Induction of Apoptosis and Modulation of Caspase Activity on MCF-7 Human Breast Cancer Cells by Bioactive Fractionated Cocoa Leaf Extract.

BACKGROUND: The objective of this study was to investigate the potential anti-proliferative activities of a methanolic extract of cocoa leaves (CL) obtained through sequential partition and fractionation against MCF-7 breast cancer cells.  Methods: The methanolic extract of CL was partitioned in three separated solvents (hexane, dichloromethane, and methanol). Hexane partition was the most potent against MCF-7 cells growth with the lowest IC50 value. Then, it was subjected to two fractionation procedures, resulting in the identification of the CL bioactive fraction (II-F7) with potent toxicity against MCF-7 cells. RESULTS: Further investigation into CL bioactive fraction (II-F7) revealed significant dose-dependent growth inhibitory effects on MCF-7 cells, which were attributed to the induction of apoptosis, as evidenced by the presence of apoptotic bodies, fragmented DNA, and disruption of mitochondrial membrane potential. Additionally, treatment with CL bioactive fraction (II-F7) upregulated the expression of pro-apoptotic genes (DDIT3, GADD45G and HRK) and significantly increased the activities of caspase-8 and caspase-9. CONCLUSION: Overall, this study suggests that bioactive fraction (II-F7) from CL extract has significant and selective cytotoxicity against MCF-7 cells through inducing apoptosis and has potential as a therapeutic agent for breast cancer treatment.

Permixon®, hexane-extracted Serenoa repens, inhibits human prostate and bladder smooth muscle contraction and exerts growth-related functions in human prostate stromal cells.

AIMS: Recently, the European Association of Urology recommended hexane-extracted fruit of Serenoa repens (HESr) in their guidelines on management of non-neurogenic male lower urinary tracts symptoms (LUTS). Despite previously lacking recommendations, Permixon® is the most investigated HESr in clinical trials, where it proved effective for male LUTS. In contrast, underlying mechanisms were rarely addressed and are only marginally understood. We therefore investigated effects of Permixon® on human prostate and detrusor smooth muscle contraction and on growth-related functions in prostate stromal cells. MAIN METHODS: Permixon® capsules were dissolved using n-hexane. Contractions of human prostate and detrusor tissues were induced in organ bath. Proliferation (EdU assay), growth (colony formation), apoptosis and cell death (flow cytometry), viability (CCK-8) and actin organization (phalloidin staining) were studied in cultured human prostate stromal cells (WPMY-1). KEY FINDINGS: Permixon® inhibited α1-adrenergic and thromboxane-induced contractions in prostate tissues, and methacholine-and thromboxane-induced contractions in detrusor tissues. Endothelin-1-induced contractions were not inhibited. Neurogenic contractions were inhibited in both tissues in a concentration-dependent manner. In WPMY-1 cells, Permixon® caused concentration-dependent breakdown of actin polymerization, inhibited colony formation, reduced cell viability, and proliferation, without showing cytotoxic or pro-apoptotic effects. SIGNIFICANCE: Our results provide a novel basis that allows, for the first time, to fully explain the ubiquitous beneficial effects of HESr in clinical trials. HESr may inhibit at least neurogenic, α1-adrenergic and thromboxane-induced smooth muscle contraction in the prostate and detrusor, and in parallel, prostate stromal cell growth. Together, this may explain symptom improvements by Permixon® in previous clinical trials.

[Our experience of using hexane extract of Serenoa Repens fruit (Permixone) in the treatment of LUTS in clinical practice].

Benign prostatic hyperplasia (BPH) and chronic prostatitis (CP) are among the most common causes of LUTS in men. LUTS occur on average in 62.5% of males, with irritative symptoms occurring in 51%, obstructive symptoms in 26%, and postmicturic symptoms in 17% of cases. According to the literature, moderate and severe LUTS were observed in 13% of men under the age of 50 and in 28% after 70 years. It should be noted that LUTS are not BPH-specific, since may be caused by prostate inflammation. According to publications, 57% of patients examined for CP have BPH, and 39% of patients with BPH have CP. The first line of drug therapy in patients with BPH is currently considered to be alpha-blockers and inhibitors of 5-a-reductase. In addition, it is possible to use herbal preparations made from fruits, roots, seeds, pollen and plant bark. Preparations based on Serenoa repens extract are among the most studied and are widely used both in our country and worldwide for the treatment of patients with BPH and LUTS. Only lipidosterol hexane extract of Serenoa repens is recognized as a drug, the use of which has a good evidence base. The clinical examples illustrating the pharmacological properties and results of the use of the preparation of lipidosterol hexane extract Serenoa repens are presented in the article. CONCLUSION: The presented clinical cases demonstrate the efficiency of the hexane extract of Serenoa repens fruit for the treatment of LUTS associated with BPH and CP. At the same time, the drug can be effectively used both as monotherapy and in combination with alphablockers. Therefore, it is reasonable to use the hexane extract of Serenoa repens fruit in clinical practice for the treatment of LUTS associated with BPH.

