Gastroprotective Effects of Sulphated Polysaccharides from the Alga Caulerpa mexicana Reducing Ethanol-Induced Gastric Damage

Gastroprotective effect of fucoidan from Sargassum siliquastrum against ethanol-induced gastric mucosal injury

The ethanol-induced BALB/c mice and human gastric epithelial cell (Ges-1 cell) models were used to investigate the Sargassum siliquastrum fucoidan (SFuc) gastroprotective capability. The injury score and histopathological sections of the stomach were used to evaluate the gastroprotective capability. The western blotting and RT-PCR methods determined the signaling mechanism of mice's gastric injury. SFuc is fucoidan with a molecular weight of 300.7 and 25.1 kDa. The injury score and ulcer index of the SFuc-200 group decreased by 3.85 and 2.06 folds in contrast with the Model group, respectively. The findings indicated that SFuc reduced oxidative stress and inflammatory factor expression in the gastric mucosa by downregulating the levels of associated genes within the TLR-4, MyD88, and MAPK/NF-κB signaling pathways. Meanwhile, the SFuc-200 group promoted the expressions of EGF and PGE 2 by 1.53 and 1.52 folds, respectively. Together with the expression inhibition of p38, ERK, JNK, and NF-κB proteins in gastric tissue to help for differentiation of gastric cells. In addition, SFuc significantly reduced apoptosis occurrence in mice and Ges-1 cells. Our study provides potential mechanism clues of the SFuc's resistance to ethanol-induced gastric mucosal damage, suggesting its potential functional food for gastric protection.

Marine Algae and Deriving Biomolecules for the Management of Inflammatory Bowel Diseases: Potential Clinical Therapeutics to Decrease Gut Inflammatory and Oxidative Stress Markers?

The term "inflammatory bowel disease" (IBD) describes a class of relapse-remitting conditions that affect the gastrointestinal (GI) tract. Among these, Crohn's disease (CD) and ulcerative colitis (UC) are two of the most globally prevalent and debilitating conditions. Several articles have brought attention to the significant role that inflammation and oxidative stress cooperatively play in the development of IBD, offering a different viewpoint both on its etiopathogenesis and on strategies for the effective treatment of these conditions. Marine ecosystems may be a significant source of physiologically active substances, supporting the search for new potential clinical therapeutics. Based on this evidence, this review aims to comprehensively evaluate the activity of marine algae and deriving biomolecules in decreasing pathological features of CD and UC. To match this purpose, a deep search of the literature on PubMed (MEDLINE) and Google Scholar was performed to highlight primary biological mechanisms, the modulation of inflammatory and oxidative stress biochemical parameters, and potential clinical benefits deriving from marine species. From our findings, both macroalgae and microalgae have shown potential as therapeutic solutions for IBD due to their bioactive compounds and their anti-inflammatory and antioxidant activities which are capable of modulating markers such as cytokines, the NF-κB pathway, reactive oxidative and nitrosative species (ROS and RNS), trefoil factor 3 (TFF3), lactoferrin, SIRT1, etc. However, while we found promising preclinical evidence, more extensive and long-term clinical studies are necessary to establish the efficacy and safety of marine algae for IBD treatment.

Fucoidan mitigates gastric ulcer injury through managing inflammation, oxidative stress, and NLRP3-mediated pyroptosis

This study aimed to elucidate the gastro-protective effect of fucoidan against ethanol-induced gastric ulcer mediated via NLRP3-induced pyroptosis as an underlying mechanism, not yet assessed in prior research. Forty-eight male Albino mice were divided into six groups: Group I (normal control), group II (Ulcer/ethanol control), group III (Omeprazole + ethanol), group IV (fucoidan 25 mg + ethanol), group V (fucoidan 50 mg + ethanol) and group VI (fucoidan only). Fucoidan was administered orally for seven consecutive days followed by ulcer induction by a single oral dose of ethanol. Using colorimetric analysis, ELISA, qRT-PCR, histological assessment, and immunohistochemical studies, the results revealed that ethanol-induced ulcer exhibited an ulcer score of 42.5 ± 5.1 and a significant increase (p < 0.05) in malondialdehyde (MDA), nuclear factor kappa B (NF-κB), and interleukin 6 (IL-6) with a significant decrease in the gastro-protective mediators, prostaglandin E2 (PGE2), superoxide dismutase (SOD) and glutathione (GSH), accompanied with an increase in NLRP3, interleukin 1β (IL-1β), interleukin 18 (IL-18), caspase 1, caspase 11, gasdermin D, and toll-like receptor 4 (TLR4), compared with the normal control. Pre-treatment with fucoidan showed a comparable result with omeprazole. Additionally, pre-treatments elevated the levels of the gastro-protective mediators and lessened oxidative stress, relative to the positive control findings. Conclusively, fucoidan has a promising gastro-protective role by inhibiting inflammation and pyroptosis.

