Nuclear factor kappa-B- and activator protein-1-mediated immunostimulatory activity of compound K in monocytes and macrophages

Comparative Assessment of In Vitro Xanthine Oxidase and α-Glucosidase Inhibitory Activities of Cultured Cambial Meristematic Cells, Adventitious Roots, and Field-Cultivated Ginseng

Panax ginseng, a traditional Chinese medicine with a history spanning thousands of years, faces overexploitation and challenges related to extended growth periods. Tissue-cultured adventitious roots and stem cells are alternatives to wild and field-cultivated ginseng. In this study, we assessed the in vitro xanthine oxidase and α-glucosidase inhibitory activities of saponin extracts among cultured cambial meristematic cells (CMC), adventitious ginseng roots (AGR), and field-cultivated ginseng roots (CGR). The xanthine oxidase (XO) and α-glucosidase inhibitory activities were determined by uric acid estimation and the p-NPG method, respectively. Spectrophotometry and the Folin-Ciocalteu, aluminum nitrate, and Bradford methods were employed to ascertain the total saponins and phenolic, flavonoid, and protein contents. The calculated IC50 values for total saponin extracts against XO and α-glucosidase were 0.665, 0.844, and >1.6 mg/mL and 0.332, 0.745, and 0.042 mg/mL for AGR, CMC, CGR, respectively. Comparing the total saponin, crude protein, and total phenolic contents revealed that AGR > CMC > CGR. To the best of our knowledge, this study presents the first report on the in vitro comparison of xanthine oxidase and α-glucosidase inhibitory activities among AGR, CMC, and CGR. The findings offer valuable insights into the development of hypoglycemic and antihyperuricemic medicinal, nutraceutical, and functional products utilizing AGR and CMC.

The Potential of Korean Bioactive Substances and Functional Foods for Immune Enhancement

In this review, we explore the immunomodulatory properties of Korean foods, focusing on ginseng and fermented foods. One notable example is Korean red ginseng, known for its immune system-regulating effects attributed to the active ingredient, ginsenoside. Ginsenoside stimulates immune cells, enhancing immune function and suppressing inflammatory responses. With a long history, Korean red ginseng has demonstrated therapeutic effects against various diseases. Additionally, Korean fermented foods like kimchi, doenjang, chongkukjang, gochujang, vinegar, and jangajji provide diverse nutrients and bioactive substances, contributing to immune system enhancement. Moreover, traditional Korean natural herbs such as Cirsium setidens Nakai, Gomchwi, Beak-Jak-Yak, etc. possess immune-boosting properties and are used in various Korean foods. By incorporating these foods into one's diet, one can strengthen their immune system, positively impacting their overall health and well-being.

In vitro evaluation of ginsenoside Rg1 immunostimulating effect in bovine mononuclear cells

The aim of this study was to evaluate the immunomodulatory effect of ginsenoside Rg1 on mammary secretion and peripheral blood mononuclear cells (MSMC and PBMC, respectively). The mRNA expression of TLR2, TLR4 and selected cytokines were evaluated on MSMC after Rg1 treatment. Also, TLR2 and TLR4 protein expression was evaluated on MSMC and PBMC after Rg1 treatment. Phagocytic activity and capacity, ROS production and MHC-II expression were evaluated on MSMC and PBMC after Rg1 treatment and co-culture with Staphylococcus aureus strain 5011. Rg1 induced mRNA expression of TLR2, TLR4, TNF-α, IL-1β, IL-6 and IL-8 in groups treated with different concentrations and at different times in MSMC, and induced TLR2 and TLR4 protein expression in MSMC and PBMC. Rg1 increased phagocytic capacity and ROS production in MSMC and PBMC. Rg1 increased MHC-II expression by PBMC. However, Rg1 pre-treatment had no effect on cells co-cultured with S. aureus. In conclusion, Rg1 was able to stimulate several sensing and effector activities in these immune cells.

Syk promotes phagocytosis by inducing reactive oxygen species generation and suppressing SOCS1 in macrophage-mediated inflammatory responses

OBJECTIVE

Inflammation, a vital innate immune response against infection and injury, is mediated by macrophages. Spleen tyrosine kinase (Syk) regulates inflammatory responses in macrophages; however, its role and underlying mechanisms are uncertain.

MATERIALS AND METHODS

In this study, overexpression and knockout (KO) cell preparations, phagocytosis analysis, confocal microscopy, reactive oxygen species (ROS) determination, mRNA analysis, and immunoprecipitation/western blotting analyses were used to investigate the role of Syk in phagocytosis and its underlying mechanisms in macrophages during inflammatory responses.

RESULTS

Syk inhibition by Syk KO, Syk-specific small interfering RNA (siSyk), and a selective Syk inhibitor (piceatannol) significantly reduced the phagocytic activity of RAW264.7 cells. Syk inhibition also decreased cytochrome c generation by inhibiting ROS-generating enzymes in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and ROS scavenging suppressed the phagocytic activity of RAW264.7 cells. LPS induced the tyrosine nitration (N-Tyr) of suppressor of cytokine signaling 1 (SOCS1) through Syk-induced ROS generation in RAW264.7 cells. On the other hand, ROS scavenging suppressed the N-Tyr of SOCS1 and phagocytosis. Moreover, SOCS1 overexpression decreased phagocytic activity, and SOCS1 inhibition increased the phagocytic activity of RAW264.7 cells.

CONCLUSION

These results suggest that Syk plays a critical role in the phagocytic activity of macrophages by inducing ROS generation and suppressing SOCS1 through SOCS1 nitration during inflammatory responses.

