Gßγ subunit inhibitor decreases DOM-induced head twitch response via the PLCß/IP3/Ca2+/ERK and cAMP signaling pathways.

AIMS: (-)-2,5-dimethoxy-4-methylamphetamine (DOM) induces the head-twitch response (HTR) primarily by activating the serotonin 5-hydroxytryptamine 2A receptor (5-HT2A receptor) in mice. However, the mechanisms underlying 5-HT2A receptor activation and the HTR remain elusive. Gßγ subunits are a potential treatment target in numerous diseases. The present study investigated the mechanism whereby Gßγ subunits influence DOM-induced HTR. MAIN METHODS: The effects of the Gßγ inhibitor 3',4',5',6'-tetrahydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one (gallein) and antagonistic peptide ßARKct (ß-adrenergic receptor kinase C-terminal fragment) on DOM-induced HTR were studied via an HTR test. The activation of the phospholipase C ß (PLCß)/inositol triphosphate (IP3)/calcium (Ca2+) signaling pathway and extracellular signal-regulated kinase (ERK) following Gßγ subunit inhibition was detected by western blotting, Homogeneous Time-Resolved Fluorescence (HTRF) inositol phosphate (IP1) assay and Fluorometric Imaging Plate Reader (FLIPR) calcium 6 assay. The Gßγ subunit-mediated regulation of cyclic adenosine monophosphate (cAMP) was assessed via a GloSensor™ cAMP assay. KEY FINDINGS: The Gßγ subunit inhibitors gallein and ßARKct reduced DOM-induced HTR in C57BL/6J mice. Like the 5-HT2A receptor-selective antagonist (R)-[2,3-di(methoxy)phenyl]-[1-[2-(4-fluorophenyl)ethyl]piperidin-4-yl]methanol (M100907), gallein inhibited PLCß phosphorylation (pPLCß), IP1 production, Ca2+ transients, ERK1/2 phosphorylation (pERK1/2) and cAMP accumulation induced by DOM in human embryonic kidney (HEK) 293T cells stably or transiently transfected with the human 5-HT2A receptor. Moreover, PLCß protein inhibitor 1-[6-[[(8R,9S,13S,14S,17S)-3-methoxy-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthren-17-yl]amino]hexyl]pyrrole-2,5-dione (U73122) (10 nmol/mouse), intracellular Ca2+ blocker 6-[6-[6-[5-acetamido-4,6-dihydroxy-2-(sulfooxymethyl)oxan-3-yl]oxy-2-carboxy-4-hydroxy-5-sulfooxyoxan-3-yl]oxy-2-(hydroxymethyl)-5-(sulfoamino)-4-sulfooxyoxan-3-yl]oxy-3,4-dihydroxy-5-sulfooxyoxane-2-carboxylic acid (heparin) (5 nmol/mouse), L-type Ca2+ channel blocker 3-O-(2-methoxyethyl) 5-O-propan-2-yl 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate (nimodipine) (4 mg/kg), mitogen extracellular regulating kinase 1/2 (MEK1/2) inhibitor (Z)-3-amino-3-(4-aminophenyl)sulfanyl-2-[2-(trifluoromethyl)phenyl]prop-2-enenitrile (SL327) (30 mg/kg), and Gαs protein selective antagonist 4,4',4″,4‴-(Carbonylbis-(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakisbenzene-1,3-disulfonic acid (NF449) (10 nmol/mouse) reduced DOM-induced HTR in C57BL/6J mice. SIGNIFICANCE: The Gßγ subunits potentially mediate the HTR after 5-HT2A receptor activation via the PLCß/IP3/Ca2+/ERK1/2 and cAMP signaling pathways. Inhibitors targeting the Gßγ subunits potentially inhibit the hallucinogenic effects of 5-HT2A receptor agonists.

Escin avoids hemorrhagic transformation in ischemic stroke by protecting BBB through the AMPK/Cav-1/MMP-9 pathway.

