Mitigation of stress from gastric mucosal injuries by mulberry extract may occur via nitric oxide synthase signaling in mice

Protective role of fruits of Rosa odorata var. gigantea against WIRS-induced gastric mucosal injury in rats by modulating pathway related to inflammation, oxidative stress and apoptosis

Objective

Rosa odorata var. gigantea is a popular medicinal plant. Some studies have demonstrated that ethanolic extract of the fruits of R. odorata var. gigantea (FOE) has gastroprotective properties. The aim of this study was to investigate the gastroprotective activity of FOE on water immersion restrained stress (WIRS)-induced gastric mucosal injury in a rat model and elucidate the possible molecular mechanisms involved.

Methods

A rat stress ulcer model was established in this study using WIRS. After rats were treated with FOE orally for 7 d, the effect of FOE treatment was analyzed by hematoxylin and eosin (H&E) staining, and the changes of inflammatory factors, oxidative stress factors, and gastric-specific regulatory factors and pepsin in the blood and gastric tissues of rats were examined by ELISA assay. Molecular mechanism of FOE was investigated by immunohistochemical assay and Western blot.

Results

Compared with the WIRS group, FOE could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. FOE significantly preserved the antioxidants glutathione peroxidase (GSH-PX), superoxide dismutase (SOD) and catalase (CAT) contents; anti-inflammatory cytokines interleukin-10 (IL-10) and prostaglandin E2 (PGE2) levels as well as regulatory factors tumor necrosis factor-α (TGF-α) and somatostatin (SS) contents, while decreasing malondialdehyde (MDA), nitric oxide synthase (iNOS), tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), gastrin (GAS) and endothelin (ET) levels. Moreover, FOE distinctly upregulated the expression of Nrf2, HO-1, Bcl2 and proliferating cell nuclear antigen (PCNA). In addition, FOE activated the expression of p-EGFR and downregulated the expression of NF-κB, Bax, Cleaved-caspase-3, Cyto-C and Cleaved-PARP1, thus promoting gastric mucosal cell survival.

Conclusion

The current work demonstrated that FOE exerted a gastroprotective activity against gastric mucosal injury induced by WIRS. The underlying mechanism might be associated with the improvement of anti-inflammatory, anti-oxidation and anti-apoptosis systems.

Protective effect of alpha-ketoglutarate against water-immersion restraint stress-induced gastric mucosal damage in mice

Gastric lesions have several aetiologies, among which stress is the most prominent. Therefore, identification of new therapies to prevent stress is of considerable importance. Alpha-ketoglutarate (α-kg) several beneficial effects and has shown promise in combating oxidative stress, inflammation, and premature aging. Thus, this study aimed to evaluate the protective effect of α-kg in a gastric damage model by water-immersion restraint stress (WIRS). Pretreatment with α-kg decreased stress-related histopathological scores of tissue oedema, cell loss, and inflammatory infiltration. The α-kg restored the percentage of type III collagen fibres. Mucin levels were preserved as well as the structure and area of the myenteric plexus ganglia were preserved after pretreatment with α-kg. Myeloperoxidase (MPO) levels and the expression of pro-inflammatory cytokines (TNF-α and IL-1β) were also reduced following α-kg pretreatment. Decreased levels of glutathione (GSH) in the stress group were restored by α-kg. The omeprazole group was used as standard drug e also demonstrated improve on some parameters after the exposition to WIRS as inflammatory indexes, GSH and mucin. Through this, was possible to observe that α-kg can protect the gastric mucosa exposed to WIRS, preserve tissue architecture, reduce direct damage to the mucosa and inflammatory factors, stimulate the production of type III collagen and mucin, preserve the myenteric plexus ganglia, and maintain antioxidant potential. Due to, we indicate that α-kg has protective activity of the gastric mucosa, demonstrating its ability to prevent damage associated with gastric lesions caused by stress.

Mulberry plant as a source of functional food with therapeutic and nutritional applications: A review

