Autophagy in Gastric Mucosa: The Dual Role and Potential Therapeutic Target

High-Salt Diet Exacerbates H. pylori Infection and Increases Gastric Cancer Risks

Gastric cancer ranks as the fifth-leading contributor to global cancer incidence and the fourth-highest in terms of cancer-related mortality. Helicobacter pylori (H. pylori) infection leads to inflammation and ulceration, atrophic and chronic gastritis, and eventually, increases the risk of developing gastric adenocarcinoma. In this paper, we delve into the combined impact of a high-salt diet (HSD) and concurrent H. pylori infection, which act as predisposing factors for gastric malignancy. A multitude of mechanisms come into play, fostering the development of gastric adenocarcinoma due to the synergy between an HSD and H. pylori colonization. These encompass the disruption of mucosal barriers, cellular integrity, modulation of H. pylori gene expression, oxidative stress induction, and provocation of inflammatory responses. On the whole, gastric cancer patients were reported to have a higher median sodium intake with respect to healthy controls. H. pylori infection constitutes an additional risk factor, with a particular impact on the population with the highest daily sodium intake. Consequently, drawing from epidemiological discoveries, substantial evidence suggests that diminishing salt intake and employing antibacterial therapeutics could potentially lower the susceptibility to gastric cancer among individuals.

Gastroprotective effects of Pikad Tri-phol-sa-mut-than herbal remedy on multiple gastric ulcer models in rats

In Thai traditional medicine, Pikad Tri-phol-sa-mut-than has long been used to alleviate gastrointestinal symptoms, renal disease, inflammation-related disorders, and severe malady. This recipe is composed of dried fruits of Morinda citrifolia L., Coriandrum sativum L., and Aegle marmelos (L.) Corrêa. The aim of this study was to assess the anti-gastric ulcer property of the water extract of Pikad Tri-phol-sa-mut-than (TS), using various animal models with different inducers, including restraint water immersion stress, indomethacin, and ethanol/hydrochloric acid (EtOH/HCl). Its mechanisms of anti-gastric ulcer actions were also elucidated using both in vitro and in vivo experiments. When compared with the control groups, the oral pretreatment of TS at the doses of 150, 300 and 600 mg/kg significantly reduced the gastric ulcer formation in all models. It was also found that TS at the dose of 600 mg/kg could increase gastric wall mucus in rats but could not produce the significant reduction of the gastric volume or total acidity of gastric content. Results from hematoxylin and eosin (H&E) and Periodic acid-Schiff (PAS) staining examinations of gastric tissues confirmed that TS visibly reduced gastric mucosal damage, while immunohistochemistry revealed that TS remarkably suppressed the protein expression of Bcl-2-associated X (BAX), a regulator of apoptosis, compared to those of the control group. The DPPH, ABTS, and FRAP assays showed antioxidant effects of TS. All of these findings demonstrated that TS has gastroprotective effects, which may be related to the increase in the gastric wall mucus secretion, not anti-secretory activity, as well as its antioxidant and antiapoptotic activities.

Liuwei Anxiao San protects gastric mucosa from gastric ulcer in rats by regulating the JAK2/STAT3 pathway

Mongolian medicine prescriptions are recognized as promising gastroprotective agents. This study is to explore the effects and mechanisms of Liuwei Anxiao San (LAS) in gastric ulcer (GU). GU rat models were established using acetic acid, followed by treatment with LAS at different doses and/or the JAK2 agonist Coumermycin A1 (CA1). The ulcerous area and inhibition rates were calculated. The mucosal damage and cell apoptosis in gastric tissues were assessed by H&E and TUNEL staining. The activities of SOD, GSH-Px, and CAT, and MDA levels were measured. The levels of pro-inflammatory and anti-inflammatory factors were determined by ELISA. The activation of the JAK2/STAT3 pathway was determined by Western blot. As the results suggested, LAS dose-dependently ameliorated gastric mucosal damage and inhibited oxidative stress and inflammatory response, evidenced by increased activities of SOD, GSH-Px, and CAT, decreased MDA level, increment of anti-inflammatory factors and decrement of pro-inflammatory factors, and inhibited the activation of the JAK2/STAT3 pathway in GU rats. CA1 partly abolished the function of LAS on gastric mucosal injury, oxidative stress, and inflammation in GU rats. In conclusion, LAS protects against gastric mucosal injury in GU rats through inhibition of oxidative stress and inflammation by suppressing the JAK2/STAT3 pathway.

