Anti-Inflammatory Effect of Ebractenoid F, a Major Active Compound of Euphorbia ebracteolata Hayata, through Inhibition of Nuclear Factor-κB Activation.

Euphorbia ebracteolata Hayata (Euphorbiaceae family) is a perennial plant that is widely distributed in Korea, Japan, and China. Its roots contain bioactive diterpenes that have anti-inflammatory properties. However, the anti-inflammatory mechanisms are not yet fully understood. This study aimed to identify the most active anti-inflammatory compound from the roots of E. ebracteolata Hayata, using bioassay-guided fractionation and a combinative method of high-speed countercurrent chromatography (HSCCC) and preparative high-performance liquid chromatography (HPLC). Then, we investigated its anti-inflammatory mechanism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Ebractenoid F was identified as the most potent bioactive compound of E. ebracteolata Hayata. Ebractenoid F significantly decreased nitric oxide (NO) production and nuclear factor-κB (NF-κB) activation induced by LPS in RAW 264.7 macrophages. Moreover, ebractenoid F decreased the degradation of inhibitory κB-α, the nuclear translocation of the p65 and p50 subunits of NF-κB, and the expression of NF-κB downstream genes. Furthermore, ebractenoid F inhibited the phosphorylation of Akt and mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK) and c-Jun NH2 terminal kinase (JNK), in LPS-stimulated RAW 264.7 cells. In conclusion, ebractenoid F exerts the most potent anti-inflammatory effect by suppressing NF-κB-mediated NO production in LPS-stimulated RAW 264.7 cells. Ebractenoid F may be a useful therapeutic compound for the prevention or treatment of inflammation-associated diseases.

Cellular Target Proteome in Breast Cancer Cells of an Oplopane Sesquiterpenoid Isolated from Tussilago farfara.

Tussilago farfara is a traditional herbal medicine used to treat coughs, bronchitis, and asthma. Its bioactive compounds include sesquiterpenoids with anti-inflammatory, antiproliferative, neuroprotective, and other effects. Biochemical studies have highlighted the mechanisms of action, but the investigations of related molecular pathways have not specified direct molecular targets. Therefore, this study profiled cellular target proteins of a sesquiterpenoid isolated from T. farfara using quantitative chemical proteomics in MDA-MB-231 and MCF-7 human breast cancer cells. Compound 8, 7ß-(3'-ethyl-cis-crotonoyloxy)-1α-(2'-methyl butyryloxy)-3,14-dehydro-Z-notonipetranone, exhibited potent antiproliferative activity based on its α,ß-unsaturated carbonyl moiety, and its potential cellular target proteins were identified using a compound 8-based clickable probe. Among >200 identified proteins, 17 showed enrichment ratios of >3 in both cell lines, while recombinant 14-3-3 protein zeta and peroxiredoxin-1 were verified using isothermic calorimetry and their alkylation sites. Considering the interaction between the α,ß-unsaturated carbonyl moiety of compound 8 and cysteine residues of the proteins, peptides containing Cys25 and Cys94 of 14-3-3 protein zeta and Cys83 of peroxiredoxin-1 were significantly reduced by this sesquiterpene ester. Although the results did not elucidate the effects of compound 8 in breast cancer cells, identification of potential target proteins contributes to enhanced understanding of its antiproliferative and anti-inflammatory effects.

Development and Validation of Liquid Chromatography-Tandem Mass Spectrometry Method for Pharmacokinetic Evaluation of 7ß-(3-Ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranon in Rats.