Medicinal plants from the family Moraceae have diverse applications in agriculture, cosmetics, food, and the pharmaceutical industry. Their extensive spectrum of pharmacological activity for treating numerous inflammatory illnesses, cancer, cardiovascular diseases, and gastrointestinal problems reflects their biological and therapeutic value. This article summarizes the molecular mechanisms related to the biological implications of mulberry extracts, fractions, and isolated bioactive compounds from different parts in various health-related ailments. Additionally, the food industry and animal nutrition applications are summarized. Phytochemicals such as steroids, saponins, alkaloids, glycosides, polysaccharides, and phenolic compounds including terpenoids, flavonoids, anthocyanins, and tannins are found in this medicinal plant. The aqueous, ethanolic, and methanolic extracts, as well as bioactive compounds, have anti-oxidative, hypoglycemic, nephroprotective, antimicrobial, neuroprotective, anti-mutagenic, hepatoprotective, anthelmintic, immune-modulatory, cardioprotective, and skin protecting activities. Mulberry supplementation in food products improves the stability of phenolics, sensory properties, antioxidant activity, and antimicrobial properties. Mulberry leaves in animal feed increase the nutrient digestibility, growth parameters, antimicrobial, and antioxidant properties. PRACTICAL APPLICATIONS: This review summarized the in vivo and in vitro biological activities of the mulberry and isolated constituents in various health conditions. In addition, the food uses such as antioxidant potential, antimicrobial, and physicochemical properties were discussed. Furthermore, in vivo studies revealed mulberry as a significant protein source and its flavonoids as potential animal foliage.

Morus macroura Miq. Fruit extract protects against acetic acid-induced ulcerative colitis in rats: Novel mechanistic insights on its impact on miRNA-223 and on the TNFα/NFκB/NLRP3 inflammatory axis

Nod-like receptor pyrin domain-1 containing 3 (NLRP3) inflammasome/tumor necrosis factor alpha (TNFα)/nuclear factor kappa B (NFκB) inflammatory pathway is known to be involved in the pathogenesis of ulcerative colitis (UC). Inversely, miRNA-223 can exert counter-regulatory effect on NLRP3 expression. The mulberry tree (Morus macroura) fruit is attaining increased importance for its antioxidant and anti-inflammatory activity in addition to its high safety profile. Accordingly, we attempted to explore the possible protective effect of mulberry fruit extract (MFE) in acetic acid (AA)-induced UC rat model. Phytochemical constituents of MFE were characterized using high performance liquid chromatography coupled to mass spectrometry (HPLC-MS). In the in vivo study, three doses of MFE were orally given for seven days before intra-rectal induction of UC by AA on day eight. Screening study revealed that MFE (300 mg/kg) significantly reduced macroscopic and microscopic UC scores. Biochemically, MFE ameliorated oxidative stress, levels of TNFR1, NLRP3, p-NFκB p65, TNFα, IL-1β, and IL-18, caspase-1 activity, but enhanced miRNA-223 expression. In conclusion, our study provided a novel protective impact for MFE against UC, in which miRNA-223 and TNFα/NFκB/NLRP3 pathway are involved. These results provide a promising step that might encourage further investigations of MFE as a protective agent in UC patients.

Tricholoma matsutake-Derived Peptides Show Gastroprotective Effects against Ethanol-Induced Acute Gastric Injury

Acute gastric injury caused by ethanol is a frequent disorder of the gastrointestinal tract. In this study, we investigated the potential gastroprotective effects of Tricholoma matsutake-derived peptides against ethanol-triggered acute gastric injury and the associated mechanisms. Peptides SDLKHFPF and SDIKHFPF significantly attenuated the ethanol-induced decrease in GES-1 cell survival (82.39 ± 1.93 and 80.10 ± 1.08% vs 56.58 ± 1.86%), inhibited GES-1 cell apoptosis, and alleviated the ethanol-induced gastric mucosal injury (64.76 ± 3.98 and 49.29 ± 3.25%), ulcer index (3.33 ± 0.47 and 4.67 ± 0.47 vs 6.67 ± 0.47), and histopathological changes in mice. Peptide treatment inhibited the phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB), the secretion of tumor necrosis factor-α, interleukin-6, and endothelin-1. In addition, T. matsutake peptide pretreatment increased growth factor secretion, upregulated B-cell lymphoma-2, downregulated Bcl-2-associated X (Bax), and cleaved cysteinyl aspartate specific proteinase 3, thereby promoting gastric cell survival. These findings strongly suggest that T. matsutake peptides attenuate ethanol-induced inflammatory responses and apoptosis by suppressing NF-κB signaling activation, thereby enhancing gastric epithelial barrier functions.

Dietary Regulation of Oxidative Stress in Chronic Metabolic Diseases

Oxidative stress is a status of imbalance between oxidants and antioxidants, resulting in molecular damage and interruption of redox signaling in an organism. Indeed, oxidative stress has been associated with many metabolic disorders due to unhealthy dietary patterns and may be alleviated by properly increasing the intake of antioxidants. Thus, it is quite important to adopt a healthy dietary mode to regulate oxidative stress and maintain cell and tissue homeostasis, preventing inflammation and chronic metabolic diseases. This review focuses on the links between dietary nutrients and health, summarizing the role of oxidative stress in ‘unhealthy’ metabolic pathway activities in individuals and how oxidative stress is further regulated by balanced diets.