[Iscussion on the use of hexane extract of Serenoa repens for combination therapy in patients with LUTS/BPH].

Based on literature data, feasibility of combined therapy with Serenoa repens extracts (including Permixon) and 1-adrenoblocators in patients with LUTS/BPH based on the pathogenesis of these drugs and clinical results was analyzed. The composition and biological activity of various SRE is influenced by the extraction method, as well as the production technology used by the manufacturer, which can lead to different results of experimental and clinical studies. The mechanism of action of SRE, including hexane extract Permixon, is multicomponent, which combines an antiandrogenic effect, influence on neurogenic regulation of urinary tract function (-adrenoreceptors, M-holinoreceptors, vanilloid receptors), anti-inflammatory and anti-edematous actions. At the same time, the effect of these preparations is not limited to the influence on the prostate gland, but can directly affect the bladder, helping to reduce functional disorders. A wider range of mechanisms of action and a possible direct effect of SRE on the bladder provides the same clinical effect as other traditionally used drugs (-blockers, 5-reductase inhibitors) with a significantly lower frequency of side effects of therapy. A number of publications demonstrate the feasibility of combined therapy with 1-adrenoblockers and SRE in patients with LUTS/BPH, especially with a high degree of urination dysfunction. Futher investigations are needed. The role of Serenoa repens extracts in the combination therapy of LUTS/BPH is still under discussion. Serenoa repens extracts monotherapy demonstrates similar effectiveness in patients with LUTS as 1-adrenoblockers and 5-reductase inhibitors. Recent studies indicate the advantages of combining Serenoa repens extracts with 1-adrenoblockers, especially in patients with moderate or severe symptoms. These advantages are associated with the multicomponent action of Serenoa repens extracts, which complements the blockade of 1-adrenergic receptors with other mechanisms of action (in particular, anti-inflammatory). The combination of drugs with different mechanisms of action, in particular, Serenoa repens extracts (Permixon) and 1-adrenoblockers has certain pathophysiologically based advantages, which allows to increase the efficiency of therapy. In addition, combination therapy is not associated with an increased rate of side effects.

Ameliorative effects of Magnolia sieboldii buds hexane extract on experimental reflux esophagitis.

Gastroesophageal reflux disease (GERD) is a disease that stomach contents continually refluxing into esophagus causes symptoms and/or complications. The study was working to find natural plant extracts with good effects and small side effects to treat reflux esophagitis (RE). The anti-inflammatory effects of hexane extract of Magnolia sieboldii (MsHE) were conducted on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The ameliorative effects of MsHE on esophageal damage in rats induced by gastric acid reflux was explored in vivo. The results showed that MsHE decreased the production of nitric oxide (NO) and expression levels of iNOS, COX-2 and TNF-α on LPS-stimulated RAW 264.7 cells and MsHE treatment ameliorated the rats' esophageal tissue damage induced by gastric acid and inhibited the increase of inflammatory mediators and pro-inflammatory cytokines by regulating NF-κB signaling pathway. In addition, MsHE protected the function of barrier of epithelial cells against inflammatory conditions through increasing the expression of tight junctions. Furthermore, liquid chromatography-mass spectrometry analysis was used for determine the active ingredients contained in MsHE. The results show that MsHE can alleviate experimental rat RE by regulating NF-κB signaling pathway. In summary, MsHE may be used as a source material of drug candidate for the treatment of RE.

Rapid chemical clearing of white matter in the post-mortem human brain by 1,2-hexanediol delipidation.

Three-dimensional (3D) imaging based on chemical tissue clearing in the post-mortem human brain is a promising approach for stereoscopic understanding of central nervous system diseases. Especially, delipidation of lipid-rich white matter (WM) is a rate-determining step in human brain clearing by hydrophilic reagents. In this study, we described the rapid delipidation of WM by a 1,2-hexanediol (HxD)-based aqueous solution. HxD delipidation enabled rapid clearing of a formalin-fixed human brain specimen including the WM. Although harsh HxD delipidation was applied to the brain tissue, conventional pathological staining patterns and various types of antigenicity were sufficiently preserved. Furthermore, HxD delipidation was compatible with 3D imaging of fluorescently-labeled tissue samples. HxD delipidation could be useful in future 3D neuropathological diagnosis.