Recently, potent neuroprotective and anti-diabetic effects of 7ß-(3-Ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid isolated from Tussilago farfara Linnaeus, have been elucidated. To facilitate further pre-clinical evaluation in rats, an analytical method for the determination of ECN in rat plasma was developed and optimized by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma samples were pretreated by the protein precipitation method with an acetonitrile solution of losartan (LST) as the internal standard. Chromatographic separation was performed using a an Octadecyl-silica (ODS) column (2.6 µm, 100 x 4.6 mm) in the isocratic mode. The mobile phase, comprising 10 mM ammonium formate in water pH 5.75) and acetonitrile (11:89, v/v), was eluted at a flow rate of 0.4 mL/min. Mass spectrometric detection was performed in the multiple reaction monitoring mode with positive electrospray ionization, and the mass transitions of ECN and LST were m/z 431.3 to 97.3 and m/z 423.1 to 207.2, respectively. The calibration curves of spiked plasma samples were linear in the 10.0-10,000 ng/mL range (r2 > 0.996). The lower limit of quantification (LLOQ) was determined as 10.0 ng/mL. Validation was conducted in the LLOQ, and three quality control (QC) sample levels (10.0, 25.0, 3750, and 7500 ng/mL) were studied. Among them, the relative standard deviation for the within- and between-run precisions was under 9.90%, and the relative error of the accuracies was within the -8.13% to 0.42% range. The validated method was successfully employed to investigate the pharmacokinetic properties of ECN in rats, which revealed the linear pharmacokinetic behavior of ECN for the first time.

Igalan from Inula helenium (L.) suppresses the atopic dermatitis-like response in stimulated HaCaT keratinocytes via JAK/STAT3 signaling.

OBJECTIVE: This study aimed to evaluate the protective effect of igalan, a sesquiterpene lactone isolated from Inula helenium (L.), on inhibiting inflammation, regulating the epidermal differentiation gene expression, and reactive oxygen species scavenging in atopic dermatitis (AD)-like inflammatory keratinocytes. METHODS: HaCaT human keratinocytes were treated with igalan at indicated concentrations before being activated by a combination of TNF-α and IFN-γ or IL-4 representative for T-helper 1 and T-helper 2 cell cytokines, which are associated with AD pathogenesis. RESULTS: By inhibiting the NF-κB pathway as well as the STAT activation, igalan could downregulate several marker inflammatory genes in AD, such as TARC/CCL17, MDC/CCL22, and RANTES/CCL5. In contrast, igalan, acting as JAK inhibitor, could promote the mRNA expression levels of the genes FLG, LOR, KRT10, and DSC1, which encode for essential proteins responsible for keratinocyte differentiation, by inhibiting STAT3 signaling. Furthermore, igalan exerts its antioxidant effect through activating the Nrf2 pathway, triggering the expression of some enzymes that contribute to preventing intracellular ROS generation during inflammation. CONCLUSION: These findings indicate that igalan, via suppressing JAK/STAT3 signaling, could impair the production of pro-inflammatory chemokines and enhance expression levels of several genes involved in keratinocyte differentiation in AD-like stimulated keratinocytes.

Tussilagonone Ameliorates Psoriatic Features in Keratinocytes and Imiquimod-Induced Psoriasis-Like Lesions in Mice via NRF2 Activation.

Psoriasis is a common inflammatory skin disorder that is characterized by keratinocyte hyperproliferation and abnormal differentiation, resulting in the thickening of the epidermis and stratum corneum. In this study, we investigated in vitro and in vivo pharmacological effects of tussilagonone (TGN), a sesquiterpenoid isolated from Tussilago farfara, on transcription factors relevant for the pathogenesis of psoriasis. TGN inhibited activation of NF-κB and STAT3, leading to the attenuated expression of psoriasis-related inflammatory genes and suppression of keratinocyte hyperproliferation. Mechanistically, we show that the inhibition of NF-κB and STAT3 by TGN is mediated through activation of the cytoprotective transcription factor NRF2. Evaluation of in vivo antipsoriatic effects of topical TGN in the imiquimod-induced psoriasis-like dermatitis mouse model demonstrated amelioration of imiquimod-induced phenotypical changes, lesion severity score, epidermal thickening, and reduction in dermal cellularity. The spleen index also diminished in TGN-treated mice, suggesting anti-inflammatory properties of TGN. Moreover, TGN significantly attenuated the imiquimod-induced mRNA levels of psoriasis-associated inflammatory cytokines and antimicrobial peptides and reduced epidermal hyperproliferation. Taken together, TGN, as a potent NRF2 activator, is a promising therapeutic candidate for the development of antipsoriatic agents derived from medicinal plants.

