Anti-inflammatory action of mollugin and its synthetic derivatives in HT-29 human colonic epithelial cells is mediated through inhibition of NF-kappaB activation

Oxomollugin, an oxidized substance in mollugin, inhibited LPS-induced NF-κB activation via the suppressive effects on essential activation factors of TLR4 signaling

Oxomollugin is a degraded product of mollugin and was found to be an active compound that inhibits LPS-induced NF-κB activation. In this study, we investigated the inhibitory activity of oxomollugin, focusing on TLR4 signaling pathway, resulting in NF-κB activation. Oxomollugin inhibited the LPS-induced association of essential factors for initial activation of TLR4 signaling, MyD88, IRAK4 and TRAF6. Furthermore, oxomollugin showed suppressive effects on LPS-induced modification of IRAK1, IRAK2 and TRAF6, LPS-induced association of TRAF6-TAK1/TAB2, and followed by IKKα/β phosphorylation, which critical in signal transduction leading to LPS-induced NF-κB activation. The consistent results suggested that oxomollugin inhibits LPS-induced NF-κB activation via the suppression against signal transduction in TLR4 signaling pathway.The activities of oxomollugin reported in this study provides a deeper understanding on biological activity of mollugin derivatives as anti-inflammatory compounds.

Mollugin suppresses proliferation and drives ferroptosis of colorectal cancer cells through inhibition of insulin-like growth factor 2 mRNA binding protein 3/glutathione peroxidase 4 axis

Increasing researches have demonstrated that targeting ferroptosis might be a new conceptual avenue to treat colorectal cancer (CRC). Mollugin is a phytochemical isolated from Rubia cordifolia L. with antitumor activity. However, whether ferroptosis mediates the antitumor activity of mollugin in CRC has not been explored. Our study aims to investigate the antitumor and pro-ferroptosis effects, and mechanisms of mollugin in CRC. We found that mollugin led to ferroptosis in CRC cells, resulting in reduced GSH level and elevated levels of ROS, Fe2+, and MDA. Mollugin treatment caused obvious decrease in cell viability and proliferation in CRC cells, which were aggravated by ferroptosis inducer erastin and attenuated by ferroptosis inhibitor ferrostatin-1. Tumor xenografts experiments proved that mollugin suppressed the tumor growth, while treatment with ferrostatin-1 attenuated the antitumor activity of mollugin in vivo. Integrated bioinformatics analysis showed that insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) was highly expressed in CRC tissues and indicated poor prognosis. Further investigation indicated that the IGF2BP3/glutathione peroxidase 4 (GPX4) axis was involved in mollugin-regulated ferroptosis in CRC. In conclusions, Mollugin suppresses proliferation and drives ferroptosis of CRC cells by inhibiting the IGF2BP3/GPX4 axis, suggesting that mollugin may be a potential therapeutic option for CRC.

Dauricine exhibits anti-inflammatory property against acute ulcerative colitis via the regulation of NF-κB pathway

We aim to investigate the therapeutic effect of dauricine on ulcerative colitis (UC). Our results indicated that dauricine attenuated the reduction of colonic length, weight loss, disease activity index, colonic tissue damage, and inflammatory cytokine levels in dextran sulfate sodium mice. In addition, dauricine reduced lipopolysaccharide-induced inflammation in HT-29 cells. Mechanically, dauricine docked with p65, a member of nuclear transcription factor kappaB (NF-κB) family, through which reduced the inflammatory cytokine release from HT-29 cells. Together, the above results inferred that dauricine had therapeutic effect for UC by suppressing NF-κB pathway, which provided a promising mean for UC treatment.

Synthesis and Evaluation of NF-κB Inhibitory Activity of Mollugin Derivatives

(1) Background: Nuclear factor κB (NF-κB) is an important transcriptional regulator that regulates the inflammatory pathway and plays a key role in cellular inflammatory and immune responses. The presence of a high concentration of NF-κB is positively correlated with the severity of inflammation. Therefore, the inhibition of this pathway is an important therapeutic target for the treatment of various types of inflammation; (2) Methods: we designed and synthesized 23 mollugin derivatives and evaluated their inhibitory activity against NF-κB transcription; (3) Results: Compound 6d exhibited the most promising inhibitory activity (IC₅₀ = 3.81 µM) and did not show any significant cytotoxicity against the tested cell lines. Investigation of the mechanism of action indicated that 6d down-regulated NF-κB expression, possibly by suppressing TNF-α-induced expression of the p65 protein. Most of the compounds exhibited potent anti-inflammatory activity. Compound 4f was the most potent compound with 83.08% inhibition of inflammation after intraperitoneal administration, which was more potent than mollugin and the reference drugs (ibuprofen and mesalazine). ADMET prediction analysis indicated that compounds 6d and 4f had good pharmacokinetics and drug-like behavior; (4) Conclusions: Several series of mollugin derivatives were designed, synthesized, and evaluated for NF-κB inhibitory activity and toxicity. These results provide an initial basis for the development of 4f and 6d as potential anti-inflammatory agents.