Hexane fraction of Annona muricata (Sour sop) seed ameliorates testosterone-induced benign prostatic hyperplasia in rats.

BACKGROUND: Annona muricata is used in traditional African medicine to manage urinary obstruction. In this study, we hypothesized that hexane fraction of Annona muricata (HFAM) seeds will ameliorate testosterone propionate (Tp)-induced benign prostatic hyperplasia (BPh). METHODS: Castrated rats were assigned into six groups: non-castrated control, castrated control, castrated rats that received Tp (BPh group), [BPh+HFAM], [BPh+HFAM + finasteride], [BPh + finasteride]. RESULTS: The BPh rats had 3.8 and 3.9 folds increases in prostatic and organo-somatic weight, while treatment with HFAM alone and [HFAM + finasteride] decreased prostatic weight by 22% and 34%, respectively. BPh increased the activities of serum and prostatic total acid phosphatase by 95% and 121%; and activities of serum and prostatic alkaline phosphatase by 54% and 281%, respectively. Serum and prostatic lipid peroxidation were increased by 44% and 82%, respectively, in BPh rats with a concomitant decrease in prostatic superoxide dismutase by 73%. In BPh rats, serum and prostatic myeloperoxidase increased by 4.0 and 2.0 folds, while serum nitric oxide increased by 2.4 folds, respectively. Strong expression of inducible nitric oxide synthase, Bcl2, beta-catenin, androgen and estrogen receptors were observed in BPh rats. Importantly, treatment with HFAM or finasteride (or combination) attenuated prostatic weight, inflammatory and antioxidant indices in BPh rats. CONCLUSION: HFAM may serve as novel therapeutic agent against BPh.

C-Reactive Protein Mediating Immunopathological Lesions: A Potential Treatment Option for Severe Influenza A Diseases.

Severe influenza diseases with high mortality have been frequently reported, especially in those patients infected with avian influenza A (H5N1, H7N9 or H10N8) or during a pandemic. Respiratory distress, which is attributed to alveolar damage associated with immunopathological lesions, is the most common cause of death. There is a wealth of information on pathogenesis or treatment options. In this study, we showed that high levels of C-reactive protein (CRP) were induced and correlated with complement activation in patients infected with severe influenza A (H5N1, H7N9 or H10N8), and higher levels were induced in fatal patients than in survivors. CRP treatment enhanced the phagocytosis of monocytes THP-1 to H5N1 virus as well as the expression of proinflammatory cytokines or apoptosis-associated genes in THP-1 cells or pneumocytes A-549 respectively. CRP may link to proinflammatory mediators contributing to activation of complement and boosting inflammatory response in severe influenza infections. Compound 1,6-bis(phosphocholine)-hexane improved the severity and mortality of mice infected with lethal influenza virus significantly. These observations showed that CRP is involved in deterioration of severe influenza diseases, and indicated a substantial candidate molecule for immunotherapy of severe influenza diseases.

Hematological and lipid profile evaluation of a hexane fraction of Costus afer leaves in arthritic rats.

CONTEXT: Costus afer Ker Gawl. (Costaceae) is an ethnomedical plant used as therapy against inflammatory disorders. OBJECTIVE: The objective of this study was to evaluate the hematological and lipid profile analysis of hexane fraction of C. afer leaves (CAHLF) in arthritic rats. MATERIALS AND METHODS: Male albino rats were randomly distributed into seven groups of six rats each. Rats were induced with arthritis using formaldehyde and Complete Freund's Adjuvant (CFA) for 7 and 21 d, respectively. The animals were administered orally with 50, 100, and 250 mg/kg CAHLF, 10 mg/kg diclofenac and prednisolone, 0.9% NaCl (control), and 0.9% NaCl (normal). At the end of treatment periods, blood samples were withdrawn and subjected to hematological and biochemical analysis using auto-analyzer and spectrophotometric methods. RESULTS: Hematological analysis revealed that in formaldehyde- and CFA-induced arthritic rat models, 250 mg/kg CAHLF-treated groups had significantly reduced (p < 0.05) hematocrit counts (HC) (30.98 ± 1.59% and 33.55 ± 1.10%), white blood cell counts (WBC) (5.50 ± 0.35 and 4.15 ± 0.82 × 10(9)/L), and platelet counts (PC) (401.50 ± 48.94 and 246.33 ± 5.54 × 10(9)/L) compared with control HC (46.90 ± 1.92 and 41.88 ± 2.19%), WBC (11.09 ± 0.26 and 7.37 ± 0.34 × 10(9)/L), and PC (783.67 ± 59.51 and 593.83 ± 36.3 × 10(9)/L). Furthermore, blood analysis showed that CAHLF-treated groups had reduced total cholesterol, low-density lipoprotein cholesterol, and triglycerides while they had an elevated high-density lipoprotein compared with the control group. DISCUSSION AND CONCLUSION: Findings from this study indicated that CAHLF could possess immunomodulatory and hypolipidemic properties in arthritic rats. CAHLF could be considered as a source of biopharmaceutical agents in anti-arthritis drug discovery process.

