Ovotransferrin alleviated acute gastric mucosal injury in BALB/c mice caused by ethanol

Protection effect of Dioscoreae Rhizoma against ethanol-induced gastric injury in vitro and in vivo: A phytochemical and pharmacological study

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscoreae Rhizoma, a kind of Chinese yam, is a medicinal and edible plant used in China for strengthening the spleen and stomach. However, there is a lack of modern pharmacology studies regarding its anti-gastric injury activity.

AIM OF THE STUDY

This study aimed to investigate the phytochemical composition of Chinese yam aqueous extract (CYW) and evaluate its gastroprotective effects against ethanol-induced gastric injury in vitro and in vivo.

MATERIALS AND METHODS

The active components of CYW were identified using HPLC-QTOF-MS/MS in combination with the GNPS molecular networking and network pharmacology. In vitro studies were performed in the RAW264.7/GES-1 cell coculture system. In vivo study, mice were treated with CYW (0.31, 0.63, and 3.14 g/kg BW, orally) for 14 days, followed by a single oral dose of ethanol (10 mL/kg BW) to induce gastric injury. The biochemical, inflammation and oxidative stress markers were analyzed using commercial kits. Histopathology was used to assess the degree of gastric injury. Gene and protein expressions were studied using RT-qPCR and western blotting, respectively.

RESULTS

CYW significantly restored the levels of SOD, GPx and CAT, and reduced the MDA content. Further analyses showed that CYW significantly alleviated the gastric oxidative stress by inhibiting the inflammation via decreasing p-NF-κB and p-IκB-α expression levels and inhibiting the generation of IL-6, TNF-α, and IL-1β. At the same time, the fraction remarkably upregulated Bcl-2, downregulated Bax and increased growth factor secretion, thereby prevented gastric mucous cell. Besides, The combination of HPLC-QTOF-MS/MS, GNPS molecular networking analysis, and network pharmacology demonstrated that linoleic acid, 3-acetyl-11-keto-beta-boswellic acid, adenosine, aminocaproic acid, tyramine, DL-tryptophan, cycloleucine, lactulose, melibiose, alpha-beta-trehalose, and sucrose would be the main active compounds of CYW against ethanol-induced gastric injury.

CONCLUSION

This study showed that CYW is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds. It showed efficacy against ethanol-induced gastric injury by inhibiting inflammation, oxidative stress, and apoptosis in the stomach. The results of the current work indicate that Dioscoreae Rhizoma could be utilized as a type of natural resource for production of new medicine and functional foods to prevent and/or ameliorate ethanol-induced gastric injury.

Ovotransferrin, an alternative and potential protein for diverse food and nutritional applications

Ovotransferrin(OVT)is a protein found in many types of egg white and has a wide range of functional properties. It has 50% homology with human/bovine lactoferrin, and is expected to be one of the most important alternative proteins for use in food and nutritional applications. This paper mainly reviews the structural characteristics and chemical properties of OVT, as well as its extraction and purification methods. It also systematically describes the various biological activities of OVT and its applications in food and medical industries. The challenges and limitations in the research of OVT were suggested. This review recommends some possible methods such as nanoparticle carriers and microencapsulation to improve the bioavailability and stability of OVT. In addition, this review highlights several strategies to overcome the limitations of OVT in terms of preparation and purification. This review systematically summarizes the recent advances in OVT and will provide guidance for the its development for food and nutritional applications.

Effects of unfolding treatment assisted glycation on the IgE/IgG binding capacity and antioxidant activity of ovomucoid

Ovomucoid is the immune-dominant allergen in the egg white of hens. Due to its structure based on nine disulfide bonds as well as its resistance to heat and enzymatic hydrolysis, the allergenicity of this food protein is difficult to decrease by technological processes. We sought to reduce its allergenicity through the Maillard reaction. The unfolding of ovomucoid with L-cysteine-mediated reduction was used to increase accessibility to conformational and linear epitopes by modifying the secondary and tertiary structures of the allergen. Glycation with different saccharides revealed the beneficial effect of maltose glycation on the IgG-binding capacity reduction. By determining the better glycation conditions of unfolded ovomucoid, we produced ovomucoid with reduced IgE binding capacity due to the glycation sites (K17, K112, K129, and K164) on epitopes. Moreover, after simulated infant and adult gastrointestinal digestion, the unfolded plus glycated ovomucoid showed higher ABTS˙+ scavenging activity, O2˙- scavenging activity, ˙OH scavenging activity, Fe2+ chelating activity, and a FRAP value; in particular, for ˙OH scavenging activity, there was a sharp increase of more than 100%.