Synthesis and Antitumor Activity of 1-Substituted 1,2,3-Triazole-Mollugin Derivatives

A new series of mollugin-1,2,3-triazole derivatives were synthesized using a copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of corresponding O-propargylated mollugin with aryl azides. All the compounds were evaluated for their cytotoxicity on five human cancer cell lines (HL-60, A549, SMMC-7721, SW480, and MCF-7) using MTS assays. Among the synthesized series, most of them showed cytotoxicity and most of all, compounds 14 and 17 exhibited significant cytotoxicity of all five cancer cell lines.

Network Pharmacology-Based Study on the Molecular Biological Mechanism of Action for Qingdu Decoction against Chronic Liver Injury

Background

Qingdu Decoction (QDD) is a traditional Chinese medicine formula for treating chronic liver injury (CLI). Materials and methods. A network pharmacology combining experimental validation was used to investigate potential mechanisms of QDD against CLI. We firstly screened the bioactive compounds with pharmacology analysis platform of the Chinese medicine system (TCMSP) and gathered the targets of QDD and CLI. Then, we constructed a compound-target network and a protein-protein interaction (PPI) network and enriched core targets in Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. At last, we used a CLI rat model to confirm the effect and mechanism of QDD against CLI. Enzyme-linked immunosorbent assay (ELISA), western blot (WB), and real-time quantitative polymerase chain reaction (RT-qPCR) were used.

Results

48 bioactive compounds of QDD passed the virtual screening criteria, and 53 overlapping targets were identified as core targets of QDD against CLI. A compound-CLI related target network containing 94 nodes and 263 edges was constructed. KEGG enrichment of core targets contained some pathways related to CLI, such as hepatitis B, tumor necrosis factor (TNF) signaling pathway, apoptosis, hepatitis C, interleukin-17 (IL-17) signaling pathway, and hypoxia-inducible factor (HIF)-1 signaling pathway. Three PPI clusters were identified and enriched in hepatitis B and tumor necrosis factor (TNF) signaling pathway, apoptosis and hepatitis B pathway, and peroxisome pathway, respectively. Animal experiment indicated that QDD decreased serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), endotoxin (ET), and IL-17 and increased prothrombin time activity (PTA) level. WB and RT-qPCR analyses indicated that, compared with the model group, the expression of cysteinyl aspartate specific proteinase-9 (caspase-9) protein, caspase-3 protein, B-cell lymphoma-2 associated X protein (Bax) mRNA, and cytochrome c (Cyt c) mRNA was inhibited and the expression of B-cell lymphoma-2 (Bcl-2) mRNA was enhanced in the QDD group.

Conclusions

QDD has protective effect against CLI, which may be related to the regulation of hepatocyte apoptosis. This study provides novel insights into exploring potential biological basis and mechanisms of clinically effective formula systematically.

Anti-inflammatory Activity of Mollugin on DSS-induced Colitis in Mice

We aimed to explore the anti-inflammatory activity of mollugin extracted from Rubia cordifolia L, a traditional Chinese medicine, on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. Thirty C57BL/6 mice were divided into a control group (n=6), a model group (n=6), and three experimental groups (40, 20, 10 mg/kg of mollugin, n=6 each). DSS solution (3%) was given to mice in the model group and experimental groups from day 4 to day 10 to induce the mouse UC model. Mice in the experimental groups were intragastrically administrated mollugin from day 1 to day 10. Animals were orally given distilled water in the control group for the whole experiment time and in the model group from day 1 to day 3. The changes in colon pathology were detected by hematoxylin and eosin (HE) staining. Interleukin-1β (IL-1β) in the serum, and tumor necrosis factor-α (TNF-α) and interferon-γ (IFN) in the tissues were measured by enzyme linked immunosorbent assay. Expression levels of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 in the colon tissues were detected by immunohistochemistry. Results showed that mollugin could significantly reduce weight loss and the disease activity index in the DSS-induced UC mouse model. HE examinations demonstrated that mollugin treatment effectively improved the histological damage (P<0.05). The overproduction of IL-1β and TNF-α was remarkably inhibited by mollugin treatment at doses of 20 and 40 mg/kg (P<0.05). Additionally, the levels of TLR4 in colon tissues were significantly reduced in mollugin-treated groups compared with the DSS group. Our findings demonstrated that mollugin ameliorates DSS-induced UC by inhibiting the production of pro-inflammatory chemocytokines.

