Effects of Korean Red Ginseng extract on tissue plasminogen activator and plasminogen activator inhibitor-1 expression in cultured rat primary astrocytes

1,3-Dichloroadamantyl-Containing Ureas as Potential Triple Inhibitors of Soluble Epoxide Hydrolase, p38 MAPK and c-Raf

Soluble epoxide hydrolase (sEH) is an enzyme involved in the metabolism of bioactive lipid signaling molecules. sEH converts epoxyeicosatrienoic acids (EET) to virtually inactive dihydroxyeicosatrienoic acids (DHET). The first acids are "medicinal" molecules, the second increase the inflammatory infiltration of cells. Mitogen-activated protein kinases (p38 MAPKs) are key protein kinases involved in the production of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2). p38 MAPK signaling plays an important role in the regulation of cellular processes, especially inflammation. The proto-oncogenic serine/threonine protein kinase Raf (c-Raf) is a major component of the mitogen-activated protein kinase (MAPK) pathway: ERK1/2 signaling. Normal cellular Raf genes can also mutate and become oncogenes, overloading the activity of MEK1/2 and ERK1/2. The development of multitarget inhibitors is a promising strategy for the treatment of socially dangerous diseases. We synthesized 1,3-disubstituted ureas and diureas containing a dichloroadamantyl moiety. The results of computational methods show that soluble epoxide hydrolase inhibitors can act on two more targets in different signaling pathways of mitogen-activated protein kinases p38 MAPK and c-Raf. The two chlorine atoms in the adamantyl moiety may provide additional Cl-π interactions in the active site of human sEH. Molecular dynamics studies have shown that the stability of ligand-protein complexes largely depends on the "spacer effect." The compound containing a bridge between the chloroadamantyl fragment and the ureide group forms more stable ligand-protein complexes with sEH and p38 MAPK, which indicates a better conformational ability of the molecule in the active sites of these targets. In turn, a compound containing two chlorine atoms forms a more stable complex with c-Raf, probably due to the presence of additional halogen bonds of chlorine atoms with amino acid residues.

Chinese Herbal Medicine Adjusting Brain Microenvironment via Mediating Central Nervous System Lymphatic Drainage in Alzheimer's Disease

Due to its complex pathogenesis and lack of effective therapeutic methods, Alzheimer's disease (AD) has become a severe public health problem worldwide. Recent studies have discovered the function of central nervous system lymphatic drainage, which provides a new strategy for the treatment of AD. Chinese herbal medicine (CHM) has been considered as a cure for AD for hundreds of years in China, and its effect on scavenging β-amyloid protein in the brain of AD patients has been confirmed. In this review, the mechanism of central nervous system lymphatic drainage and the regulatory functions of CHM on correlation factors were briefly summarized. The advances in our understanding regarding the treatment of AD via regulating the central lymphatic system with CHM will promote the clinical application of CHM in AD patients and the discovery of new therapeutic drugs.

Novel antidepressant mechanism of ginsenoside Rg1: Regulating biosynthesis and degradation of connexin43

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C. A. Meyer is a valuable medicinal herb and "alternative" remedy for the prevention and treatment of depression. Dysfunction of connexin43 (Cx43)-gap junction in astrocytes is predisposed to the precipitation of depression. Ginsenoside Rg1 (Rg1), the main bioactive constituent extracted from ginseng, is efficacious in the management of depression by upregulating the content of Cx43. Our previous results indicated that pretreatment with Rg1 significantly improved Cx43-gap junction in corticosterone (CORT)-treated astrocytes. However, the antidepressant mechanism underlying how Rg1 upregulates Cx43-gap junction in astrocytes hasn't been proposed.

AIM OF THE STUDY

To dissect the mechanisms of Rg1 controlling Cx43 levels in primary astrocytes.

METHODS

We examined the changes of the level of Cx43 mRNA, the degradation of Cx43, as well as the ubiquitin-proteasomal and autophagy-lysosomal degradation pathways of Cx43 followed by Rg1 prior to CORT in rat primary astrocytes isolated from prefrontal cortex and hippocampus. Furthermore, the recognized method of scrape loading/dye transfer was performed to detect Cx43-gap junctional function, an essencial indicator of the antidepressant effect.