Essential Oils from Zingiber striolatum Diels Attenuate Inflammatory Response and Oxidative Stress through Regulation of MAPK and NF-κB Signaling Pathways

Zingiber striolatum Diels (Z. striolatum), a widely popular vegetable in China, is famous for its medicinal and nutritional values. However, the anti-inflammatory effects of essential oil from Z. striolatum (EOZS) remain unclear. In this study, EOZS from seven regions in China were extracted and analyzed by GC–MS. LPS-induced RAW264.7 cells and 12-O-Tetradecanoylphorbol 13-acetate (TPA)-stimulated mice were used to evaluate the anti-inflammatory effects of EOZS. Results show that 116 compounds were identified in EOZS from seven locations. Samples 2, 4 and 5 showed the best capability on DPPH radical scavenging and NO inhibition. They also significantly reduced the production of ROS, pro-inflammatory cytokines, macrophage morphological changes, migration and phagocytic capability. Transcriptomics revealed MAPK and NF-κB signaling pathways may be involved in the anti-inflammatory mechanism, and the predictions were proven by Western blotting. In TPA-induced mice, EOZS reduced the degree of ear swelling and local immune cell infiltration by blocking the activation of MAPK and NF-κB signaling pathways, which was consistent with the in vitro experimental results. Our research unveils the antioxidant capability and potential molecular mechanism of EOZS in regulating inflammatory response, and suggests the application of EOZS as a natural antioxidant and anti-inflammatory agent in the pharmaceutical and functional food industries.

The immunomodulatory effects of ginsenoside derivative Rh2-O on splenic lymphocytes in H22 tumor-bearing mice is partially mediated by TLR4

PURPOSE

Previously, we reported the octyl ester derivative of ginsenoside Rh2 (Rh2-O) had better antitumor and immunomodulatory effects than Rh2 in H22 tumor-bearing mice. Therefore, this study further explored the effects of Rh2-O on splenic lymphocytes in H22 tumor-bearing mice and the underlying mechanism.

METHODS

Wild type and Tlr4^-/- mice were selected to establish the H22 tumor-bearing mice model. After the treatment of Rh2-O (10 mg/kg by gavage) for 15 days, the sizes of tumor were measured. Subsequently, the splenic lymphocytes were isolated and the activities (eg. cell proliferation, cytotoxicity and cytokine secretion) were evaluated. Then, the proteins and mRNA expression levels of TRAF6 and NF-ĸB p65 in splenic lymphocytes were examined.

RESULTS

The results showed that Rh2-O administration enhanced the proliferative capacity and cytotoxicity of splenic lymphocytes, and the effects were Tlr4-associated. Compared to WT mice, the up-regulation of cytokines secretion (eg. IFN-γ, IL-2 and IL-4) in isolated splenic lymphocytes after Rh2-O administration was lower in Tlr4^-/- mice. Moreover, the results showed Rh2-O increased the expression of TRAF6 and the level of endonuclear NF-ĸB p65, which was inhibited in Tlr4^-/- mice (P < 0.05).

CONCLUSION

Rh2-O could exert immunomodulatory effects on splenic lymphocytes with the partial participation of TLR4 in H22 tumor-bearing mice.

Therapeutic effect of various ginsenosides on rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is an autoimmune disease which causes disability and threatens the health of humans. Therefore, it is of great significance to seek novel effective drugs for RA. It has been reported that various ginsenoside monomers are able to treat RA. However, it is still unclear which ginsenoside is the most effective and has the potential to be developed into an anti-RA drug.

Methods

The ginsenosides, including Rg1, Rg3, Rg5, Rb1, Rh2 and CK, were evaluated and compared for their therapeutic effect on RA. In in vitro cell studies, methotrexate (MTX) and 0.05% dimethyl sulfoxide (DMSO) was set as a positive control group and a negative control group, respectively. LPS-induced RAW264.7 cells and TNF-α-induced HUVEC cells were cultured with MTX, DMSO and six ginsenosides, respectively. Cell proliferation was analyzed by MTT assay and cell apoptosis was carried out by flow cytometry. CIA mice model was developed to evaluate the therapeutic efficacy of ginsenosides. The analysis of histology, immunohistochemistry, flow cytometry and cytokine detections of the joint tissues were performed to elucidate the action mechanisms of ginsenosides.

Results

All six ginsenosides showed good therapeutic effect on acute arthritis compared with the negative control group, Ginsenoside CK provided the most effective treatment ability. It could significantly inhibit the proliferation and promote the apoptosis of RAW 264.7 and HUVEC cells, and substantially reduce the swelling, redness, functional impairment of joints and the pathological changes of CIA mice. Meanwhile, CK could increase CD8 + T cell to down-regulate the immune response, decrease the number of activated CD4 + T cell and proinflammatory M1-macrophages, thus resulting in the inhibition of the secretion of proinflammatory cytokine such as TNF-α and IL-6.

Conclusion

Ginsenoside CK was proved to be a most potential candidate among the tested ginsenosides for the treatment of RA, with a strong anti-inflammation and immune modulating capabilities.

Enhancement of skin barrier and hydration-related molecules by protopanaxatriol in human keratinocytes

Background

Protopanaxatriol (PPT) is a secondary intestinal metabolite of ginsenoside in ginseng. Although the effects of PPT have been reported in various diseases including cancer, diabetes and inflammatory diseases, the skin protective effects of PPT are poorly understood.

Methods

HaCaT cells were treated with PPT in a dose-dependent manner. mRNA and protein levels which related to skin barrier and hydration were detected compared with retinol. Luciferase assay was performed to explore the relative signaling pathway. Western blot was conducted to confirm these pathways and excavated further signals.

Results

PPT enhanced the expression of filaggrin (FLG), transglutaminase (TGM)-1, claudin, occludin and hyaluronic acid synthase (HAS) −1, −2 and −3. The mRNA expression levels of FLG, TGM-1, HAS-1 and HAS-2 were suppressed under NF-κB inhibition. PPT significantly augmented NF-κB-luc activity and upregulated Src/AKT/NF-κB signaling. In addition, PPT also increased phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK and p38 and upstream MAPK activators (MEK and MKK). Furthermore, transcriptional activity of AP-1 and CREB, which are downstream signaling targets of MAPK, was enhanced by PPT.

