Angelica gigas NAKAI and Its Active Compound, Decursin, Inhibit Cellular Injury as an Antioxidant by the Regulation of AMP-Activated Protein Kinase and YAP Signaling

Response surface methodology mediated optimization of phytosulfokine and plant growth regulators for enhanced protoplast division, callus induction, and somatic embryogenesis in Angelica Gigas Nakai

BACKGROUND

Angelica Gigas (Purple parsnip) is an important medicinal plant that is cultivated and utilized in Korea, Japan, and China. It contains bioactive substances especially coumarins with anti-inflammatory, anti-platelet aggregation, anti-cancer, anti-diabetic, antimicrobial, anti-obesity, anti-oxidant, immunomodulatory, and neuroprotective properties. This medicinal crop can be genetically improved, and the metabolites can be obtained by embryonic stem cells. In this context, we established the protoplast-to-plant regeneration methodology in Angelica gigas.

RESULTS

In the present investigation, we isolated the protoplast from the embryogenic callus by applying methods that we have developed earlier and established protoplast cultures using Murashige and Skoog (MS) liquid medium and by embedding the protoplast in thin alginate layer (TAL) methods. We supplemented the culture medium with growth regulators namely 2,4-dichlorophenoxyaceticacid (2,4-D, 0, 0.75, 1.5 mg L- 1), kinetin (KN, 0, 0.5, and 1.0 mg L- 1) and phytosulfokine (PSK, 0, 50, 100 nM) to induce protoplast division, microcolony formation, and embryogenic callus regeneration. We applied central composite design (CCD) and response surface methodology (RSM) for the optimization of 2,4-D, KN, and PSK levels during protoplast division, micro-callus formation, and induction of embryogenic callus stages. The results revealed that 0.04 mg L- 1 2,4-D + 0.5 mg L- 1 KN + 2 nM PSK, 0.5 mg L- 1 2,4-D + 0.9 mg L- 1 KN and 90 nM PSK, and 1.5 mg L- 1 2,4-D and 1 mg L- 1 KN were optimum for protoplast division, micro-callus formation and induction embryogenic callus. MS basal semi-solid medium without growth regulators was good for the development of embryos and plant regeneration.

CONCLUSIONS

This study demonstrated successful protoplast culture, protoplast division, micro-callus formation, induction embryogenic callus, somatic embryogenesis, and plant regeneration in A. gigas. The methodologies developed here are quite useful for the genetic improvement of this important medicinal plant.

Angelica gigas extract inhibits acetylation of eNOS via IRE1α sulfonation/RIDD-SIRT1-mediated posttranslational modification in vascular dysfunction

Angelica gigas NAKAI (AG) is a popular traditional medicinal herb widely used to treat dyslipidemia owing to its antioxidant activity. Vascular disease is intimately linked to obesity-induced metabolic syndrome, and AG extract (AGE) shows beneficial effects on obesity-associated vascular dysfunction. However, the effectiveness of AGE against obesity and its underlying mechanisms have not yet been extensively investigated. In this study, 40 high fat diet (HFD) rats were supplemented with 100-300 mg/kg/day of AGE to determine its efficacy in regulating vascular dysfunction. The vascular relaxation responses to acetylcholine were impaired in HFD rats, while the administration of AGE restored the diminished relaxation pattern. Endothelial dysfunction, including increased plaque area, accumulated reactive oxygen species, and decreased nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) Ser1177 phosphorylation, were observed in HFD rats, whereas AGE reversed endothelial dysfunction and its associated biochemical signaling. Furthermore, AGE regulated endoplasmic reticulum (ER) stress and IRE1α sulfonation and its subsequent sirt1 RNA decay through controlling regulated IRE1α-dependent decay (RIDD) signaling, ultimately promoting NO bioavailability via the SIRT1-eNOS axis in aorta and endothelial cells. Independently, AGE enhanced AMPK phosphorylation, additionally stimulating SIRT1 and eNOS deacetylation and its associated NO bioavailability. Decursin, a prominent constituent of AGE, exhibited a similar effect in alleviating endothelial dysfunctions. These data suggest that AGE regulates dyslipidemia-associated vascular dysfunction by controlling ROS-associated ER stress responses, especially IRE1α-RIDD/sirt1 decay and the AMPK-SIRT1 axis.