Mucoprotective effects of Saikosaponin-A in 5-fluorouracil-induced intestinal mucositis in mice model.

5-Fluorouracil (5-FU)-induced intestinal mucositis (IM) is one of the most common oncological problem. It involves serious clinical consequences such as diarrhea, erythematous lesions of mucosa, and eventually development of ulcers accompanied by severe pain. The aim of the present study was to demonstrate the mucoprotective effects of Saikosaponin-A in 5-FU-induced intestinal mucositis in mice. Mucositis was induced in BALB/c mice by intraperitoneal injection of 5-FU (50 mg/kg/day) for three consecutive days and IM was assessed by both behavioral and histochemical analysis. While, Saikosaponin-A (1, 5, 10 mg/kg/day) was administered 1 h before 5-FU injection for consecutive seven days. Pre-treatment of Saikosaponin-A significantly ameliorated the severity of mucositis reflected as food intake, body weight loss, severity of diarrhea and mortality rate in a dose depended manner as compared to mice treated with 5-FU. Moreover, histopathological analysis furthered reinforced the mucoprotective potential of Saikosaponin-A against 5-FU-induced intestinal abnormalities referred as villus atrophy, mitotic crypt stem cells damage, inflammatory cells infiltration, vacuolization and edema. Furthermore, Saikosaponin-A administration strongly inhibited pro-inflammatory mediators (TNF-α, COX-2, IL-1ß and IL-6) and apoptotic markers (p-JNK, Casp-3). Saikosaponin-A pre-treatment significantly reduced the production of nitric oxide (NO) in intestinal tissue, inhibited acetic acid-induced Evans blue vascular permeability. The Siaikosaponin-A treatment markedly enhanced the anti-oxidants enzymes (Nrf2, HO-1, SOD, GSH, GST and Catalase), while decreased the oxidative stress markers i.e. Malonaldehde (MDA). Hence, these data suggest that Saikosaponin-A maybe a potential candidate for the treatment of chemotherapy-induced intestinal mucositis.

Anti-hyperalgesic properties of a flavanone derivative Poncirin in acute and chronic inflammatory pain models in mice.

BACKGROUND: Poncirin is flavanone derivative (isolated from Poncirus trifoliata) with known pharmacological activities such as anti-tumor, anti-osteoporotic, anti-inflammatory and anti-colitic. The present study aimed to explore the anti-allodynic and anti-hyperalgesic potentials of poncirin in murine models of inflammatory pain. METHODS: The analgesic potential of poncirin was evaluated in formalin-, acetic acid-, carrageenan- and Complete Freund's Adjuvant (CFA)-induced inflammatory pain models in mice. Anti-allodynic and anti-hyperalgesic activities were measured using Von Frey filaments, Randall Selitto, hotplate and cold acetone tests. The serum nitrite levels were determined using Griess reagent. The Quantitative Real-time PCR (qRT-PCR) was performed to assess the effect of poncirin on mRNA expression levels of inflammatory cytokines and anti-oxidant enzymes. RESULTS: Intraperitoneal administration of poncirin (30 mg/kg) markedly reduced the pain behavior in both acetic acid-induced visceral pain and formalin-induced tonic pain models used as preliminary screening tools. The poncirin (30 mg/kg) treatment considerably inhibited the mechanical hyperalgesia and allodynia as well as thermal hyperalgesia and cold allodynia. The qRT-PCR analysis showed noticeable inhibition of pro-inflammatory cytokines (mRNA expression levels of TNF-α, IL-1ß and IL-6) (p < 0.05) in poncirin treated group. Similarly, poncirin treatment also enhanced the mRNA expressions levels of anti-oxidant enzymes such as transcription factor such as nuclear factor (erythroid-derived 2)-like 2 (Nrf2) (p < 0.05), heme oxygenase (HO-1) (p < 0.05) and superoxide dismutase (SOD2) (p < 0.05). Chronic treatment of poncirin for 6 days did not confer any significant hepatic and renal toxicity. Furthermore, poncirin treatment did not altered the motor coordination and muscle strength in CFA-induced chronic inflammatory pain model. CONCLUSION: The present study demonstrated that poncirin treatment significantly reduced pain behaviors in all experimental models of inflammatory pain, suggesting the promising analgesic potential of poncirin in inflammatory pain conditions.

