Activation of the Nrf2/HO-1 Pathway by Amomum villosum Extract Suppresses LPS-Induced Oxidative Stress In Vitro and Ex Vivo. Evid Based Complement Alternat Med. 2020;2020:2837853. [PMID: 32454852 PMCID: PMC7218974 DOI: 10.1155/2020/2837853]

Amomum villosum Lour.: An insight into ethnopharmacological, phytochemical, and pharmacological overview

ETHNOPHARMACOLOGICAL RELEVANCE

Amomum villosum Lour. is a widely esteemed species of medicinal plant on a global scale. Its medicinal properties have been documented as early as the Tang Dynasty, particularly the fruit, which holds significant medicinal and culinary value. This plant is extensively found in tropical and subtropical regions across Asia. It possesses the properties of warming the middle and dispelling cold, regulating Qi to invigorate the spleen, harmonizing the stomach to alleviate vomiting, and nourishing deficiencies. In recent years, A. villosum has garnered global attention for its remarkable biological activity. Currently, numerous bioactive compounds have been successfully isolated and identified, showcasing a diverse array of pharmacological activities and medicinal benefits.

AIM OF THE WORK

This review aims to provide a comprehensive analysis of the research advancements in the geographical distribution, botany, traditional applications, phytochemistry, pharmacological activity, quality control, clinical applications, and toxicology of A. villosum. Furthermore, a critical summary of the current research and future prospects of this plant is presented.

MATERIALS AND METHODS

Obtain information about A. villosum from ancient literature, doctoral and master's theses, and scholarly databases including Google Scholar, Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), ScienceDirect, plant directories, and clinical reports.

RESULTS

At present, about 500 compounds have been isolated and identified from various organs of A. villosum, including monoterpenoids, sesquiterpenoids, diterpenoids, flavonoids, phenols, polysaccharides, and other components. Modern pharmacological studies have revealed that A. villosum exhibits exceptional biological activities in vitro and in vivo, such as anti-inflammatory, antioxidant, liver protection, anti-tumor, hypoglycemic, anti-microbial, regulating gastrointestinal activity, immune regulation, regulating flora, anti-obesity, estrogen, and more. Some of these activities have found extensive application in clinical practice.

CONCLUSION

A. villosum, as a well-established medicinal herb, holds significant therapeutic potential and is also valued for its culinary applications. Currently, the research on the active components or crude extracts of A. villosum and their potential mechanisms of action remains limited. Furthermore, certain pharmacological activities require further elucidation for a comprehensive understanding of its internal mechanisms. Moreover, it is strongly recommended to prioritize research on pharmacokinetics and toxicity studies. These efforts will facilitate a thorough exploration of the potential of A. villosum and establish a robust foundation for its potential clinical applications.

Antioxidant aromatic compounds from Amomum villosum and target prediction of active ingredients

The dried fruit of Amomum villosum is an important spice and medicinal plant that has received great attention in recent years due to its high content of bioactive components and its potential for food additives and drug development. However, the stems and leaves of A. villosum are usually disposed of as waste. Based on the study of the fruits of A. villosum, we also systematically studied its stems and leaves. Fourteen aromatic compounds (1-14) were isolated and identified from A. villosum, including five new compounds (1-5) and nine known compounds (6-14). Among them, compounds 2-5, 8-10, 12-13 were obtained from the fruits of A. villosum, and compounds 1, 6-7,11, 14 were isolated from the stems and leaves of A. villosum. Based on chemical evidence and spectral data analysis (UV, ECD, Optical rotation data, 1D and 2D-NMR, and HR-ESI-MS), the structures of new compounds were elucidated. Furthermore, all compounds were tested for their effects on the survival rate of BV-2 cells in the presence of hydrogen peroxide. Among them, compound 5 showed antioxidant effects. Through network pharmacology screening and the cell thermal shift assay (CETSA), the Phosphoglycerate Mutase 5 (PGAM5) protein was identified as the antioxidant target of compound 5. Molecular docking results showed that compound 5 maintains binding to PGAM5 by forming hydrogen bond interactions with Lys93 and Agr214. In summary, A. villosum had potential medicinal and food values due to the diverse bioactive components.

