moderate rise in the expression of the OTR mRNA (♀: 1.52 ± 0.07; ♂: 1.49 ± 0.07) was observed in comparison to both vehicle(saline)-treated and untreated controls. Our results furnish evidence for inflammation-induced activation of peptidergic neurons, and it is suggested that oxytocin modulates inflammation-induced nociception by enhancing their signaling capacity due to its elevated expression in the sensory ganglion cells, thus providing new therapies for orofacial pain relief that target the OTRs.

Contemporary Aspects of Designing Marine Polysaccharide Microparticles as Drug Carriers for Biomedical Application

The main goal of modern pharmaceutical technology is to create new drug formulations that are safer and more effective. These formulations should allow targeted drug delivery, improved drug stability and bioavailability, fewer side effects, and reduced drug toxicity. One successful approach for achieving these objectives is using polymer microcarriers for drug delivery. They are effective for treating various diseases through different administration routes. When creating pharmaceutical systems, choosing the right drug carrier is crucial. Biomaterials have become increasingly popular over the past few decades due to their lack of toxicity, renewable sources, and affordability. Marine polysaccharides, in particular, have been widely used as substitutes for synthetic polymers in drug carrier applications. Their inherent properties, such as biodegradability and biocompatibility, make marine polysaccharide-based microcarriers a prospective platform for developing drug delivery systems. This review paper explores the principles of microparticle design using marine polysaccharides as drug carriers. By reviewing the current literature, the paper highlights the challenges of formulating polymer microparticles, and proposes various technological solutions. It also outlines future perspectives for developing marine polysaccharides as drug microcarriers.

Anti-Inflammatory Study and Phytochemical Characterization of Zingiber officinale Roscoe and Citrus limon L. Juices and Their Formulation

Zingiber officinale and Citrus limon, well known as ginger and lemon, are two vegetals widely used in traditional medicine and the culinary field. The juices of the two vegetals were evaluated based on their inflammation, both in vivo and in vitro. High-performance liquid chromatography (HPLC) was used to characterize different juices from Zingiber officinale Roscoe and Citrus limon. After the application of the HPLC method, different compounds were identified, such as 6-gingerol and 6-gingediol from the ginger juice and isorhamnetin and hesperidin from the lemon juice. In addition, the two juices and their formulation were assessed for their anti-inflammatory activity, in vitro by utilizing the BSA denaturation test, in vivo using the carrageenan-induced inflammation test, and the vascular permeability test. Important and statistically significant anti-inflammatory activities were observed for all juices, especially the formulation. The results of our work showed clearly that the Zingiber officinale and Citrus limon juices protect in vivo the development of the rat paw edema, especially the formulation F composed of the Zingiber officinale and Citrus limon juices, which shows an anti-inflammatory activity equal to -35.95% and -44.05% using 10 and 20 mg/kg of the dose, respectively. Our work also showed that the formulation was the most effective tested extract since it inhibits the vascular permeability by -37% and -44% at the doses of 200 and 400 mg/kg, respectively, and in vitro via the inhibition of the denaturation of BSA by giving a synergetic effect with the highest IC50 equal to 684.61 ± 7.62 μg/mL corresponding to the formulation F. This work aims to develop nutraceutical preparations in the future and furnishes the support for a new investigation into the activities of the various compounds found in Zingiber officinale Roscoe and Citrus limon.

Nanoemulsion curcumin injection showed significant anti-inflammatory activities on carrageenan-induced paw edema in Sprague-Dawley rats

Medicinal plants are candidates for the discovery of potential new anti-inflammatory agents. Curcumin is the active compound found in turmeric root, which has high anti-inflammatory activity. One of the limitations of curcumin as a therapeutic agent is its low solubility in water and extensive first-pass effect metabolism. The aim of this study was to formulate curcumin nanoemulsion for parenteral injection. We prepared curcumin nanoemulsions with a homogenizer using three surfactant concentrations (1.8%; 2.4%; and 3%) and two curcumin concentrations (1% and 3%). Formulas were evaluated for droplet diameter, polydispersity index, zeta potential, viscosity, pH, entrapment efficiency (EE), osmolality, sterility, and morphology. The nanoemulsion containing 1% curcumin and 3% surfactant (F3) demonstrated good stability. Curcumin nanoemulsions at 20 and 40 mg/kg doses showed anti-inflammatory activity on carrageenan-induced paw edema in male Sprague-Dawley rats. These two doses inhibited paw edema by 33% and 56% respectively at 5 h after carrageenan induction. Inhibition of edema volume by curcumin nanoemulsion at a dose of 40 mg/kg did not show a significant difference (P > 0.05) compared to the activity of the standard drug ketorolac at a dose of 2.7 mg/kg. We conclude that curcumin nanoemulsion has anti-inflammatory activity and can be a promising anti-inflammatory agent.

