Self-assembled nanoparticles of costunolide and glycyrrhizic acid for enhanced ulcerative colitis treatment.

Ulcerative colitis (UC) is a persistent inflammatory condition that specifically targets the colon and rectum. Existing therapies fail to adequately address the clinical requirements of people suffering from this ailment. Despite the acknowledged potential of nanomedicines in the field of anti-inflammatory treatment, their widespread use in clinical settings is impeded by their expensive nature and the uncertainty surrounding their safety profiles. This study illustrates that two naturally occurring phytochemicals, Costunolide (COS) and Glycyrrhizic acid (GA), form carrier-free, multifunctional spherical nanoparticles (NPs) through noncovalent interactions, such as π-π stacking and hydrogen bonding. The COS-GA NPs displayed a synergistic anti-inflammatory effect, providing much more evidently improved therapeutic benefits for dextran sodium sulfate (DSS)-induced UC mice due to more effective reduction in inflammation and oxidative stress than did equal dosages of COS or GA used alone. In addition, COS-GA NPs have biocompatibility and biosafety properties unique to them. This study will serve as affirmation of the potential of COS-GA NPs as innovative natural anti-inflammatory and antioxidant activities and also such agents as drug discovery in UC, leading possibly to better outcomes in people living with this disabling condition.

A Novel Approach: Targeting Virulence Factors of Candida albicans with Essential Oil Components.

AIMS: Focusing on phytochemicals to target the virulence factors of Candida albicans is a promising avenue for novel antifungal compounds. Given the limited prior research on essential oil (EO) components and their specific effects on C. albicans virulence, our study aimed to explore their impact and uncover the underlying mechanisms. METHODS AND RESULTS: We examined the effects on viability, dimorphic transition, biofilm formation, and changes in the expression of critical virulence-related genes. The results showed that Dehydrocostus Lactone, displayed the most potent growth-inhibiting activity with the lowest MIC value, followed by Thymol, and Costunolide. A substantial, dose-dependent decrease in germ tube formation occurred after exposure to sub-inhibitory concentrations of the EO components, with Carvacrol, Dehydrocostus Lactone, and Thymol exerting the most potent inhibitory effects. Across sub-inhibitory concentrations, Alpha Bisabolol consistently showcased the most potent antibiofilm activity followed by lower but significant inhibitory effects with Dehydrocostus Lactone, Thymol, Alpha Pinene, Costunolide, Carvone, and Carvacrol. Alpha Bisabolol, Alpha Pinene and Dehydrocostus Lactone caused almost total downregulation of ACT1 whilst minimal changes occurred in expression of HWP1, SAP4, ALS3 and ECE1. CONCLUSIONS: Considering that actin is essential for various cellular processes, including budding, cell shape maintenance, and the formation of filaments in C. albicans, it is a plausible hypothesis that inhibiting ACT1 or disturbing actin's normal functioning could potentially affect the fungus's virulence, which warrants additional research and exploration. This study underscores the potent antifungal and anti-virulence properties of various EO components which effectively cripple C. albicans and reduce its disease-causing ability. This innovative approach holds promise for effective clinical therapies.

Exploration of costunolide derivatives as potential anti-inflammatory agents for topical treatment of atopic dermatitis by inhibiting MAPK/NF-κB pathways.

Atopic dermatitis (AD) is a common inflammatory disease and it is very difficult to treat. In the present work, a series of costunolide derivatives have been prepared, and in vitro and in vivo anti-inflammatory activities have evaluated. The results showed that most derivatives displayed good inhibition of NO generation with low cytotoxicity, and 7d could inhibit the phosphorylation of P38, P65 NF-κB and IκB-α in LPS-induced RAW264.7 model. The in vivo researches showed that 7d could improve skin injury symptoms, decrease Th2-type cytokine levels, inhibit HIS levels, alleviate scratching and repaire the damaged skin barrier through the inhibition of phosphorylation of MAPK and NF-κB signaling pathways on MC903-induced AD model. Therefore, costunolide derivatives may be new potent anti-AD agents for further study.

