Schisandrae Fructus ethanol extract attenuates particulate matter 2.5-induced inflammatory and oxidative responses by blocking the activation of the ROS-dependent NF-κB signaling pathway

A Mixture of Morus alba and Angelica keiskei Leaf Extracts Improves Muscle Atrophy by Activating the PI3K/Akt/mTOR Signaling Pathway and Inhibiting FoxO3a In Vitro and In Vivo

Muscle atrophy, which is defined as a decrease in muscle mass and strength, is caused by an imbalance between the anabolism and catabolism of muscle proteins. Thus, modulating the homeostasis between muscle protein synthesis and degradation represents an efficient treatment approach for this condition. In the present study, the protective effects against muscle atrophy of ethanol extracts of Morus alba L. (MA) and Angelica keiskei Koidz. (AK) leaves and their mixtures (MIX) were evaluated in vitro and in vivo. Our results showed that MIX increased 5-aminoimidazole-4-carboxamide ribonucleotide-induced C2C12 myotube thinning, and enhanced soleus and gastrocnemius muscle thickness compared to each extract alone in dexamethasone-induced muscle atrophy Sprague Dawley rats. In addition, although MA and AK substantially improved grip strength and histological changes for dexamethasone-induced muscle atrophy in vivo, the efficacy was superior in the MIX-treated group. Moreover, MIX further increased the expression levels of myogenic factors (MyoD and myogenin) and decreased the expression levels of E3 ubiquitin ligases (atrogin-1 and muscle-specific RING finger protein-1) in vitro and in vivo compared to the MA- and AK-alone treatment groups. Furthermore, MIX increased the levels of phosphorylated phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) that were reduced by dexamethasone, and downregulated the expression of forkhead box O3 (FoxO3a) induced by dexamethasone. These results suggest that MIX has a protective effect against muscle atrophy by enhancing muscle protein anabolism through the activation of the PI3K/Akt/mTOR signaling pathway and attenuating catabolism through the inhibition of FoxO3a.

A Mixture of Fermented Schizandrae Fructus Pomace and Hoveniae Semen cum Fructus Extracts Synergistically Protects against Oxidative Stress-Mediated Liver Injury

Schizandrae Fructus (SF) and Hoveniae Semen cum Fructus (HSCF) have long been used as medicinal herbs for treating various diseases in Asian traditional medicine. In the current study, we investigated the protective effect of fermented SF pomace and HSCF extract 1:1 (w:w) combination mixture (MSH) against carbon tetrachloride (CCl4)-induced acute liver injury mice. After MSH (50-200 mg/kg) oral administration for 7 consecutive days, animals were injected intraperitoneally with CCl4 (0.5 mL/kg). Histopathological observation revealed that administration of MSH synergistically decreased the degeneration of hepatocytes and the infiltration of inflammatory cells induced by CCl4. Moreover, MSH administration reduced the activities of alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase in serum, and mitigated apoptotic cell death in hepatic parenchyma. In addition, MSH alleviated CCl4-mediated lipid peroxidation by restoring endogenous antioxidants capacities including glutathione contents, superoxide dismutase, and catalase activities. In vitro assessments using tert-butyl hydroperoxide-induced oxidative stress in HepG2 cells revealed that MSH protects hepatocytes by lowering ROS generation and lipid peroxidation via upregulating the transcriptional activity of nuclear factor erythroid-2-related factor 2 and the expression of antioxidant genes. Furthermore, MSH synergistically attenuated the expression of proinflammatory cytokines in CCl4-injured liver and lipopolysaccharide-stimulated RAW 264.7 cells. Taken together, these findings suggest that MSH has the potential to prevent acute liver damage by effectively suppressing oxidative stress and inflammation.

An analysis of the nutritional effects of Schisandra chinensis components based on mass spectrometry technology

OBJECTIVE

Schisandra chinensis (Turcz.) Baill. (S. chinensis) is a Traditional Chinese medicinal herb that can be used both for medicinal purposes and as a food ingredient due to its beneficial properties, and it is enriched with a wide of natural plant nutrients, including flavonoids, phenolic acids, anthocyanins, lignans, triterpenes, organic acids, and sugars. At present, there is lack of comprehensive study or systemic characterization of nutritional and active ingredients of S. chinensis using innovative mass spectrometry techniques.

METHODS

The comprehensive review was conducted by searching the PubMed databases for relevant literature of various mass spectrometry techniques employed in the analysis of nutritional components in S. chinensis, as well as their main nutritional effects. The literature search covered the past 5 years until March 15, 2023.

RESULTS

The potential nutritional effects of S. chinensis are discussed, including its ability to enhance immunity, function as an antioxidant, anti-allergen, antidepressant, and anti-anxiety agent, as well as its ability to act as a sedative-hypnotic and improve memory, cognitive function, and metabolic imbalances. Meanwhile, the use of advanced mass spectrometry detection technologies have the potential to enable the discovery of new nutritional components of S. chinensis, and to verify the effects of different extraction methods on these components. The contents of anthocyanins, lignans, organic acids, and polysaccharides, the main nutritional components in S. chinensis, are also closely associated to its quality.