Effects of Quinoa (Chenopodium quinoa) on inflammatory mediators: a systematic review of preclinical studies

The aim of the current systematic review was to gather the researches about the effect of quinoa (chenopodium quinoa) on inflammatory parameters interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α). Search was performed using PubMed, Scopus, WOS, ProQuest, and Google scholar databases without any restriction on language or publication date until July 2022 and search alert services were used to detect novel papers published after the initial search. Only 20 animal and in vitro investigations were eligible for this systematic review. According to in vitro researches and 8 of 14 animal investigations, IL-6, IL-1β, and TNF-α level decreased remarkably after quinoa administration, which indicates the capability of quinoa in alleviating inflammatory factors. Quinoa is favorable but not yet a confirmed agent for alleviating systemic inflammation in inflammatory diseases.

Gastroprotective polysaccharide from natural sources: Review on structure, mechanism, and structure–activity relationship

Polysaccharides from natural sources have the potentials in being used as substitutes of chemosynthetic drugs for gastroprotection because of its safety and efficacy. For giving a better understanding of gastroprotective polysaccharides, the research progress on preparation, structure, bioactivity, and their action mechanism is comprehensively summarized in this review. Moreover, the structure–activity relationship of gastroprotective polysaccharides is discussed. Accumulating evidence has indicated that natural polysaccharides, which were widely prepared by water extraction and column chromatography purifications, exhibited gastroprotective effects in vitro and in vivo. The action mechanism might be related to gastric secretions, promotion of gastric defensive factor releases, antioxidation, anti‐inflammatory, antiapoptosis, and facilitation of proliferation. Phenolic compounds, molecular weight and conformation, monosaccharide composition, backbone structure and side chain, and functional group have great influences on the gastroprotective activities of polysaccharides. This review gives comprehensive guidance to the exploitation and application of natural polysaccharides in food and other industries for gastroprotection.

Preventive and Regenerative Effect of Glutamine and Probiotics on Gastric Mucosa in an Experimental Model of Alcohol-Induced Injury in Male Holtzman Rats

Background: The purpose of this study was to measure the preventive and regenerative effect of glutamine and probiotics induced by alcohol injury in Holtzman rats. Methods: Analytical, experimental and prospective study. The population consisted of 56 male rats between 300 and 350 g, distributed in three experimental phases: Pre-pilot phase PPP (6 rats), Pilot phase PP (10 rats), and Experimental phase EP (40 rats). In the pilot phase, 10 rats were subjected to damage with 8.5% ethanol, which was given intragastrically. The dosage was calculated for 10 rats in two groups: the first with 7.5 mL/kg in 5 rats and the second with 8.5 mL/kg in 5 rats. The experimental phase was performed in 40 rats divided into 6 groups, the negative control group (healthy), positive control group (injured), preventive experimental group (glutamine and glutamine with probiotic) and regenerative experimental group (glutamine and glutamine with probiotic). At the end of each phase, the rats were sacrificed with sodium pentobarbital (Halathal) and a portion of their stomachs was stored in formol. Results: The evaluation of stomach tissue samples (desquamation, erythema, hyperemia) showed that in the preventive phase, glutamine shows effectiveness in comparison to glutamine with probiotic. In the regenerative phase, glutamine and glutamine with probiotic did not show significant differences. Conclusions: Glutamine and probiotics can potentially serve as a therapy for the treatment for gastritis.