Sulfated polysaccharides of seagrass Halophila ovalis suppresses tumor necrosis factor-α-induced chemokine interleukin-8 secretion in HT-29 cell line

OBJECTIVES:

The present study aims to investigate the anti-oxidant and anti-inflammatory properties of seagrass Halophila ovalis sulfated polysaccharide on HT-29 cell line.

SUBJECTS AND METHODS:

Monosaccharides composition was identified using liquid chromatography-mass spectrometry (LC-MS) and the functional groups were analyzed using Fourier transform-infrared (FT-IR) spectroscopy. The antioxidant and anti-inflammatory potential of crude extract and purified fractions was investigated in vitro.

RESULTS:

FT-IR spectra revealed that the presence of different functional groups and the presence of galactose (82.4%), xylose (7.6%), fructose (4.0%), mannose (2.0%), fucose (1.6%), glucose (1.2%), and arabinose (1.0%) was observed using LC-MS. Ho-SP and its fractions showed radical scavenging activity in hydroxyl, 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, and ferric reducing antioxidant power assay in a dose-dependent manner. Noticeable anti-inflammatory activity of purified fraction Ho FrIV (IC ₅₀= 43.85 μg/ml) was observed in a noncytotoxic range of concentrations and inhibited the tumor necrosis factor-α (TNF-α)-induced interleukin-8 (IL-8) secretion (0.27 ng/ml) in HT-29 cell line.

CONCLUSION:

Overall, the results presented in this study suggest that purified fraction Ho FrIV of Ho-SP could suppress the TNF-α-induced secretion of IL-8 in HT-29 and thus could be used as a promising antioxidant and anti-inflammatory candidate with potential benefits.

Acute exposure to organic and inorganic sources of copper: Differential response in intestinal cell lines

SCOPE

Copper supplementation in nutrition has evolved from using inorganic mineral salts to organically chelated minerals but with limited knowledge of the impact at the cellular level.

METHODS

Here, the impact of inorganic and organic nutrient forms (glycinate, organic acid, and proteinate) of copper on the cellular level is investigated on intestinal cell lines, HT29 and Caco-2, after a 2-hr acute exposure to copper compounds and following a 10-hr recovery.

RESULTS

Following the 10-hr recovery, increases were observed in proteins involved in metal binding (metallothioneins) and antioxidant response (sulfiredoxin 1 and heme oxygenase 1), and global proteomic analysis suggested recruitment of the unfolded protein response and proteosomal overloading. Copper organic acid chelate, the only treatment to show striking and sustained reactive oxygen species generation, had the greatest impact on ubiquitinated proteins, reduced autophagy, and increased aggresome formation, reducing growth in both cell lines. The least effect was noted in copper proteinate with negligible impact on aggresome formation or extended growth for either cell line.

CONCLUSION

The type and source of copper can impact significantly at the cellular level.

Isolation and identification of peptides from simulated gastrointestinal digestion of preserved egg white and their anti-inflammatory activity in TNF-α-induced Caco-2 cells

Simulated gastrointestinal digestion of preserved egg white (SGD-PEW) exerts anti-inflammatory effects on Caco-2 cells and a mouse model of DSS-induced colitis. Here, we aimed to separate peptides derived from SGD-PEW and evaluate their anti-inflammatory effects using an in vitro inflammatory model. Six peptides were isolated and identified. DEDTQAMPFR (DR-10), DEDTQAMPF (DF-9), MLGATSL (ML-7) and MSYSAGF (MF-7) significantly inhibited IL-8 secretion and markedly decreased gene expression, including TNF-α, IL-8, IL-6, IL-1β and IL-12 and promoted IL-10 gene expression in Caco-2 cells. DR-10, DF-9, ML-7 and MF-7 significantly inhibited the phosphorylation of JNK. In the meantime, DR-10 and DF-9 significantly reduced the phosphorylation of IκB and p38. These results indicated that ML-7 and MF-7 exerted their anti-inflammatory activity through the MAPK signaling pathway in TNF-α-induced Caco-2 cells. Whereas, DR-10 and DF-9 inhibited the NF-κB and MAPK signaling pathways. The results suggested that DR-10, DF-9, ML-7 and MF-7 derived from SGD-PEW may be a new type of prophylactic food for the treatment of inflammation.