Conclusion

PPT improves skin barrier function and hydration through Src/AKT/NF-κB and MAPK signaling. Therefore, PPT may be a valuable component for cosmetics or treating skin disorders.

To Inhibit or Enhance? Is There a Benefit to Positive Allosteric Modulation of P2X Receptors?

The family of ligand-gated ion channels known as P2X receptors were discovered several decades ago. Since the cloning of the seven P2X receptors (P2X1-P2X7), a huge research effort has elucidated their roles in regulating a range of physiological and pathophysiological processes. Transgenic animals have been influential in understanding which P2X receptors could be new therapeutic targets for disease. Furthermore, understanding how inherited mutations can increase susceptibility to disorders and diseases has advanced this knowledge base. There has been an emphasis on the discovery and development of pharmacological tools to help dissect the individual roles of P2X receptors and the pharmaceutical industry has been involved in pushing forward clinical development of several lead compounds. During the discovery phase, a number of positive allosteric modulators have been described for P2X receptors and these have been useful in assigning physiological roles to receptors. This review will consider the major physiological roles of P2X1-P2X7 and discuss whether enhancement of P2X receptor activity would offer any therapeutic benefit. We will review what is known about identified compounds acting as positive allosteric modulators and the recent identification of drug binding pockets for such modulators.

Photoaging Protective Effects of Ranunculus bulumei Methanol Extract

Ultraviolet B (UVB) radiation is the main cause of photoaging processes including cellular senescence, skin drying, collagen degradation, melanogenesis, and inflammation. These responses occur because UVB induces a change in expression of aging-related genes through regulation of signal pathways such as that of mitogen-activated protein kinases- (MAPKs-) activator protein 1 (AP-1). Ranunculus bulumei, which is used as an herb in Indonesia, belongs to the Ranunculaceae family, which has been reported to perform various physiological effects including antioxidant and anti-inflammation. However, data on the pharmaceutical and cosmeceutical utility of Ranunculus bulumei have not been reported. Therefore, we evaluated the antiaging efficacy of RB-ME, a methanol extract of Ranunculus bulumei. Rb-ME attenuated MMP9 and COX-2 gene expression but enhanced SIRT1 and type-1 collagen in UVB-irradiated HaCaT cells. Rb-ME regulated these gene expressions through inhibition of p38 phosphorylation and inactivation of AP-1. In addition, mRNA expression of HAS-2 and -3, which are involved in skin hydration, was elevated in Rb-ME-treated HaCaT cells. Rb-ME also inhibited melanogenesis by suppression of tyrosinase, MITF, and TYRP-1 mRNA in B16F10 cells under α-MSH treatment. Taken together, these results indicate that Rb-ME has a protective effect on some UVB-induced skin photoaging events such as inflammation, collagen degradation, cellular senescence, skin drying, and melanin production through inhibition of the p38-AP-1 signal cascade, indicating that Rb-ME can be used as an active ingredient for antiaging cosmetics.

Src/NF-κB-Targeted Anti-Inflammatory Effects of Potentilla glabra var. Mandshurica (Maxim.) Hand.-Mazz. Ethanol Extract

Inflammation is a complex protective response of body tissues to harmful stimuli. Acute inflammation can progress to chronic inflammation, which can lead to severe disease. Therefore, this research focuses on the development of anti-inflammatory drugs, and natural extracts have been explored as potential agents. No study has yet examined the inflammation-associated pharmacological activity of Potentilla glabra Var. mandshurica (Maxim.) Hand.-Mazz ethanol extract (Pg-EE). To examine the mechanisms by which Pg-EE exerts anti-inflammatory effects, we studied its activities in lipopolysaccharide (LPS)-treated murine macrophage RAW264.7 cells and an HCl/EtOH-induced gastritis model. LPS-triggered nitric oxide (NO) release and mRNA levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in RAW264.7 cells were suppressed by Pg-EE in a dose-dependent manner. Using a luciferase assay and western blot assay, we found that the NF-κB pathway was inhibited by Pg-EE, particularly by the decreased level of phosphorylated proteins of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunits (p65 and p50), inhibitor of kappa B alpha (IκBα), p85, and Src. Using an overexpression strategy, cellular thermal shift assay, and immunoprecipitation analysis, we determined that the anti-inflammatory effect of Pg-EE was mediated by the inhibition of Src. Pg-EE further showed anti-inflammatory effects in vivo in the HCl/EtOH-induced gastritis mouse model. In conclusion, Pg-EE exerts anti-inflammatory activities by targeting Src in the NF-κB pathway, and these results suggest that Pg-EE could be used as an anti-inflammatory herbal medicine.

In Vitro Effects of Dehydrotrametenolic Acid on Skin Barrier Function

Dehydrotrametenolic acid (DTA) is a lanostane-type triterpene acid isolated from Poria cocos Wolf (Polyporaceae). Several studies have reported the anti-inflammatory and antidiabetic effects of DTA; however, its effects on the skin are poorly understood. In this study, we investigated the effects of DTA on skin barrier function in vitro and its regulatory mechanism in human keratinocyte cell line HaCaT cells. DTA increased the microRNA (mRNA) expression of natural moisturizing factor-related genes, such as HAS-2, HAS-3, and AQP3 in HaCaT cells. DTA also upregulated the mRNA expression of various keratinocyte differentiation markers, including TGM-1, involucrin, and caspase-14. Moreover, the protein expression of HAS-2, HAS-3, and TGM-2 were significantly increased by DTA. To examine the regulatory mechanisms of DTA, Western blotting, luciferase-reporter assays, and RT-PCR were conducted. The phosphorylation of mitogen-activated protein kinases (MAPKs) and IκBα were increased in DTA-treated HaCaT cells. In addition, AP-1 and NF-κB transcriptional factors were dose-dependently activated by DTA. Taken together, our in vitro mechanism studies indicate that the regulatory effects of DTA on skin hydration and keratinocyte differentiation are mediated by the MAPK/AP-1 and IκBα/NF-κB pathways. In addition, DTA could be a promising ingredient in cosmetics for moisturizing and increased skin barrier function.