Three New Labdane-Type Diterpenoids from the Fruits of Amomum villosum and Their Anti-Inflammatory Activities

Three new labdane-type diterpenoids, calcaratarin E, villosumtriol, and 12-epi-villosumtriol (1-3) were isolated from the fruits of Amomum villosum, along with seven known diterpenoids (4-10). Through comprehensive analysis of chemical evidence and spectral data including UV, 1D and 2D NMR, HR-ESI-MS, IR, and X-ray crystallography, the structures of these novel compounds were successfully determined. Additionally, the inhibitory effects of compounds 2-10 on NO production in lipopolysaccharide (LPS)-induced RAW264.7 cells were evaluated. Notably, compound 6 exhibited the most significant inhibitory effect with an IC50 value of 1.74±0.69 μM.

(R)-8-Methylsulfinyloctyl isothiocyanate from Nasturtium officinale inhibits LPS-induced immunoinflammatory responses in mouse peritoneal macrophages: chemical synthesis and molecular signaling pathways involved

The aim of this study was to develop an optimal synthetic route to obtain natural (R)-8-methylsulfinyloctyl isothiocyanate ((R)-8-OITC), present in watercress, based on the "DAG methodology" as well as to evaluate its potential antioxidant and immunomodulatory effects, exploring possible signaling pathways that could be involved in an ex vivo model of murine peritoneal macrophages stimulated with LPS. Treatment with (R)-8-OITC inhibited the levels of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-17 and IL-18), intracellular ROS production and expression of pro-inflammatory enzymes (COX-2, iNOS and mPGES-1) through modulation of the expression of Nrf2, MAPKs (p38, JNK and ERK) and JAK/STAT, and the canonical and non-canonical pathways of the inflammasome. Taking all these together, our results provide a rapid and cost-effective synthetic route to obtain natural (R)-8-OITC and demonstrate that it could be a potential nutraceutical candidate for managing immuno-inflammatory pathologies. Therefore, further in vivo trials are warranted.

Chitooligosaccharide from Pacific White Shrimp Shell Chitosan Ameliorates Inflammation and Oxidative Stress via NF-κB, Erk1/2, Akt and Nrf2/HO-1 Pathways in LPS-Induced RAW264.7 Macrophage Cells

Chitooligosaccharide (COS), found in both insects and marine sources, has several bioactivities, such as anti-inflammation and antioxidant activities. However, the mechanism of shrimp shell COS on retardation of inflammatory and antioxidant effects is limited. Therefore, the aim of this study is to examine the mechanism of the aforementioned activities of COS in LPS-activated RAW264.7 macrophage cells. COS significantly improved cell viability in LPS-activated cells. COS at the level of 500 µg/mL could reduce the TNF-α, NO and IL-6 generations in LPS-activated cells (p < 0.05). Furthermore, COS could reduce ROS formation, NF-κB overactivation, phosphorylation of Erk1/2 and Akt and Nrf2/HO-1 in LPS-exposed cells. These results indicate that COS manifests anti-inflammatory activity and antioxidant action via NF-κB, Erk1/2, Akt and Nrf2/HO-1 signaling with an increasing relevance for inflammatory disorders.

Artemisia argyi extract ameliorates IL-17A-induced inflammatory response by regulation of NF-κB and Nrf2 expression in HIG-82 synoviocytes

Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease that results in joint destruction and disability in the adult population. RA is characterized by the accumulation and proliferation of fibroblast-like synoviocytes. Many pro-inflammatory mediators are associated with RA, such as interleukin (IL)-1β, IL-6, IL-17, cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB). Furthermore, IL-17 upregulates the production of other pro-inflammatory mediators, including IL-1β and IL-6, and promotes the recruitment of neutrophils in RA. Artemisia argyi, a traditional Chinese herbal medicine, is used for the treatment of diseases associated with inflammation and microbial infections. In this study, synoviocytes (HIG-82) were treated with varying doses of A. argyi extract (AAE) following IL-17A stimulation. Proliferation of the IL-17A-stimulated cells was increased compared to that of the non-stimulated control cells. However, cell proliferation decreased significantly in a dose-dependent manner following AAE treatment. Treatment of IL-17A-stimulated cells with AAE resulted in decreased levels of phosphorylated (p)-NF-κB, p-IκB-α, and COX-2. Enzyme-linked immunosorbent assay results showed that IL-1β and IL-6 levels were increased in the IL-17A-stimulated group but decreased in the AAE treatment group. Additionally, we found that AAE facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) expression and promoted its nuclear translocation, thereby inducing the expression of heme oxygenase-1. Moreover, AAE did not attenuate IL-17A-induced inflammatory mediator production in the presence of ML385, an Nrf2-specific inhibitor. These results suggest that the downregulation of expression of pro-inflammatory cytokines and the transcription factor NF-κB by AAE may be a potential therapeutic strategy for reducing inflammation associated with RA.