Dissociation of pentameric to monomeric C-reactive protein localizes and aggravates inflammation: in vivo proof of a powerful proinflammatory mechanism and a new anti-inflammatory strategy.

BACKGROUND: The relevance of the dissociation of circulating pentameric C-reactive protein (pCRP) to its monomeric subunits (mCRP) is poorly understood. We investigated the role of conformational C-reactive protein changes in vivo. METHODS AND RESULTS: We identified mCRP in inflamed human striated muscle, human atherosclerotic plaque, and infarcted myocardium (rat and human) and its colocalization with inflammatory cells, which suggests a general causal role of mCRP in inflammation. This was confirmed in rat intravital microscopy of lipopolysaccharide-induced cremasteric muscle inflammation. Intravenous pCRP administration significantly enhanced leukocyte rolling, adhesion, and transmigration via localized dissociation to mCRP in inflamed but not noninflamed cremaster muscle. This was confirmed in a rat model of myocardial infarction. Mechanistically, this process was dependent on exposure of lysophosphatidylcholine on activated cell membranes, which is generated after phospholipase A2 activation. These membrane changes could be visualized intravitally on endothelial cells, as could the colocalized mCRP generation. Blocking of phospholipase A2 abrogated C-reactive protein dissociation and thereby blunted the proinflammatory effects of C-reactive protein. Identifying the dissociation process as a therapeutic target, we stabilized pCRP using 1,6-bis(phosphocholine)-hexane, which prevented dissociation in vitro and in vivo and consequently inhibited the generation and proinflammatory activity of mCRP; notably, it also inhibited mCRP deposition and inflammation in rat myocardial infarction. CONCLUSIONS: These results provide in vivo evidence for a novel mechanism that localizes and aggravates inflammation via phospholipase A2-dependent dissociation of circulating pCRP to mCRP. mCRP is proposed as a pathogenic factor in atherosclerosis and myocardial infarction. Most importantly, the inhibition of pCRP dissociation represents a promising, novel anti-inflammatory therapeutic strategy.

Demodex folliculitis presenting as periocular vesiculopustular rash.

PURPOSE: To report an unusual case of Demodex folliculitis presenting as periocular vesiculopustular rash. DESIGN: Case report. RESULTS: A 68 year-old woman presented with a unilateral periocular rash that was initially treated by her primary ophthalmologist with topical steroids and antivirals. Slit-lamp examination revealed severe bilateral blepharitis, right greater than left, with waxy sleeves around the eyelashes. The diagnosis of Demodex infestation was considered. Treatment with daily lid scrub with polyhexamethylene biguanide (PHMB), 1,2-hexanediol and 1,2-octanediol (OCuSOFT PLUS) and erythromycin ointment twice a day resulted in complete resolution of the symptoms after 4 weeks. CONCLUSIONS: Ophthalmologists should be aware of Demodex and consider it in the differential diagnosis of periocular skin lesions.

Inhaled pan-selectin antagonist Bimosiamose attenuates airway inflammation in COPD.