Mexican Plants and Derivates Compounds as Alternative for Inflammatory and Neuropathic Pain Treatment-A Review

Despite the availability of many anti-pain drugs, in the form of NSAIDs, steroids, gabapentinoids, opioids, and antidepressants, in this study we address the natural compounds belonging to the group of Mexican medicinal plants or "Mexican folk medicine", used for pain management in Mexico. Our interest in this subject is due to the growing idea that "natural is harmless" and to the large number of side effects exhibited in pharmacotherapy. The objective of this review was to document the scientific evidence about Mexican medicinal plants and their derivatives used for inflammatory and neuropathic pain treatment, as well as the mechanisms of action implicated in their antinociceptive effects, their possible adverse effects, and the main pharmacological aspects of each plant or compound. Our data review suggested that most studies on Mexican medicinal plants have used inflammatory experimental models for testing. The anti-pain properties exerted by medicinal plants lack adverse effects, and their toxicological assays report that they are safe to consume; therefore, more studies should be performed on preclinical neuropathic pain models. Moreover, there is no convincing evidence about the possible mechanisms of action involved in the anti-pain properties exerted by Mexican plants. Therefore, the isolation and pharmacological characterization of these plant derivatives' compounds will be important in the design of future preclinical studies.

Protective effects of polysaccharides from Panax ginseng on acute gastric ulcers induced by ethanol in rats

Panax ginseng is a traditional medicine used in China to treat many diseases. Polysaccharides are primary active components and have many pharmacological effects. Gastric ulcer is a serious gastrointestinal disease. However, whether polysaccharides influence gastric ulcers is unclear. In this study, the effective gastroprotective impacts and potential mechanisms of Panax ginseng polysaccharides (GPS) on gastric damage induced by ethanol in rats were investigated by macroscopically evaluating gastric mucosal injuries (improved ulcer index (UI)), histopathological staining (H&E and PAS), increased NO and PGE2 levels, and suppression of oxidative stress (increased superoxide dismutase (SOD) and catalase (CAT) and decreased malondialdehyde (MDA)) and inflammation (reduced tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and myeloperoxidase (MPO)). Pretreatment with GPS ameliorated the expression of I-κB/NF-κB and JAK/STAT proteins in the rat stomach exposed to ethanol. The results indicated that GPS prevent ethanol-induced gastric injuries in rats by predominantly suppressing gastric inflammation and oxidative stress through NF-κB and STAT inhibition.

Immunological effects of Chondrus armatus carrageenans and their low molecular weight degradation products

Ability of high molecular weight (HMW) κ- and λ-carrageenans of the red marine algae Chondrus armatus and their low molecular weight degradation products (LMWDPs) (0.7-20 and 10-170 kDa respectively) to influence functional properties (motility and phagocytosis) of murine peritoneal macrophages was assessed in this study as an in vitro and a weeklong feeding experiment. We demonstrated that, with an exception of one, all carrageenan samples at 100 μg/ml increased cellular motility and dose-dependently decreased phagocytic activity; LMWDPs of λ-carrageenan suppressed motility and had no effect on phagocytosis. Oral administration of all the carrageenan samples at 100 μg/kg/day for 7 days to mice had no effect on their clinical appearance, body weight, weight of their liver, spleen or thymus or development of noticeable changes to their inner organs. All samples induced a shift of the cell composition of the peritoneal cavity towards macrophages. Consumption of LMWDPs of κ-carrageenan resulted in development of leukopenia, however, no changes to relative WBC count were introduced by either of the samples. All samples decreased murine peritoneal macrophages phagocytic activity, with λ-samples possessing higher efficacy than their κ-counterparts; all LMWDPs stimulated peritoneal macrophages motility, with κ-samples possessing higher efficacy than their λ-counterparts In conclusion, we have shown that κ- and λ-carrageenans of the C. armatus and their LMWDPs suppress phagocytotic activity of peritoneal macrophages under both in vitro and in vivo conditions. This allows them to be viewed as pharmacologically active substances andpropagates the need for their further investigation as such.

Bioinformatic Characterization of Sulfotransferase Provides New Insights for the Exploitation of Sulfated Polysaccharides in Caulerpa

Caulerpa is an unusual algal genus from Caulerpaceae (Chlorophyta, Bryopsidales). Species from this family produce a wide range of metabolites suitable for biotechnology applications. Among these, sulfated polysaccharides (SPs) are often highly desirable for pharmaceutical and nutraceutical applications. Here, we provide a classification of sulfotransferases from Caulerpa; these important enzymes catalyze the nodal step for the biosynthesis of SPs. For this, we performed phylogenetic, genomic, expression analyses and prediction of the protein structure on sulfotransferases from Caulerpa. Sequences, domains and structures of sulfotransferases generally shared common characteristics with other plants and algae. However, we found an extensive duplication of sulfotransferase gene family, which is unique among the green algae. Expression analysis revealed specific transcript abundance in the pinnae and rachis of the alga. The unique genomic features could be utilized for the production of complex SPs, which require multiple and specific sulfation reactions. The expansion of this gene family in Caulerpaceae would have resulted in a number of proteins characterizing the unique SPs found in these algae. We provide a putative biosynthetic pathway of SPs, indicating the unique characteristics of this pathway in Caulerpa species. These data may help in the future selection of Caulerpa species for both commercial applications and genetic studies to improve the synthesis of valuable products from Caulerpa.