Anti-Apoptotic and Anti-Inflammatory Activities of Edible Fresh Water Algae Prasiola japonica in UVB-Irradiated Skin Keratinocytes

Skin is the outer tissue layer and is a barrier protecting the body from various external stresses. The fresh water green edible algae Prasiola japonica has antiviral, antimicrobial, and anti-inflammatory properties; however, few studies of its effects on skin-protection have been reported. In this study, Prasiola japonica ethanol extract (Pj-EE) was prepared, and its skin-protective properties were investigated in skin keratinocytes. Pj-EE inhibited ROS production in UVB-irradiated HaCaT cells without cytotoxicity. Pj-EE also suppressed the apoptotic death of UVB-irradiated HaCaT cells by decreasing the generation of apoptotic bodies and the proteolytic activation of apoptosis caspase-3, -8, and -9. Moreover, Pj-EE downregulated the mRNA expression of the inflammatory gene cyclooxygenase-2 (COX-2), the pro-inflammatory cytokine genes interleukin (IL)-1β, IL-8, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, and the tissue remodeling genes matrix metalloproteinase (MMP)-1, -2, -3, and -9. The Pj-EE-induced anti-inflammatory effect was mediated by suppressing the activation of nuclear factor-kappa B (NF-κB) signaling pathway in the UVB-irradiated HaCaT cells. Taken together, these results suggest that Pj-EE exerts skin-protective effects through anti-oxidant, anti-apoptotic, and anti-inflammatory activities in skin keratinocytes.

Ginsenoside compound K inhibits nuclear factor-kappa B by targeting Annexin A2

BACKGROUND

Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B (NF-κB) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated.

METHODS

Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for NF-кB, immunofluorescence imaging for the subcellular localization of Annexin A2 and NF-кB p50 subunit, coimmunoprecipitation of Annexin A2 and NF-кB p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability.

RESULTS

Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and NF-кB p50 subunit and their nuclear colocalization, which attenuated the activation of NF-кB and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2.

CONCLUSION

This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.

Anti-inflammatory activities of Canarium subulatum Guillaumin methanol extract operate by targeting Src and Syk in the NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Canarium subulatum Guillaumin is an herbal medicinal plant native to Southeast Asia. Ethnopharmacological evidence suggests that plants of the genus Canarium cure a variety of inflammatory diseases.

AIM OF THE STUDY

The pharmacological mechanisms of C. subulatum Guillaumin remain poorly understood. In this study, we investigate inflammatory mechanisms and target molecules using C. subulatum Guillaumin methanol extract (Cs-ME) in inflammatory reactions managed by macrophages.

MATERIALS AND METHODS

To identify the anti-inflammatory activities of Cs-ME, lipopolysaccharide (LPS)-stimulated macrophages and a murine HCl/EtOH-induced gastritis model were chosen. The luciferase reporter gene assay, Western blot analysis, overexpression strategy, and the cellular thermal shift assay (CETSA) were employed to investigate the molecular mechanisms and target enzymes of Cs-ME. The active ingredients of this extract were also determined by HPLC.

RESULTS

Released levels of nitric oxide (NO) and mRNA expression levels of iNOS and IL-6 were downregulated by Cs-ME without exhibiting cytotoxicity. This extract inhibited MyD88-induced promoter activity and the nuclear translocation of nuclear factor (NF)-κB. Moreover, we found that Cs-ME reduced the phosphorylation of NF-κB upstream signaling molecules including IκBα, IKKα/β, Src, and Syk in LPS-stimulated macrophage-like RAW264.7 cells. The results of Western blot and CETSA confirmed that Src and Syk are anti-inflammatory targets of Cs-ME. In addition, orally injected Cs-ME alleviated HCl/EtOH-induced gastric ulcers in mice. HPLC analysis indicated that quercetin, luteolin, and kaempferol are major active components of this extract with anti-inflammatory activity.

CONCLUSIONS

Cs-ME exhibits anti-inflammatory effects in vitro and in vivo by targeting Src and Syk in the NF-κB signaling pathway. Consequently, Cs-ME could be developed as an anti-inflammatory herbal medicine.

Red ginseng extract regulates differentiation of monocytes to macrophage and inflammatory signalings in human monocytes

This study was aimed to investigate the effect of red ginseng extract (RGE) on monocyte to macrophage differentiation and inflammatory signalings in THP-1 human monocytes. In HPLC analysis, RGE contained saponin level of 516 μg/mg (extract) with 14 ginsenosides. RGE effectively suppressed the monocyte-to-macrophage differentiation induced by phorbol 12-myristate 13-acetated (PMA) by inhibiting the THP-1 cell adhesion. This result is evidenced by the down-regulation of cluster of differentiation molecule β (CD11β) and CD36. RGE significantly reduced translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) (78%), while cytosolic NF-κB was increased (53%), compared with LPS group. In addition, RGE significantly increased the protein abundance of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its target protein, hemoxygenase-1 (HO-1), but, Kelch-like ECH-associated protein 1 (KEAP1), a negative regulator of Nrf2, was greatly decreased by RGE. Furthermore, RGE effectively mediated the regulation of Nrf2 level in nucleus and cytoplasm of THP-1.