BACKGROUND: Hemorrhagic transformation (HT) seriously affects the clinical application of recombinant tissue plasminogen activator (rt-PA). The main strategy for combating HT is to keep the blood-brain barrier (BBB) stable. Escin is the active ingredient of Aesculus hippocastanum and a natural mixture of triterpene saponins, and may play a part in mitigation of HT. PURPOSE: This study sought to investigate the effect of Escin in improving rt-PA-induced HT, explore possible mechanisms, and provide new ideas for the treatment of clinical HT. STUDY DESIGN AND METHODS: In in vivo experiments, transient middle cerebral artery occlusion (tMCAO) was undertaken in 6-week-old and 12-month-old mice, and rt-PA was administered to induce HT injury. The inhibitory effect of Escin on HT and its protective effect on neurobehavior, the BBB, and cerebrovascular endothelial cells was determined. In in vitro experiments, bEnd.3 cells were injured by oxygen-glucose deprivation/reperfusion (OGD/R) and rt-PA. The protective effect of Escin was measured by the CCK8 assay, release of lactate dehydrogenase (LDH), and expression of tight junction (TJ) proteins. In mechanistic studies, the effect of Escin on the adenosine monophosphate-activated kinase / caveolin-1 / matrix metalloprotease-9 (AMPK/Cav-1/MMP-9) pathway was investigated by employing AMPK inhibitor and Cav-1 siRNA. RESULTS: In mice suffering from ischemia, rt-PA caused HT as well as damage to the BBB and cerebrovascular endothelial cells. Escin reduced the infarct volume, cerebral hemorrhage, improved neurobehavioral deficits, and maintained BBB integrity in rt-PA-treated tMCAO mice while attenuating bEnd.3 cells damage caused by rt-PA and OGD/R injury. Under physiological and pathological conditions, Escin increased the expression of p-AMPK and Cav-1, leading to decreased expression of MMP-9, which further attenuated damage to cerebrovascular endothelial cells, and these effects were verified with AMPK inhibitor and Cav-1 siRNA. CONCLUSION: We revealed important details of how Escin protects cerebrovascular endothelial cells from HT, these effects were associated with the AMPK/Cav-1/MMP-9 pathway. This study provides experimental foundation for the development of new drugs to mitigate rt-PA-induced HT and the discovery of new clinical application for Escin.

Identification of a novel heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) ligand that disrupts HnRNPA2B1/nucleic acid interactions to inhibit the MDMX-p53 axis in gastric cancer.

Gastric carcinoma is a highly malignant tumor that still lacks effective molecular targets. Heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) is an essential oncogenic driver overexpressed in various cancers. The potential role of hnRNPA2B1 in oncotherapy has not been revealed because of the absence of active chemical molecules. In this study, we identified the pseudourea derivative XI-011 as a novel hnRNPA2B1 ligand using chemical proteomics. An interaction study indicated that XI-011 could bind the nucleotide-binding domain to disrupt the recruitment of hnRNPA2B1 to the promoter and untranslated region of the murine double minute X (MDMX) gene, thereby inhibiting its transcription. In addition, chemical targeting of hnRNPA2B1 recovered inactivated p53 and enhanced the therapeutic efficacy of apatinib in vivo. This work presented a novel strategy to restore p53 activity for the treatment of gastric cancers via chemically targeting hnRNPA2B1.

Integrated systematic pharmacology analysis and experimental validation to reveal the mechanism of action of Semen aesculi on inflammatory bowel diseases.