Costunolide attenuates high-fat diet-induced inflammation and oxidative stress in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease that can further evolve towards liver fibrosis and hepatocellular carcinoma in the end stage. Costunolide (Cos) is a natural sesquiterpene lactone that exhibits both anti-inflammatory and antioxidant properties. However, the therapeutic effect of Cos on NAFLD is not clear. In this study, we explored the potential protective effect and mechanism of Cos on NAFLD. C57BL/6 mice were fed with high-fat diet (HFD) to induce NAFLD. Cos was administered by gavage to observe the effect of Cos on NAFLD. We demonstrated that oral administration of Cos reduced HFD-induced hepatic fibrosis and the release of inflammatory cytokines, limiting the generation of reactive oxygen species. In vitro experiments revealed that pretreatment with Cos significantly decreased PA-induced production of inflammatory cytokines and fibrosis in AML-12 cells. Mechanism study showed that the effect of Cos was correlated to the induction of Nrf-2 and inhibition of NF-κB pathways. Collectively, these findings indicated that Cos exerts hepatoprotective effect against NAFLD through blocking inflammation and oxidative stress. Our study suggested that Cos might be an effective pharmacotherapy for the treatment of NAFLD.

Sesquiterpene Lactones Containing an α-Methylene-γ-Lactone Moiety Selectively Down-Regulate the Expression of Tumor Necrosis Factor Receptor 1 by Promoting Its Ectodomain Shedding in Human Lung Adenocarcinoma A549 Cells.

Alantolactone is a eudesmane-type sesquiterpene lactone containing an α-methylene-γ-lactone moiety. Previous studies showed that alantolactone inhibits the nuclear factor κB (NF-κB) signaling pathway by targeting the inhibitor of NF-κB (IκB) kinase. However, in the present study, we demonstrated that alantolactone selectively down-regulated the expression of tumor necrosis factor (TNF) receptor 1 (TNF-R1) in human lung adenocarcinoma A549 cells. Alantolactone did not affect the expression of three adaptor proteins recruited to TNF-R1. The down-regulation of TNF-R1 expression by alantolactone was suppressed by an inhibitor of TNF-α-converting enzyme. Alantolactone increased the soluble forms of TNF-R1 that were released into the culture medium as an ectodomain. The structure-activity relationship of eight eudesmane derivatives revealed that an α-methylene-γ-lactone moiety was needed to promote TNF-R1 ectodomain shedding. In addition, parthenolide and costunolide, two sesquiterpene lactones with an α-methylene-γ-lactone moiety, increased the amount of soluble TNF-R1. Therefore, the present results demonstrate that sesquiterpene lactones with an α-methylene-γ-lactone moiety can down-regulate the expression of TNF-R1 by promoting its ectodomain shedding in A549 cells.

Costunolide alleviates hyperglycaemia-induced diabetic cardiomyopathy via inhibiting inflammatory responses and oxidative stress.

Hyperglycaemia-induced myocardial injury promotes the induction of heart failure in diabetic patients. Impaired antioxidant capability and sustained chronic inflammation play a vital role in the progression of diabetic cardiomyopathy (DCM). Costunolide (Cos), a natural compound with anti-inflammatory and antioxidant properties, has exhibited therapeutic effects in various inflammatory diseases. However, the role of Cos in diabetes-induced myocardial injury remains poorly understood. In this study, we investigated the effect of Cos on DCM and explored the potential mechanisms. C57BL/6 mice were administered intraperitoneal streptozotocin for DCM induction. Cos-mediated anti-inflammatory and antioxidation activities were examined in heart tissues of diabetic mice and high glucose (HG)-stimulated cardiomyocytes. Cos markedly inhibited HG-induced fibrotic responses in diabetic mice and H9c2 cells, respectively. The cardioprotective effects of Cos could be correlated to the reduced expression of inflammatory cytokines and decreased oxidative stress. Further investigations demonstrated Cos reversed diabetes-induced nuclear factor-κB (NF-κB) activation and alleviated impaired antioxidant defence system, principally via activation of nuclear factor-erythroid 2 p45-related factor-2 (Nrf-2). Cos alleviated cardiac damage and improved cardiac function in diabetic mice by inhibiting NF-κB-mediated inflammatory responses and activating the Nrf-2-mediated antioxidant effects. Therefore, Cos could be a potential candidate for the treatment of DCM.