Anti-inflammatory functions of the CDC25 phosphatase inhibitor BN82002 via targeting AKT2

This study presents BN82002 as an anti-inflammatory drug candidate. It was found that BN82002 inhibited the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in RAW 264.7 cells and peritoneal macrophages that were activated by toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS). BN82002 dose-dependently down-regulated mRNA levels of nitric oxide synthase, tumor necrosis factor-α, and cyclooxygenase-2. The nuclear translocation of nuclear factor (NF)-κB (p65 and p50) was also blocked by BN82002 in RAW265.7 cells stimulated by LPS. According to reporter gene assay performed with NF-κB construct, BN82002 clearly reduced increased level of luciferase activity mediated by transcription factor NF-κB in LPS-treated RAW264.7 cells and in MyD88- and AKT2-overexpressing HEK293 cells. However, BN82002 did not inhibit NF-κB activity in AKT1- or IKKβ-overexpressing HEK293 cells. NF-κB upstream signaling events specifically targeted AKT2 but had no effect on AKT1. The specific target of BN82002 was Tyr-178 in AKT2. BN82002 bound to Tyr-178 and interrupted the kinase activity of AKT2, according to a cellular thermal shift assay analysis of the interaction of BN82002 with AKT2 and an AKT2 mutant (Tyr-178 mutated to Ala; AKT2 Y178A). These results suggest that BN82002 could reduce inflammatory pathway by controlling NF-κB pathway and specifically targeting AKT2.

Antiphotoaging and Antimelanogenic Effects of Penthorum chinense Pursh Ethanol Extract due to Antioxidant- and Autophagy-Inducing Properties

Ethnopharmacological Relevance. Penthorum chinense Pursh (Penthoraceae) is a traditional herbal plant that has been used in China for the treatment of jaundice, cholecystitis, edema, and infectious hepatitis. In addition, the Korea Medicinal Plant Dictionary states that Penthorum chinense Pursh can be used to treat contusions and skin bruises by improving blood flow. Recent studies have shown that Penthorum chinense Pursh ethanol extract (Pc-EE) exhibits strong antioxidant effects. In this study, we examined the effects of Pc-EE on UVB-induced or H₂O₂-induced oxidative stress, as well as its antimelanogenic properties. Cell viability, matrix metalloproteinase (MMP) expression, cyclooxygenease-2 (COX-2), and interleukin-6 (IL-6) expression and moisturizing factors were investigated in keratinocytes. Collagen synthesis induction was measured in HEK293T cells. For melanogenesis, the effects of Pc-EE on melanin content and tyrosinase activity were measured. Additionally, the antimelanogenic- and autophagy-inducing activities of Pc-EE were examined using immunoblotting and confocal microscopy. Pc-EE protected HaCaT cells against death from UVB irradiation- or H₂O₂-induced oxidative stress. Pc-EE increased the promoter activity of the type 1 procollagen gene Col1A1 and decreased the expression of MMPs, COX-2, IL-6, and hyaluronidase induced by UVB irradiation- or H₂O₂-induced oxidative stress. Pc-EE showed a strong antioxidant effect in the DPPH assay. In α-melanocyte-stimulating hormone- (α-MSH-) stimulated B16F10 cells, Pc-EE reduced melanin production, decreased tyrosinase expression and microphthalmia-associated transcription factor (MITF) protein levels, and decreased the phosphorylation levels of p38 and JNK. In HEK293T cells, Pc-EE promoted the expression of GFP-LC3B. In B16F10 cells, the LC3B and melanin contents were reduced by Pc-EE and were restored by the autophagy inhibitor 3-methyladenine (3-MA). These results suggest that Pc-EE can be used as a skin protection agent due to its antiapoptotic, antiaging, anti-inflammatory, and antimelanogenic properties.

Mycetia cauliflora methanol extract exerts anti-inflammatory activity by directly targeting PDK1 in the NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mycetia cauliflora Reinw. (Rubiaceae) has been used as a traditional remedy to ameliorate clinical signs of inflammatory diseases, including pain, inflammation, ulcers, and wounds. Among the Mycetia subfamilies, the molecular and cellular mechanisms of Mycetia longifolia (Rubiaceae) have been studied. However, those of Mycetia cauliflora are not clearly understood. Comprehensive investigation of this plant is necessary to evaluate its potential for ethnopharmacological use.

MATERIALS

and methods: The activities of Mycetia cauliflora methanol extract (Mc-ME) on the secretion of inflammatory mediators, the mRNA expression of proinflammatory cytokines, and identification of its molecular targets were elucidated using lipopolysaccharide (LPS)-induced macrophage-like cells. Moreover, the suppressive actions of Mc-ME were examined in an LPS-induced peritonitis mouse model.

RESULTS

At nontoxic concentrations, Mc-ME downregulated the release of nitric oxide (NO), the mRNA expression of inducible nitric oxide synthase (iNOS), and the mRNA expression of interleukin (IL)-1β from LPS-activated RAW264.7 cells. This extract also inhibited the nuclear translocation of p65 and p50 and the phosphorylation of IκBα, IKK, and AKT. Western blot analysis and in vitro kinase assays confirmed that phosphoinositide-dependent kinase-1 (PDK1) is the direct immunopharmacological target of Mc-ME effect. In addition, Mc-ME significantly reduced inflammatory signs in an animal model of acute peritonitis. These effects were associated with decreased NO production and decreased AKT phosphorylation.

CONCLUSION

Our results suggest that Mc-ME displays anti-inflammatory actions in LPS-treated macrophage-like cells and in an animal model of acute inflammatory disease. These actions are preferentially managed by targeting PDK1 in the nuclear factor (NF)-κB signaling pathway.