Effects of Oleacein, a New Epinutraceutical Bioproduct from Extra Virgin Olive Oil, in LPS-Activated Murine Immune Cells

The present study was designed to evaluate the immunomodulatory effects of the secoiridoid from extra virgin olive oil, oleacein (OLA), deepening into the possible signaling pathways involved in LPS-activated murine peritoneal macrophages. Moreover, we have explored OLA-induced epigenetic changes in histone markers and related cytokine production in murine LPS-stimulated murine splenocytes. Murine cells were treated with OLA in the presence or absence of LPS (5 μg/mL) for 18 or 24 h. OLA modulated the oxidative stress and the inflammatory response produced by LPS stimulation in murine peritoneal macrophages, by the inhibition of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, IFN-γ, IL-17 and IL-18) and ROS production and the expression of pro-inflammatory enzymes such as iNOS, COX-2 and m-PGES1. These protective effects could be due to the activation of the Nrf-2/HO-1 axis and the inhibition of JAK/STAT, ERK and P38 MAPKs and inflammasome canonical and non-canonical signaling pathways. Moreover, OLA modulated epigenetic modifications throughout histone methylation deacetylation (H3K18ac) and (H3K9me3 and H3K27me) in LPS-activated spleen cells. In conclusion, our data present OLA as an interesting anti-inflammatory and antioxidant natural compound that is able to regulate histone epigenetic markers. Nevertheless, additional in vivo studies are required to further investigate the beneficial effects of this EVOO secoiridoid, which might be a promising epinutraceutical bioproduct for the management of immune-related inflammatory diseases.

Calycosin alleviates H2 O2 -induced astrocyte injury by restricting oxidative stress through the Akt/Nrf2/HO-1 signaling pathway

Oxidative stress-induced brain cell damage is a crucial factor in the pathogenesis of reactive oxygen species (ROS)-associated neurological diseases. Further, studies show that astrocytes are an important immunocompetent cell in the brain and play a potentially significant role in various neurological diseases. Therefore, elimination of ROS overproduction might be a potential strategy for preventing and treating neurological diseases. Accumulating evidence indicates that calycosin, a main active ingredient in the Chinese herbal medicine Huangqi (Radix Astragali Mongolici), is a potential therapeutic candidate with anti-inflammation and/or anticancer effects. Here, we investigated the protective effect of calycosin in brain astrocytes by mimicking in vitro oxidative stress using H₂ O₂ . The results revealed that H₂ O₂ significantly induced ROS and inflammatory factor (tumor necrosis factor [TNF]-α and interleukin [IL]-1β) production, whereas post-treatment with calycosin dramatically and concentration-dependently suppressed H₂ O₂ -induced damage by enhancing cell viability, repressing ROS and inflammatory factor production, and increasing superoxide dismutase (SOD) expression. Additionally, we found that calycosin facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) expression and promoted its nuclear translocation, thereby inducing the expression of antioxidant molecules (heme oxygenase [HO]-1 and SOD) following H₂ O₂ treatment. Moreover, calycosin did not attenuated H₂ O₂ -induced astrocyte damage and ROS production in the presence of the ML385 (a Nrf2-specific inhibitor) and following Nrf2 silencing. Furthermore, calycosin failed to increase Akt phosphorylation and mitigate H₂ O₂ -induced astrocyte damage in the presence of the LY294002 (a selective phosphatidylinositol 3-kinase inhibitor), indicating that calycosin-mediated regulation of oxidative-stress homeostasis involved Akt/Nrf2/HO-1 signaling. These findings demonstrated that calycosin protects against oxidative injury in brain astrocytes by regulating oxidative stress through the AKT/Nrf2/HO-1 signaling pathway.

