Naturally-derived diterpenoid sphaeropsidin C as an activator of Nrf2/ARE pathway and its potential capability of relieving intracellular oxidative stress in human lung epithelial cells

Beneficial effects of Chrysin on Cadmium-induced nephrotoxicity in rats: Modulating the levels of Nrf2/HO-1, RAGE/NLRP3, and Caspase-3/Bax/Bcl-2 signaling pathways

Cadmium (Cd) is a toxic heavy metal that targets the kidney directly in the body. Chrysin (CHR) is a natural flavonoid with many properties such as antioxidant, anti-inflammatory and anti-apoptotic. The current study discloses new evidence as regards of the curative effects of CHR on Cd-induced nephrotoxicity by regulating oxidative stress, apoptosis, autophagy, and inflammation. Cd was administered orally at a dose of 25 mg/kg body weight alone or in combination with orally administered CHR (25 and 50 mg/kg body weight) for 7 days. Biochemical, molecular, and histological methods were used to investigate inflammation, apoptosis, autophagy, and oxidant pathways in renal tissue. Renal function tests were also evaluated. Cd caused an increase in serum toxicity markers, lipid peroxidation and a decrease in the activities of antioxidant enzymes. Nrf-2 triggered inflammatory responses by suppressing HO-1 and NQO1 mRNA transcripts and increasing NF-κB, TNF-α, IL-1β and iNOS mRNA transcripts. Cd caused inflammasome by increasing RAGE and NLRP3 mRNA transcripts. In addition, Cd application caused apoptosis by increasing Bax, Apaf-1 and Caspase-3 mRNA transcripts and decreasing Bcl-2 mRNA transcript level. It caused autophagy by increasing the activity of Beclin-1 level. CHR treatment had the opposite effect on all these values and reduced the damage caused by all these signal pathways. Overall, the data of this study indicate that renal damage associated with Cd toxicity could be ameliorated by CHR administration.

Antioxidant and anti-inflammation effects of dietary phytochemicals: The Nrf2/NF-κB signalling pathway and upstream factors of Nrf2

Oxidative stress (OS) is created by an imbalance between reactive oxygen species and antioxidant levels. OS promotes inflammation and is associated with many diseases, such as neurodegenerative disorders, diabetes, and cardiovascular disease. Nrf2 and NF-κB are critical in the cellular defence against OS and the regulators of inflammatory responses, respectively. Recent studies revealed that the Nrf2 signalling pathway interacts with the NF-κB signalling pathway in OS. More importantly, many natural compounds have long been recognized to ameliorate OS and inflammation via the Nrf2 and/or NF-κB signalling pathway. Thus, we briefly overview the potential crosstalk between Nrf2 and NF-κB and the upstream regulators of Nrf2 and review the literature on the antioxidant and anti-inflammatory effects of dietary phytochemicals (DPs) that can activate these defence systems. The aim is to provide evidence for the development of DPs into functional food for the regulation of the Nrf2/NF-κB signalling pathway by upstream regulators of Nrf2.

Endoplasmic reticulum stress in airway hyperresponsiveness

Airway hyperresponsiveness(AHR) is a major clinical phenomenon in lung diseases (asthma, COPD and pulmonary fibrosis) and not only a high-risk factor for perioperative airway spasm leading to hypoxaemia, haemodynamic instability and even "silent lung", but also a potential risk for increased mortality from underlying diseases (e.g. asthma, COPD). Airway reactivity is closely linked to airway inflammation, remodelling and increased mucus secretion, and endoplasmic reticulum stress is an important mechanism for the development of these pathologies. This review, therefore, focuses on the effects of endoplasmic reticulum stress on the immune cells involved in airway hyperreactivity (epithelial cells, dendritic cells, eosinophils and neutrophils) in inflammation and mucus & sputum secretion; and on the differentiation and remodelling of airway smooth muscle cells and epithelial cells. The aim is to clarify the mechanisms associated with endoplasmic reticulum stress in airway hyperresponsiveness and to find new ideas and methods for the prevention of airway hyperresponsiveness in the perioperative period.

Recent advances of cereal β-glucan on immunity with gut microbiota regulation functions and its intelligent gelling application

β-glucan from cereals such as wheat, barley, oats and rye are a water-soluble dietary fiber, which are composed of repeating (1→4)-β-bond β-D-glucopyranosyl units and a single (1→3)-β-D-bond separated unit. β-glucan has a series of physicochemical properties (such as viscosity, gelling properties, solubility, etc.), which can be used as a food gel and fat substitute. Its structure endows the healthy functions, including anti-oxidative stress, lowering blood glucose and serum cholesterol, regulating metabolic syndrome and exerting gut immunity via gut microbiota. Due to their unique structural properties and efficacy, cereal β-glucan are not only applied in food substrates in the food industry, but also in food coatings and packaging. This article reviewed the applications of cereal β-glucan in hydrogels, aerogels, intelligent packaging systems and targeted delivery carriers in recent years. Cereal β-glucan in edible film and gel packaging applications are becoming more diversified and intelligent in recent years. Those advances provide a potential solution based on cereal β-glucan as biodegradable substances for immune regulation delivery system and intelligent gelling material in the biomedicine field.

Paeoniflorin ameliorates oxidase stress in Glutamate-stimulated SY5Y and prenatally stressed female offspring through Nrf2/HO-1 signaling pathway

BACKGROUND

Prenatal stress (PS) can cause brain retardation, reduce the learning and memory ability of the offspring and significantly increase the incidence of depression in offspring. Paeoniflorin (PF), a kind of monoterpenoid glycoside, is one of the main active ingredients of Chinese Medicine Paeonia lactiflora Pall, has anti-inflammation and potential neuroprotective effects. However, few reports have shown that the neuroprotective effects of PF are exerted through ameliorating Glutamate toxicity in vivo and in vitro.