BACKGROUND AND ETHNOPHARMACOLOGICAL RELEVANCE: Semen aesculi (SA), a traditional Chinese herb, has been used in the treatment of gastrointestinal disease for thousands of years. The escin was the main components of SA. A growing number of research showed that escin has a wide range of pharmacological activities in intestinal barrier dysfunction. AIM OF THE STUDY: Inflammatory bowel diseases (IBD) are an idiopathic disease of the intestinal tract with the hallmark features of mucosal inflammation and loss of barrier function. The theory of traditional Chinese medicine (TCM) suggests that SA plays a potential role in protecting the gastrointestinal diseases. The present study aimed to explore the effects of SA on the intestinal barrier under existing inflammatory conditions and elucidate underlying mechanisms. MATERIALS AND METHODS: The bioactive components of SA and their predicted biological targets were combined to develop a compound target pathway network. It is used to predict the bioactive components, molecular targets, and molecular pathways of SA in improving IBD. The ingredients of SA were extracted by decoction either in water and ethanol and separated into four fractions (AE, EE, PEE and PCE). The effects of extractions were evaluated in the lipopolysaccharide (LPS)-induced RAW264.7 macrophages cell model, LPS-induced intestinal barrier injury model and imodium-induced constipation model. The high-performance liquid chromatography (HPLC) analysis was performed to identify the bioactive components. RESULTS: The compound-target pathway network was identified with 10 bioactive compounds, 166 IBD-related targets, and 52 IBD-related pathways. In LPS-induced RAW264.7 cells, PEE and PCE significantly decreased nitric oxide (NO) production and TNF-α level. In mice, PEE and PCE administration improved intestinal barrier damage, increased intestinal motility, reduced levels of TNF-α and diamine oxidase (DAO). Furthermore, PEE and PCE administration not only decreased expression of p-Akt, p-IκBα, nuclear p-p65, and TNF-α level, but also increased expression of the zonula occludin-1 (ZO-1) in LPS-induced intestinal barrier injury model. The escin content of AE, EE, PEE and PCE gradually increased with an increase of the bioactivity. CONCLUSIONS: Escin was the main bioactive components of SA. The effects of SA on IBD were mediated by repairing the intestinal barrier and promoting intestinal motility. The mechanism of action of SA is related to inhibiting the Akt/NF-κB signaling pathway in intestinal tissue, at least, in part. Our results provide a scientific basis for further exploring the mechanisms involved in the beneficial effects of SA in IBD.

Continuous Activation of Dopamine Receptors Alleviates LPS-Induced Liver Injury in Mice via ß-arrestin2 Dependent Akt/NF-κB Pathway.

Many studies showed that dopamine receptors (DRs) agonists have anti-inflammatory effects. Rotigotine, a non-ergot dopamine receptor agonist, mainly actives DRD2/DRD3/DRD1. Rotigotine extended-release microspheres (RoMS) are a sustained-release formulation that can release sustainably rotigotine for more than 7 days after a single dose of RoMS. This study aimed to investigate whether RoMS can attenuate the lipopolysaccharide (LPS)-induced liver injury of mice. The liver injury was evaluated by assaying serum transaminase and observing histopathological changes. The levels of pro-inflammatory cytokines in serum were also detected. Western blot was employed to assay the expression of proteins in the Akt/NF-κB pathway. The results showed that pre-administration with a single dose of RoMS could inhibit the increase of serum transaminase induced by LPS, alleviate the pathological damage of liver tissue, and decrease the levels of tumor necrosis factor-α and interleukin-6. In addition, RoMS decreased Toll-like receptor 4 protein expression in liver tissue. RoMS mitigated liver injury by activating DRs and negatively regulating the ß-arrestin2-dependent Akt/NF-κB signaling pathway. The effects of RoMS could be weakened or abolished by the specific DRD2 antagonist, R121. In conclusion, activation of DRs inhibited the releases of pro-inflammatory cytokines and alleviated the immune-mediated liver injury induced by LPS in mice. The anti-inflammatory mechanism of RoMS may be related to the regulation of the ß-arrestin2-dependent Akt/NF-κB signaling pathway.

A small-molecule inhibitor of MDMX suppresses cervical cancer cells via the inhibition of E6-E6AP-p53 axis.

Dysfunction of p53 is observed in many malignant tumors, which is related to cancer susceptibility. In cervical cancer, p53 is primarily degradated through the complex of high-risk human papillomaviruses (HPV) oncoprotein E6 and E6-associated protein (E6AP) ubiquitin ligase. What is less clear is the mechanism and role of murine double minute X (MDMX) in cervical carcinogenesis due to the inactive status of murine double minute 2 (MDM2). In the current study, XI-011 (NSC146109), a small-molecule inhibitor of MDMX, showed robust anti-proliferation activity against several cervical cancer cell lines. XI-011 promoted apoptosis of cervical cancer cells via stabilizing p53 and activating its transcription activity. Moreover, XI-011 inhibited the growth of xenograft tumor in HeLa tumor-bearing mice, as well as enhanced the cytotoxic activity of cisplatin both in vitro and in vivo. Interestingly, MDMX co-localized with E6AP and seems to be a novel binding partner of E6AP to promote p53 ubiquitination. In conclusion, this work revealed a novel mechanism of ubiquitin-dependent p53 degredation via MDMX-E6AP axis in cervical carcinogenesis, and offered the first evidence that MDMX could be a viable drug target for the treatment of cervical cancer.