Costunolide alleviates atherosclerosis in high-fat diet-fed ApoE-/- mice through covalently binding to IKKß and inhibiting NF-κB-mediated inflammation.

Costunolide (CTD) is a sesquiterpene lactone isolated from costus root and exhibits various biological activities including anti-inflammation. Since atherosclerosis is a chronic inflammatory disease, we herein investigated the anti-atherosclerotic effects of CTD and the underlying mechanism. Atherosclerosis was induced in ApoE-/- mice by feeding them with a high-fat diet (HFD) for 8 weeks, followed by administration of CTD (10, 20 mg ·kg-1·d-1, i.g.) for 8 weeks. We showed that CTD administration dose-dependently alleviated atherosclerosis in HFD-fed ApoE-/- mice. Furthermore, we found that CTD dose-dependently reduced inflammatory responses in aortas of the mice, as CTD prevented infiltration of inflammatory cells in aortas and attenuated oxLDL uptake in macrophages, leading to reduced expression of pro-inflammatory and pro-fibrotic molecules in aortas. Similar results were observed in oxLDL-stimulated mouse primary peritoneal macrophages (MPMs) in vitro. We showed that pretreatment with CTD (2.5, 5. 10 µM) restrained oxLDL-induced inflammatory responses in MPMs by blocking pro-inflammatory NF-κB/p65 signaling pathway. We further demonstrated that CTD inactivated NF-κB via covalent binding to cysteine 179 on IKKß, a canonical upstream regulator of NF-κB, reducing its phosphorylation and leading to conformational change in the active loop of IKKß. Our results discover IKKß as the target of CTD for its anti-inflammatory activity and elucidate a molecular mechanism underlying the anti-atherosclerosis effect of CTD. CTD is a potentially therapeutic candidate for retarding inflammatory atherosclerotic diseases.

Investigation of Molecular Mechanisms Involved in Sensitivity to the Anti-Cancer Activity of Costunolide in Breast Cancer Cells.

Costunolide (CTL), an active compound isolated from Saussurea lappa Clarke and Laurus nobilis L, has been shown to induce apoptosis via reactive oxygen species (ROS) generation in various types of cancer cells. However, details of molecular mechanisms underlying the difference in sensitivity of cancer cells to CTL are still largely unknown. Here, we tested the effect of CTL on the viability of breast cancer cells and found that CTL had a more efficient cytotoxic effect against SK-BR-3 cells than MCF-7 cells. Mechanically, ROS levels were significantly increased upon CTL treatment only in SK-BR-3 cells, which leads to lysosomal membrane permeabilization (LMP) and cathepsin D release, and subsequent activation of the mitochondrial-dependent intrinsic apoptotic pathway by inducing mitochondrial outer membrane permeabilization (MOMP). In contrast, treatment of MCF-7 cells with CTL activated PINK1/Parkin-dependent mitophagy to remove damaged mitochondria, which prevented the elevation of ROS levels, thereby contributing to their reduced sensitivity to CTL. These results suggest that CTL is a potent anti-cancer agent, and its combination with the inhibition of mitophagy could be an effective method for treating breast cancer cells that are less sensitive to CTL.

HPLC-PDA Method for Quantification of Bioactive Compounds in Crude Extract and Fractions of Aucklandia costus Falc. and Cytotoxicity Studies against Cancer Cells.