Protective effect of soloxolone derivatives in carrageenan- and LPS-driven acute inflammation: Pharmacological profiling and their effects on key inflammation-related processes

The anti-inflammatory potential of three cyanoenone-containing triterpenoids, including soloxolone methyl (SM), soloxolone (S) and its novel derivative bearing at the C-30 amidoxime moiety (SAO), was studied in murine models of acute inflammation. It was found that the compounds effectively suppressed the development of carrageenan-induced paw edema and peritonitis as well as lipopolysaccharide (LPS)-driven acute lung injury (ALI) with therapeutic outcomes comparable with that of the reference drugs indomethacin and dexamethasone. Non-immunogenic carrageenan-stimulated inflammation was more sensitive to the transformation of C-30 of SM compared with immunogenic LPS-induced inflammation: the anti-inflammatory properties of the studied compounds against carrageenan-induced paw edema and peritonitis decreased in the order of SAO > S > > SM, whereas the efficiency of these triterpenoids against LPS-driven ALI was similar (SAO ≈ S ≈ SM). Further studies demonstrated that soloxolone derivatives significantly inhibited a range of immune-related processes, including granulocyte influx and the expression of key pro-inflammatory cytokines and chemokines in the inflamed sites as well as the functional activity of macrophages. Moreover, SM was found to prevent inflammation-associated apoptosis of A549 pneumocytes and effectively inhibited the protease activity of thrombin (IC₅₀ = 10.3 µM) tightly associated with rodent inflammatome. Taken together, our findings demonstrate that soloxolone derivatives can be considered as novel promising anti-inflammatory drug candidates with multi-targeted mechanism of action.

Antioxidant, anti-inflammatory and analgesic activity of Mimosa acutistipula (Mart.) Benth

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants belonging to the genus Mimosa, such as Mimosa tenuiflora, M. caesalpinifolia, and M. verrucosa are known for their popular use for asthma, bronchitis and fever. Ethnopharmacological studies report that Mimosa acutistipula is used to treat alopecia and pharyngitis, conditions that can be related to oxidative stress, inflammatory processes and painful limitations. However, there is no studies on its efficacy and mechanism of action.

AIM OF THE STUDY

To elucidate the antioxidant, anti-inflammatory, analgesic and antipyretic activity of M. acutistipula leaves.

MATERIALS AND METHODS

Phytochemical profile of M. acutistipula extracts was evaluated by several reaction-specific methods. Secondary metabolites such as tannins, phenols and flavonoids were quantified with colorimetric assays. In vitro antioxidant potential was evaluated using DPPH and ABTS + as free radical scavenging tests, FRAP and phosphomolybdenum as oxide-reduction assays, and anti-hemolytic for lipid peroxidation evaluation. In vivo anti-inflammatory evaluation was performed by paw edema, and peritonitis induced by carrageenan. Analgesic effect and its possible mechanisms were determined by acetic acid-induced abdominal writhing and the formalin test. Antipyretic activity was evaluated by yeast-induced fever.