Preparation of Long-Acting Somatostatin and GnRH Analogues and Their Applications in Tumor Therapy.

Hormonal drugs are essential treatment options for some hormone-dependent or hormone- sensitive tumors. The common dosage forms of hormonal drugs have a short half-life. Hence, frequent administration is needed, which results in poor patient compliance. Nevertheless, using drug delivery technology, somatostatin analogues (SSAs) and gonadotropin-releasing hormone (GnRH) analogues are prepared into long-acting formulations that can significantly prolong the action time of these drugs, reducing medication frequency and increasing patient compliance. Such drugs are advantageous when treating acromegaly, gastroenteropancreatic neuroendocrine tumors (GEP-NETs), breast cancer, prostate cancer, and other diseases having a relatively long course. SSAs and GnRH analogues are two typical hormonal drugs, the long-acting formulations of which are essential in clinical practice. This review summarized the preparation methods and clinical application of long-acting formulations in cancer. Further, the action mechanism and new research of SSAs and GnRH analogues were discussed, and suggestions related to the development of long-acting SSAs and GnRH analogues were provided.

VE-822, a novel DNA Holliday junction stabilizer, inhibits homologous recombination repair and triggers DNA damage response in osteogenic sarcomas.

Homologous recombination repair (HRR) is crucial for genomic stability of cancer cells and is an attractive target in cancer therapy. Holliday junction (HJ) is a four-way DNA intermediate that performs an essential role in homology-directed repair. However, few studies about regulatory mechanisms of HJs have been reported. In this study, to better understand the biological effects of HJs, VE-822 was identified as an effective DNA HJ stabilizer to promote the assembly of HJs both in vitro and in cells. This compound could inhibit the HRR level, activate DNA-PKCS to trigger DNA damage response (DDR) and induce telomeric DNA damage via stabilizing DNA HJs. Furthermore, VE-822 was demonstrated to sensitize the osteosarcoma cells to doxorubicin (Dox) by enhancing DNA damage and cellular apoptosis. This work thus reports one novel HJ stabilizer, and provide a potential anticancer strategy through the modulation of DNA HJs.

Lipopolysaccharide/D-galactosamine-induced acute liver injury could be attenuated by dopamine receptor agonist rotigotine via regulating NF-κB signaling pathway.

The pathological of lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury is similar to what is seen clinically, and be mediated by the release of pro-inflammatory mediators. A growing body of studies have shown that dopamine (DA) and DA receptor agonist are associated with inflammation and immune response. Rotigotine, a non-ergoline dopamine receptor agonist, is a drug for the treatment of Parkinson's disease. Rotigotine-loaded microspheres (RoMS) is an intramuscular extended-release agent, which can steadily release rotigotine for more than 7 days after a single administration. The present study aimed to investigate the effects of rotigotine and RoMS on inflammation and acute liver injury induced by LPS/D-Gal in mice. The LPS/D-Gal-induced liver injury was evidenced by increases of serum aminotransferases activities and liver histological lesions. Pretreatment with rotigotine or RoMS not only ameliorated the liver histologic lesions, but also reduced the activities of serum aminotransferases and the production of TNF-α. It also showed that rotigotine and RoMS increased DA receptor 2 (DRD2) expression in LPS/D-Gal-exposed mice. Rotigotine and RoMS activated ß-arrestin 2, inhibited the phosphorylation of Akt, IκB and the transposition of NF-κB. In line with the above findings, the protective effects of rotigotine and RoMS were abrogated by haloperidol, a DA receptor antagonist. In conclusion, dopamine receptor agonist can regulate NF-κB inflammatory signaling pathway and exert protective effects in LPS/D-Gal-induced liver injury.