Hunan insect tea polyphenols provide protection against gastric injury induced by HCl/ethanol through an antioxidant mechanism in mice

The purposes of this study were to explore the preventive and treatment effects of Hunan insect tea polyphenols (HITPs) on gastric injury in mice induced by HCl/ethanol and to investigate their molecular mechanisms of action. Both HITPs and ranitidine inhibited the formation and further deterioration of gastric mucosal lesions, reduced the secretion of gastric juice, and raised gastric juice pH compared to the control. The HITPs-H treated group had lower serum levels of motilin, substance P, and endothelin than the control group, but they had higher serum levels of vasoactive intestinal peptide and somatostatin. Mice treated with HITPs had lower serum levels of cytokines interleukin (IL)-6, IL-12, tumor necrosis factor-α (TNF-α), and interferon-γ than the control group. The activities of superoxide dismutase (SOD), nitric oxide, and glutathione peroxidase (GSH-Px) were higher in the gastric tissues of HITP-treated mice, but the malondialdehyde content was lower. Quantitative PCR analysis indicated that the mRNA expression of occludin, epidermal growth factor (EGF), EGF receptor (EGFR), vascular EGF (VEGF), inhibitor kappaB-α, cuprozinc-superoxide dismutase, manganese-superoxide dismutase, GSH-Px, neuronal nitric oxide synthase, and endothelial NOS increased significantly in the gastric tissues of HITP-treated mice. However, the activated B cell, inducible NOS, cyclooxygenase-2, TNF-α, IL-1 beta, and IL-6 mRNA expression levels in the HITPs group were lower than those in the control group. The protective effect of a high concentration (200 mg per kg bw) of HITPs on gastric injury induced by HCl/ethanol was stronger than that of a low concentration (100 mg per kg bw) of HITPs. High-performance liquid chromatography (HPLC) revealed that the HITPs contained cryptochlorogenic acid, (-)-epicatechin gallate, and isochlorogenic acid C. Taken together, our findings indicate that the HITPs played a role in the prevention of gastric damage. The antioxidant effect of the HITPs contributed to their potential value in the prevention and treatment of gastric injury. HITPs have broad prospects as biologically active substances for food development.

Nervous mechanisms of restraint water-immersion stress-induced gastric mucosal lesion

Stress-induced gastric mucosal lesion (SGML) is one of the most common visceral complications after trauma. Exploring the nervous mechanisms of SGML has become a research hotspot. Restraint water-immersion stress (RWIS) can induce GML and has been widely used to elucidate the nervous mechanisms of SGML. It is believed that RWIS-induced GML is mainly caused by the enhanced activity of vagal parasympathetic nerves. Many central nuclei, such as the dorsal motor nucleus of the vagus, nucleus of the solitary tract, supraoptic nucleus and paraventricular nucleus of the hypothalamus, mediodorsal nucleus of the thalamus, central nucleus of the amygdala and medial prefrontal cortex, are involved in the formation of SGML in varying degrees. Neurotransmitters/neuromodulators, such as nitric oxide, hydrogen sulfide, vasoactive intestinal peptide, calcitonin gene-related peptide, substance P, enkephalin, 5-hydroxytryptamine, acetylcholine, catecholamine, glutamate, γ-aminobutyric acid, oxytocin and arginine vasopressin, can participate in the regulation of stress. However, inconsistent and even contradictory results have been obtained regarding the actual roles of each nucleus in the nervous mechanism of RWIS-induced GML, such as the involvement of different nuclei with the time of RWIS, the different levels of involvement of the sub-regions of the same nucleus, and the diverse signalling molecules, remain to be further elucidated.

Nitric Oxide Synthase Is Involved in Follicular Development via the PI3K/AKT/FoxO3a Pathway in Neonatal and Immature Rats