Aucklandia costus Falc. (Synonym: Saussurea costus (Falc.) Lipsch.) is a perennial herb of the family Asteraceae. The dried rhizome is an essential herb in the traditional systems of medicine in India, China and Tibet. The important pharmacological activities reported for Aucklandia costus are anticancer, hepatoprotective, antiulcer, antimicrobial, antiparasitic, antioxidant, anti-inflammatory and anti-fatigue activities. The objective of this study was the isolation and quantification of four marker compounds in the crude extract and different fractions of A. costus and the evaluation of the anticancer activity of the crude extract and its different fractions. The four marker compounds isolated from A. costus include dehydrocostus lactone, costunolide, syringin and 5-hydroxymethyl-2-furaldehyde. These four compounds were used as standard compounds for quantification. The chromatographic data showed good resolution and excellent linearity (r2 ˃ 0.993). The validation parameters, such as inter- and intraday precision (RSD < 1.96%) and analyte recovery (97.52-110.20%; RSD < 2.00%),revealed the high sensitivity and reliability of the developed HPLC method. The compounds dehydrocostus lactone and costunolide were concentrated in the hexane fraction (222.08 and 65.07 µg/mg, respectively) and chloroform fraction (99.02 and 30.21 µg/mg, respectively), while the n-butanol fraction is a rich source of syringin (37.91 µg/mg) and 5-hydroxymethyl-2-furaldehyde (7.94 µg/mg). Further, the SRB assay was performed for the evaluation of anticancer activity using lung, colon, breast and prostate cancer cell lines. The hexane and chloroform fractions show excellent IC50 values of 3.37 ± 0.14 and 7.527 ± 0.18 µg/mL, respectively, against the prostate cancer cell line (PC-3).

Three sesquiterpene lactones suppress lung adenocarcinoma by blocking TMEM16A-mediated Ca2+-activated Cl- channels.

Transmembrane protein TMEM16A, which encodes calcium-activated chloride channel has been implicated in tumorigenesis. Overexpression of TMEM16A is associated with poor prognosis and low overall survival in multiple cancers including lung adenocarcinoma, making it a promising biomarker and therapeutic target. In this study, three structure-related sesquiterpene lactones (mecheliolide, costunolide and dehydrocostus lactone) were extracted from the traditional Chinese medicine Aucklandiae Radix and identified as novel TMEM16A inhibitors with comparable inhibitory effects. Their effects on the proliferation and migration of lung adenocarcinoma cells were examined. Whole-cell patch clamp experiments showed that these sesquiterpene lactones potently inhibited recombinant TMEM16A currents in a concentration-dependent manner. The half-maximal concentration (IC50) values for three tested sesquiterpene lactones were 29.9 ± 1.1 µM, 19.7 ± 0.4 µM, and 24.5 ± 2.1 µM, while the maximal effect (Emax) values were 100.0% ± 2.8%, 85.8% ± 0.9%, and 88.3% ± 4.6%, respectively. These sesquiterpene lactones also significantly inhibited the endogenous TMEM16A currents and proliferation, and migration of LA795 lung cancer cells. These results demonstrate that mecheliolide, costunolide and dehydrocostus lactone are novel TMEM16A inhibitors and potential candidates for lung adenocarcinoma therapy.

Costunolide is a dual inhibitor of MEK1 and AKT1/2 that overcomes osimertinib resistance in lung cancer.

EGFR-TKI targeted therapy is one of the most effective treatments for lung cancer patients harboring EGFR activating mutations. However, inhibition response is easily attenuated by drug resistance, which is mainly due to bypass activation or downstream activation. Herein, we established osimertinib-resistant cells by stepwise dose-escalation in vitro and an osimertinib-resistant patient-derived xenograft model through persistent treatment in vivo. Phosphorylated proteomics identified that MEK1 and AKT1/2 were abnormally activated in resistant cells compared with parental cells. Likewise, EGFR inhibition by osimertinib induced activation of MEK1 and AKT1/2, which weakened osimertinib sensitivity in NSCLC cells. Consequently, this study aimed to identify a novel inhibitor which could suppress resistant cell growth by dual targeting of MEK1 and AKT1/2. Based on computational screening, we identified that costunolide could interact with MEK1 and AKT1/2. Further exploration using in vitro kinase assays validated that costunolide inhibited the kinase activity of MEK1 and AKT1/2, which restrained downstream ERK-RSK2 and GSK3ß signal transduction and significantly induced cell apoptosis. Remarkably, the combination of osimertinib and costunolide showed synergistic or additive inhibitory effects on tumor growth in osimertinib-resistant cell lines and PDX model. Hence, this study highlights a potential therapeutic strategy for osimertinib-resistant patients through targeting of MEK1 and AKT1/2 by costunolide.