CF₃-Substituted Mollugin 2-(4-Morpholinyl)-ethyl ester as a Potential Anti-inflammatory Agent with Improved Aqueous Solubility and Metabolic Stability

Although mollugin, the main ingredient of the oriental medicinal herb Rubia cordifolia, has considerable anti-inflammatory effects, it has poor aqueous solubility as well as poor metabolic and plasma stability. To overcome these shortfalls, various mollugin derivatives have been synthesized and evaluated for their ability to inhibit U937 monocyte cell adhesion to HT-29 colonic epithelial cells in TNF-α- or IL-6-induced models of colon inflammation. The 2-(4-morpholinyl)-ethyl ester of CF3-substituted mollugin (compound 15c) showed good water solubility, improved metabolic and plasma stability, and greater inhibitory activity than mesalazine in both the TNF-α- and IL-6-induced colonic epithelial cell adhesion assays, suggesting that 15c is a potential anti-inflammatory agent.

Mollugin enhances the osteogenic action of BMP-2 via the p38-Smad signaling pathway

Bone morphogenetic protein 2 (BMP-2) has been used clinically to encourage bone regeneration; although, there can be major side effects with larger doses. Therefore, there is a need to identify new small molecules to potentiate the osteogenic action of BMP-2. In this study, we investigated the effect of mollugin on bone formation in murine bi-potential mesenchymal progenitor C2C12 cells by combination with BMP-2. We found mollugin could enhance the BMP-2-mediated osteoblast differentiation of C2C12 cells. This was accompanied by the induction of other osteogenic BMPs. We also found the enhancing potential of mollugin may involve activation of the p38-Smad1/5/8 signaling axis. Furthermore, mollugin promoted skeletal development in zebrafish. The combination of BMP-2 with small molecules, including mollugin, could minimize its clinical limitations, and these molecules might lead to the development of effective stem cell stimulants for bone regeneration and fracture healing.

Mollugin Has an Anti-Cancer Therapeutic Effect by Inhibiting TNF-α-Induced NF-κB Activation

The NF-κB signaling pathway plays a pivotal role in regulating the immune response and inflammation. However, it has been shown that NF-κB also has a major role in oncogenesis. Therefore, NF-κB inhibitors have been considered as potential drugs against cancer. Herein, we searched for NF-κB inhibitors from natural sources and identified mollugin from the roots of Rubia cordifolia L. as an inhibitor of NF-κB activation. We found that mollugin significantly inhibited the expression of an NF-κB reporter gene induced by tumor necrosis factor (TNF)-α in a dose-dependent manner. Moreover, mollugin inhibited TNF-α-induced phosphorylation and nuclear translocation of p65, phosphorylation and degradation of inhibitor of κB (IκBα), and IκB kinase (IKK) phosphorylation. Furthermore, we discovered that pretreatment of cells with mollugin prevented the TNF-α-induced expression of NF-κB target genes, such as genes related to proliferation (COX-2, Cyclin D1 and c-Myc), anti-apoptosis (Bcl-2, cIAP-1 and survivin), invasion (MMP-9 and ICAM-1), and angiogenesis (VEGF). We also demonstrated that mollugin potentiated TNF-α-induced apoptosis and inhibited proliferation of HeLa cells. We further demonstrated in vivo that mollugin suppressed the growth of tumor xenografts derived from HeLa cells. Taken together, mollugin may be a valuable candidate for cancer treatment by targeting NF-κB.

Anti-inflammatory action of 2-carbomethoxy-2,3-epoxy-3-prenyl-1,4-naphthoquinone (CMEP-NQ) suppresses both the MyD88-dependent and TRIF-dependent pathways of TLR4 signaling in LPS-stimulated RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Rubia cordifolia L. have been widely used as a traditional herbal medicine in Northeast Asia for treating inflammatory diseases.

AIM OF THE STUDY

To elucidate the anti-inflammatory mechanism of 2-carbomethoxy-2,3-epoxy-3- prenyl-1,4-naphthoquinone (CMEP-NQ), purified from the roots of R. cordifolia L. as the major anti-inflammatory component, in LPS-treated RAW264.7 murine macrophage cells.

MATERIALS AND METHODS

Anti-inflammatory activity of CMEP-NQ was investigated in LPS-treated RAW264.7 cells by measuring the levels of NO, PGE₂, and cytokines (IL1β, IL-6, TNF-α) in the culture supernatants and the TLR4-mediated intracellular events including association of MyD88 with IRAK1, activation of IRAK1, TAK1, MAPKs, NF-κB/AP-1, and IRF3, and generation of ROS.