It is assumed that nitric oxide synthase and nitric oxide are involved in the regulation of female reproduction. This study aimed to assess the roles of nitric oxide synthase (NOS) in follicular development. The endothelial NOS (eNOS) inhibitor L-NAME, inducible NOS (iNOS) inhibitor S-Methylisothiourea (SMT) and NOS substrate L-arginine (L-Arg) were used in the NOS inhibition models in vivo. Neonatal female rats were treated with phosphate buffer saline (PBS, control), L-NAME (L-NG-Nitroarginine Methyl Ester, 40 mg/kg), SMT (S-Methylisothiourea, 10 mg/kg), L-NAME + SMT, or L-Arg (L-arginine, 50 mg/kg) via subcutaneous (SC) injection on a daily basis for 19 consecutive days, with the samples being collected on specific postnatal days (PD5, PD10, and PD19). The results indicated that the number of antral follicles, the activity of total-NOS, iNOS, neuronal NOS (nNOS), and eNOS, and the content of NO in the ovary were significantly (p < 0.05) increased in the L-Arg group at PD19, while those in L + S group were significantly (p < 0.05) decreased. Meanwhile, the ovarian expression in the L-Arg group in terms of p-AKT, p-FoxO3a, and LC3-II on PD19 were significantly (p < 0.05) upregulated, while the expressions of PTEN and cleaved Caspase-3 were (p < 0.05) downregulated as a result of NOS/NO generation, respectively. Therefore, the results suggest that NOS is possibly involved in the maturation of follicular development to puberty via the PI3K/ AKT/FoxO3a pathway, through follicular autophagia and apoptosis mechanisms.

Liubao Insect tea polyphenols prevent HCl/ethanol induced gastric damage through its antioxidant ability in mice

The aim of this study was to study the preventive effects of polyphenols extracted from Liubao Insect tea on gastric injury. The content of Liubao Insect tea polyphenols (LITP) was 72.36% by ion precipitation extraction method. HCl/ethanol-induced gastric injury in mice led to increased gastric juice volume and decreased pH. LITP increased the gastric juice pH value and reduced the gastric juice volume at slightly lower quantities than ranitidine. Visual observation of gastric tissue showed that LITP could effectively reduce the area of gastric injury, and higher concentrations of LITP had a greater effect. Pathological observation also confirmed that LITP can reduce the cell damage and inflammatory effects, and play a role in preventing gastric injury. Serum cytokine assays showed that LITP could reduce the levels of IL-6 (interleukin 6), TNF-α (tumor necrosis factor alpha) and IFN-γ (interferon gamma) induced by gastric injury, and the effects of higher concentration of LITP were similar to those of ranitidine. The results showed that LITP could increase SOD (superoxide dismutase) and GSH (glutathione) levels; decrease MDA (malondialdehyde) and MPO (myeloperoxidase) levels; up-regulate the expression of Cu/Zn-SOD (cuprozinc-superoxide dismutase), Mn-SOD (manganese superoxide dismutase), CAT (catalase), nNOS (neuronal nitric oxide synthase), eNOS (endothelial nitric oxide synthase); and down-regulate the expression of iNOS (inducible nitric oxide synthase), COX-2 (cyclooxygenase-2), TNF-α, and IL-1β (interleukin-1 beta) in mice with gastric injury, thus inhibiting gastric injury. We demonstrate that LITP is an active substance which could prevent gastric injury in experimental animals. With the increase of LITP concentration, its effects on preventing gastric injury were stronger and similar to those of ranitidine.

The aim of this study was to study the preventive effects of polyphenols extracted from Liubao Insect tea on gastric injury.

Induction of Secretagogue Independent Gastric Acid Secretion via a Novel Aspirin-Activated Pathway

Aspirin has been widely recommended for acute and chronic conditions for over 2,000 years. Either single or repetitive doses are commonly used for analgesic and antipyretic reasons and to prevent heart attacks, stroke, and blood clot formation. Recent studies show that it can also be used chronically to dramatically reduce the risk of a variety of cancers. However, prolonged usage of aspirin can cause severe damage to the mucosal barrier, increasing the risk of ulcer formation and GI-bleeding events. In the present study, we show the effects of acute low-dose aspirin exposure as an active secretagogue-inducing gastric acid secretion. Studies were carried out with isolated gastric glands using the pH-sensitive dye BCECF-AM to assess acid secretion. The non-selective NOS inhibitor L-NAME (30 μM), or the specific inhibitor ODQ (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one) was applied while monitoring intracellular pH. The effects of basolateral exposure to aspirin (acetylsalicylic acid, ASA) caused activation of gastric acid secretion via the H⁺, K⁺-ATPase. Our data suggest that aspirin increases nitric oxide (NO) production, which in turn activates acid secretion. Exposure of gastric glands to either the non-selective NOS inhibitor L-NAME, and the highly selective, soluble guanylyl cyclase inhibitor 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) effectively inhibited aspirin-dependent gastric acid secretion. Aspirin can be considered as a novel secretagogue, in the way that it activates the H⁺, K⁺-ATPase. With increased daily aspirin consumption, our findings have important implications for all individuals consuming aspirin even in low doses and the potential risks for increased acid secretion.