The Efficacy of Processing Strategies on the Gastroprotective Potentiality of Chenopodium quinoa Seeds

The current study has been conducted to evaluate the effect of different processing techniques on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and the gastroprotective potential of Chenopodium quinoa red seeds in acute gastric injury induced by absolute ethanol in rats. Seven groups of female Sprague Dawley rats were assigned to normal and absolute ethanol (absolute EtOH) groups, given distilled water, reference control omeprazole (OMP, 20 mg/kg), pressure-cooked quinoa seeds (QP, 200 mg/kg), first stage-germinated quinoa seeds (QG, 200 mg/kg), Lactobacillus plantarum bacteria-fermented quinoa seeds (QB, 200 mg/kg), and Rhizopus oligosporus fungus-fermented quinoa seeds (QF, 200 mg/kg). One hour after treatment, all groups were given absolute ethanol, except for the normal control rats. All animals were sacrificed after an additional hour, and the stomach tissues were examined for histopathology of hematoxylin and eosin staining, immunohistochemistry of cyclooxygenase 2 (COX-2), and nitric oxide synthase (iNOS). Stomach homogenates were evaluated for oxidative stress parameters and prostaglandin E₂ (PGE₂). Gene expression was performed for gastric tumor necrosis factor alpha (TNF-α) and nuclear factor kappa of B cells (NF-kB). QB and QG recorded the highest DPPH scavengers compared to QF and QP. The gastroprotective potential of QB was comparable to that of OMP, followed by QF, then QG, and QP as confirmed by the histopathology, immunohistochemistry, and gene expression assessments. In conclusion, differently processed red quinoa seeds revealed variable antioxidant capacity and gastroprotective potential, while the bacterial fermented seeds (QB) showed the highest potential compared to the other processing techniques. These results might offer promising new therapy in the treatment of acute gastric injury.

The role of hydrogen sulfide in gastric mucosal damage

Gastrointestinal disease is a major global threat to public health. In the past few decades, numerous studies have focuses on the application of small molecule gases in the disease treatment. Increasing evidence has shown that hydrogen sulfide (H₂S) has anti-inflammatory and anti-oxidative effects, and can regulate gastric mucosal blood flow in the gastric mucosa. After gastric mucosa damage, the level of H₂S in the stomach decreases. Administration of H₂S can protect and repair the damaged gastric mucosa. Therefore, H₂S is a new target for the repair and treatment of gastric mucosa damage. In this review, we introduce the roles of H₂S in the treatment of gastric mucosa damage and provide the potential strategies for further clinical treatment.

Orofacial antinociceptive effect of sulphated polysaccharide from the marine algae Hypnea pseudomusciformis in rodents

This study aimed to evaluate the antinociceptive effect of sulphated polysaccharide from the marine algae Hypnea pseudomusciformis (PLS) using rodent models of orofacial pain. Acute pain was induced by formalin, capsaicin, cinnamaldehyde, acidified saline or glutamate (cutaneous modes) and hypertonic saline (corneal model). In one experiment, animals were pretreated with ruthenium red, glibenclamide, naloxone, L-NAME, methylene blue or ketamine to investigate the mechanism of antinociception. In another experiment, animals pretreated with PLS or saline were submitted to the temporomandibular joint formalin test. In yet another, animals were submitted to craniofacial pain induced by mustard oil. Motor activity was evaluated with the open-field test. Cytotoxicity and antioxidant activities were also assessed. Pre-treatment with PLS significantly reduced nociceptive behavior associated with acute pain. Antinociception was effectively reduced, but not inhibited, by ruthenium red and ketamine. L-NAME and glibenclamide enhanced the PLS effect. PLS antinociception was resistant to methylene blue, naloxone and heating. PLS presented no cytotoxicity or antioxidant properties. Our results confirm the potential pharmacological relevance of PLS as an inhibitor of orofacial nociception in acute pain probably mediated by glutamatergic, nitrergic, TRPs and K + ATP pathways.