Comparative Evaluation of Forsythiae Fructus From Different Harvest Seasons and Regions by HPLC/NIR Analysis and Anti-inflammatory and Antioxidant Assays

Forsythiae Fructus (FF), the dry fruit of Forsythia suspensa (Thunb.) Vahl, has a long history of use in traditional Chinese Medicine for its heat-clearing and detoxifying properties. It possesses clinical therapeutic effects and biological functions showing efficacy in handling different diseases. To investigate the FF differences in Henan, Shanxi, and Shaanxi in August and October, the surface morphology, mid-infrared and near-infrared spectrums, and HPLC were analyzed. Concurrently, the anti-inflammatory and antioxidant effects on LPS-induced J774A.1 cells were evaluated by western blot and RT-qPCR. The results showed that FF from different Harvest Seasons and Regions are provided with different microstructures and mid-infrared and near-infrared spectrums, and the levels of forsythiaside A and phillyrin of FF from Shanxi in August and phillygenin of FF from Shaanxi in August were the highest. Meanwhile, FF from Shanxi and Shaanxi in August markedly reduced the levels of inflammatory cytokines and mediators (TNF-α, IL-1β, NF-κB, and iNOS) and the protein expression levels of phosphorylated total IKKα/β and nuclear NF-κB. In August, SXFF and SAXFF also promoted the mRNA expression levels of HO-1 and NQO1 and the protein expression levels of HO-1 and nuclear Nrf2 and suppressed the protein expression levels of KEAP1. Spearman correlation analysis showed that phillygenin had a strong correlation with the protein expression on LPS-induced J774A.1 cells. In summary, our results showed that FF from harvest seasons and regions contributed to the distinct differences in microstructure, the mid-infrared and near-infrared spectrums, and compound content. More importantly, FF from Shanxi and Shaanxi in August showed marked anti-inflammatory and antioxidant activities, but with some differences, which may be because of different contents of phillygenin and phillyrin of lignans in FF.

Knockdown of long noncoding RNA growth arrest-specific transcript 5 regulates forkhead box O3 to inhibit lipopolysaccharide-induced human bronchial epithelial cell pyroptosis

Pyroptosis is a novel proinflammatory programmed cell death process. This study was designed to investigate the functional mechanisms of long noncoding RNA growth arrest-specific transcript 5 (lncRNA GAS5) on lipopolysaccharide (LPS)-induced human bronchial epithelial cell (HBEC) pyroptosis. LPS was used to induce pyroptosis in HBECs, followed by the detection of the expression of GAS5, forkhead box O3 (FOXO3), and nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathway-related factors. Cell viability was evaluated using CCK-8 assay, lactate dehydrogenase (LDH) release was assessed by LDH assay kit and caspase-1 activity by flow cytometry. Furthermore, expression of NOD-like receptor family pyrin domain containing 3 and pyroptosis-related proteins was evaluated using Western blot analysis, while enzyme-linked immunosorbent assay was used to determine the levels of inflammatory factors. The interaction between GAS5 and FOXO3 was confirmed using bioinformatic prediction, RNA immunoprecipitation assay, RNA pull-down, and dual-luciferase reporter gene assay. Treatment of HBECs with LPS upregulated the expression of GAS5 and FOXO3, resulting in the inactivation of the Nrf2/HO-1 signaling pathway. On the other hand, inhibition of both GAS5 and FOXO3 promoted cell viability, reduced LDH release, pyroptosis, and inflammatory response in LPS-induced HBECs. Furthermore, FOXO3 could interact with GAS5, while FOXO3 overexpression reversed the inhibitory effect of GAS5 knockdown on cell pyroptosis. Thus, mechanistically, inhibition of FOXO3 activates the Nrf2/HO-1 pathway to suppress LPS-induced pyroptosis in HBECs. This study revealed that GAS5 knockdown attenuates FOXO3 expression thereby activating the Nrf2/HO-1 pathway to inhibit LPS-induced pyroptosis in HBECs. These findings may contribute to identifying novel targets that inhibit pyroptosis in HBECs.

Purification, Structural Characterization and Immunomodulatory Effects of Polysaccharides from Amomumvillosum Lour. on RAW 264.7 Macrophages