RESULTS

Cyclohexane, chloroform, ethyl acetate and methanol extracts of leaves had presence of tannins, flavonoids, phenol, alkaloids, terpenes (except methanolic extract), and saponins (only for methanolic and chloroformic extracts). In phenols, flavonoids and tannins quantification, methanolic and ethyl acetate extract had higher amounts of this phytocompounds. Ethyl acetate extract, due to its more expressive quantity of phenols and flavonoids, was chosen for carrying out the in vivo tests. Due to the relationship between oxidative stress and inflammation, antioxidant tests were performed, showing that ethyl acetate extract had a high total antioxidant activity (70.18%), moderate activity in DPPH radical scavenging, and a moderate ABTS + radical inhibition (33.61%), and FRAP assay (112.32 μg Fe²⁺/g). M. acutistipula showed anti-inflammatory activity, with 54.43% of reduction in paw edema (50 mg/kg) when compared to the vehicle. In peritonitis test, a reduction in the concentration of NO could be seen, which is highly involved in the anti-inflammatory activity and is responsible for the increase in permeability. In the analgesic evaluation, most significant results in writhing test were seen at 100 mg/kg, with a 34.7% reduction of writhing. A dual mechanism of action was confirmed with the formalin test, both neurogenic and inflammatory pain were reduced, with a mechanism via opioid route. In the antipyretic test, results were significantly decreased at all concentrations tested.

CONCLUSION

M. acutistipula leaves ethyl acetate extract showed expressive concentrations of phenolic compounds and antioxidant activity. It also exhibited anti-inflammatory and analgesic activity, besides its antipyretic effect. Thus, these results provide information regarding its popular use and might help future therapeutics involving this specimen.

Evaluation of antibacterial, antioxidant, and anti-inflammatory properties of GC/MS characterized methanol leaf extract of Terminalia superba (Combretaceae, Engl. & Diels)

Background

Terminalia superba is a well-known medicinal plant used in folk medicine for the management of various diseases and swelling. Validation of its efficacy in standardized scientific models is lacking. This gap needs to be filled as a way of enhancing modern drug discovery. The aim is to evaluate the antibacterial, antioxidant, and anti-inflammatory properties of T. superba in known and established models. Also, to establish and possibly correlate the established activity with the phytochemicals identified using GC/MS and qualitative methods.

Results

The result showed a dose-dependent percentage inhibition of DPPH, HO•, and Fe3+ reducing activity. The antibacterial activity showed dose-dependent significant (p < 0.05) inhibition against all the organisms used. The anti-inflammatory activity of METS was confirmed in the carrageenan model with significant (p < 0.05) inhibition of paw volume when compared to control while significantly decreasing (p < 0.05) weight of xylene-induced ear. For instance, after 6 h, there was  a reduction of 42%, 33%, and 22% for diclofenac, 200 mg, and 100 mg, respectively, as against 4% in control. The significant (p < 0.05) increase in MDA was attenuated by the treatment with METS dose dependently. Phytochemical assay and GC/MS characterization showed that alkaloids, saponins, phenols, quinone, tannins, coumarins, proteins, flavonoids, and amino acids were dominant with fatty acids accounting for 53%. Others are esters (23%), organic compounds (12%), alkanes (9%), and carboxylic acids (3%).

Conclusions

T. superba possesses antioxidant, antibacterial, and anti-inflammatory properties which are believed to arise from the secondary metabolites observed in the GC–MS characterization.

Graphical Abstract

Phytochemical Variability, In Vitro and In Vivo Biological Investigations, and In Silico Antibacterial Mechanisms of Mentha piperita Essential Oils Collected from Two Different Regions in Morocco

The objective of this work is to explore the phytochemical profile of Mentha piperita essential oils (MPEO) collected from two different Moroccan regions using gas chromatography-mass spectrophotometer (GC-MS) and to investigate their antioxidant, anti-inflammatory, antidiabetic and, antimicrobial effects using in vivo and in vitro assays. The chemical constituent of MPEO from the Azrou zone is dominated by carvone (70.25%), while MPEO from the Ouazzane zone is rich in Menthol (43.32%) and Menthone (29.4%). MPEO from Ouezzane showed higher antioxidant activity than EO from Azrou. Nevertheless, EO from Ouezzane considerably inhibited 5-Lipoxygenase (IC50 = 11.64 ± 0.02 µg/mL) compared to EO from Azro (IC50 = 23.84 ± 0.03 µg/mL). Both EOs from Azrou and Ouazzane inhibited the α-amylase activity in vitro, with IC50 values of 131.62 ± 0.01 µg/mL and 91.64 ± 0.03 µg/mL, respectively. The EOs were also tested for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The discdiffusion test revealed that MPEOs from both regions have significant antibacterial efficacy, and MPEOs from the north region showed the highest effect. The gram-positive bacteria were the most susceptible organisms. The MIC concentrations were in the range of 0.05 to 6.25 mg/mL, and the MBC concentrations were within 0.05-25.0 mg/mL. The MBC/MIC index indicated that MPEO has strong bactericidal effects.