Anticancer Activity of Smallanthus sonchifolius Methanol Extract against Human Hepatocellular Carcinoma Cells.

Background: This research aimed to investigate the cytotoxicity of methanol extract of Smallanthus sonchifolius leaf (YLE) against a human hepatocellular carcinoma cell line (HepG2). This plant is currently used as a traditional herbal remedy in the treatment of liver diseases in some rural parts of Myanmar. Methods: The cytotoxic activity of the plant extract against the cancerous cell line was assessed using an MTT assay. YLE demonstrated a significant effect (IC50 = 58.2 ± 1.9 µg/mL) on anti-cancer activity, which was further investigated using various assays including an in vitro cell migration assay, a colony formation assay, cell cycle analysis, western blot analysis, and a ROS assay. The significance of the phytochemical constituents of YLE could be identified using LC/Q-TOF-MS techniques. Results: We putatively identified the active components in YLE, which were possibly melampolide-type sesquiterpenoids. YLE showed an inhibitory effect on HepG2 cell proliferation and cell migration. YLE also induced cell cycle arrest and necrosis in a dose-dependent manner. Additionally, YLE significantly suppressed ROS formation in HepG2 cells. Conclusions: These findings suggest that YLE is sufficient for application as a promising anti-liver drug in herbal medicine.

A Sesquiterpenoid from Farfarae Flos Induces Apoptosis of MDA-MB-231 Human Breast Cancer Cells through Inhibition of JAK-STAT3 Signaling.

Triple-negative breast cancers (TNBCs) are hard-to-treat breast tumors with poor prognosis, which need to be treated by chemotherapy. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor involved in proliferation, metastasis, and invasion of cancer cells. Therefore, research on searching for promising compounds with metabolism that suppress phosphorylation or transcription of STAT3 in TNBC cells is important. Farfarae Flos is well known as a traditional medicine for treating inflammation. However, few studies have shown that sesquiterpenoids from Farfarae Flos have an anticancer effect. In this study, efficient separation methods and an MTT assay were conducted to isolate an anticancer compound from Farfarae Flos against TNBC MDA-MB-231 cells. Here, 7ß-(3-Ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a compound isolated from Farfarae Flos showed a potent cytotoxic effect on MDA-MB-231 cells. ECN inhibited JAK-STAT3 signaling and suppressed the expression of STAT3 target genes. In addition, ECN induced apoptosis through both extrinsic and intrinsic pathways. Furthermore, we investigated that ECN inhibited the growth of tumors by intraperitoneal administration in mice injected with MDA-MB-231 cells. Therefore, ECN can be an effective chemotherapeutic agent for breast cancer treatment.

Anomalin attenuates LPS-induced acute lungs injury through inhibition of AP-1 signaling.

In the present study, the anomalin was investigated to determine the protective effects and underlying mechanism against LPS-induced acute lung injury in mice. Anomalin administration 30 min after the LPS injection, significantly attenuated the mechanical allodynia, decrease body temperature, and improved the histological changes and inhibited the infiltration of leukocytes. The anomalin treatment markedly inhibited the production of pro-inflammatory mediators such as cytokines (IL-1ß, IL-6 and TNF-α) and NO in contrast to the LPS treated groups. Similarly, the anomalin also enhanced the level of anti-oxidant enzymes such as GST, GSH, Catalase and inhibited oxidative stress marker such as MDA. In order to explore the molecular mechanism the effect of anomalin was evaluated for mitogen activated protein kinases (MAPK) in LPS-stimulated RAW264.7 cells. The anomalin treatment significantly attenuated the MAPK proteins such as ERK1/2, JNK and p38 (which is downstream signaling proteins to the MAPKKKs and MAPKKs protein) in the RAW264.7 macrophages using western blot analysis. Furthermore, the western blot analysis showed that anomalin treatment significantly inhibited the activation of the Akt proteins in the RAW264.7 macrophages. The AP-1 served as downstream target for the MAPK pathways and the blocking MAPK pathways is responsible for the inhibition of the AP-1 protein. The AP-1/DNA binding was assessed in the RAW264.7 cells using EMSA. The anomalin treatment significantly restricted the AP-1/DNA binding activity and the decrease in the AP-1/DNA binding activity might be contributed due to the upstream inhibition of the MAPKs signaling.