Selectins, a family of cell adhesion molecules, are involved in leukocyte extravasation to sites of inflammation. We investigated the safety and efficacy of the inhaled pan-selectin antagonist Bimosiamose in patients with chronic obstructive pulmonary disease (COPD). 77 COPD patients (mean forced expiratory volume in 1 s, 57% pred.) were enrolled in a cross-over, double-blind, randomized, Placebo-controlled, multi-center trial. Bimosiamose (10 mg) or Placebo was inhaled twice daily via the breath actuated nebulizer Akita2 Apixneb™ for 28 days on top of standard bronchodilator therapy. Efficacy was assessed by measurement of inflammatory parameters in induced sputum (differential cell count, interleukin-8, matrix-metalloproteinase-9, myeloperoxidase) and lung function at day 28 of both treatment periods. The total adverse event ratio of Bimosiamose compared to Placebo treatment was balanced. Compared to Placebo, treatment with Bimosiamose led to a decrease of the interleukin-8 concentration (-9.49 ng/mL, 95%CI -18.8 to -2.7 ng/mL, p = 0.008), for the neutrophil count a difference of -0.368 × 10(6) cells/mL (95%CI -1.256 to 0.407 × 10(6)/mL, p = 0.313) was found. The macrophage count decreased by -0.200 × 10(6) cells/mL (95%CI -0.365 to -0.044 × 10(6) cells/mL, p = 0.012). Most lung function parameters showed a small numeric increase. Inhalation of Bimosiamose for 28 days was safe and well tolerated in patients with COPD. It led to an attenuation of airway inflammation (EudraCT 2009-017257-35; NCT ID: NCT01108913).

Discovery and synthesis of a new class of opioid ligand having a 3-azabicyclo[3.1.0]hexane core. An example of a 'magic methyl' giving a 35-fold improvement in binding.

In looking for a novel achiral µ opioid receptor antagonist for the treatment of pruritus, we designed and synthesised azabicyclo[3.1.0]hexane compounds as a new class of opioid ligand. During optimisation, an addition of a single methyl resulted in a 35-fold improvement in binding. An early example from the series had excellent µ opioid receptor antagonist antagonist activity and was very effective in an in vivo pruritus study.

Targeting C-reactive protein for the treatment of cardiovascular disease.

Complement-mediated inflammation exacerbates the tissue injury of ischaemic necrosis in heart attacks and strokes, the most common causes of death in developed countries. Large infarct size increases immediate morbidity and mortality and, in survivors of the acute event, larger non-functional scars adversely affect long-term prognosis. There is thus an important unmet medical need for new cardioprotective and neuroprotective treatments. We have previously shown that human C-reactive protein (CRP), the classical acute-phase protein that binds to ligands exposed in damaged tissue and then activates complement, increases myocardial and cerebral infarct size in rats subjected to coronary or cerebral artery ligation, respectively. Rat CRP does not activate rat complement, whereas human CRP activates both rat and human complement. Administration of human CRP to rats is thus an excellent model for the actions of endogenous human CRP. Here we report the design, synthesis and efficacy of 1,6-bis(phosphocholine)-hexane as a specific small-molecule inhibitor of CRP. Five molecules of this palindromic compound are bound by two pentameric CRP molecules, crosslinking and occluding the ligand-binding B-face of CRP and blocking its functions. Administration of 1,6-bis(phosphocholine)-hexane to rats undergoing acute myocardial infarction abrogated the increase in infarct size and cardiac dysfunction produced by injection of human CRP. Therapeutic inhibition of CRP is thus a promising new approach to cardioprotection in acute myocardial infarction, and may also provide neuroprotection in stroke. Potential wider applications include other inflammatory, infective and tissue-damaging conditions characterized by increased CRP production, in which binding of CRP to exposed ligands in damaged cells may lead to complement-mediated exacerbation of tissue injury.

Bimosiamose, an inhaled small-molecule pan-selectin antagonist, attenuates late asthmatic reactions following allergen challenge in mild asthmatics: a randomized, double-blind, placebo-controlled clinical cross-over-trial.

BACKGROUND: Asthma is characterized by increased recruitment of inflammatory cells from the circulation into the airways. As selectins mediate tethering and rolling of leukocytes on the vascular endothelium, they constitute a promising target for the therapeutic modulation of inflammation. We evaluated the effect of inhaled bimosiamose (TBC1269), a synthetic pan-selectin antagonist, on allergen-induced late asthmatic reactions (LAR) in mild asthmatics. METHODS: Twelve male subjects with mild allergic asthma (only beta-agonists prn) with demonstrable LAR (fall of FEV1 3-8h after allergen inhalation >15% of baseline) at screening completed a randomized, double-blind, placebo-controlled clinical cross-over-trial. Subjects were treated with inhaled bimosiamose 70 mg bid or matching placebo on days 1-3 and 70 mg once on the morning of day 4. On day 4 following the last inhalation of study drug, an allergen challenge was performed. The primary endpoint was the maximum fall in FEV1 between 3 and 8h after allergen inhalation on active treatment vs. placebo. Secondary endpoints included early asthmatic response, exhaled nitric oxide, and airway hyperresponsiveness to methacholine 24h post allergen. RESULTS: Bimosiamose significantly attenuated the maximum LAR compared to placebo by 50.2% (placebo mean+/-SEM fall -13.10+/-2.30%, bimosiamose -6.52+/-3.86%, treatment effect p=0.045; linear mixed-effects model). There was no effect of active treatment on early asthmatic response, post allergen airway hyperresponsiveness or exhaled nitric oxide, and peripheral blood cells. CONCLUSIONS: Administration of the pan-selectin antagonist bimosiamose is effective in a human allergen challenge model of asthma. The result of this proof-of-concept exploratory trial is the first study that demonstrates clinical efficacy of selectin-antagonists as novel therapeutic strategy in asthma.