Phosphatidylinositide 3-Kinase Contributes to the Anti-Inflammatory Effect of Abutilon crispum L. Medik Methanol Extract

Abutilon crispum L. Medik, better known as bladdermallow, is used as a traditional remedy in India, for its anti-inflammatory effect due to its high content of flavonoids. However, research about its anti-inflammatory effect at the molecular level has not been performed. In this study, we aimed to investigate the mechanism of Abutilon crispum methanol extract (Ac-ME) in inhibiting the inflammatory response by conducting several experiments including cellular and molecular assays. Ac-ME inhibited the production of nitric oxide (NO) in RAW264.7 cells during treatment of LPS and Pam3CSK4 without exhibiting cytotoxicity. Ac-ME also suppressed the mRNA expression of inducible nitric oxide (iNOS) and proinflammatory cytokines such as interleukin (IL)-1β and IL-6. Moreover, Ac-ME was shown to inhibit the NF-κB pathway, according to the luciferase reporter gene assay performed with a NF-κB-Luc construct containing NF-κB-binding promoter regions under MyD88 and TRIF overexpression conditions, and immunoblotting analysis by determining the phospho-form levels of IκBα, IKKα/β, and p85, a regulatory domain of phosphatidylinositide 3-kinase (PI3K). Finally, we observed that the level of phospho-p85 induced by the overexpression of spleen tyrosine kinase (Syk) and Src was decreased by Ac-ME at 200 μg/ml. Therefore, these results suggest that Ac-ME has an anti-inflammatory effect by targeting PI3K in the NF-κB signaling pathway.

Compound K, a ginsenoside metabolite, plays an antiinflammatory role in macrophages by targeting the AKT1-mediated signaling pathway

Background

Compound K (CK) is an active metabolite of ginseng saponin, ginsenoside Rb1, that has been shown to have ameliorative properties in various diseases. However, its role in inflammation and the underlying mechanisms are poorly understood. In this report, the antiinflammatory role of CK was investigated in macrophage-like cells.

Methods

The CK-mediated antiinflammatory mechanism was explored in RAW264.7 and HEK293 cells that were activated by lipopolysaccharide (LPS) or exhibited overexpression of known activation proteins. The mRNA levels of inflammatory genes and the activation levels of target proteins were identified by quantitative and semiquantitative reverse transcription polymerase chain reaction and Western blot analysis.

Results

CK significantly inhibited the mRNA expression of inducible nitric oxide synthase and tumor necrosis factor-α and morphological changes in LPS-activated RAW264.7 cells under noncytotoxic concentrations. CK downregulated the phosphorylation of AKT1, but not AKT2, in LPS-activated RAW264.7 cells. Similarly, CK reduced the AKT1 overexpression-induced expression of aldehyde oxidase 1, interleukin-1β, interferon-β, and tumor necrosis factor-α in a dose-dependent manner.

Conclusion

Our results suggest that CK plays an antiinflammatory role during macrophage-mediated inflammatory actions by specifically targeting the AKT1-mediated signaling pathway.

Ginsenosides, catechins, quercetin and gut microbiota: Current evidence of challenging interactions

Recent studies have shown the role of gut microbiota in favoring the absorption of herbal products and the transformation of their active principles into metabolites endowed with biological activity. This review focuses on the evidence supporting the changes occurring, after metabolic reactions by specific bacteria that colonize the human gut, to ginseng-derived ginsenosides, green tea-derived catechins, and quercetin, this latter being a flavonoid aglycon bound to sugars and abundant in some vegetables and roots. Furthermore, the results of several studies demonstrating the potential beneficial effects of the active metabolites generated by these biotransformations on ginsenosides, catechins and quercetin will be reported.

Ethanol Extract of Lilium Bulbs Plays an Anti-Inflammatory Role by Targeting the IKK[Formula: see text]/[Formula: see text]-Mediated NF-[Formula: see text]B Pathway in Macrophages

Lilium bulbs have long been used as Chinese traditional medicines to alleviate the symptoms of various human inflammatory diseases. However, mechanisms of Lilium bulb-mediated anti-inflammatory activity and the bioactive components in Lilium bulbs remain unknown. In the present study, the anti-inflammatory activity of Lilium bulbs and the underlying mechanism of action were investigated in macrophages using Lilium bulb ethanol extracts (Lb-EE). In a dose-dependent manner, Lb-EE inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and bone marrow-derived macrophages (BMDMs) without causing significant cytotoxicity. Lb-EE also down-regulated mRNA expression of inflammatory genes in LPS-stimulated RAW264.7 cells, which included inducuble nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]). Furthermore, Lb-EE markedly restored LPS-induced morphological changes in RAW264.7 cells to a normal morphology. HPLC analysis identified quercetin, luteolin, and kaempferol as bioactive components contained in Lb-EE. Mechanistic studies in LPS-stimulated RAW264.7 cells revealed that Lb-EE suppressed MyD88- and TRIF-induced NF-[Formula: see text]B transcriptional activation and the nuclear translocation of NF-[Formula: see text]B transcription factors. Moreover, Lb-EE inhibited IKK[Formula: see text]/[Formula: see text]-induced activation of the NF-[Formula: see text]B signaling pathway and IKK inhibition significantly reduced NO production in LPS-stimulated RAW264.7 cells. Taken together, these results suggest that Lb-EE plays an anti-inflammatory role by targeting IKK[Formula: see text]/[Formula: see text]-mediated activation of the NF-[Formula: see text]B signaling pathway during macrophage-mediated inflammatory responses.

Artemisia asiatica ethanol extract exhibits anti-photoaging activity

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia asiatica Nakai is a traditional herbal plant that has long been used in anti-inflammatory, anti-infective and skin protective remedies.

AIM OF THE STUDY

In this study, traditionally known skin-protective activity of Artemisia asiatica Nakai was examined with its ethanol extract (Aa-EE) under various photoaging conditions using skin-originated cells, and the underlying mechanism was also examined using various types of cells.