Allisartan isoproxil reduces mortality of stroke-prone rats and protects against cerebrovascular, cardiac, and aortic damage.

Stroke is a common cause of death and disability. Allisartan isoproxil (ALL) is a new angiotensin II receptor blocker and a new antihypertensive drug discovered and developed in China. In the present study we investigated the therapeutic effects of ALL in stroke-prone renovascular hypertensive rats (RHR-SP) and the underlying mechanisms. The model rats were generated via two-kidney two-clip (2K2C) surgery, which led to 100% of hypertension, 100% of cerebrovascular damage as well as 100% of mortality 1 year after the surgery. Administration of ALL (30 mg · kg-1 · d-1 in diet, for 55 weeks) significantly decreased stroke-related death and prolonged lifespan in RHR-SP, but the survival ALL-treated RHR-SP remained of hypertension and cardiovascular hypertrophy compared with sham-operated normal controls. In addition to cardiac, and aortic protection, ALL treatment for 10 or 12 weeks significantly reduced cerebrovascular damage incidence and scoring, along with a steady reduction of blood pressure (BP) in RHR-SP. Meanwhile, it significantly decreased serum aldosterone and malondialdehyde levels and cerebral NAD(P)H oxidase expressions in RHR-SP. We conducted 24 h continuous BP recording in conscious freely moving RHR-SP, and found that a single intragastric administration of ALL produced a long hypotensive effect lasting for at least 12 h on systolic BP. Taken together, our results in RHR-SP demonstrate that ALL can be used for stroke prevention via BP reduction and organ protection, with the molecular mechanisms related to inhibition of angiotensin-aldosterone system and oxidative stress. This study also provides a valuable scoring for evaluation of cerebrovascular damage and drug efficacy.

Nanocarrier-based Drug Delivery System for Cancer Therapeutics: A Review of the Last Decade.

In recent years, due to the shortcomings of conventional chemotherapy, such as poor bioavailability, low treatment index, and unclear side effects, the focus of cancer research has shifted to new nanocarriers of chemotherapeutic drugs. By using biodegradable materials, nanocarriers generally have the advantages of good biocompatibility, low side effects, targeting, controlled release profile, and improved efficacy. More to the point, nanocarrier based anti-cancer drug delivery systems clearly show the potential to overcome the problems associated with conventional chemotherapy. In order to promote the in-depth research and development in this field, we herein summarized and analyzed various nanocarrier based drug delivery systems for cancer therapy, including the concepts, types, characteristics, and preparation methods. The active and passive targeting mechanisms of cancer therapy were also included, along with a brief introduction of the research progress of nanocarriers used for anti-cancer drug delivery in the past decade.

Anti-Rheumatic Properties of Gentiopicroside Are Associated With Suppression of ROS-NF-κB-NLRP3 Axis in Fibroblast-Like Synoviocytes and NF-κB Pathway in Adjuvant-Induced Arthritis.

Rheumatoid arthritis (RA) is among the most prevalent forms of autoimmunity. Gentiopicroside (Gent) is an iridoid glucoside derived from the Gentiana Macrophylla Pall which is used in traditional Chinese medicine to treat RA. The present study was designed to explore the ability of Gent to combat RA and to explore the molecular basis for such anti-RA activity both in vitro using tumor necrosis factor alpha (TNF-α)-stimulated human RA fibroblast-like synoviocytes (RA-FLS) and in vivo using a rat adjuvant-induced arthritis (AIA) model. We found that Gent was able to significantly reduce the swelling of joints and arthritic index scores, with corresponding reductions in synovial inflammatory cell infiltration, synovial hyperplasia, and bone erosion in treated AIA rats. Importantly, Gent 200 mg/kg reduced thymus index in AIA rats, but had no effect on spleen index and body weight, it revealed that Gent was relatively safe at the dose we chose. We further found that Gent was able to suppress the TNF-α-induced proliferation and migration of RA-FLS cells. This suppression was attributed to the ability of Gent to block NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), and caspase-1, thereby disrupting the activation of the NLRP3 inflammasome. Consistent with such suppression, Gent led to a significant decrease in IL-1ß secretion by treated cells. Furthermore, this reduction in NLRP3 inflammasome activation was also associated with decreases in the activation of nuclear factor (NF-κB), the production of reactive oxygen species (ROS), and the expression of inflammatory IL-6. Together these findings indicate that Gent can suppress the ROS-NF-κB-NLRP3 axis to alleviate RA symptoms. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Gentiopicroside (PubChem CID: 88708).