RESULTS

Pretreatment with Rg1 could reverse CORT-induced downregulation of Cx43 biosynthesis, acceleration of Cx43 degradation, and upregulation of two Cx43 degradation pathways in primary astrocytes.

CONCLUSION

The findings in the present study provide the first evidence highlighting that Rg1 increases Cx43 protein levels through the upregulation of Cx43 mRNA and downregulation of Cx43 degradation, which may be attributed to the effect of Rg1 on the ubiquitin-proteasomal and autophagy-lysosomal degradation pathways of Cx43.

A Systematic Review of the Biological Effects of Cordycepin

We conducted a systematic review of the literature on the effects of cordycepin on cell survival and proliferation, inflammation, signal transduction and animal models. A total of 1204 publications on cordycepin were found by the cut-off date of 1 February 2021. After application of the exclusion criteria, 791 papers remained. These were read and data on the chosen subjects were extracted. We found 192 papers on the effects of cordycepin on cell survival and proliferation and calculated a median inhibitory concentration (IC50) of 135 µM. Cordycepin consistently repressed cell migration (26 papers) and cellular inflammation (53 papers). Evaluation of 76 papers on signal transduction indicated consistently reduced PI3K/mTOR/AKT and ERK signalling and activation of AMPK. In contrast, the effects of cordycepin on the p38 and Jun kinases were variable, as were the effects on cell cycle arrest (53 papers), suggesting these are cell-specific responses. The examination of 150 animal studies indicated that purified cordycepin has many potential therapeutic effects, including the reduction of tumour growth (37 papers), repression of pain and inflammation (9 papers), protecting brain function (11 papers), improvement of respiratory and cardiac conditions (8 and 19 papers) and amelioration of metabolic disorders (8 papers). Nearly all these data are consistent with cordycepin mediating its therapeutic effects through activating AMPK, inhibiting PI3K/mTOR/AKT and repressing the inflammatory response. We conclude that cordycepin has excellent potential as a lead for drug development, especially for age-related diseases. In addition, we discuss the remaining issues around the mechanism of action, toxicity and biodistribution of cordycepin.

Role of intracellular signaling pathways and their inhibitors in the treatment of inflammation

Inflammation is not only a defense mechanism of the innate immune system against invaders, but it is also involved in the pathogenesis of many diseases such as atherosclerosis, thrombosis, diabetes, epilepsy, and many neurodegenerative disorders. The World Health Organization (WHO) reports worldwide estimates of people (9.6% in males and 18.0% in females) aged over 60 years, suffering from symptomatic osteoarthritis, and around 339 million suffering from asthma. Other chronic inflammatory diseases, such as ulcerative colitis and Crohn's disease are also highly prevalent. The existing anti-inflammatory agents, both non-steroidal and steroidal, are highly effective; however, their prolonged use is marred by the severity of associated side effects. A holistic approach to ensure patient compliance requires understanding the pathophysiology of inflammation and exploring new targets for drug development. In this regard, various intracellular cell signaling pathways and their signaling molecules have been identified to be associated with inflammation. Therefore, chemical inhibitors of these pathways may be potential candidates for novel anti-inflammatory drug approaches. This review focuses on the anti-inflammatory effect of these inhibitors (for JAK/STAT, MAPK, and mTOR pathways) describing their mechanism of action through literature search, current patents, and molecules under clinical trials.

Reactive Gliosis Contributes to Nrf2-Dependent Neuroprotection by Pretreatment with Dimethyl Fumarate or Korean Red Ginseng Against Hypoxic-Ischemia: Focus on Hippocampal Injury