MATERIALS AND METHODS

Effects of Aa-EE on cell viability, photocytotoxicity, and expression of matrix metalloproteinases (MMPs), cyclooxygenase (COX)-2, and moisturizing factors were measured in B16F10, HEK293, NIH3T3, and HaCaT cells under untreated and ultraviolet B (UVB)-irradiation conditions. Anti-melanogenic effect of Aa-EE was also examined by measuring both melanin content in B16F10 cells and tyrosinase activity. Anti-photoaging mechanism of Aa-EE was explored by determining the activation levels of signaling molecules by immunoblotting analysis.

RESULTS

Aa-EE protected HaCaT cells from UVB irradiation-induced death. Aa-EE increased the expression of a type 1 pro-collagen gene and decreased the expression of matrix metalloproteinases, and COX-2 in NIH3T3 cells induced by UVB. Aa-EE increased the expression of transglutamase-1, hyaluronic acid synthase (HAS)-2, and HAS-3 in HaCaT cells and decreased the production of melanin in α-melanocyte-stimulating hormone-stimulated B16F10 cells by suppressing tyrosinase activity and the expression of tyrosinase, microphthalmia-associated transcription factor, tyrosinase-related protein (TRP)-1 and TRP-2.

CONCLUSION

The results suggest that Aa-EE could be skin-protective remedy with anti-photoaging, anti-apoptotic, skin remodeling, moisturizing, and anti-melanogenesis properties.

Ethnopharmacological properties of Artemisia asiatica: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia asiatica Nakai (Compositae) has a long history as a traditional remedy. Preparation from various parts of the plant (aerial parts and leaves) are used to treat a wide range of diseases including gastric trouble, liver dysfunction, and skin inflammation.

AIMS OF THIS REVIEW

The aims of this review were: 1) to provide an overview of recent studies and progress on A. asiatica-derived ethnopharmacological compounds and their pharmacological activities; and 2) to summarize existing evidence and provide insight for future studies.

MATERIALS AND METHODS

This investigation was carried out by analyzing published books and research papers via scientific databases, namely Science Direct, PubMed ACS Publication, Wiley Online Library, CNKI and information obtained online. The keywords "Artemisia asiatica traditional uses," "Compounds isolated and studied in Artemisia asiatica," and "Pharmacological advances in Artemisia asiatica" were used and articles published between 1995 and 2017 were considered. In total, 500 works related to biological activities of A. asiatica were identified, and only materials published in English were included in the review.

RESULTS

Comparative analysis of literature searched through sources available confirmed that the ethnopharmacological use of A. asiatica was recorded in Korea, China, and Japan. Phytochemical studies revealed the presence of flavonoids, sesquiterpene lactones, monoterpenes, and steroids in A. asiatica. Of these, flavonoids have been shown to exhibit significant pharmacological effects such as gastroprotective, anti-inflammatory, anti-tumor, and anti-microbial actions.

CONCLUSIONS

Phytochemical and pharmacological studies of Artemisia asiatica have proven that this plant is one of valuable medicinal sources with neuroprotective, gastroprotective, anti-oxidative, anti-inflammatory, and anti-cancer effects. Although ethanol extract of this plant is now being prescribed as gastroprotective and anti-ulcerative medicine, it is now time to expand its application to other human inflammatory diseases such as pancreatitis and hepatitis and further extensive study on toxicity in human. Therefore, the present review will encourage further studies of A. asiatica in the pursuit of wide range of therapeutic remedy.

Arctigenin Induces an Activation Response in Porcine Alveolar Macrophage Through TLR6-NOX2-MAPKs Signaling Pathway

Arctigenin (ARG), one of the most active ingredients abstracted from seeds of Arctium lappa L., has been proved to exert promising biological activities such as immunomodulatory, anti-viral, and anti-cancer etc. However, the mechanism behind its immunomodulatory function still remains elusive to be further investigated. In this study, we found that ARG had no significant effects on the cell proliferation in both porcine alveolar macrophage cell line (3D4/21) and primary porcine derived alveolar macrophage. It remarkably increased the expression and secretion of the two cytokines including tumor necrosis factor-alpha (TNF-α) and transforming growth factor beta1 (TGF-β1) in a dose-dependent manner with the concomitant enhancement of phagocytosis, which are the indicators of macrophage activation. ARG also elevated the intracellular reactive oxygen species (ROS) production by activating NOX2-based NADPH oxidase. Furthermore, inhibition of ROS generation by diphenyliodonium and apocynin significantly suppressed ARG-induced cytokine secretion and phagocytosis increase, indicating the requirement of ROS for the porcine alveolar macrophage activation. In addition, TLR6-My88 excitation, p38 MAPK and ERK1/2 phosphorylation were all involved in the process. As blocking TLR6 receptor dramatically attenuated the NOX2 oxidase activation, cytokine secretion and phagocytosis increase. Inhibiting ROS generation almost abolished p38 and ERK1/2 phosphorylation, and the cytokine secretion could also be remarkably reduced by p38 and ERK1/2 inhibitors (SB203580 and UO126). Our finding gave a new insight of understanding that ARG could improve the immune-function of porcine alveolar macrophages through TLR6-NOX2 oxidase-MAPKs signaling pathway.