Hsp90ß positively regulates µ-opioid receptor function.

AIMS: Many µ-opioid receptor (MOR)-associated proteins can regulate the MOR signaling pathway. Using a bacterial two-hybrid screen, we found that the C-terminal of the MOR associated with heat shock protein 90 isoform ß (Hsp90ß). Here, we explored the effect of Hsp90ß on MOR signaling transduction and function. MAIN METHODS: The interaction of Hsp90ß with MOR was detected by co-immunoprecipitation and immunofluorescence. The effects of Hsp90ß on MOR signaling induced by opioids were studied in vitro and in vivo. The effects of the Hsp90ß inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) on morphine tolerance and dependence were studied via a hot plate test and CPP test. KEY FINDINGS: Hsp90ß, instead of Hsp90α, interacted with the MOR in HEK293 cells and SH-SY5Y cells, and the interaction was augmented after morphine pretreatment. The interaction of Hsp90ß and MOR increased the inhibition of cAMP and decreased PKA activity under opioid treatment. The functional Hsp90ß-MOR complex also promoted the phosphorylation and internalization of the MOR induced by DAMGO in MOR-CHO cells. 17-AAG blocked Hsp90ß-MOR interactions and decreased the effect of Hsp90ß on the MOR signal transduction. In C57BL/6 mice, 17-AAG decreased morphine-induced acute anti-nociception in the hot plate test, with an increase in phosphorylated PKA and phosphorylated JNK and a decrease in phosphorylated CREB and phosphorylated ERK in murine brains. Chronic morphine treatment induced tolerance, and dependence was inhibited by 17-AAG co-administration. SIGNIFICANCE: Hsp90ß is a positive co-regulator of the MOR via the activation of a G-protein-dependent and ß-arrestin-dependent pathway. Hsp90ß has the potential to improve the pharmacologic profile of existing opiates. It is conceivable that in future clinical treatments, the Hsp90ß inhibitor, 17-AAG, could decrease the tolerance and dependence in cancer patients induced by opioids.

Neuroprotective effects of Danshensu on rotenone-induced Parkinson's disease models in vitro and in vivo.

BACKGROUND: Danshensu is an active constituent in the extracts of Danshen which is a traditional Chinese medical herb. Rotenone inhibits complex I of the mitochondrial electron transport chain in dopaminergic neurons leading to glutathione (GSH) level reduction and oxidative stress. The aim of this study is to investigate neuroprotective effects of Danshensu on rotenone-induced Parkinson's disease (PD) in vitro and in vivo. METHODS: In vitro, SH-SY5Y human neuroblastoma cell line was pretreated with Danshensu and challenged with rotenone. Then the reactive oxygen species (ROS) production was assayed. In vivo, male C57BL/6 mice were intragastrically administered with Danshensu (15, 30, or 60 mg/kg), followed by oral administration with rotenone at a dose of 30 mg/kg. Pole and rotarod tests were carried out at 28 d to observe the effects of Danshensu on PD. RESULTS: Danshensu repressed ROS generation and therefore attenuated the rotenone-induced injury in SH-SY5Y cells. Danshensu improved motor dysfunction induced by rotenone, accompanied with reducing MDA content and increasing GSH level in striatum. Danshensu increased the number of TH positive neurons, the expression of TH and the dopamine contents. The expressions of p-PI3K, p-AKT, Nrf2, hemeoxygenase (HO-1), glutathione cysteine ligase regulatory subunit (GCLC), glutathione cysteine ligase modulatory subunit (GCLM) were significantly increased and the expression of Keap1 was decreased in Danshensu groups. CONCLUSIONS: The neuroprotective effects of Danshensu on rotenone-induced PD are attributed to the anti-oxidative properties by activating PI3K/AKT/Nrf2 pathway and increasing Nrf2-induced expression of HO-1, GCLC, and GCLM, at least in part.