Sesquiterpenoids from Tussilago farfara Flower Bud Extract for the Eco-Friendly Synthesis of Silver and Gold Nanoparticles Possessing Antibacterial and Anticancer Activities.

Sesquiterpenoids from the flower bud extract of Tussilago farfara were effectively utilized as a reducing agent for eco-friendly synthesis of silver and gold nanoparticles. The silver and gold nanoparticles had a characteristic surface plasmon resonance at 416 nm and 538 nm, respectively. Microscopic images revealed that both nanoparticles were spherical, and their size was measured to be 13.57 ± 3.26 nm for the silver nanoparticles and 18.20 ± 4.11 nm for the gold nanoparticles. The crystal structure was determined to be face-centered cubic by X-ray diffraction. Colloidal stability of the nanoparticle solution was retained in a full medium, which was used in the cell culture experiment. The antibacterial activity result demonstrated that the silver nanoparticles showed better activity (two- to four-fold enhancement) than the extract alone on both Gram-positive and Gram-negative bacteria. Interestingly, the highest antibacterial activity was obtained against vancomycin-resistant Enterococci Van-A type Enterococcus faecium. Cytotoxicity on cancer cell lines confirmed that gold nanoparticles were more cytotoxic than silver nanoparticles. The highest cytotoxicity was observed on human pancreas ductal adenocarcinoma cells. Therefore, both nanoparticles synthesized with the sesquiterpenoids from T. farfara flower bud extract can be applicable as drug delivery vehicles of anticancer or antibacterial agents for future nanomedicine applications.

A strategy for identification and structural characterization of oplopane- and bisabolane-type sesquiterpenoids from Tussilago farfara L. by multiple scan modes of mass spectrometry.

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS)-based dereplicative method was developed for identifying oplopane- and bisabolane-type sesquiterpenoids from buds of Tussilago farfara L. The analysis of these chemical analogues, sesquiterpene esters, is challenging by MS-based nontargeted metabolomic approaches because of their in-source fragmentation and structural diversity. To profile these sesquiterpenoids, four diagnostic ions (m/z 215.143, 217.158, 229.123, and 231.138) were suggested in the positive ion mode and the developed method utilized two sequential MS/MS scan modes to identify common skeletons and investigate the fragmentation patterns of their parent molecules. Precursor ion scan by triple quadrupole MS/MS provided the parent molecular ions from their diagnostic ions, and product ion scan by quadrupole time-of-flight MS/MS confirmed their fragmentation behaviors. Under the optimized UHPLC-MS/MS method, 74 sesquiterpenoids were characterized from the Farfarae Flos and 11 compounds were isolated for the method validation. Among those compounds, three sesquiterpenoids were newly separated from the Farfarae Flos. Furthermore, the diagnostic ions and the MS/MS fragment behaviors were applied to the accurate quantification of the 8 isolated sesquiterpenoids. Therefore, the developed LC-MS/MS-based method highlighted the chemical composition of the Farfarae Flos and could be extended to the screening and quantification of other sesquiterpene esters.

N-Pyrazoloyl and N-thiopheneacetyl hydrazone of isatin exhibited potent anti-inflammatory and anti-nociceptive properties through suppression of NF-κB, MAPK and oxidative stress signaling in animal models of inflammation.