Natural essential oils efficacious in internal organs fibrosis treatment: Mechanisms of action and application perspectives.

Internal organs fibrosis (IOF) is the leading cause of morbidity and mortality in most chronic inflammatory diseases, which is responsible for 45% of deaths due to disease. However, there is a paucity of drugs used to treat IOF, making it urgent to find medicine with good efficacy, low toxic side effects and good prognosis. Essential oils (EOs) extracted from natural herbs with a wide range of pharmacological components, multiple therapeutic targets, low toxicity, and broad sources have unique advantages and great potential in the treatment of IOF. In this review, we summarized EOs and their monomeric components with anti-IOF, and found that they work mainly through inhibiting TGF-ß-related signaling pathways, modulating inflammatory cytokines, suppressing NF-κB, and anti-oxidative stress. The prognostic improvement of natural EOs on IOF was further discussed, as well as the quality and safety issues in the current development of natural EOs. This review hopes to provide scientific basis and new ideas for the development and application of natural medicine EOs in anti-IOF.

Costunolide protects against alcohol-induced liver injury by regulating gut microbiota, oxidative stress and attenuating inflammation in vivo and in vitro.

Costunolide (cos) derived from the roots of Dolomiaea souliei (Franch.), which belongs to the Dolomiaea genus in the family Compositae, exert the anti-inebriation effect mainly by inhibiting the absorption of alcohol in the gastrointestinal tract. However, the protective effect of cos against alcohol-induced liver injury (ALI) remains obscure. The present study was aimed to evaluate the hepatoprotective effects of cos (silymarin was used as positive control) against ALI and its potential mechanisms. MTT was used to examine the effect of cos on the cell viability of L-02 cells. Plasma was separated from blood that used to test the levels of TNF-α, IL-6 and IL-12, and LPS while serum separated from blood which used to detect the level of ALT and AST. Liver tissues were obtained for histopathological examination and western blot analysis. Fresh mice feces samples were collected for the detection of bacterial composition. Cos exhibited protective effect against alcoholic-induced liver injury by regulating gut microbiota capacities (higher relative abundance of Firmicutes and Actinobacteria while lower in Bacteroidetes and Proteobacteria), adjusting oxidative stress (reduced the activities of MDA and ROS while promoted SOD, GSH and GSH-PX in L-02 cells) and attenuating inflammation (decreased the levels of ALT, AST, LPS, IL-6, IL-12 and TNF-α) via LPS-TLR4-NF-κB p65 signaling pathway, which might be an active therapeutic agent for treatment of ALI.

Cardiorenal Protective Effect of Costunolide against Doxorubicin-Induced Toxicity in Rats by Modulating Oxidative Stress, Inflammation and Apoptosis.