Pan-selectin antagonism improves psoriasis manifestation in mice and man.

The selectin family of vascular cell adhesion molecules is comprised of structurally related carbohydrate binding proteins, which mediate the initial rolling of leukocytes on the activated vascular endothelium. Because this process is one of the crucial events in initiating and maintaining inflammation, selectins are proposed to be an attractive target for the development of new antiinflammatory therapeutics. Here, we demonstrate that the synthetic pan-selectin antagonist bimosiamose is effective in pre-clinical models of psoriasis as well as in psoriatic patients. In vitro bimosiamose proved to be inhibitory to E- or P-selectin dependent lymphocyte adhesion under flow conditions. Using xenogeneic transplantation models, bimosiamose reduced disease severity as well as development of psoriatic plaques in symptomless psoriatic skin. The administration of bimosiamose in patients suffering from psoriasis resulted in a reduction of epidermal thickness and lymphocyte infiltration. The clinical improvement was statistically significant (P=0.02) as analyzed by comparison of psoriasis area and severity index before and after treatment. Assessment of safety parameters showed no abnormal findings. These data suggest that pan-selectin antagonism may be a promising strategy for the treatment of psoriasis and other inflammatory diseases.

Selectin antagonists : therapeutic potential in asthma and COPD.

Asthma and COPD are chronic inflammatory conditions that affect hundreds of millions of patients worldwide. New therapeutics are desperately needed, especially those that target the underlying causes and prevent disease progression. Although asthma and COPD have distinct etiologies, both are associated with reduced airflow caused by excess infiltration of inflammatory cells into healthy lung tissues. As selectin-mediated adhesion of leukocytes to the vascular endothelium is a key early event in the initiation of the inflammatory response, selectin inhibition is thought to be a good target for therapeutic intervention. Three known selectins are expressed in distinct subsets of cells: P-selectin is presented on the surface of activated platelets and endothelial cells, L-selectin is constitutively expressed on leukocytes, and E-selectin synthesis is upregulated in activated endothelial cells. They mediate cell-cell adhesion in the shear flow of the bloodstream via specialized interactions with clusters of oligosaccharides presented on cell surface glycopeptide ligands. The role of selectin-ligand interactions in the inflammatory response has been demonstrated in various animal models, prompting considerable attention from the pharmaceutical industry.Drug discovery efforts have yielded many different classes of selectin inhibitors, including soluble protein ligands, antibodies, oligosaccharides and small molecules. Although many selectin inhibitors have shown activity in preclinical models, clinical progress of selectin-directed therapies has been slow. Early approaches employed carbohydrate-based inhibitors to mimic the natural ligand sialyl Lewis X; however, these compounds proved challenging to develop. Cytel's CY 1503, a complex oligosaccharide, progressed to phase II/III trials for reperfusion injury, but further development was halted when it failed to demonstrate clinical efficacy. Two protein-based selectin inhibitors have reached phase II development. These included Wyeth's recombinant soluble P-selectin ligand, TSI (PSGL-1), which was discontinued after disappointing results in myocardial infarction trials and Protein Design Labs' humanized anti-L-selectin monoclonal antibody, which is currently in development for trauma. Bimosiamose, discovered by Encysive Pharmaceutical and presently being developed by Revotar Biopharmaceuticals, is an 863 g/mol molecular weight dimer with minimal carbohydrate content and is, to date, the leading selectin inhibitor in clinical development. This compound has shown promise in a phase IIa 'proof of concept' trial in patients with asthma, reducing airway recruitment of eosinophils after intravenous administration. Further clinical development of an inhaled formulation is underway. Despite a significant need for new therapeutics, selectin inhibitors have not yet been explored for the treatment of COPD. Bimosiamose represents an important proof of principle, and hopefully continued success will spark renewed interest in selectin-directed therapeutics for respiratory diseases.