METHODS

Here, we used a prenatal restraint stress model and Glu-induced excitotoxic neurotoxicity in SH-SY5Y cells to study the effects of PF.

RESULTS

Our results showed that PF can ameliorate learning and memory impairments and increases the density of hippocampal neurons, typical Golgi-positive pyramidal cells, and neuronal Neurogranin (Ng) expression in PS rat offspring. Furthermore, PF can significantly up-regulate the decrease of Glu-induced SH-SY5Y cell viability. At the same time, PF can significantly reduce apoptosis, ROS, NO levels, and intracellular Ca²⁺ concentration, and significantly inhibit the increase of mitochondrial membrane potential. Besides, PF significantly increased the expression of Nrf2 and iNOS, decreased p-JNK/JNK, p-P38/P38, Bax/Bcl-2, active-caspase-3, and active-caspase-9.

CONCLUSIONS

Our results demonstrate that PF may be an effective treatment in preventing the development of PS-induced learning and memory impairment and have therapeutic potential in Glu-related neurological diseases.

The water-soluble non-starch polysaccharides from natural resources against excessive oxidative stress: A potential health-promoting effect and its mechanisms

The water-soluble non-starch polysaccharides isolated from natural resources have become research hotpots in the field of food science and human health due to widely distributed in nature and low toxicity. It has indicated that the health-promoting effect of water-soluble non-starch polysaccharides were partly attributable to against excessive oxidative stress. Indeed, excessive oxidative stress in the body has been reported in occurrence of disease. The water-soluble non-starch polysaccharides from natural resources exhibit antioxidant activity to against oxidative stress via scavenging free radicals promoting antioxidant enzymes activity and/or regulating antioxidant signaling pathways. In this review, the water-soluble non-starch polysaccharides as medicine agent and the factor affecting antioxidant as well as the relationship between oxidative stress and disease are summarized, and the mechanisms of water-soluble non-starch polysaccharides therapy in disease are also discussed. It will provide a theoretical basis for natural polysaccharides used for the treatment of diseases.

Potential neuroprotection of wheat alkylresorcinols in hippocampal neurons via Nrf2/ARE pathway

5-n-Alkylresorcinols (ARs) are abundant in wheat bran and potentially antioxidative, although the neuroprotective mechanism is not fully understood. The neuroprotective effect of wheat bran ARs on H2O2-induced neuronal cells and the relationship between neuroprotection and the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-response element (ARE) pathway were investigated in this study. Seven homologs were identified in the purified ARs by high-performance liquid chromatography-tandem mass spectrometry. Pretreatment with 80 μg mL-1 ARs alleviated 23% HT22 cell death and the up-regulation of intracellular reactive oxygen species level and malondialdehyde under H2O2 stimulation. The neuroprotection effect was proved by the increase in the Nrf2 nuclear location and up-regulation of mRNA and protein expressions of heme oxygenase-1, NAD(P)H quinone dehydrogenase 1, glutamate-cysteine ligase catalytic subunit, and glutamate-cysteine ligase modifier subunit l. Wheat bran ARs displayed a neuroprotective function, possibly by promoting the endogenous antioxidant defense system. ARs may be regarded as a functional food ingredient for preventing neurodegenerative diseases in the future.

Herbal decoction Divya-Swasari-Kwath attenuates airway inflammation and remodeling through Nrf-2 mediated antioxidant lung defence in mouse model of allergic asthma

BACKGROUND AND PURPOSE

Asthma is a chronic respiratory disease orchestrated by immune and structural cells. Identification of novel therapeutic strategies are needed for asthma due to the limitations of existing therapies. We have validated the anti-inflammatory, anti-asthmatic and immunomodulatory therapeutic properties of herbal decoction, Divya-Swasari-Kwath (DSK) using mouse model of ovalbumin (OVA) induced allergic asthma.

METHODS AND RESULTS

HPLC analysis identified the presence of Rutin, Glycyrrchzin, Gallic acid, Cinnamic acid, Chlorogenic acid, Caffeic acid and Piperine as bioactive herbal metabolites in DSK. Therapeutic treatment with herbal decoction DSK significantly alleviated the pathological features of allergic asthma including inflammatory cell accumulation in Broncho-Alveolar Lavage (BAL) fluids, specifically lymphocytes and eosinophils, lung inflammation, oxidative stress, airway remodelling, and pro-inflammatory cytokine levels. H&E analysis of lung tissue sections identified attenuated inflammatory cell infiltration and thickening of bronchial epithelium by DSK. PAS staining and MT staining identified decrease in OVA-induced mucus hyper secretion and peri-bronchial collagen deposition respectively, upon DSK treatment. Treatment with DSK increased the mRNA expression of antioxidative defence gene Nrf-2 and its downstream target genes HO-1 and NQO-1. In the same line, biochemical analysis for the markers of oxidative/antioxidant system confirmed the restoration of activity of Catalase, GPx, SOD and EPO and the levels of GSH, GSSG, MDA and Nitrite in whole lungs. In line with PAS staining, DSK treatment decreased the OVA-induced expression of Muc5AC and Muc5B genes. DSK treatment reduced the steady state mRNA expression levels of IL-6, IL-1β, TNF-α, IL-4, -5, -33, IFN-γ in whole lung; and IL-6, TNF-α and IL-1β protein levels in BALF.

CONCLUSION

Collectively, our results suggest that herbal decoction DSK is effective in protecting against allergic airway inflammation and remodelling by regulating anti-oxidant mechanisms. We postulate that DSK could be the potential therapeutic option for allergic asthma management.