Can proteins, protein hydrolysates and peptides cooperate with probiotics to inhibit pathogens?

Studies have shown that probiotics can effectively inhibit pathogens in the presence of proteins, protein hydrolysates and peptides (protein derivates). However, it is still unclear the modes of probiotics to inhibit pathogens regulated by protein derivates. Therefore, we summarized the possible effects of protein derivates from different sources on probiotics and pathogens. There is abundant evidence that proteins and peptides from different sources can significantly promote the proliferation of probiotics and increase their secretion of antibacterial substances. Such proteins and peptides can also stimulate the adhesion of probiotics to intestinal epithelial cells and contribute to regulating intestinal immunity, but they seem to have the negative effects on pathogens. Moreover, a direct effect of proteins on intestinal cells is summarized. Whether or not they can cooperate with probiotics to inhibit pathogens using above possible mechanisms were discussed. Furthermore, there seems to be no consistent conclusions that protein derivates have synergistic effects with probiotics, and there is still limited evidence on the inhibiting patterns. Therefore, the existing problems and shortcomings are noted, and future research direction is proposed.

The Gastroprotective Effect of Walnut Peptides: Mechanisms and Impact on Ethanol-Induced Acute Gastric Mucosal Injury in Mice

The objective of this research was to explore the protective impact of walnut peptides (WP) against ethanol-induced acute gastric mucosal injury in mice and to investigate the underlying defense mechanisms. Sixty male BALB-c mice were divided into five groups, and they were orally administered distilled water, walnut peptides (200 and 400 mg/kg bw), and omeprazole (20 mg/kg bw) for 24 days. Acute gastric mucosal injury was then induced with 75% ethanol in all groups of mice except the blank control group. Walnut peptides had significant protective and restorative effects on tissue indices of ethanol-induced gastric mucosal damage, with potential gastric anti-ulcer effects. Walnut peptides significantly inhibited the excessive accumulation of alanine aminotransferase (ALT), aspartate transferase (AST), and malondialdehyde (MDA), while promoting the expression of reduced glutathione (GSH), total antioxidant capacity (T-AOC), glutathione disulfide (GSSG), and mouse epidermal growth factor (EGF). Furthermore, the Western blot analysis results revealed that walnut peptides significantly upregulated the expression of HO-1 and NQO1 proteins in the Nrf2 signaling pathway. The defensive impact of walnut peptides on the gastric mucosa may be achieved by mitigating the excessive generation of lipid peroxides and by boosting cellular antioxidant activity.

Ovotransferrin Inhibits TNF-α Induced Inflammatory Response in Gastric Epithelial Cells via MAPK and NF-κB Pathway

Ovotransferrin (OVT) has been confirmed to have anti-inflammatory activity. However, its effect and mechanism on gastric inflammation are unclear. In this study, the effect and mechanism of the OVT on the tumor necrosis factor-α (TNF-α) induced inflammatory response in gastric epithelial cells (GES-1) were investigated. The enzyme linked immunosorbent assay (ELISA) was used to determine the levels of inflammation cytokines, followed by RNA sequencing to explore the potential pathways of its anti-inflammatory effect, and then it was validated by Western blotting and pathways inhibitors. Results showed that the OVT at concentrations of 50-400 μg/mL displayed nontoxicity against GES-1 cells. Additionally, 100 μg/mL of OVT obviously reduced the secretion of interleukin (IL)-8, IL-6, and TNF-α by 63.02% (630.09/1703.98), 35.53% (935.81/1451.43), and 36.19% (964.60/1511.63), respectively. The results of RNA sequencing exhibited that the OVT significantly influences the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor kappa-light-chain enhancer of activated B cell (NF-κB) pathways, which was verified by the levels of p-IKK, p-IκB, p-P65, p-ERK, p-JNK, and p-P38 protein. IL-8 contents released by GES-1 cells after incubation with inhibitors of NF-κB and MAPK pathways further confirmed that OVT hindered activation of these two pathways. Collectively, these results suggested that OVT was a natural protein with the potential to treat gastric inflammation.