Plasma proteome responses in zebrafish following λ-carrageenan-Induced inflammation are mediated by PMN leukocytes and correlate highly with their human counterparts

Regulation of inflammation is a critical process for maintaining physiological homeostasis. The λ-carrageenan (λ-CGN) is a mucopolysaccharide extracted from the cell wall of red algae (Chondrus crispus) capable of inducing acute intestinal inflammation, which is translated into the production of acute phase reactants secreted into the blood circulation. However, the associated mechanisms in vertebrates are not well understood. Here, we investigated the crucial factors behind the inflammatory milieu of λ-CGN-mediated inflammation administered at 0, 1.75, and 3.5% (v/w) by i.p. injection into the peritoneal cavity of adult zebrafish (ZF) (Danio rerio). We found that polymorphonuclear leukocytes (neutrophils) and lymphocytes infiltrating the ZF peritoneal cavity had short-term persistence. Nevertheless, they generate a strong pattern of inflammation that affects systemically and is enough to produce edema in the cavity. Consistent with these findings, cell infiltration, which causes notable tissue changes, resulted in the overexpression of several acute inflammatory markers at the protein level. Using reversed-phase high-performance liquid chromatography followed by a hybrid linear ion-trap mass spectrometry shotgun proteomic approach, we identified 2938 plasma proteins among the animals injected with PBS and 3.5% λ-CGN. First, the bioinformatic analysis revealed the composition of the plasma proteome. Interestingly, 72 commonly expressed proteins were recorded among the treated and control groups, but, surprisingly, 2830 novel proteins were differentially expressed exclusively in the λ-CGN-induced group. Furthermore, from the commonly expressed proteins, compared to the control group 62 proteins got a significant (p < 0.05) upregulation in the λ-CGN-treated group, while the remaining ten proteins were downregulated. Next, we obtained the major protein-protein interaction networks between hub protein clusters in the blood plasma of the λ-CGN induced group. Moreover, to understand the molecular underpinnings of these effects based on the unveiled protein sets, we performed a bioinformatic structural similarity analysis and generated overlapping 3D reconstructions between ZF and humans during acute inflammation. Biological pathway analysis pointed to the activation and abundance of diverse classical immune and acute phase reactants, several catalytic enzymes, and varied proteins supporting the immune response. Together, this information can be used for testing and finding novel pharmacological targets to treat human intestinal inflammatory diseases.

In vitro effects of λ-carrageenin in the head-kidney leucocytes of gilthead seabream (Sparus aurata)

The λ-carrageenin is a sulphated mucopolysaccharide that has been used for decades to induce experimental inflammation in mammals. However, it has been little considered in fish. We studied the in vitro effects of λ-carrageenin on gilthead seabream (Sparus aurata L.) head-kidney leucocytes (HKLs). For this purpose, HKLs were incubated with serial concentrations (from 0 to 1,000 μg mL-1) of λ-carrageenin for 3, 6, 12 and 24 h to assess its influence on cell viability and morphology, cell activity and modulation of several selected inflammation-related genes. The viability results demonstrated that λ-carrageenin has no negative effects on HKLs. The respiratory burst activity and phagocytic ability of HKLs after being incubated with λ-carrageenin (100 and 1,000 μg mL^-1) for 24 h were increased, whereas the phagocytic capacity was inhibited by the higher dose at the same experimental time compared with control samples. However, the peroxidase activity of HKLs was not changed by incubation with λ-carrageenin. According to transmission electron microscopy results, incubation of HKLs with the higher dose of λ-carrageenin appeared to activate the cells being evident different morphological changes without sign of cell death. Furthermore, up-regulation of three proinflammatory cytokines (il1b, tnfa, and il6) and down-regulation of anti-inflammatory genes (tgfb) were denoted in HKLs incubated with carrageenin. The present results provide a detailed approach to the effects of λ-carrageenin on fish leucocytes, which could have some impact on how we understand the response of these cells when inducing an inflammatory process in fish.

