Cytoprotective effects of Avenathramide C against oxidative and inflammatory stress in normal human dermal fibroblasts

Phenolic amides (avenanthramides) in oats - an update review

Oats (Avena sativa L.) are one of the worldwide cereal crops. Avenanthramides (AVNs), the unique plant alkaloids of secondary metabolites found in oats, are nutritionally important for humans and animals. Numerous bioactivities of AVNs have been investigated and demonstrated in vivo and in vitro. Despite all these, researchers from all over the world are taking efforts to learn more knowledge about AVNs. In this work, we highlighted the recent updated findings that have increased our understanding of AVNs bioactivity, distribution, and especially the AVNs biosynthesis. Since the limits content of AVNs in oats strictly hinders the demand, understanding the mechanisms underlying AVN biosynthesis is important not only for developing a renewable, sustainable, and environmentally friendly source in both plants and microorganisms but also for designing effective strategies for enhancing their production via induction and metabolic engineering. Future directions for improving AVN production in native producers and heterologous systems for food and feed use are also discussed. This summary will provide a broad view of these specific natural products from oats.

Avenanthramide-C Activates Nrf2/ARE Pathway and Inhibiting Ferroptosis Pathway to Improve Cognitive Dysfunction in Aging Rats

Postoperative neurocognitive impairment (POCD) is a common complication after surgery and anesthesia, especially in elderly patients. Avenanthramide-C (AVC) test is a vascular endothelial cell adhesion molecule inhibitor with strong anti-inflammatory and antioxidant effects. The aim of this study was to investigate the effect and mechanism of AVC on POCD in aged rats to clarify the effect of AVC on POCD in aged rats. The aging rat model was established by continuous 200 mg/kg propofol anesthesia. Repeated propofol anesthesia could severely impair spatial learning ability, memory and cognitive function, and could promote hippocampal apoptosis, oxidative stress injury, neuroinflammation and ferroptosis in aging rats. In addition, AVC not only improved cognitive dysfunction, but also significantly inhibited apoptosis, neuroinflammatory response, ferroptosis and oxidative stress level in the hippocampus of aging rats induced by repeated anesthesia. Further mechanistic studies manifested that the above protective effects of AVC on aging rats induced by repeated propofol anesthesia may be achieved by activating Nrf2/ARE pathway activity. AVC pretreatment has a preventive effect on cognitive dysfunction induced by repeated propofol anesthesia in aging rats, and the preventive effect of AVC may be realized by activating the Nrf2/ARE signaling pathway activity. Our results demonstrate that AVC preconditioning reduces postoperative neuronal loss and neuroinflammation, activates the Nrf2/ARE pathway, reduces oxidative stress injury, and improves POCD in aged rats.

Genome Tectonics: Linking Dynamic Genome Organization with Cellular Nutrients

BACKGROUND

Our daily intake of food provides nutrients for the maintenance of health, growth, and development. The field of nutrigenomics aims to link dietary intake/nutrients to changes in epigenetic status and gene expression.

SUMMARY

Although the relationship between our diet and our genes in under intense investigation, there is still a significant aspect of our genome that has received little attention with regard to this. In the past 15 years, the importance of genome organization has become increasingly evident, with research identifying small-scale local changes to large segments of the genome dynamically repositioning within the nucleus in response to/or mediating change in gene expression. The discovery of these dynamic processes and organization maybe as significant as dynamic plate tectonics is to geology, there is little information tying genome organization to specific nutrients or dietary intake.

KEY MESSAGES

Here, we detail key principles of genome organization and structure, with emphasis on genome folding and organization, and link how these contribute to our future understand of nutrigenomics.