Metabolites Profiling and Bioassays Reveal Bassia indica Ethanol Extract Protective Effect against Stomach Ulcers Development via HMGB1/TLR-4/NF-κB Pathway

Clinical manifestation of gastric ulcers is frequent, in addition to their costly drug regimens, warranting the development of novel drugs at lower costs. Although Bassia indica is well characterized for its anti-inflammatory and antioxidant potential, capacity of its ethanol extract (BIEE) to prevent stomach ulcers' progression has not been reported. A nuclear protein termed high-mobility group box 1 (HMGB1) plays a key role in the formation of stomach ulcers by triggering a number of inflammatory responses. The main purpose of the current investigation was to evaluate the in vivo anti-inflammatory and anti-ulcerogenic capabilities of BIEE against ethanol-induced gastric ulcers in rats via the HMGB1/TLR-4/NF-B signaling pathway. HMGB1 and Nuclear factor kappa (NF-B) expression, IL-1β and Nrf2 contents showed an increase along with ulcer development, concurrent with an increase in immunohistochemical TLR-4 level. In contrast, pre-treatment with BIEE significantly reduced HMGB1 and Nuclear factor kappa (NF-B) expression levels, IL-1β and Nrf2 contents and ulcer index value. Such protective action was further confirmed based on histological and immunohistochemical TLR-4 assays. Untargeted analysis via UPLC-ESI-Qtof-MS has allowed for the comprehensive characterization of 40 metabolites in BIEE mostly belonged to two main chemical classes, viz., flavonoids and lipids. These key metabolites, particularly flavonoids, suggesting a mediation for the anti-inflammatory and anti-ulcerogenic properties of BIEE, pose it as a promising natural drug regimen for treatment of stomach ulcers.

Progress in traditional Chinese medicine against chronic gastritis: From chronic non-atrophic gastritis to gastric precancerous lesions

Chronic gastritis (CG) is a persistent inflammation of the gastric mucosa that can cause uncomfortable symptoms in patients. Traditional Chinese medicine (TCM) has been widely used to treat CG due to its precise efficacy, minimal side effects, and holistic approach. Clinical studies have confirmed the effectiveness of TCM in treating CG, although the mechanisms underlying this treatment have not yet been fully elucidated. In this review, we summarized the clinical research and mechanisms of TCM used to treat CG. Studies have shown that TCM mechanisms for CG treatment include H. pylori eradication, anti-inflammatory effects, immune modulation, regulation of gastric mucosal cell proliferation, apoptosis, and autophagy levels.

Role of Macroautophagy in Mammalian Male Reproductive Physiology

Physiologically, autophagy is an evolutionarily conserved and self-degradative process in cells. Autophagy carries out normal physiological roles throughout mammalian life. Accumulating evidence shows autophagy as a mechanism for cellular growth, development, differentiation, survival, and homeostasis. In male reproductive systems, normal spermatogenesis and steroidogenesis need a balance between degradation and energy supply to preserve cellular metabolic homeostasis. The main process of autophagy includes the formation and maturation of the phagophore, autophagosome, and autolysosome. Autophagy is controlled by a group of autophagy-related genes that form the core machinery of autophagy. Three types of autophagy mechanisms have been discovered in mammalian cells: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy is classified as non-selective or selective. Non-selective macroautophagy randomly engulfs the cytoplasmic components in autophagosomes that are degraded by lysosomal enzymes. While selective macroautophagy precisely identifies and degrades a specific element, current findings have shown the novel functional roles of autophagy in male reproduction. It has been recognized that dysfunction in the autophagy process can be associated with male infertility. Overall, this review provides an overview of the cellular and molecular basics of autophagy and summarizes the latest findings on the key role of autophagy in mammalian male reproductive physiology.