Mitigation of Memory Impairment with Fermented Fucoidan and λ-Carrageenan Supplementation through Modulating the Gut Microbiota and Their Metagenome Function in Hippocampal Amyloid-β Infused Rats

Attenuating acetylcholinesterase and insulin/insulin-like growth factor-1 signaling in the hippocampus is associated with Alzheimer’s disease (AD) development. Fucoidan and carrageenan are brown and red algae, respectively, with potent antibacterial, anti-inflammatory, antioxidant and antiviral activities. This study examined how low-molecular-weight (MW) and high-MW fucoidan and λ-carrageenan would improve memory impairment in Alzheimer’s disease-induced rats caused by an infusion of toxic amyloid-β(Aβ). Fucoidan and λ-carrageenan were dissected into low-MW by Luteolibacter algae and Pseudoalteromonas carrageenovora. Rats receiving an Aβ(25–35) infusion in the CA1 region of the hippocampus were fed dextrin (AD-Con), 1% high-MW fucoidan (AD-F-H), 1% low-MW fucoidan (AD-F-L), 1% high-MW λ-carrageenan (AD-C-H), and 1% low-MW λ-carrageenan (AD-C-L) for six weeks. Rats to receive saline infusion (Normal-Con) had an AD-Con diet. The AD-F-L group showed an improved memory function, which manifested as an enhanced Y-maze spontaneous alternation test, water maze, and passive avoidance tests, similar to the Normal-Con group. AD-F-L also potentiated hippocampal insulin signaling and increased the expression of ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in the hippocampus. AD-C-L improved the memory function mainly by increasing the BDNF content. AD-F-H and AD-C-H did not improve the memory function. Compared to AD-Con, the ascending order of AD-C-H, AD-F-H, AD-C-L, and AD-F-L increased insulin signaling by enhancing the pSTAT3→pAkt→pGSK-3β pathway. AD-F-L improved glucose tolerance the most. Compared to AD-CON, the AD-F-L treatment increased the serum acetate concentrations and compensated for the defect of cerebral glucose metabolism. AD-Con increased Clostridium, Terrisporobacter and Sporofaciens compared to Normal-Con, and AD-F-L and AD-C-L increased Akkermentia. In conclusion, AD-F-L and AD-C-L alleviated the memory function in the rats with induced AD symptoms by modulating.

Analysis of combinatorial chemokine receptor expression dynamics using multi-receptor reporter mice

Inflammatory chemokines and their receptors are central to the development of inflammatory/immune pathologies. The apparent complexity of this system, coupled with lack of appropriate in vivo models, has limited our understanding of how chemokines orchestrate inflammatory responses and has hampered attempts at targeting this system in inflammatory disease. Novel approaches are therefore needed to provide crucial biological, and therapeutic, insights into the chemokine-chemokine receptor family. Here, we report the generation of transgenic multi-chemokine receptor reporter mice in which spectrally distinct fluorescent reporters mark expression of CCRs 1, 2, 3, and 5, key receptors for myeloid cell recruitment in inflammation. Analysis of these animals has allowed us to define, for the first time, individual and combinatorial receptor expression patterns on myeloid cells in resting and inflamed conditions. Our results demonstrate that chemokine receptor expression is highly specific, and more selective than previously anticipated.

Anti-inflammatory activities of the mixture of strawberry and rice powder as materials of fermented rice cake on RAW264.7 macrophage cells and mouse models

Rice cake is a traditional food in Korea, and is made by rice alone, or with other grain powder. To improve the health benefits of fermented rice cake, the rice powder was supplemented with strawberry powder. Anti-inflammatory activities of the mixture of strawberry and rice powder were evaluated. Treatment with the mixture significantly decreased the production of nitric oxide (NO). The mixture of strawberry and rice powder in the ratio 10: 90 effectively and dose-dependently reduced the immune-associated genes iNOS, IL-1β, IL-6, COX-2, and TNF-α. Furthermore, carrageenan-injected mice were used to study the anti-inflammatory effect of the mixture. Pre-oral administration of the mixture of strawberry and rice powder at doses of 50 and 100 mg/kg BW significantly reduced paw edema induced by carrageenan. These results suggest that for fermented rice cake production and processing, the strawberry and rice powder mixture may be a potential source of anti-inflammatory activity.