Thymoquinone Suppresses IRF-3-Mediated Expression of Type I Interferons via Suppression of TBK1

Interferon regulatory factor (IRF)-3 is known to have a critical role in viral and bacterial innate immune responses by regulating the production of type I interferon (IFN). Thymoquinone (TQ) is a compound derived from black cumin (Nigella sativa L.) and is known to regulate immune responses by affecting transcription factors associated with inflammation, including nuclear factor-κB (NF-κB) and activator protein-1 (AP-1). However, the role of TQ in the IRF-3 signaling pathway has not been elucidated. In this study, we explored the molecular mechanism of TQ-dependent regulation of enzymes in IRF-3 signaling pathways using the lipopolysaccharide (LPS)-stimulated murine macrophage-like RAW264.7 cell line. TQ decreased mRNA expression of the interferon genes IFN-α and IFN-β in these cells. This inhibition was due to its suppression of the transcriptional activation of IRF-3, as shown by inhibition of IRF-3 PRD (III-I) luciferase activity as well as the phosphorylation pattern of IRF-3 in the immunoblotting experiment. Moreover, TQ targeted the autophosphorylation of TANK-binding kinase 1 (TBK1), an upstream key enzyme responsible for IRF-3 activation. Taken together, these findings suggest that TQ can downregulate IRF-3 activation via inhibition of TBK1, which would subsequently decrease the production of type I IFN. TQ also regulated IRF-3, one of the inflammatory transcription factors, providing a novel insight into its anti-inflammatory activities.

Therapeutic Potential of Ginsenosides as an Adjuvant Treatment for Diabetes

Ginseng, one of the oldest traditional Chinese medicinal herbs, has been used widely in China and Asia for thousands of years. Ginsenosides extracted from ginseng, which is derived from the roots and rhizomes of Panax ginseng C. A. Meyer, have been used in China as an adjuvant in the treatment of diabetes mellitus. Owing to the technical complexity of ginsenoside production, the total ginsenosides are generally extracted. Accumulating evidence has shown that ginsenosides exert antidiabetic effects. In vivo and in vitro tests revealed the potential of ginsenoside Rg1, Rg3, Rg5, Rb1, Rb2, Rb3, compound K, Rk1, Re, ginseng total saponins, malonyl ginsenosides, Rd, Rh2, F2, protopanaxadiol (PPD) and protopanaxatriol (PPT)-type saponins to treat diabetes and its complications, including type 1 diabetes mellitus, type 2 diabetes mellitus, diabetic nephropathy, diabetic cognitive dysfunction, type 2 diabetes mellitus with fatty liver disease, diabetic cerebral infarction, diabetic cardiomyopathy, and diabetic erectile dysfunction. Many effects are attributed to ginsenosides, including gluconeogenesis reduction, improvement of insulin resistance, glucose transport, insulinotropic action, islet cell protection, hepatoprotective activity, anti-inflammatory effect, myocardial protection, lipid regulation, improvement of glucose tolerance, antioxidation, improvement of erectile dysfunction, regulation of gut flora metabolism, neuroprotection, anti-angiopathy, anti-neurotoxic effects, immunosuppression, and renoprotection effect. The molecular targets of these effects mainly contains GLUTs, SGLT1, GLP-1, FoxO1, TNF-α, IL-6, caspase-3, bcl-2, MDA, SOD, STAT5-PPAR gamma pathway, PI3K/Akt pathway, AMPK-JNK pathway, NF-κB pathway, and endoplasmic reticulum stress. Rg1, Rg3, Rb1, and compound K demonstrated the most promising therapeutic prospects as potential adjuvant medicines for the treatment of diabetes. This paper highlights the underlying pharmacological mechanisms of the anti-diabetic effects of ginsenosides.

Hydroquinone Exhibits In Vitro and In Vivo Anti-Cancer Activity in Cancer Cells and Mice

Hydroquinone (HQ, 1,4-benzenediol) is a hydroxylated benzene metabolite with various biological activities, including anti-oxidative, neuroprotective, immunomodulatory, and anti-inflammatory functions. However, the anti-cancer activity of HQ is not well understood. In this study, the in vitro and in vivo anti-cancer activity of HQ was investigated in various cancer cells and tumor-bearing mouse models. HQ significantly induced the death of A431, SYF, B16F10, and MDA-MB-231 cells and also showed a synergistic effect on A431 cell death with other anti-cancer agents, such as adenosine-2′,3′-dialdehyde and buthionine sulfoximine. In addition, HQ suppressed angiogenesis in fertilized chicken embryos. Moreover, HQ prevented lung metastasis of melanoma cells in mice in a dose-dependent manner without toxicity and adverse effects. HQ (10 mg/kg) also suppressed the generation of colon and reduced the thickness of colon tissues in azoxymethane/dextran sodium sulfate-injected mice. This study strongly suggests that HQ possesses in vitro and in vivo anti-cancer activity and provides evidence that HQ could be developed as an effective and safe anti-cancer drug.

Skin Protective Effect of Epigallocatechin Gallate

Epigallocatechin gallate (EGCG) is a catechin and an abundant polyphenol in green tea. Although several papers have evaluated EGCG as a cosmetic constituent, the skin hydration effect of EGCG is poorly understood. We aimed to investigate the mechanism by which EGCG promotes skin hydration by measuring hyaluronic acid synthase (HAS) and hyaluronidase (HYAL) gene expression and antioxidant and anti-pigmentation properties using cell proliferation assay, Western blotting analysis, luciferase assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and reverse transcription polymerase chain reaction (RT-PCR) analysis. RT-PCR showed that EGCG increased the expression of natural moisturizing factor-related genes filaggrin (FLG), transglutaminase-1, HAS-1, and HAS-2. Under UVB irradiation conditions, the expression level of HYAL was decreased in HaCaT cells. Furthermore, we confirmed the antioxidant activity of EGCG and also showed a preventive effect against radical-evoked apoptosis by downregulation of caspase-8 and -3 in HaCaT cells. EGCG reduced melanin secretion and production in melanoma cells. Together, these results suggest that EGCG might be used as a cosmetic ingredient with positive effects on skin hydration, moisture retention, and wrinkle formation, in addition to radical scavenging activity and reduction of melanin generation.