Gastroprotective 2-(2-phenylethyl)chromone-sesquiterpene hybrids from the resinous wood of Aquilaria sinensis (Lour.) Gilg

Six previously unprecedented 2-(2-phenylethyl)chromone-sesquiterpene hybrids, aquisinenins A-F (1 - 6), were isolated from the resinous wood of Aquilaria sinensis by a LC-MS-guided fractionation procedure. Their structures were determined by extensive spectroscopic analysis (1D and 2D NMR, UV, IR, and HRMS) and experimental and computed ECD data. Compounds 1 - 6 were rare dimeric 2-(2-phenylethyl)chromone-sesquiterpene derivatives featuring 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone hybridized with different sesquiterpene (eudesmane/guaiane type) moieties via ester bond. Furthermore, all the isolated compounds were evaluated for their protective effects on taurocholic acid (TCA)-induced GES-1 cell injury. The most effective aquisinenin F (6) was used to elucidate the involved mechanism on protection against TCA-induced gastric mucosal damage. Our results indicated that 6 protected against gastric mucosal cell insult by downregulation of the ER stress triggered by TCA.

Irbesartan reprofiling for the amelioration of ethanol-induced gastric mucosal injury in rats: Role of inflammation, apoptosis, and autophagy

BACKGROUND

Pronounced anti-inflammatory and anti-apoptotic features have been characterized for the angiotensin receptor blocker irbesartan. Yet, its effect on ethanol-induced gastropathy has not been studied. The present work explored the potential modulation of inflammatory, apoptotic, and autophagic events by irbesartan for the attenuation of ethanol-evoked gastric mucosal injury.

METHODOLOGY

Wistar rats were divided into control, control + irbesartan, ethanol, ethanol + irbesartan, and ethanol + omeprazole groups. Macroscopic examination, histopathology, immunohistochemistry, and biochemical assays were applied to examine the gastric tissues.

KEY FINDINGS

Irbesartan administration (50 mg/kg; by gavage) in ethanol-evoked gastropathy improved the gastric pathological manifestations (area of gastric lesion and ulcer index scores), histopathological changes, and microscopic damage scores. These beneficial effects were interceded by suppression of the HMGB1-associated inflammatory events and the linked downregulation of the nuclear NF-κBp65 protein expression. In the meantime, curtailing of the NLRP3 inflammasome by irbesartan was observed with consequent decline of the pro-inflammatory cytokine IL-1β. In tandem, upregulation of the antioxidant Nrf2 and the cytoprotective PPAR-γ were seen. Together, suppression of the pro-inflammatory cues and pro-oxidant signals attenuated the pro-apoptotic events as evidenced by Bcl-2 upregulation, Bax downregulation, and caspase 3 dampened activity. Regarding gastric autophagy signals, irbesartan diminished SQSTM-1/p62 accumulation and upregulated Beclin 1. This was associated with gastric AMPK/mTOR pathway activation evidenced by increased AMPK (Ser487) phosphorylation and lowered mTOR (Ser2448) phosphorylation.

CONCLUSION

Suppression of the inflammatory and apoptotic signals and upregulation of the pro-autophagy events may advocate the promising gastroprotective actions of irbesartan against ethanol-induced gastric injury.

Systems pharmacology to reveal multi-scale mechanisms of traditional Chinese medicine for gastric cancer

Because of the complex etiology, the treatment of gastric cancer is a formidable challenge for contemporary medical. The current treatment method focuses on traditional surgical procedures, supplemented by other treatments. Among these other treatments, Traditional Chinese Medicine (TCM) plays an important role. Here, we used the systems pharmacology approach to reveal the potential molecular mechanism of PRGRC on gastric cancer which composes of Pinellia ternata(Thunb.) Breit., Rheum palmatumL., Gentiana scabraBunge, Radix Aucklandiae and Citrus aurantium L. This approach combines pharmacokinetics analysis with pharmacodynamics evaluation for the active compounds screening, targets prediction and pathways assessing. Firstly, through pharmacokinetic evaluation and target prediction models, 83 potential compounds and 184 gastric cancer-related targets were screened out. Then, the results of network analysis suggested that the targets of PRGRC were mainly involved two aspects: apoptosis and inflammation. Finally, we verified the reliability of the above analysis at the cellular level by using naringenin and luteolin with good pharmacokinetic activity as representative compounds. Overall, we found that PRGRC could influence the development of gastric cancer from a multi-scale perspective. This study provided a new direction for analyzing the mechanism of TCM.