Red Seaweed-Derived Compounds as a Potential New Approach for Acne Vulgaris Care

Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.

Food additive E407a stimulates eryptosis in a dose-dependent manner

BACKGROUND

Concerns about the biosafety of the common food additive E407a have been raised. It has been demonstrated to induce intestinal inflammation, accompanied by activation of apoptosis, upon oral exposure. Thus, it is of interest to investigate how E407a affects eryptosis, a suicidal cell death mode of red blood cells.

OBJECTIVE

To evaluate the effects of semi-refined carrageenan (E407a) on eryptosis.

METHODS

Flow cytometry was employed to assess eryptosis in blood exposed to various concentrations of E407a (0 g/L, 1 g/L, 5 g/L, and 10 g/L) during incubation for 24 h by analyzing phosphatidylserine externalization in erythrocytes using annexin V staining and via evaluating reactive oxygen species (ROS) generation using 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA). In addition, the eryptosis indices mentioned above were determined in rats orally administered E407a at a dose of 140 mg/kg weight for 2 weeks. Confocal scanning laser microscopy was performed to visualize cell membrane scrambling.

RESULTS

Oral intake of E407a for 2 weeks by rats was not associated with membrane scrambling in erythrocytes. However, ROS overproduction was observed. Meanwhile, incubation of blood with various concentrations of semi-refined carrageenan resulted in a dose-dependent promotion of eryptosis, evidenced by the enhanced percentage of annexin V-positive erythrocytes and higher mean fluorescence intensity (MFI) values of annexin V-FITC in all erythrocytes. The highest concentration of E407a promotes a statistically significant increase in ROS generation in erythrocytes, suggesting the role of ROS-mediated induction of eryptosis in this case.

CONCLUSION

Incubation of blood with the food additive E407a leads to the activation of eryptosis in a dose-dependent manner. ROS-mediated mechanisms are partially responsible for E407a-induced eryptosis.

Asymmetric Synthesis and Biological Screening of Quinoxaline-Containing Synthetic Lipoxin A4 Mimetics (QNX-sLXms)

Failure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing synthetic-LXA₄-mimetics (QNX-sLXms). Eight novel compounds were screened for their impact on inflammatory responses. Structure–activity relationship (SAR) studies showed that (R)-6 (also referred to as AT-02-CT) was the most efficacious and potent anti-inflammatory compound of those tested. (R)-6 significantly attenuated lipopolysaccharide (LPS)- and tumor-necrosis-factor-α (TNF-α)-induced NF-κB activity in monocytes and vascular smooth muscle cells. The molecular target of (R)-6 was investigated. (R)-6 activated the endogenous LX receptor formyl peptide receptor 2 (ALX/FPR2). The anti-inflammatory properties of (R)-6 were further investigated in vivo in murine models of acute inflammation. Consistent with in vitro observations, (R)-6 attenuated inflammatory responses. These results support the therapeutic potential of the lead QNX-sLXm (R)-6 in the context of novel inflammatory regulators.

Synthesis, Physicochemical Characteristics and Plausible Mechanism of Action of an Immunosuppressive Isoxazolo[5,4-e]-1,2,4-Triazepine Derivative (RM33)