Forsythiaside A Activates AMP-Activated Protein Kinase and Regulates Oxidative Stress via Nrf2 Signaling

Forsythiaside A (FA) is an active constituent isolated from Forsythia suspensa, a beneficial herb used in traditional medicine known for its antioxidant and anti-inflammatory properties. Although various studies have suggested that FA has the protective effects, its impacts on arachidonic acid (AA) plus iron in vitro models and carbon tetrachloride (CCl₄)-induced mouse liver damage in vivo have not been explored. In this study, HepG2 cells were subjected to AA + iron treatment to induce apoptosis and mitochondrial impairment and determine the molecular mechanisms. FA exhibited protective effects by inhibiting cell damage and reactive oxygen species (ROS) production induced by AA + iron, as assessed via immunoblot and flow cytometry analyses. Further molecular investigations revealed that FA resulted in the activation of extracellular-signal-related protein kinase (ERK), which subsequently triggered the activation of AMP-activated protein kinase (AMPK), a critical regulator of cellular oxidative stress. Additionally, FA modulated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which is a significant antioxidant transcription factor regulated by the AMPK pathway. For in vivo studies, mice were orally administered FA and then subjected to induction of CCl₄-based hepatotoxicity. The protective effect of FA was confirmed via blood biochemistry and immunohistochemical analyses. In conclusion, our findings demonstrated the protective effects of FA against oxidative stress both in vitro and in vivo, thus indicating that FA is a potential candidate for liver protection. Our study sheds light on the mechanistic pathways involved in the antioxidant effects of FA, highlighting the hepatoprotective potential of naturally occurring compounds in traditional herbs, such as FA.

Neuroprotective Potential of Pyranocoumarins from Angelica gigas Nakai on Glutamate-Induced Hippocampal Cell Death

Chronic neurodegenerative diseases are typically associated with oxidative stress conditions leading to neuronal cell death. We aimed to investigate the neuroprotective effect of three pyranocoumarins (decursin, decursinol angelate, and decursinol) targeting oxidative stress factors. Decursin (also known as dehydro-8-prenylnaringenin) is a prenylated coumarin compound consisting of a coumarin ring system with a prenyl group attached to one of the carbons in the ring. As a secondary metabolite of plants, pyranocoumarin decursin from Angelica gigas Nakai presented protective effects against glutamate-induced oxidative stress in HT22, a murine hippocampal neuronal cell line. Decursinol (DOH) is a metabolite of decursin, sharing same coumarin ring system but a slightly different chemical structure with the prenyl group replaced by a hydroxyl group (-OH). In our findings, DOH was ineffective while decursin was, suggesting that this prenyl structure may be important for compound absorption and neuroprotection. By diminishing the accumulation of intracellular reactive oxygen species as well as stimulating the expression of HO-1, decursin triggers the self-protection system in neuronal cells. Additionally, decursin also revealed an anti-apoptotic effect by inhibiting chromatin condensation and reducing the forming of annexin-V-positive cells.

Integrative approach to uncover antioxidant properties of Bupleuri Radix and its active compounds: Multiscale interactome-level analysis with experimental validation

Acute and chronic liver disease are global problems with high morbidity and mortality. Bupleuri Radix (BR) is an herbal medicine that has been prescribed empirically in traditional Asian medicine to modulate liver metabolism. However, its active compounds and therapeutic mechanisms remain unclear. Here, we integrated a network-based approach and experimental validation to elucidate BR's therapeutic potential in treating oxidative liver injury. Our approach incorporated data collection and network construction utilizing bioinformatics tools, and identified active compounds and key mechanisms based on the multiscale interactome. The proposed mechanisms were validated using an in vitro oxidative stress model and an in vivo carbon tetrachloride-induced model. We found that BR ameliorated the oxidative hepatic damage by acting on multiple proteins (STAT3, TNF, and BCL2) and signaling pathways (AMPK and Hippo signaling pathways). Subsequent in vitro experiments confirmed that BR significantly inhibited oxidative stress and mitochondrial damage. We further validated the effect of BR on the AMPK and Hippo-YAP pathways; a key mechanism for the antioxidant properties of BR. We prioritized the active compounds in BR based on a multiscale interactome-based approach, and further experiments revealed that saikosaponin A was a key active compound involved in hepatocyte protection (EC₅₀ = 50 μM), similar to the result using metformin and 5-aminoimidazole-4-carboxamide ribonucleotide. Histochemistry and blood biochemistry established that BR significantly inhibited carbon tetrachloride-induced oxidative tissue damage in mice. Thus, BR can be used to develop novel therapeutics for oxidative liver injury. Moreover, we suggest a novel strategy to prioritize and validate the active compounds and key mechanisms of herbal medicine based on the multiscale interactome.