Amomum Villosum Lour. (A. villosum) is a folk medicine that has been used for more than 1300 years. However, study of the polysaccharides of A. villosum is seriously neglected. The objectives of this study are to explore the structural characteristics of polysaccharides from A. villosum (AVPs) and their effects on immune cells. In this study, the acidic polysaccharides (AVPG-1 and AVPG-2) were isolated from AVPs and purified via anion exchange and gel filtration chromatography. The structural characteristics of the polysaccharides were characterized by methylation, HPSEC-MALLS-RID, HPLC, FT-IR, SEM, GC-MS and NMR techniques. AVPG-1 with a molecular weight of 514 kDa had the backbone of → 4)-α-d-Glcp-(1 → 3,4)-β-d-Glcp-(1 → 4)-α-d-Glcp-(1 →. AVPG-2 with a higher molecular weight (14800 kDa) comprised a backbone of → 4)-α-d-Glcp-(1 → 3,6)-β-d-Galp-(1 → 4)-α-d-Glcp-(1 →. RAW 264.7 cells were used to investigate the potential effect of AVPG-1 and AVPG-2 on macrophages, and lipopolysaccharide (LPS) was used as a positive control. The results from bioassays showed that AVPG-2 exhibited stronger immunomodulatory activity than AVPG-1. AVPG-2 significantly induced nitric oxide (NO) production as well as the release of interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), and upregulated phagocytic capacities of RAW 264.7 cells. Real-time PCR analysis revealed that AVPG-2 was able to turn the polarization of macrophages to the M1 direction. These results suggested that AVPs could be explored as potential immunomodulatory agents of the functional foods or complementary medicine.

Sinapic acid ameliorates D-galactosamine/lipopolysaccharide-induced fulminant hepatitis in rats: Role of nuclear factor erythroid-related factor 2/heme oxygenase-1 pathways

BACKGROUND

Sinapic acid (SA) has been shown to have various pharmacological properties such as antioxidant, antifibrotic, anti-inflammatory, and anticancer activities. Its mechanism of action is dependent upon its ability to curb free radical production and protect against oxidative stress-induced tissue injuries.

AIM

To study the hepatoprotective effects of SA against lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver failure (ALF) in rats.

METHODS

Experimental ALF was induced with an intraperitoneal (i.p.) administration of 8 μg LPS and 800 mg/kg D-GalN in normal saline. SA was administered orally once daily starting 7 d before LPS/D-GalN treatment.

RESULTS

Data showed that SA ameliorates acute liver dysfunction, decreases serum levels of alanine transaminase (ALT), and aspartate aminotransferase (AST), as well as malondialdehyde (MDA) and NO levels in ALF model rats. However, pretreatment with SA (20 mg/kg and 40 mg/kg) reduced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and levels of inflammatory cytokines (tumor necrosis factor-α and interleukin 6). Also, SA increased the activity of the nuclear factor erythroid-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway.

CONCLUSION

In conclusion, SA offers significant protection against LPS/D-GalN-induced ALF in rats by upregulating Nrf2/HO-1 and downregulating NF-κB.

Anti‑inflammatory effects of leaf and branch extracts of honeyberry (Lonicera caerulea) on lipopolysaccharide‑stimulated RAW264.7 cells through ATF3 and Nrf2/HO‑1 activation

Honeyberry (Lonicera caerulea) has long been used as a traditional medicine in China, Japan and northern Russia. Functional studies of honeyberry have mainly focused on the fruits, which have been reported to exert various pharmacological activities, including anti-inflammatory activity, with limited or no studies on the other parts of the plant, such as the leaves and branches. In the present study, the anti-inflammatory effects of extracts of the leaves (HBL), branches (HBB) and fruit (HBF) of honeyberry plant were evaluated in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. HBL and HBB significantly inhibited the production of pro-inflammatory mediators in LPS-stimulated RAW264.7 cells, and the inhibitory effects of HBL and HBB were stronger than those of HBF. HBL and HBB blocked the nuclear accumulation of p65 independently of IκB-α. HBL did not inhibit the phosphorylation of ERK1/2 or p38; however, HBB effectively inhibited the phosphorylation of p38 but not ERK1/2. HBL and HBB increased the expression of heme oxygenase-1 (HO-1) protein by inducing the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) through the activation of the reactive oxygen species (ROS)/p38 pathway; the reduction in inducible nitric oxide synthase (iNOS) and interleukin-1β (IL-1β) expression by HBL and HBB was inhibited by HO-1 knockdown. In addition, HBL and HBB increased the expression of activating transcription factor-3 (ATF3), and the reduction in iNOS and IL-1β expression by HBL and HBB was inhibited by ATF3 knockdown. Collectively, HBL and HBB inhibited LPS-induced nuclear factor-κB activation by blocking the nuclear accumulation of p65, increasing HO-1 expression through activation of the ROS/p38/Nrf2 pathway, and increasing ATF3 expression. Furthermore, HBB inhibited LPS-induced p38 phosphorylation. These findings suggest that HBL and HBB may have great potential as natural products for the development of anti-inflammatory drugs.