RESULTS

Pretreatment of RAW264.7 cells with CMEP-NQ reduced LPS-induced production of NO and PGE₂ by suppressing iNOS and COX-2 gene expression. CMEP-NQ also reduced the secretion of IL-1β, IL-6, and TNF-α by down-regulating mRNA levels. Under these conditions, TLR4-mediated MyD88-dependent events were inhibited by CMEP-NQ, including the association of MyD88 with IRAK1, phosphorylation of IRAK1, TAK1, and MAPKs (ERK, JNK and p38 MAPK), and activation of NF-κB and AP-1. As TRIF-dependent events of TLR4 signaling, phosphorylation of IRF3 and induction of iNOS protein expression were also inhibited by CMEP-NQ. However, the binding of FITC-conjugated LPS to cell surface TLR4 was not affected by CMEP-NQ. Following LPS stimulation, intracellular ROS production was first detected by DCFH-DA staining at 1h; then it continuously increased until 16h. Although CMEP-NQ failed to exhibit DPPH radical- or ABTS radical-scavenging activity in vitro, LPS-induced ROS production in RAW264.7 cells was more efficiently blocked by CMEP-NQ than by NAC.

CONCLUSIONS

These results demonstrate that the suppressive effect of CMEP-NQ on LPS-induced inflammatory responses in RAW264.7 cells was mainly exerted via its inhibition of TLR4-mediated proximal events, such as MyD88-dependent NF-κB/AP-1 activation and ROS production, and TRIF-dependent IRF3 activation.

A Review of the Botany, Phytochemistry, Pharmacology and Toxicology of Rubiae Radix et Rhizoma

Rubia cordifolia Linn (Rubiaceae) is a climbing perennial herbal plant, which is widely distributed in China and India. Its root and rhizome, Rubiae Radix et Rhizoma (called Qiancao in China and Indian madder in India), is a well known phytomedicine used for hematemesis, epistaxis, flooding, spotting, traumatic bleeding, amenorrhea caused by obstruction, joint impediment pain, swelling and pain caused by injuries from falls. In addition, it is a kind of pigment utilized as a food additive and a dye for wool or fiber. This review mainly concentrates on studies of the botany, phytochemistry, pharmacology and toxicology of this Traditional Chinese Medicine. The phytochemical evidences indicated that over a hundred chemical components have been found and isolated from the medicine, such as anthraquinones, naphthoquinones, triterpenoids, cyclic hexapeptides and others. These components are considered responsible for the various bioactivities of the herbal drug, including anti-oxidation, anti-inflammation, immunomodulation, antitumor, effects on coagulation-fibrinolysis system, neuroprotection and other effects. Additionally, based on these existing results, we also propose some interesting future research directions. Consequently, this review should help us to more comprehensively understand and to more fully utilize the herbal medicine Rubiae Radix et Rhizoma.

Syntheses and anti-inflammatory activity of azamollugin derivatives

Oxomollugin (2) is a degradation product of mollugin (1) and a potent inhibitor of NO-production including nuclear factor kappa B signals. In our endeavor to develop a potent anti-inflammatory compound, we synthesized several aza-derivatives of oxomollugin (2) and evaluated their NO-production inhibitory activity. Azamollugin (3) showed a potent inhibitory activity, and its activity (IC50 0.34μM) was proved to be more potent than that of oxomollugin (2, IC50 1.3μM).

Re2O7-catalyzed formal [3 + 2] cycloaddition for diverse naphtho[1,2-b]furan-3-carboxamides and their biological evaluation

Diverse naphtho[1,2-b]furan-3-carboxamide derivatives 12a-12q were synthesized in high yield via the novel Re2O7-catalyzed formal [3 + 2] cycloaddition of 1,4-naphthoquinones with β-ketoamides as the key step. This methodology offers several advantages, such as environmentally benign character, the use of a mild catalyst, high yields, and ease of handling. The synthesized compounds were screened for their tyrosinase inhibitory, antioxidant, and antibacterial activities. The results showed that compound 12c exhibited excellent tyrosinase inhibitory activity with an IC50 of 13.48 μg/mL, which is comparable to that of kojic acid (IC50 = 19.45 μg/mL). Compounds 12a, 12b, and 12i displayed moderate antioxidant activities in a DPPH assay. Compound 12m showed good activity against S. aureus (MIC = 16 μg/mL), and compound 12p was found to be active against E. coli (MIC = 16 μg/mL).

Mollugin from Rubea cordifolia suppresses receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis and bone resorbing activity in vitro and prevents lipopolysaccharide-induced bone loss in vivo