Multivesicular liposomes for sustained release of bevacizumab in treating laser-induced choroidal neovascularization.

Bevacizumab is an anti-vascular endothelial growth factor drug that can be used to treat choroidal neovascularization (CNV). Bevacizumab-loaded multivesicular liposomes (Bev-MVLs) have been designed and developed to increase the intravitreal retention time of bevacizumab and reduce the number of injection times. In this study, Bev-MVLs with high encapsulation efficiency were prepared by double emulsification technique, and antibody activity was determined. The results revealed that 10% of human serum albumin (HSA) could preserve the activity of bevacizumab. In vitro release of Bev-MVLs appeared to be in a more sustained manner, the underlying mechanisms of Bev-MVLs indicated that bevacizumab was released from MVLs through diffusion and erosion. Results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that bevacizumab could retain its structural integrity after being released from MVLs in vitro. In vivo imaging was used to evaluate the retention time of antibody in rat eyes, while pharmacokinetic analysis was performed on rabbit eyes. These results indicated that Bev-MVLs exhibited sustained release effects as compared to bevacizumab solution (Bev-S). Bev-MVLs could effectively inhibit the thickness of CNV lesion as compared to Bev-S at 28 days after treatment. Furthermore, these data suggest that Bev-MVLs are biologically feasible to increase the retention time of bevacizumab in vitreous humor. This novel Bev-MVLs may therefore serve as a promising sustained release drug delivery system for the treatment of CNV.

H6, a novel hederagenin derivative, reverses multidrug resistance in vitro and in vivo.

Multidrug resistance (MDR) is a serious obstacle encountered in cancer treatment, in which the overexpression of P-glycoprotein (P-gp) plays an important role. Here, a novel α-hederagenin derivative, designated H6, was designed, synthesized and evaluated for its ability to reverse MDR. Our results showed that H6 could sensitize KBV and MCF7/T cells to paclitaxel and vincristine. Meanwhile, H6 could increase both rhodamine 123 and paclitaxel accumulation in MDR cells without affecting the expression of P-gp. Interestingly, siRNA knockdown of MDR1 further sensitized the cytotoxic activity of paclitaxel when co-administrated with H6. In addition, H6 could directly stimulate P-gp ATPase activity in vitro. Importantly, H6 enhanced the efficacy of paclitaxel against KBV cancer cell-derived xenograft tumors in nude mice. Finally, H6 showed high binding affinity with P-gp with a high docking score. Overall, we show H6 is a novel and potent MDR reversal agent, which has the potential to be administered in combination with conventional anticancer drugs.

Dysifragilone A inhibits LPS­induced RAW264.7 macrophage activation by blocking the p38 MAPK signaling pathway.

Dysifragilone A, a sesquiterpene aminoquinone based on a rearranged avarone skeleton, has been previously isolated and identified from the South China Sea sponge Dysidea fragilis. In the present study, anti­inflammatory activity and the underlying molecular mechanism of dysifragilone A were studied using the classical inflammation model of lipopolysaccharide (LPS)­activated RAW264.7 macrophage cells and an MTT assay, Griess method, ELISA and western blotting were used. The results revealed that dysifragilone A significantly reduced the release of inflammatory mediators and inflammatory cytokines in activated RAW264.7 cells, including nitric oxide (NO), prostaglandin E2,(PGE2) and interleukin­6 (IL­6). The protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase­2 (COX­2), and the enzymatic activity of iNOS and COX­2 were also inhibited by dysifragilone A in a dose dependent manner. Further mechanistic investigations suggested that the anti­inflammatory activity of dysifragilone A results from the suppression of p38 mitogen­activated protein kinase (MAPK) activation in LPS­activated macrophages; however, this was not associated with inhibition of the extracellular signal­regulated kinase (ERK) or c­Jun N­terminal kinase (JNK) signaling pathways. Therefore, dysifragilone A and similar compounds may be anti­inflammatories that have potential to be used in the clinic.