BACKGROUND: Hydrazide derivatives constitute an important class of compounds for new drug development as they are reported to possess good anti-inflammatory and analgesic activity. The present study was aimed to investigate the role of newly synthesized hydrazide derivatives N-pyrazoloyl hydrazone of isatin (PHI) and N-thiopheneacetyl hydrazone of isatin (THI) in acute and chronic inflammatory pain models induced by carrageenan and complete Freud's adjuvant (CFA). MATERIALS: PHI and THI (0.1, 1 and 10 mg/kg) pretreatments were provided intraperitoneally to male BALB/c mice prior to inflammatory inducers. Behavioral responses to inflammation and pain were evaluated by assessment of paw edema, mechanical allodynia, mechanical and thermal hyperalgesia. Cytokines production and NF-κB levels were evaluated by ELISA. Western blot analysis was performed for the detection of IκBα, p38, JNK and ERK. Hematoxylin and eosin (H&E) staining and radiographic analysis were performed to evaluate the effect of PHI and THI treatment on bone and soft tissues. Oxidative stress was determined by reduced glutathione, glutathione-S-transferase and catalase assays. Evans blue dye was used to monitor vascular protein leakage. RESULT: PHI and THI dose dependently (0.1, 1 and 10 mg/kg) reduced inflammation and pain in mice, however, the dose of 10 mg/kg exhibited significant activity. The anti-inflammatory and analgesic effects were attributed to suppression of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6) production levels. PHI and THI significantly blocked CFA-induced activation of NF-κB and MAPK signaling pathways. Oxidative stress and plasma nitrite levels were reduced remarkably. The PHI and THI (10 mg/kg) treatment did not exhibit any apparent toxicity on the liver, kidney, muscles strength, and motor co-ordination in mice. CONCLUSION: Both PHI and THI possess significant anti-inflammatory and analgesic activity via inhibition of inflammatory mediators.

Novel Galiellalactone Analogues Can Target STAT3 Phosphorylation and Cause Apoptosis in Triple-Negative Breast Cancer.

Aberrant activation of signal transducer and activator of transcription 3 (STAT3) has been documented in various malignancies including triple-negative breast cancers (TNBCs). The STAT3 transcription factor can regulate the different important hallmarks of tumor cells, and thus, targeting it can be a potential strategy for treating TNBC, for which only limited therapeutic options are available. In this study, we analyzed the possible effect of (-)-galiellalactone and its novel analogues, SG-1709 and SG-1721, and determined whether these agents exerted their antineoplastic effects by suppressing the STAT3 signaling pathway in TNBC cells. The two analogues, SG-1709 and SG-1721, inhibited both constitutive as well as inducible STAT3 phosphorylation at tyrosine 705 more effectively than (-)-galiellalactone, which indicates that the analogues are more potent STAT3 blockers. Moreover, SG-1721 not only inhibited nuclear translocation and DNA binding of STAT3 but also induced apoptosis, and decreased expression of diverse oncogenic proteins. Interestingly, SG-1721 also exhibited an enhanced apoptotic effect when combined with radiotherapy. Furthermore, in vivo administration of SG-1721 significantly attenuated breast xenograft tumor growth via decreasing levels of p-STAT3. Therefore, SG-1721 may be a promising candidate for further application as a pharmacological agent that can target STAT3 protein in treating TNBC.

Suppression of TRPV1 and P2Y nociceptors by honokiol isolated from Magnolia officinalis in 3rd degree burn mice by inhibiting inflammatory mediators.