Osteopenic diseases, such as osteoporosis, are characterized by progressive and excessive bone resorption mediated by enhanced receptor activator of nuclear factor-κB ligand (RANKL) signaling. Therefore, downregulation of RANKL downstream signals may be a valuable approach for the treatment of bone loss-associated disorders. In this study, we investigated the effects of the naphthohydroquinone mollugin on osteoclastogenesis and its function in vitro and in vivo. Mollugin efficiently suppressed RANKL-induced osteoclast differentiation of bone marrow macrophages (BMMs) and bone resorbing activity of mature osteoclasts by inhibiting RANKL-induced c-Fos and NFATc1 expression. Mollugin reduced the phosphorylation of signaling pathways activated in the early stages of osteoclast differentiation, including the MAP kinase, Akt, and GSK3β and inhibited the expression of different genes associated with osteoclastogenesis, such as OSCAR, TRAP, DC-STAMP, OC-STAMP, integrin αν, integrin β3, cathepsin K, and ICAM-1. Furthermore, mice treated with mollugin showed significant restoration of lipopolysaccharide (LPS)-induced bone loss as indicated by micro-CT and histological analysis of femurs. Consequently, these results suggested that mollugin could be a novel therapeutic candidate for bone loss-associated disorders including osteoporosis, rheumatoid arthritis, and periodontitis.

Studies of synthetic chalcone derivatives as potential inhibitors of secretory phospholipase A2, cyclooxygenases, lipoxygenase and pro-inflammatory cytokines

Arachidonic acid metabolism leads to the generation of key lipid mediators which play a fundamental role during inflammation. The inhibition of enzymes involved in arachidonic acid metabolism has been considered as a synergistic anti-inflammatory effect with enhanced spectrum of activity. A series of 1,3-diphenyl-2-propen-1-one derivatives were investigated for anti-inflammatory related activities involving inhibition of secretory phospholipase A2, cyclooxygenases, soybean lipoxygenase, and lipopolysaccharides-induced secretion of interleukin-6 and tumor necrosis factor-alpha in mouse RAW264.7 macrophages. The results from the above mentioned assays exhibited that the synthesized compounds were effective inhibitors of pro-inflammatory enzymes and cytokines. The results also revealed that the chalcone derivatives with 4-methlyamino ethanol substitution seem to be significant for inhibition of enzymes and cytokines. Molecular docking experiments were carried out to elucidate the molecular aspects of the observed inhibitory activities of the investigated compounds. Present findings increase the possibility that these chalcone derivatives might serve as a beneficial starting point for the design and development of improved anti-inflammatory agents.

Pharmacological evaluation and docking studies of α,β-unsaturated carbonyl based synthetic compounds as inhibitors of secretory phospholipase A₂, cyclooxygenases, lipoxygenase and proinflammatory cytokines

Arachidonic acid and its metabolites have generated high level of interest among researchers due to their vital role in inflammation. The inhibition of enzymes involved in arachidonic acid metabolism has been considered as synergistic anti-inflammatory effect. A series of novel α,β-unsaturated carbonyl based compounds were synthesized and evaluated for their inhibitory activity on secretory phospholipase A₂ (sPLA₂), cyclooxygenases (COX), soybean lipoxygenase (LOX) in addition to proinflammatory cytokines comprising IL-6 and TNF-α. Six α,β-unsaturated carbonyl based compounds (2, 3, 4, 12, 13 and 14) exhibited strong inhibition of sPLA₂ activity, with IC₅₀ values in the range of 2.19-8.76 μM. Nine compounds 1-4 and 10-14 displayed inhibition of COX-1 with IC₅₀ values ranging from 0.37 to 1.77 μM (lower than that of reference compound), whereas compounds 2, 10, 13 and 14 strongly inhibited the COX-2. The compounds 10-14 exhibited strong inhibitory activity against LOX enzyme. All compounds were evaluated for the inhibitory activities against LPS-induced TNF-α and IL-6 release in the macrophages. On the basis of screening results, five active compounds 3, 4, 12, 13 and 14 were found strong inhibitors of TNF-α and IL-6 release in a dose-dependent manner. Molecular docking experiments were performed to clarify the molecular aspects of the observed COX and LOX inhibitory activities of the investigated compounds. Present findings increases the possibility that these α,β-unsaturated carbonyl based compounds might serve as beneficial starting point for the design and development of improved anti-inflammatory agents.

Anti-inflammatory activity of traditional Chinese medicinal herbs

Accumulating epidemiological and clinical evidence shows that inflammation is an important risk factor for various human diseases. Thus, suppressing chronic inflammation has the potential to delay, prevent, and control various chronic diseases, including cerebrovascular, cardiovascular, joint, skin, pulmonary, blood, lymph, liver, pancreatic, and intestinal diseases. Various natural products from traditional Chinese medicine (TCM) have been shown to safely suppress proinflammatory pathways and control inflammation-associated disease. In vivo and/or in vitro studies have demonstrated that anti-inflammatory effects of TCM occur by inhibition of the expression of master transcription factors (for example, nuclear factor-κB (NF-κB)), pro-inflammatory cytokines (for example, tumor necrosis factor-α (TNF-α), chemokines (for example, chemokine (C-C motif) ligand (CCL)-24), intercellular adhesion molecule expression and pro-inflammatory mediators (for example, inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2)). However, a handful of review articles have focused on the anti-inflammatory activities of TCM and explore their possible mechanisms of action. In this review, we summarize recent research attempting to identify the anti-inflammatory constituents of TCM and their molecular targets that may create new opportunities for innovation in modern pharmacology.