Recently, dimethyl fumarate (DMF) and Korean red ginseng (ginseng), based on their purported antioxidative and anti-inflammatory properties, have exhibited protective potential in various neurological conditions. Their effects on cerebral ischemia and underlying mechanisms remain inconclusive; however, increasing evidence indicates the involvement of the transcriptional factor Nrf2. This study evaluated the preventive effects of DMF and ginseng on hippocampal neuronal damage following hypoxia-ischemia (HI) and assessed the contributions of reactive gliosis and the Nrf2 pathway. Adult wild type (WT) and Nrf2-/- mice were pretreated with DMF or ginseng for 7 days prior to HI. At 24 h after HI, DMF or ginseng significantly reduced infarct volume (52.5 ± 12.3% and 47.8 ± 10.7%), brain edema (61.5 ± 17.4% and 39.3 ± 12.8%), and hippocampal CA1 neuronal degeneration, and induced expressions of Nrf2 target proteins in WT, but not Nrf2-/-, mice. Such hippocampal neuroprotective benefits were also observed at 6 h and 7 days after HI. The dynamic attenuation of reactive gliosis in microglia and astrocytes correlated well with this sustained neuroprotection in an Nrf2-dependent manner. In both early and late stages of HI, astrocytic dysfunctions in extracellular glutamate clearance and water transport, as indicated by glutamine synthetase and aquaporin 4, were also attenuated after HI in WT, but not Nrf2-/-, mice treated with DMF or ginseng. Together, DMF and ginseng confer robust and prolonged Nrf2-dependent neuroprotection against ischemic hippocampal damage. The salutary Nrf2-dependent attenuation of reactive gliosis may contribute to this neuroprotection, offering new insight into the cellular basis of an Nrf2-targeting strategy for stroke prevention or treatment.

Ginsenoside Rg1-induced antidepressant effects involve the protection of astrocyte gap junctions within the prefrontal cortex

Ginsenoside Rg1 (Rg1) exhibits antidepressant-like activity by increasing neurogenesis and dendritic spine density without discernible side effects. However, the molecular mechanisms underlying Rg1 antidepressant activity remain poorly understood. As the dysfunction of gap junctions between astrocytes in the prefrontal cortex (PFC) is implicated in major depression disorder, the aim of this study was to investigate the effects of Rg1 on astrocyte gap junctions in the PFC. Rats exposed to chronic unpredictable stress (CUS) were administered Rg1 (5, 10, and 20mg/kg) for 28days and analyzed for depressive symptoms using the sucrose preference and forced swimming tests. Functional and morphological changes of gap junction channels in the PFC were evaluated using dye transfer and electron microscopy, respectively. The expression of connexin 43 (Cx43) was analyzed by western blotting. Rg1 markedly alleviated depression-like behavior in rats. Long-term Rg1 treatment of CUS-exposed rats also significantly prevented the decrease in dye diffusion and improved the ultrastructure of astrocyte gap junctions in the PFC, indicating beneficial effects on the functional activity of gap junction channels in the brain. In addition, Rg1 upregulated Cx43 expression in the PFC reduced by CUS exposure, which significantly correlated with its antidepressant-like effects. The results demonstrate that Rg1-induced antidepressant effects are might be mediated, in part, by protecting astrocyte gap junctions within the prefrontal cortex.

Korean Red Ginseng improves atopic dermatitis-like skin lesions by suppressing expression of proinflammatory cytokines and chemokines in vivo and in vitro

BACKGROUND

The prevalence of allergic inflammatory diseases such as atopic dermatitis (AD), asthma, and allergic rhinitis worldwide has increased and complete recovery is difficult. Korean Red Ginseng, which is the heat-processed root of Panax ginseng Meyer, is widely and frequently used as a traditional medicine in East Asia. In this study, we investigated whether Korean Red Ginseng water extract (RGE) regulates the expression of proinflammatory cytokines and chemokines via the mitogen-activated protein kinases (MAPKs)/nuclear factor kappa B (NF-κB) pathway in allergic inflammation.

METHODS

Compound 48/80-induced anaphylactic shock and 1-fluoro-2,4-dinitrobenzene (DNFB)-induced AD-like skin lesion mice models were used to investigate the antiallergic effects of RGE. Human keratinocytes (HaCaT cells) and human mast cells (HMC-1) were also used to clarify the effects of RGE on the expression of proinflammatory cytokines and chemokines.

RESULTS

Anaphylactic shock and DNFB-induced AD-like skin lesions were attenuated by RGE administration through reduction of serum immunoglobulin E (IgE) and interleukin (IL)-6 levels in mouse models. RGE also reduced the production of proinflammatory cytokines including IL-1β, IL-6, and IL-8, and expression of chemokines such as IL-8, thymus and activation-regulated chemokine (TARC), and macrophage-derived chemokine (MDC) in HaCaT cells. Additionally, RGE decreased the release of tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and IL-8 as well as expressions of chemokines including macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1, and IL-8 in HMC-1 cells. Furthermore, our data demonstrated that these inhibitory effects occurred through blockage of the MAPK and NF-κB pathway.