Burn pain is one of the worst imaginable pain, associated with considerable morbidity and mortality worldwide. The management of pain made significant progress; however, more research is needed for burn pain. In the present study, the antinociceptive effect of honokiol extracted from Magnolia officinalis was assessed for 3 consecutive days. The third-degree burns were induced by the hot water method. The honokiol both by intraperitoneal (i.p) and intra plantar (i.pl) route and in combination with tramadol (i.p) was found to be effective in significantly reducing the mechanical allodynia, hyperalgesia, thermal hyperalgesia and paw edema. Honokiol also succeeded in reducing weight loss and spontaneous pain behavior in mice. Honokiol treatment both i.p and ipl decrease significantly the loss of total protein (3.3 and 3.4 g/dl of total protein) and albumin (2.2 and 2.6 g/dl of total albumin) respectively. It also significantly recovers the normal balance of blood electrolytes and normalizes blood profile. Effect of honokiol on cytokines and mRNA expression levels of TRPV1 and P2Y were also assessed. Honokiol significantly decreases the expression of TNF-α, IL-1ß and IL-6 and decreases expression level of TRPV1 and P2Y. Additionally, TRPV1 and P2Y proteins expression levels were also assessed by Western blot in paw skin tissue, sciatic nerve and spinal cord which were remarkably down-regulated by honokiol. Histological analysis of vehicle control and drug-treated paws were also performed through hematoxylin and eosin (H&E) staining which exhibited that honokiol significantly reduced the dermal layers distortion and inflammation associated with the burn. The antioxidant enzymes and nitric oxide (NO) were also determined through ELISA. Honokiol treatment also potentiates the expression of reduced glutathione and glutathione S-transferase, and catalase levels and reduced significantly the nitric oxide (NO) as compared to the burn-induced group. It can be concluded on the base of the results that honokiol has a significant analgesic activity through its action on cytokines and by downregulating TRPV1 and P2Y receptors. It also has a protective role against burn damage by upregulation of antioxidants.

Insight into Pain Modulation: Nociceptors Sensitization and Therapeutic Targets.

Pain is a complex multidimensional concept that facilitates the initiation of the signaling cascade in response to any noxious stimuli. Action potential generation in the peripheral nociceptor terminal and its transmission through various types of nociceptors corresponding to mechanical, chemical or thermal stimuli lead to the activation of receptors and further neuronal processing produces the sensation of pain. Numerous types of receptors are activated in pain sensation which vary in their signaling pathway. These signaling pathways can be regarded as a site for modulation of pain by targeting the pain transduction molecules to produce analgesia. On the basis of their anatomic location, transient receptor potential ion channels (TRPV1, TRPV2 and TRPM8), Piezo 2, acid-sensing ion channels (ASICs), purinergic (P2X and P2Y), bradykinin (B1 and B2), α-amino-3-hydroxy-5- methylisoxazole-4-propionate (AMPA), N-methyl-D-aspartate (NMDA), metabotropic glutamate (mGlu), neurokinin 1 (NK1) and calcitonin gene-related peptide (CGRP) receptors are activated during pain sensitization. Various inhibitors of TRPV1, TRPV2, TRPM8, Piezo 2, ASICs, P2X, P2Y, B1, B2, AMPA, NMDA, mGlu, NK1 and CGRP receptors have shown high therapeutic value in experimental models of pain. Similarly, local inhibitory regulation by the activation of opioid, adrenergic, serotonergic and cannabinoid receptors has shown analgesic properties by modulating the central and peripheral perception of painful stimuli. This review mainly focused on various classes of nociceptors involved in pain transduction, transmission and modulation, site of action of the nociceptors in modulating pain transmission pathways and the drugs (both clinical and preclinical data, relevant to targets) alleviating the painful stimuli by exploiting nociceptor-specific channels and receptors.

Matrine ameliorates anxiety and depression-like behaviour by targeting hyperammonemia-induced neuroinflammation and oxidative stress in CCl4 model of liver injury.