Mollugin induces tumor cell apoptosis and autophagy via the PI3K/AKT/mTOR/p70S6K and ERK signaling pathways

Mollugin, a bioactive phytochemical isolated from Rubia cordifolia L., has shown preclinical anticancer efficacy in various cancer models. However the effects of mollugin in regulating cancer cell survival and death remains undefined. In the present study we found that mollugin exhibited cytotoxicity on various cancer models. The suppression of cell viability was due to the induction of mitochondria apoptosis. In addition, the presence of autophagic hallmarks was observed in mollugin-treated cells. Notably, blockade of autophagy by a chemical inhibitor or RNA interference enhanced the cytotoxicity of mollugin. Further experiments demonstrated that phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) and extracellular regulated protein kinases (ERK) signaling pathways participated in mollugin-induced autophagy and apoptosis. Together, these findings support further studies of mollugin as candidate for treatment of human cancer cells.

Reversal of P-glycoprotein-mediated multidrug resistance is induced by mollugin in MCF-7/adriamycin cells

P-glycoprotein (P-gp), an important efflux transporter, is encoded by the MDR1 class of genes and is a central element of the multidrug resistance (MDR) phenomenon in cancer cells. In the present study, we investigated whether mollugin, purified from roots of Rubica cordifolia L., down-regulated MDR1 expression in MCF-7/adriamycin (MCF-7/adr) cells, a human breast multidrug-resistant cancer cell line. Mollugin treatment significantly inhibited MDR1 expression by blocking MDR1 transcription. Mollugin treatment also significantly increased intracellular accumulation of the fluorescently-tagged P-gp substrate, rhodamine-123. The suppression of MDR1 promoter activity and protein expression was mediated through mollugin-induced activation of AMP-activated protein kinase (AMPK). Furthermore, mollugin inhibited MDR1 expression through the suppression of NF-κB and CREB activation. Interestingly, mollugin also inhibited COX-2 expression. These results suggest that mollugin treatment enhanced suppression of P-gp expression by inhibiting the NF-κB signaling pathway and COX-2 expression, as well as attenuating CRE transcriptional activity through AMPK activation.

Involvement of Nrf2-mediated upregulation of heme oxygenase-1 in mollugin-induced growth inhibition and apoptosis in human oral cancer cells

Although previous studies have shown that mollugin, a bioactive phytochemical isolated from Rubia cordifolia L. (Rubiaceae), exhibits antitumor effects, its biological activity in oral cancer has not been reported. We thus investigated the effects and putative mechanism of apoptosis induced by mollugin in human oral squamous cell carcinoma cells (OSCCs). Results show that mollugin induces cell death in a dose-dependent manner in primary and metastatic OSCCs. Mollugin-induced cell death involved apoptosis, characterized by the appearance of nuclear shrinkage, flow cytometric analysis of sub-G₁ phase arrest, and annexin V-FITC and propidium iodide staining. Western blot analysis and RT-PCR revealed that mollugin suppressed activation of NF-κB and NF-κB-dependent gene products involved in antiapoptosis (Bcl-2 and Bcl-xl), invasion (MMP-9 and ICAM-1), and angiogenesis (FGF-2 and VEGF). Furthermore, mollugin induced the activation of p38, ERK, and JNK and the expression of heme oxygenase-1 (HO-1) and nuclear factor E2–related factor 2 (Nrf2). Mollugin-induced growth inhibition and apoptosis of HO-1 were reversed by an HO-1 inhibitor and Nrf2 siRNA. Collectively, this is the first report to demonstrate the effectiveness of mollugin as a candidate for a chemotherapeutic agent in OSCCs via the upregulation of the HO-1 and Nrf2 pathways and the downregulation of NF-κB.