Previous studies demonstrated strong anti-inflammatory properties of isoxazolo[5,4-e]-1,2,4-triazepine (RM33) in vivo. The aim of this investigation was to describe synthesis, determine physicochemical characteristics, evaluate biological activities in murine and human in vitro models, as well as to propose mechanism of action of the compound. The compound was devoid of cell toxicity up to 100 μg/mL against a reference A549 cell line. Likewise, RM33 did not induce apoptosis in these cells. The compound stimulated concanavalin A (ConA)-induced splenocyte proliferation but did not change the secondary humoral immune response in vitro to sheep erythrocytes. Nevertheless, a low suppressive effect was registered on lipopolysaccharide (LPS)-induced splenocyte proliferation and a stronger one on tumor necrosis factor alpha (TNFα) production by rat peritoneal cells. The analysis of signaling pathways elicited by RM33 in nonstimulated resident cells and cell lines revealed changes associated with cell activation. Most importantly, we demonstrated that RM33 enhanced production of cyclooxygenase 2 in LPS-stimulated splenocytes. Based on the previous and herein presented results, we conclude that RM33 is an efficient, nontoxic immune suppressor with prevailing anti-inflammatory action. Additionally, structural studies were carried out with the use of appropriate spectral techniques in order to unequivocally confirm the structure of the RM33 molecule. Unambiguous assignment of NMR chemical shifts of carbon atoms of RM33 was conducted thanks to full detailed analysis of ¹H, ¹³C NMR spectra and their two-dimensional (2D) variants. Comparison between theoretically predicted chemical shifts and experimental ones was also carried out. Additionally, N-deuterated isotopologue of RM33 was synthesized to eliminate potentially disturbing frequencies (such as NH, NH₂ deformation vibrations) in the carbonyl region of the IR (infrared) spectrum to confirm the presence of the carbonyl group.

Effects of R-flurbiprofen and the oxygenated metabolites of endocannabinoids in inflammatory pain mice models

Pain is one of the cardinal signs accompanying inflammation. The prostaglandins (PGs), synthetized from arachidonic acid by cyclooxygenase (COX)-2, are major bioactive lipids implicated in inflammation and pain. However, COX-2 is also able to metabolize other lipids, including the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), to give glycerol ester (PG-G) and ethanolamide (PG-EA) derivatives of the PGs. Consequently, COX-2 can be considered as a hub not only controlling PG synthesis, but also PG-G and PG-EA synthesis. As they were more recently characterized, these endocannabinoid metabolites are less studied in nociception compared to PGs. Interestingly R-profens, previously considered as inactive enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), are substrate-selective COX inhibitors. Indeed, R-flurbiprofen can selectively block PG-G and PG-EA production, without affecting PG synthesis from COX-2. Therefore, we compared the effect of R-flurbiprofen and S-flurbiprofen in models of inflammatory pain triggered by local administration of lipopolysaccharides (LPS) and carrageenan in mice. Remarkably, the effects of flurbiprofen enantiomers on mechanical hyperalgesia seem to depend on (i) the inflammatory stimuli, (ii) the route of administration, and (iii) the timing of administration. We also assessed the effect of administration of the PG-Gs, PG-EAs, and PGs on LPS-induced mechanical hyperalgesia. Our data support the interest of studying the nonhydrolytic endocannabinoid metabolism in the context of inflammatory pain.

Effect of κ-carrageenan addition on protein structure and gel properties of salted duck egg white

BACKGROUND

Salted duck egg white (SDEW) is a major by-product during salted egg yolk manufacturing. Due to the high salt concentration, SDEW has not been efficiently utilized. Moreover, functional properties of SDEW are altered by salt during pickling. To improve the functional properties, the effect of κ-carrageenan (κ-CAR) addition on the protein structure and gel properties of SDEW was investigated in this study.

RESULTS

The surface hydrophobicity and free sulfhydryl content of SDEW protein increased, while total sulfhydryl content decreased significantly with the addition of κ-CAR (0.02-0.10%). Fourier-transform infrared spectroscopy analysis revealed that the relative content of α-helix and β-turn decreased, β-sheet and random coil increased, indicating the variation tendency of protein structure from order to disorder. As κ-CAR addition increased, the texture profiles including hardness, gumminess, chewiness, springiness, cohesiveness and resilience of SDEW gel were all improved. Water holding capacity increased significantly by 32.33% in the presence of 0.10% κ-CAR addition. The scanning electron microscopy indicated that the microstructure of SDEW/κ-CAR mixed gel was more smooth and compact.

CONCLUSION

The results suggested that adding κ-CAR can be an effective method to improve gel quality of SDEW. This study is expected to provide theoretical basis for modification of SDEW protein, as well as preparation of food ingredients with better gel properties from SDEW. © 2020 Society of Chemical Industry.