CONCLUSION

RGE may be a useful therapeutic agent for the treatment of allergic inflammatory diseases such as AD-like dermatitis.

Antiproliferative and Apoptosis-Inducing Activities of 4-Isopropyl-2,6-bis(1-phenylethyl)phenol Isolated from Butanol Fraction of Cordyceps bassiana

The Cordyceps species have been widely used for treating various cancer diseases. Although the Cordyceps species have been widely known as an alternative anticancer remedy, which compounds are responsible for their anticancer activity is not fully understood. In this study, therefore, we examined the anticancer activity of 5 isolated compounds derived from the butanol fraction (Cb-BF) of Cordyceps bassiana. For this purpose, several cancer cell lines such as C6 glioma, MDA-MB-231, and A549 cells were employed and details of anticancer mechanism were further investigated. Of 5 compounds isolated by activity-guided fractionation from BF of Cb-EE, KTH-13, and 4-isopropyl-2,6-bis(1-phenylethyl)phenol, Cb-BF was found to be the most potent antiproliferative inhibitor of C6 glioma and MDA-MB-231 cell growth. KTH-13 treatment increased DNA laddering, upregulated the level of Annexin V positive cells, and altered morphological changes of C6 glioma and MDA-MB-231 cells. In addition, KTH-13 increased the levels of caspase 3, caspase 7, and caspase 9 cleaved forms as well as the protein level of Bax but not Bcl-2. It was also found that the phosphorylation of AKT and p85/PI3K was also clearly reduced by KTH-13 exposure. Therefore, our results suggest KTH-13 can act as a potent antiproliferative and apoptosis-inducing component from Cordyceps bassiana, contributing to the anticancer activity of this mushroom.

Syk/Src-targeted anti-inflammatory activity of Codariocalyx motorius ethanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Codariocalyx motorius (Houtt.) H. Ohashi (Fabaceae) is one of several ethnopharmacologically valuable South Asian species prescribed as an herbal medicine for various inflammatory diseases. Due to the lack of systematic studies on this plant, we aimed to explore the inhibitory activity of Codariocalyx motorius toward inflammatory responses using its ethanolic extract (Cm-EE).

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-treated macrophages and a HCl/EtOH-induced gastritis model were used for evaluation of the anti-inflammatory activity of Cm-EE. HPLC and spectroscopic analysis were employed to identify potential active components. Mechanistic approaches to determine target enzymes included kinase assays, reporter gene assays, and overexpression of target enzymes.

RESULTS

Cm-EE strongly suppressed nitric oxide (NO) and prostaglandin E2 (PGE2) release. Cm-EE-mediated inhibition was observed at the transcriptional level in the form of suppression of NF-κB (p65) translocation and activation. This extract also lowered the levels of phosphorylation of Src and Syk, their kinase activity, and their formation of signalling complexes by binding to the downstream enzyme p85/PI3K. In accord with these findings, the phosphorylation of p85 induced by overexpression of Src or Syk was also diminished by Cm-EE. Orally administered Cm-EE clearly inhibited gastritic ulcer formation and the phosphorylation of IκBα and Src in HCl/EtOH-treated stomachs of mice. By phytochemical analysis, luteolin and its glycoside, apigenin-7-O-glucuronide, and scutellarein-6-O-glucuronide were identified as major components of Cm-EE. Among these, it was found that luteolin was able to strongly suppress NO and PGE2 production under the same conditions.

CONCLUSION

Syk/Src-targeted inhibition of NF-κB by Cm-EE could be a major anti-inflammatory mechanism contributing to its ethno pharmacological role as an anti-inflammatory herbal medicine.

Functional roles of p38 mitogen-activated protein kinase in macrophage-mediated inflammatory responses

Inflammation is a natural host defensive process that is largely regulated by macrophages during the innate immune response. Mitogen-activated protein kinases (MAPKs) are proline-directed serine and threonine protein kinases that regulate many physiological and pathophysiological cell responses. p38 MAPKs are key MAPKs involved in the production of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2). p38 MAPK signaling plays an essential role in regulating cellular processes, especially inflammation. In this paper, we summarize the characteristics of p38 signaling in macrophage-mediated inflammation. In addition, we discuss the potential of using inhibitors targeting p38 expression in macrophages to treat inflammatory diseases.