Pharmacological and In Silico Analysis of Oat Avenanthramides as EGFR Inhibitors: Effects on EGF-Induced Lung Cancer Cell Growth and Migration

Avena sativa L. is a wholegrain cereal and an important edible crop. Oats possesses high nutritional and health promoting values and contains high levels of bioactive compounds, including a group of phenolic amides, named avenanthramides (Avns), exerting antioxidant, anti-inflammatory, and anticancer activities. Epidermal growth factor receptor (EGFR) represents one of the most known oncogenes and it is frequently up-regulated or mutated in human cancers. The oncogenic effects of EGFR include enhanced cell growth, angiogenesis, and metastasis, and down-regulation or inhibition of EGFR signaling has therapeutic benefit. Front-line EGFR tyrosine kinase inhibitor therapy is the standard therapy for patients with EGFR-mutated lung cancer. However, the clinical effects of EGFR inhibition may be lost after a few months of treatment due to the onset of resistance. Here, we showed the anticancer activity of Avns, focusing on EGFR activation and signaling pathway. Lung cancer cellular models have been used to evaluate the activity of Avns on tumor growth, migration, EMT, and anoikis induced by EGF. In addition, docking and molecular dynamics simulations showed that the Avns bind with high affinity to a region in the vicinity of αC-helix and the DGF motif of EGFR, jeopardizing the target biological function. Altogether, our results reveal a new pharmacological activity of Avns as EGFR tyrosine kinase inhibitors.

Haskap Berry Phenolic Subclasses Differentially Impact Cellular Stress Sensing in Primary and Immortalized Dermal Fibroblasts

It is generally accepted that dietary phenolics from fruits are of significant importance to human health. Unfortunately, there is minimal published data on how differences in phenolic structure(s) impact biological pathways at cellular and molecular levels. We observed that haskap berry extracts isolated with ethanol:formic acid:water or phenolic subclass fractions separated using different concentrations of ethanol (40% and 100%) impacted cell growth in a positive manner. All fractions and extracts significantly increased population doubling times. All extracts and fractions reduced intracellular free radicals; however, there were differences in these effects, indicating different abilities to scavenge free radicals. The extracts and fractions also exhibited differing impacts on transcripts encoding the antioxidant enzymes (CAT, SOD1, GPX1, GSS and HMOX1) and the phosphorylation state of nuclear factor-κB (NF-κB). We further observed that extracts and fractions containing different phenolic structures had divergent impacts on the mammalian target of rapamycin (mTOR) and sirtuin 1 (SIRT1). siRNA-mediated knockdown of SIRT1 transcripts demonstrated that this enzyme is key to eliciting haskap phenolic(s) impact on cells. We postulate that phenolic synergism is of significant importance when evaluating their dietary impact.

A Novel Sprouted Oat Fermented Beverage: Evaluation of Safety and Health Benefits for Celiac Individuals

The safety and health effects for celiac people of a novel beverage (SOFB) developed from sprouted oat flour by fermentation with Lactobacillus plantarum was explored. In vitro reactivity against anti-gliadin antibodies (AGA) and antioxidant/anti-inflammatory potential of SOFB in RAW 264.7 macrophages and Caco-2 cells were evaluated. Immunoreactivity against AGA and antioxidant activity were not detected in SOFB, but it exhibited significant anti-inflammatory activity. The tolerability and impact of SOFB consumption for 6 months on nutritional status and intestinal microbiota composition were investigated in 10 celiac adults (five treated and five control). SOFB consumption did not adversely affect duodenal mucosa nor the total IgA or anti-tissue transglutaminase antibody (IgA-tTG) levels in celiac participants, but it significantly decreased total cholesterol levels at all sampling times and folic acid levels at the end of the study compared to the placebo beverage. SOFB administration also shifted gut microbiota, leading to a higher relative abundance of some beneficial bacteria including the genera Subdoligranulum, Ruminococcus and Lactobacillus in the SOFB group. This study provides supporting evidence of the safety of health benefits of a novel functional beverage produced from sprouted oat.