CONCLUSION

This review will provide guidelines for an in-depth study on the nutritional value of S. chinensis and for the development of healthy food products with effective components.

Spermidine Attenuates High Glucose-Induced Oxidative Damage in Retinal Pigment Epithelial Cells by Inhibiting Production of ROS and NF-κB/NLRP3 Inflammasome Pathway

Diabetic retinopathy (DR) is the leading cause of vision loss and a critical complication of diabetes with a very complex etiology. The build-up of reactive oxygen species (ROS) due to hyperglycemia is recognized as a primary risk factor for DR. Although spermidine, a naturally occurring polyamine, has been reported to have antioxidant effects, its effectiveness in DR has not yet been examined. Therefore, in this study, we investigated whether spermidine could inhibit high glucose (HG)-promoted oxidative stress in human retinal pigment epithelial (RPE) cells. The results demonstrated that spermidine notably attenuated cytotoxicity and apoptosis in HG-treated RPE ARPE-19 cells, which was related to the inhibition of mitochondrial ROS production. Under HG conditions, interleukin (IL)-1β and IL-18's release levels were markedly increased, coupled with nuclear factor kappa B (NF-κB) signaling activation. However, spermidine counteracted the HG-induced effects. Moreover, the expression of nucleotide-binding oligomerization domain-like receptor (NLR) protein 3 (NLRP3) inflammasome multiprotein complex molecules, including TXNIP, NLRP3, ASC, and caspase-1, increased in hyperglycemic ARPE-19 cells, but spermidine reversed these molecular changes. Collectively, our findings demonstrate that spermidine can protect RPE cells from HG-caused injury by reducing ROS and NF-κB/NLRP3 inflammasome pathway activation, indicating that spermidine could be a potential therapeutic compound for DR treatment.

L-Methionine inhibits 4-hydroxy-2-nonenal accumulation and suppresses inflammation in growing rats

BACKGROUND/OBJECTIVES

4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of L-methionine in rats.

MATERIALS/METHODS

Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of L-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated.

RESULTS

Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed L-methionine, which were attributed to the stimulation of GST by L-methionine. With decreasing HNE levels, L-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by L-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by L-methionine. The anti-inflammatory action of L-methionine was also reflected by the up-regulation of IL-10.

CONCLUSIONS

This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to L-methionine availability. The anti-inflammatory mechanism exerted by L-methionine was to inhibit NF-κB activation and to up-regulate GST.

FGF10 mediates protective anti-oxidative effects in particulate matter-induced lung injury through Nrf2 and NF-κB signaling

Background

Particulate matter (PM), a well-known environmental pollutant, is an independent risk factor associated with the morbidity of various respiratory diseases. Oxidative stress is an important pathophysiological mechanism related to PM exposure, which mediates redox-sensitive inflammatory signaling, leading to lung injury. Fibroblast growth factor 10 (FGF10), a paracrine fibroblast growth factor that mediates mesenchymal to epithelial signaling, participates in epithelial repair during lung injury. However, whether FGF10-mediated repair in PM-induced lung injury is related to the regulation of oxidative stress remains to be elucidated.

Methods

In vivo, the C57BL/6 mice were randomly divided, with intratracheal instillation of 5 mg/kg FGF10 1 h before 4 mg/kg PM for 2 consecutive days. In vitro, the BEAS-2B cells were pretreated with 10 ng/mL FGF10 before exposed to 200 µg/mL PM. Besides, the specific Nrf2 inhibitor ML385 was adopted in vitro. The harvested lung tissues were pathologic grading scored. The state of oxidative stress was assessed with dihydroethidium (DHE) staining, malondialdehyde (MDA) activity, hydrogen peroxide (H₂O₂) assays and reactive oxygen species (ROS). The contents of IL-6 and IL-8 in bronchoalveolar lavage (BAL) as well as culture supernatant were quantified by ELISA. The protein levels of nuclear factor erythroid 2 related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling from lung tissue as well as cell lysate were determined by Western blot.

Results

In this study, recombinant FGF10 administration relieved the degree of lung injury, which is characterized by bronchitis, in a mouse model of PM exposure. In addition, reduced ROS levels, which are indicative of restrained oxidative stress, were also observed. Moreover, two redox-sensitive signaling pathways, Nrf2 and NF-κB, were found to be differentially regulated by FGF10. Using a cellular model of PM exposure, we found that the anti-inflammatory effect of FGF10 on NF-κB signaling was mediated through the regulation of oxidative stress. The anti-oxidative effect relied on the stimulation of Nrf2 signaling. Blockade of Nrf2 signaling with ML385 significantly compromised the anti-inflammatory effect of FGF10.

Conclusions

These results underscore that the protective anti-oxidative effects of FGF10 in lung injury are mediated by the stimulation of Nrf2 signaling and inhibition of the NF-κB pathway.