Compound-level identification of sasang constitution type-specific personalized herbal medicine using data science approach

Introduction

Sasang Constitutional Medicine (SCM) is a type of traditional Korean medicine where patients are classified as one of four Sasang constitution types (Sasang type) and medications consisting of medicinal herbs are prescribed according to the Sasang type. Despite the importance of personalized medicine, the operation mechanism is largely unknown. To gain a better understanding, we investigated the compound information that composes Sasang type-specific personalized herbal medicines on both multivariate and univariate levels.

Methods

Five machine learning classifiers including extremely randomized trees (ERT) were trained to investigate whether the Sasang type can be explained by compound information at the multivariate level. Hierarchical clustering was conducted to determine whether compounds are processed distributedly or specifically. Taxonomic and biosynthetic analyses were conducted on these compounds. A univariate level statistical test was conducted to provide more robust Sasang type-specific compound information.

Results

Using the trained ERT classifier, sixty important compounds were extracted. The sixty compounds were clustered into three groups, corresponding to each Sasang type-prominent compounds, suggesting that most compounds have specific preference for the Sasang type. Structural and biosynthetic characteristics of these Sasang type-prominent compounds were determined based on taxonomy and pathway analyses. Fourteen compounds showed statistically significant relevance with the Sasang type. Additionally, we predicted the Sasang type of unknown herbs, which were confirmed by their biological effects in functional assays.

Conclusion

This study investigated the personalized herbal medicines of the SCM using compound information. This study provided information on the chemical characteristics of the compounds that are essential for classifying the Sasang type of medicinal herbs, as well as predictions regarding the Sasang type of the commonly used but unidentified medicinal herbs.

Decursin alleviates LPS-induced lung epithelial cell injury by inhibiting NF-κB pathway activation

OBJECTIVE

To reveal the possible effects of decursin on viability, oxidative stress, and inflammatory response in lipopolysaccharide (LPS)-treated human bronchial epithelial cells-2B (BEAS-2B) and human pulmonary artery endothelial cells (HPAEC) cells, and revealed the potential mechanisms.

METHODS

LPS was used to induce acute lung injury (ALI) in normal human lung epithelial cells, including BEAS-2B and HPAEC cells. Cell viability and apoptosis in response to LPS and decursin in BEAS-2B and HPAEC cells were, respectively, evaluated by MTT colorimetric and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. The oxidative stress and inflammatory response in LPS-treated BEAS-2B and HPAEC cells were detected by enzyme-linked-immunosorbent serologic assay. In addition, the role of decursin in nuclear -factor-kappa B (NF-κB) activation was analyzed by immunoblot and immunofluorescence assays.

RESULTS

Our data revealed that decursin could alleviate the viability of LPS-induced BEAS-2B and HPAEC cells. Decursin could also reduce LPS-induced oxidative stress in BEAS-2B and HPAEC cells. In addition, it could reduce LPS-induced inflammation in BEAS-2B and HPAEC cells. Mechanically, decursin suppressed the activation of NF-κB pathway.

CONCLUSION

Decursin suppressed NF-κB pathway, and therefore alleviated ALI.

Coordination of AMPK and YAP by Spatholobi Caulis and Procyanidin B2 Provides Antioxidant Effects In Vitro and In Vivo

The liver is vulnerable to oxidative attacks from heavy metals, such as iron, as well as some drugs, including acetaminophen. It has been shown that enhanced oxidative stress in the liver leads to excessive ROS production and mitochondrial dysfunction, resulting in organ injury. The beneficial effects of Spatholobi Caulis (SC), a natural herbal medicine, include treating ischemic stroke, inhibiting tumor cell invasion, pro-angiogenic activities, and anti-inflammatory properties. Scientific studies on its effects against hepatotoxic reagents (e.g., iron and acetaminophen), as well as their underlying mechanisms, are insufficient. This study examined the antioxidant effects and mechanisms of SC in vitro and in vivo. In cells, the proinflammatory mediator, arachidonic acid (AA), plus iron, significantly induced an increase in ROS generation, the damage in mitochondrial membrane potential, and the resulting apoptosis, which were markedly blocked by SC. More importantly, SC affected the activation of AMP-activated protein kinase (AMPK)-related proteins, which were vital to regulating oxidative stress in cells. In addition, SC mediated the expression of Yes-associated protein (YAP)-related proteins. Among the active compounds in SC, the procyanidin B2, but not liquiritigenin, daidzein, and genistein, significantly inhibited the cytotoxicity induced by AA + iron, and activated the LKB1-AMPK pathway. In mice, the oral administration of SC alleviated the elevations of ALT and histological changes by the acetaminophen-induced liver injury. These results reveal the potential of SC and a key bioactive component, procyanidin B2, as antioxidant candidates for hepatoprotection.