Natural Nrf2 Modulators for Skin Protection

Since the discovery of antioxidant responsive elements (ARE), which are commonly found in the promoter of the Phase II metabolism/antioxidant enzymes, and nuclear factor erythroid 2-related factor 2 (Nrf2), the transcription factor that binds to ARE, the study conducted in this field has expanded remarkably over the decades, and the Nrf2-mediated pathway is now recognized to occupy a central position in cell defense mechanisms. Induction of the Phase II metabolism/antioxidant enzymes through direct activation of Nrf2 can be a promising strategy for preventing degenerative diseases in general, but a dark side of this strategy should be considered, as Nrf2 activation can enhance the survival of cancer cells. In this review, we discuss the historical discovery of Nrf2 and the regulatory mechanism of the Nrf2-mediated pathway, focusing on the interacting proteins and post-translational modifications. In addition, we discuss the latest studies that examined various natural Nrf2 modulators for the protective roles in the skin, in consideration of their dermatological and cosmetic applications. Studies are reviewed in the order of time of research as much as possible, to help understand how and why such studies were conducted under the circumstances of that time. We hope that this review can serve as a steppingstone in conducting more advanced research by providing a scientific basis for researchers newly entering this field.

Andrographis Paniculata and Its Bioactive Diterpenoids Protect Dermal Fibroblasts Against Inflammation and Oxidative Stress

Andrographis paniculata (Burm.f.) has long been used in ayurvedic medicine through its anti-inflammatory properties. However, its protective effect of skin aging has not been studied in vitro. This study aimed to investigate the anti-aging effects of methanolic extract (ME), andrographolide (ANDRO), neoandrographolide (NEO), 14-deoxyandrographolide (14DAP) and 14-deoxy-11,12-didehydroandrographolide (14DAP11-12) on human dermal fibroblasts (HDFa) under pro-oxidant or pro-inflammatory condition. The in vitro anti-aging capacity of ME, ANDRO, NEO, 14DAP, and 14DAP11-12 (1, 2.5 and 5 µg/mL) was performed in HDFa. Oxidative stress and inflammation were induced by hydrogen peroxide and lipopolysaccharide/TNF-α, respectively. Reactive oxygen species (ROS) production was measured by the fluorescence of DCF-DA probe and cytokines were quantified by ELISA (IL6 and IL8) or RTqPCR (TNF-α). Procollagen type I production was determined by an ELISA. Our results showed a decrease in ROS production with ME and 14DAP at 5 µg/mL and 1 µg/mL, respectively. Furthermore, IL-6 production and TNF-α expression decreased under ANDRO and ME at 5 µg/mL. Our data indicated that ME and 14DAP protect from oxidative stress. Additionally, ME and ANDRO decreased an inflammation marker, IL-6. This suggests their potential natural treatment against skin damage. Hence, their applications could be of interest in cosmetics for preventing skin ageing.

Overview of the Anticancer Profile of Avenanthramides from Oat

Cancer represents one of the leading causes of death worldwide. Progresses in treatment of cancer have continued at a rapid pace. However, undesirable side effects and drug resistance remain major challenges for therapeutic success. Natural products represent a valuable starting point to develop new anticancer strategies. Polyphenols, well-known as antioxidant, exert anticancer effects through the modulation of multiple pathways and mechanisms. Oat (Avena sativa L., Poaceae) is a unique source of avenanthramides (AVAs), a group of polyphenolic alkaloids, considered as its signature compounds. The present review aims to offer a comprehensive and critical perspective on the chemopreventive and chemotherapeutic potential of AVAs. AVAs prevent cancer mainly by blocking reactive species. Moreover, they exhibit potential therapeutic activity through the modulation of different pathways including the activation of apoptosis and senescence, the block of cell proliferation, and the inhibition of epithelial mesenchymal transition and metastatization. AVAs are promising chemopreventive and anticancer phytochemicals, which need further clinical trials and toxicological studies to define their efficacy in preventing and reducing the burden of cancer diseases.