Doxorubicin (DXB) is one of the most commonly used anticancer agents for treating solid and hematological malignancies; however, DXB-induced cardiorenal toxicity presents a limiting factor to its clinical usefulness in cancer patients. Costunolide (COST) is a naturally occurring sesquiterpene lactone with excellent anti-inflammatory, antioxidant and antiapoptotic properties. This study evaluated the effect of COST on DXB-induced cardiorenal toxicity in rats. Rats were orally treated with COST for 4 weeks and received weekly 5 mg/kg doses of DXB for three weeks. Cardiorenal biochemical biomarkers, lipid profile, oxidative stress, inflammatory cytokines, histological and immunohistochemical analyses were evaluated. DXB-treated rats displayed significantly increased levels of lipid profiles, markers of cardiorenal dysfunction (aspartate aminotransferase, creatine kinase, lactate dehydrogenase, troponin T, blood urea nitrogen, uric acid and creatinine). In addition, DXB markedly upregulated cardiorenal malondialdehyde, tumor necrosis factor-α, interleukin-1ß, interleukin-6 levels and decreased glutathione, superoxide dismutase and catalase activities. COST treatment significantly attenuated the aforementioned alterations induced by DXB. Furthermore, histopathological and immunohistochemical analyses revealed that COST ameliorated the histopathological features and reduced p53 and myeloperoxidase expression in the treated rats. These results suggest that COST exhibits cardiorenal protective effects against DXB-induced injury presumably via suppression of oxidative stress, inflammation and apoptosis.

Exploring the Potential Mechanism of Costunolide-Induced MCF-7 Cells Apoptosis by Multi-Spectroscopy, Molecular Docking and Cell Experiments.

Breast cancer is one of the most common cancer with high morbidity and mortality in women. This study aimed to explore the potential mechanism of costunolide inducing MCF-7 cells apoptosis by multi-spectroscopy, molecular docking, and cell experiments. The results manifested that costunolide interacted with calf thymus DNA (ct-DNA) in a spontaneous manner, and the minor groove as the preferential binding mode. Furthermore, costunolide inhibited cell proliferation and colony formation. Hoechst 33258 staining showed that cell apoptosis induced by costunolide might be related to DNA damage. The apoptosis mechanism relied on regulating the protein expression of Bax, Bcl-2, p53, Caspase-3 and the activation of p38MAPK and nuclear factor κB (NF-κB) pathways. This study will provide some experimental basis and potential therapeutic strategy for breast cancer treatment.

Costunolide Induces Apoptosis via the Reactive Oxygen Species and Protein Kinase B Pathway in Oral Cancer Cells.

Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

Costunolide, a Sesquiterpene Lactone, Suppresses Skin Cancer via Induction of Apoptosis and Blockage of Cell Proliferation.

Costunolide is a naturally occurring sesquiterpene lactone that demonstrates various therapeutic actions such as anti-oxidative, anti-inflammatory, and anti-cancer properties. Costunolide has recently emerged as a potential anti-cancer agent in various types of cancer, including colon, lung, and breast cancer. However, its mode of action in skin cancer remains unclear. To determine the anti-cancer potential of costunolide in skin cancer, human epidermoid carcinoma cell line A431 was treated with costunolide. A lactate dehydrogenase assay showed that costunolide diminished the viability of A431 cells. Apoptotic cells were detected by annexin V/propidium iodide double staining and Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay assay, and costunolide induced cell apoptosis via activation of caspase-3 as well as induction of poly-ADP ribose polymerase cleavage in A431 cells. In addition, costunolide elevated the level of the pro-apoptotic protein Bax while lowering the levels of anti-apoptotic proteins, including Bcl-2 and Bcl-xL. To address the inhibitory effect of costunolide on cell proliferation and survival, various signaling pathways, including mitogen-activated protein kinases, signal transducer and activator of transcription 3 (STAT3), nuclear factor κB (NF-κB), and Akt, were investigated. Costunolide activated the p38 and c-Jun N-terminal kinase pathways while suppressing the extracellular signal-regulated kinase (ERK), STAT3, NF-κB, and Akt pathways in A431 cells. Consequently, it was inferred that costunolide suppresses cell proliferation and survival via these signaling pathways. Taken together, our data clearly indicated that costunolide exerts anti-cancer activity in A431 cells by suppressing cell growth via inhibition of proliferation and promotion of apoptosis. Therefore, it may be employed as a potentially tumor-specific candidate in skin cancer treatment.

The specific PKC-α inhibitor chelerythrine blunts costunolide-induced eryptosis.

Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g. glutathione and glucose-6-phosphate dehydrogenase (G6PDH) respectively, have not been studied yet. Our aim was to determine the mechanisms underlying costunolide-induced eryptosis and to reverse this process. Phosphatidylserine exposure was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry, and intracellular glutathione [GSH]i from high performance liquid chromatography. The oxidized status of intracellular glutathione and enzyme activities were measured by spectrophotometry. Treatment of erythrocytes with costunolide dose-dependently enhanced the percentage of annexin-V-binding cells, decreased the cell volume, depleted [GSH]i and completely inhibited G6PDH activity. The effects of costunolide on annexin-V-binding and cell volume were significantly reversed by pre-treatment of erythrocytes with the specific PKC-α inhibitor chelerythrine. The latter, however, had no effect on costunolide-induced GSH depletion. Costunolide induces eryptosis, depletes [GSH]i and inactivates G6PDH activity. Furthermore, our study reveals an inhibitory effect of chelerythrine on costunolide-induced eryptosis, indicating a relationship between costunolide and PKC-α. In addition, chelerythrine acts independently of the GSH depletion. Understanding the mechanisms of G6PDH inhibition accompanied by GSH depletion should be useful for development of anti-malarial therapeutic strategies or for synthetic lethality-based approaches to escalate oxidative stress in cancer cells for their sensitization to chemotherapy and radiotherapy.

Elucidating genes involved in sesquiterpenoid and flavonoid biosynthetic pathways in Saussurea lappa by de novo leaf transcriptome analysis.

Saussurea lappa (family Asteraceae) possesses immense pharmacological potential mainly due to the presence of sesquiterpene lactones. In spite of its medicinal importance, S. lappa has been poorly explored at the molecular level. We initiated leaf transcriptome sequencing of S. lappa using the illumina highseq 2000 platform and generated 62,039,614 raw reads. Trinity assembler generated 122,434 contigs with an N50 value of 1053 bp. The assembled transcripts were compared against the non-redundant protein database at NCBI. The Blast2GO analysis assigned gene ontology (GO) terms, categorized into molecular functions (3132), biological processes (4477) and cellular components (1.927). Using KEGG, around 476 contigs were assigned to 39 pathways. For secondary metabolic pathways, we identified transcripts encoding genes involved in sesquiterpenoid and flavonoid biosynthesis. Relatively low number of transcripts were also found encoding for genes involved in the alkaloid pathway. Our data will contribute to functional genomics and metabolic engineering studies in this plant.

Costunolide Plays an Anti-Neuroinflammation Role in Lipopolysaccharide-Induced BV2 Microglial Activation by Targeting Cyclin-Dependent Kinase 2.

Hyperactivation of microglia in the brain is closely related to neuroinflammation and leads to neuronal dysfunction. Costunolide (CTL) is a natural sesquiterpene lactone with wide pharmacological activities including anti-inflammation and antioxidation. In this study, we found that CTL significantly inhibited the production of inflammatory mediators including nitric oxide, IL-6, TNF-α, and PGE2 in lipopolysaccharide (LPS)-stimulated BV2 microglia. Moreover, CTL effectively attenuated IKKß/NF-κB signaling pathway activation. To identify direct cellular target of CTL, we performed high-throughput reverse virtual screening assay using scPDB protein structure library, and found cyclin-dependent kinase 2 (CDK2) was the most specific binding protein for CTL. We further confirmed the binding ability of CTL with CDK2 using cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assays. Surface plasmon resonance analysis also supported that CTL specifically bound to CDK2 with a dissociation constant at micromole level. Furthermore, knocking down CDK2 obviously reversed the anti-inflammation effect of CTL via AKT/IKKß/NF-κB signaling pathway on BV-2 cells. Collectively, these results indicate that CTL inhibits microglia-mediated neuroinflammation through directly targeting CDK2, and provide insights into the role of CDK2 as a promising anti-neuroinflammation therapeutic target.