Mollugin inhibits proliferation and induces apoptosis by suppressing fatty acid synthase in HER2-overexpressing cancer cells

Mollugin is a naphthohydroquine found in the roots of Rubia cordifolia, and has been reported to have a variety of biological activities, including anti-inflammatory and apoptotic effects. In the present study, we investigated the molecular mechanisms by which mollugin exerts anti-tumor effect in HER2-overexpressing cancer cells. Our results showed that mollugin exhibited potent inhibitory effects on cancer cell proliferation, especially in HER2-overexpressing SK-BR-3 human breast cancer cells and SK-OV-3 human ovarian cancer cells in a dose- and time-dependent manner without affecting immortalized normal mammary epithelial cell line MCF-10A. Furthermore, we found that a blockade of Akt/SREBP-1c signaling through mollugin treatment significantly reduced FAS expression and subsequently suppressed cell proliferation and induced apoptosis in HER2-overexpressing cancer cells. Mollugin treatment caused a dose-dependent inhibition of HER2 gene expression at the transcriptional level, potentially in part through suppression of NF-κB activation. The combination of mollugin with a MEK1/2 inhibitor may be required in order to achieve optimal efficacy in HER2-overexpressing cancers. These data provide evidence that mollugin inhibits proliferation and induces apoptosis in HER2-overexpressing cancer cells by blocking expression of the FAS gene through modulation of a HER2/Akt/SREBP-1c signaling pathway. Our findings suggest that mollugin is a novel modulator of the HER2 pathway in HER2-overexpressing cancer cells with a potential role in the treatment and prevention of human breast and ovarian cancer with HER2 overexpression.

Mollugin inhibits the inflammatory response in lipopolysaccharide-stimulated RAW264.7 macrophages by blocking the Janus kinase-signal transducers and activators of transcription signaling pathway

Mollugin, a kind of naphthohydroquinone, is a major constituent isolated from Rubia cordifolia L. and demonstrated to possess anti-inflammatory activity in recent reports. However, the effects and mechanism of action of mollugin in inflammation have not been fully defined. The present study was therefore designed to investigate whether mollugin suppresses the inflammatory response in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Mollugin attenuated the LPS-induced expression of nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin (IL)-1β and IL-6 but augmented the expression of tumor necrosis factor (TNF)-α. Mollugin did not inhibit the degradation of inhibitory kappa B (IκB)-α or the nuclear translocation of p65 nuclear factor-kappa B (NF-κB) but rather enhanced the phosphorylation of p65 subunits evoked by LPS. Mollugin did not inhibit the phosphorylation of extracellular-signal-related kinase (ERK) 1/2, p38, and c-Jun N-terminal kinase (JNK) 1/2 either. Mollugin significantly reduced the LPS-mediated phosphorylation of Janus kinase (JAK) 2, signal transducers and activators of transcription (STAT) 1 and STAT3. Molecular docking analysis showed that mollugin binds to JAK2 in a manner similar to that of AG490, a specific JAK2 inhibitor. We conclude that mollugin may be a JAK2 inhibitor and inhibits LPS-induced inflammatory responses by blocking the activation of the JAK-STAT pathway.

Goyazensolide Induces Apoptosis in Cancer Cells in vitro and in vivo

As part of the screening program for anticancer agents from natural sources, the sesquiterpene lactone goyazensolide (GZL) was identified as a potent NF-κB inhibitor. The hollow-fiber assay was used to evaluate the anti-tumor efficacy of GZL in vivo. The mechanistic effects of GZL were evaluated in the HT-29 colonic cell line to reveal the pathway through which GZL exerts its effects. NF-κB subunits p65 and p50 were inhibited, and the upstream mediator IκB kinase (IKKβ) was downregulated in a dose-dependent manner. Apoptosis was mediated by caspase-3, and cell cycle arrest was detected in G1-phase. Consequently, 96% of the cell population was in sub G1-phase after treatment with GZL (10 μM).The antitumor effect of GZL was observed at a dose of 12.5 mg/kg. Cell adhesion was affected as a result of NF-κB inhibition. GZL appears to selectively target the transcription factor NF-κB. In summary, GZL sensitizes HT-29 colon cancer cells to apoptosis and cell death in a dose-dependent manner both in vivo and in vitro, through NF-κB inhibition (IC50 = 3.8 μM). Thus, it is a new potent lead compound for further development into a new effective chemotherapeutic agent.

Synthesis of mono-carbonyl analogues of curcumin and their effects on inhibition of cytokine release in LPS-stimulated RAW 264.7 macrophages

Curcumin has been reported to possess multifunctional bioactivities, especially the ability to inhibit proinflammatory induction. We previously demonstrated that the mono-carbonyl analogues of curcumin possessed improved pharmacokinetic profiles both in vitro and in vivo. In this study, we synthesized and examined a series of 5-carbon linker-containing mono-carbonyl analogues of curcumin with potent inhibitory activities against TNF-alpha and IL-6 release in LPS-stimulated RAW 264.7 macrophages. Discussion and conclusions are given regarding structure-activity relationships (SAR). The two most potent analogues among the tested compounds, B75 and C12, exhibited anti-inflammatory abilities in a dose-dependent manner in macrophages. This raises the possibility that mono-carbonyl analogues of curcumin might serve as potential agents for the treatment of various inflammatory diseases.