Design, synthesis and biological evaluation of novel α-hederagenin derivatives with anticancer activity.

In an attempt to arrive at a more potent cytotoxic agent than the parent compound α-hederagenin (H), 24 α-hederagenin derivatives (5-8, 11-24, 27-28, 31-32, and 35-36) were synthesized in a concise and efficient strategy and screened for in vitro cytotoxicity against the human cancer cell lines MKN45 and KB. Among these compounds, the polyamine derivative 15 exhibited more potency than the parent compound with IC50 values in the range of 4.22 µM-8.05 µM. Compound 15 increased Bax/bcl-2 ratio that disrupted the mitochondrial potential and induced apoptosis. Therefore, the present studies highlight the importance of polyamine derivatives of α-hederagenin in the discovery and development of novel anticancer agents.

Cyclic hexapeptide-conjugated nanoparticles enhance curcumin delivery to glioma tumor cells and tissue.

Glioma has one of the highest mortality rates among primary brain tumors. The clinical treatment for glioma is very difficult due to its infiltration and specific growth locations. To achieve improved drug delivery to a brain tumor, we report the preparation and in vitro and in vivo evaluation of curcumin nanoparticles (Cur-NPs). The cyclic hexapeptide c(RGDf(N-me) VK)-C (cHP) has increased affinity for cells that overexpress integrins and was designed to target Cur-NPs to tumors. Functional polyethyleneglycol-modified poly(d,l-lactide-co-glycolide) (PEG-PLGA) conjugated to cHP was synthesized, and targeted Cur-NPs were prepared using a self-assembly nanoprecipitation process. The physicochemical properties and the in vitro cytotoxicity, accuracy, and penetration capabilities of Cur-NPs targeting cells with high levels of integrin expression were investigated. The in vivo targeting and penetration capabilities of the NPs were also evaluated against glioma in rats using in vivo imaging equipment. The results showed that the in vitro cytotoxicity of the targeted cHP-modified curcumin nanoparticles (cHP/Cur-NPs) was higher than that of either free curcumin or non-targeted Cur-NPs due to the superior ability of the cHP/Cur-NPs to target tumor cells. The targeted cHP/Cur-NPs, c(RGDf(N-me)VK)-C-modified Cur-NPs, exhibited improved binding, uptake, and penetration abilities than non-targeting NPs for glioma cells, cell spheres, and glioma tissue. In conclusion, c(RGDf(N-me)VK)-C can serve as an effective targeting ligand, and cHP/Cur-NPs can be exploited as a potential drug delivery system for targeting gliomas.

Involvement of galanin and galanin receptor 2 in nociceptive modulation in anterior cingulate cortex of normal rats and rats with mononeuropathy.

The present study was performed to explore the role of galanin and galanin receptor 2 in nociceptive modulation in anterior cingulate cortex (ACC) of normal rats and rats with mononeuropathy. Intra-ACC injection of galanin induced significant increases in hindpaw withdrawal latencies (HWLs) to thermal and mechanical stimulations in both normal rats and rats with mononeuropathy, the increased HWLs were attenuated significantly by intra-ACC injection of galanin receptor 2 antagonist M871, indicating an involvement of galanin receptor 2 in nociceptive modulation in ACC. Interestingly, the galanin-induced HWL was significant higher in rats with mononeuropathy than that in normal rats tested by Randall Selitto test. Furthermore, both the galanin mRNA expression and galanin content increased significantly in ACC in rats with mononeuropathy than that in normal rats. Moreover, both the mRNA levels of galanin receptor 2 and the content of galanin receptor 2 in ACC increased significantly in rats with mononeuropathy than that in normal rats. These results found that galanin induced antinociception in ACC in both normal rats and rats with mononeuropathy. And there may be plastic changes in the expression of galanin and galanin receptor 2 in rats with mononeuropathy, as well as in the galanin-induced antinociception.