Acute or chronic liver injury is associated with hyperammonemia which induced neuroinflammation and oxidative stress in the brain. Neuroinflammation, oxidative stress, reduced neurogenesis, and apoptosis are critical factors for the development of anxiety and depression. The present study was aimed to evaluate the anxiolytic and antidepressant properties of matrine against acute liver injury in the rodent model. Acute liver injury in mice was induced by administration of the acute hepatotoxic dose of carbon tetrachloride (CCl4) (1 ml/kg, i.p.). Pretreatment of mice with matrine (50 mg/kg i.p.) remarkably ameliorated CCl4-induced anxiety and depression-like behavior as evident from the results of open field test (OFT), elevated plus maze test (EPM), light-dark box test (LDB), forced swimming test (FST), and tail suspension test (TST). Moreover, matrine significantly inhibited CCl4-induced neuroinflammation in mice by reducing pro-inflammatory cytokines such as interleukins (IL-1ß, IL-6) and tumor necrosis factor-α (TNF-α) levels in the hippocampus (HC) and prefrontal cortex (PFC). CCl4-induced oxidative stress was reduced by matrine due to its potential to enhance the levels of reduced glutathione (GSH), catalase (CAT), glutathione-S-transferase (GST), and decreased the malondialdehyde (MDA), and nitrite level in the PFC and HC of mice brain. Matrine remarkably reduced the levels of corticosterone, ammonia, AST, ALT, and creatinine. Matrine pretreatment remarkably ameliorated CCl4-induced morphological liver injury. Acute pretreatment of matrine enhanced neurogenesis by increasing the number of GFAF (glial fibrillary acidic protein) positive astrocyte, BDNF (brain-derived neurotrophic factor), and VEGF (vascular endothelial growth factor) in the hippocampus of CCl4-treated mice. Pretreatment of matrine inhibited apoptosis and DNA damage in the hippocampus. The present data revealed that hyperammonemia produced due to liver injury induced oxidative stress, neuroinflammation, reduced neurogenesis and apoptosis in the hippocampus, thus, resulting in anxiety and depression. Taken together, the present results suggested that matrine has a significant antidepressant and anxiolytic effects through modulation of neuroinflammation, oxidative stress, reduced neurogenesis and apoptosis induced by CCl4 administration.

Igalan induces detoxifying enzymes mediated by the Nrf2 pathway in HepG2 cells.

Igalan is one of the sesquiterpene lactones found in Inula helenium L., which is used as the traditional medicine to treat inflammatory diseases. However, the pharmacological effects of igalan have not been characterized. In this study, we isolated igalan from I. helenium L. and evaluated the effects of igalan on signaling pathways and expression of target genes in HepG2 cells. Igalan activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by increasing the inactive form of GSK3ß, the phosphorylated form of AKT, and the nuclear accumulation of Nrf2. Thus, target genes of Nrf2 such as HO-1 and NQO1 increased in HepG2 cells. Moreover, igalan inhibited the tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB activation and suppressed the expression of its target genes, including TNF-α, interleukin (IL)-6, and IL-8 in HepG2 cells. Our results indicate the potential of igalan as an activator of cellular defense mechanisms and a detoxifying agent.

Antinociceptive properties of 25-methoxy hispidol A, a triterpinoid isolated from Poncirus trifoliata (Rutaceae) through inhibition of NF-κB signalling in mice.

The 25-methoxy hispidol A (25-MHA) is a triterpenoid, isolated from the immature fruit of Poncirus trifoliata (Rutaceae). The pretreatment with 25-MHA markedly (p < 0.001) attenuated the formalin-induced biphasic responses as well as acetic acid-induced writhing responses. The intraperitoneal administration of 25-MHA significantly attenuated the mechanical hyperalgesia (p < 0.001) and allodynia (p < 0.05). Similarly, 25-MHA also significantly attenuated (p < 0.001) complete Freund's adjuvant (CFA)-induced paw edema in mice. The 25-MHA treatment significantly attenuated the production of nuclear kappa B (NF-κB) (p65 nuclear subunit). The cytokines are the important mediators of inflammation and pain; however, treatment with 25-MHA exhibited significant inhibition (p < 0.001) on the mRNA expression levels of various inflammatory mediators. The 25-MHA administration also significantly enhanced antioxidant enzymes (p < 0.001) and inhibited the oxidative stress markers. The current study indicates that 25-MHA significantly (p < 0.001) inhibited the nitric oxide (NO) in mice plasma. Similarly, the haematoxylin and eosin (H&E) staining shows that 25-MHA administration significantly inhibited the inflammatory process in the mice paw tissue compared with the CFA-treated group. The 25-MHA treatment did not exhibited any toxicity on the liver, kidney, muscles strength, and motor co-ordination in mice. The 25-MHA was coadministered with the various drugs such as tramadol, piroxicam, and gabapentin to observe the synergistic effect.