Natural products are essential sources of antitumor drugs. One such molecule, β-elemene, is a potent antitumor compound extracted from Curcuma wenyujin. In the present investigation, a series of novel 13,14-disubstituted nitric oxide (NO)-donor β-elemene derivatives were designed, with β-elemene as the foundational compound, and subsequently synthesized to evaluate their therapeutic potential against leukemia. Notably, the derivative labeled as compound 13d demonstrated a potent anti-proliferative activity against the K562 cell line, with a high NO release. In vivo studies indicated that compound 13d could effectively inhibit tumor growth, exhibiting no discernible toxic manifestations. Specifically, a significant tumor growth inhibition rate of 62.9% was observed in the K562 xenograft tumor mouse model. The accumulated data propound the potential therapeutic application of compound 13d in the management of leukemia.
Humans ; Mice ; Animals ; Cell Line, Tumor ; Nitric Oxide Donors/pharmacology* ; Sesquiterpenes/pharmacology* ; Leukemia/drug therapy* ; Biological Assay ; Cell Proliferation

BACKGROUND: To determine whether nitric oxide (NO) could inhibit activation of platelets stored in a cold or frozen state, we measured platelet P-selectin expression and platelet-bound fibrinogen in platelet-rich plasma (PRP) with S-nitrosoglutathione (GSNO) (Sigma, USA) by flow cytometry. METHODS: PRP was prepared by centrifuging venous blood collected in a 3.2% sodium citrate tube from 10 healthy donors. It was aliquotted into 4 groups (no cryoprotectant, GSNO, GSNO/dimethyl sulfoxide [DMSO] [Sigma], and DMSO), and stored at room, cold and freezing temperatures for 24 hrs. We performed a flow cytometric analysis of all specimens stained with FITC-fibrinogen and PE-CD62P monoclonal antibodies (Becton Dickinson, USA). The results were compared according to the storage temperature and agonist among 4 groups. RESULTS: GSNO inhibited significantly the activation of frozen platelets, but not in the presence of DMSO. GSNO was also shown to preserve the aggregability of frozen platelets because in the presence of GSNO the delta percent change of P-selectin expression and fibrinogen binding of frozen platelets increased significantly irrelevant to DMSO. CONCLUSIONS: GSNO inhibited the activation of frozen platelets and preserved the platelet aggregability; therefore, it may be used as a protectant for platelet cryopreservation.
Adult ; Blood Platelets/*drug effects/metabolism ; Cryopreservation/*methods ; Female ; Fibrinogen/metabolism ; Flow Cytometry ; Free Radical Scavengers/pharmacology ; Humans ; Male ; Nitric Oxide/metabolism ; Nitric Oxide Donors/*pharmacology ; P-Selectin/metabolism ; Platelet Aggregation/drug effects ; Platelet Aggregation Inhibitors/pharmacology ; S-Nitrosoglutathione/*pharmacology

The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a doubleedged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration.
Animals ; Apoptosis/drug effects/physiology ; Aqueous Humor/metabolism ; Blood Proteins/pharmacology ; Cell Survival/drug effects/physiology ; Cells, Cultured ; Epithelium, Corneal/*cytology/*enzymology ; Fibroblasts/cytology/enzymology ; Humans ; Nitric Oxide/biosynthesis/*physiology ; Nitric Oxide Donors/pharmacology ; Nitric Oxide Synthase/metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Penicillamine/*analogs & derivatives/pharmacology ; Peroxynitrous Acid/biosynthesis ; Rabbits ; Tears/metabolism ; Uveitis/metabolism

To find novel antihepatitis drugs, a series of nitrate-oleanolic acid (OA) hybrids (10a, 10b, 11a-11e and 12a-12c) were designed and synthesized on the basis of previous studies using OA as lead compound, which is widely found in natural plants and liver-specific metabolism. In the present study, ten novel NO-releasing derivatives of OA were synthesized by connecting nitrate to the OA-3-OH through varying lengths of linkers containing antioxidants which were designed to increase the ability of these target compounds to scavenge free radicals. The structures of these objective compounds were determined by IR, MS, 1H NMR and elemental analysis. Their protective effects on anti-Fas mediated HepG2 cell apoptosis were in vitro evaluated by LDH assay. Compound 12a is the most potent inhibitor. Its effect on anti-Fas mediated HepG2 cell apoptosis and amount of NO-releasing in vitro are similar to those of positive control NCX-1000.
Antioxidants ; chemistry ; Apoptosis ; drug effects ; Hep G2 Cells ; Humans ; Nitrates ; chemical synthesis ; chemistry ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Donors ; chemistry ; Oleanolic Acid ; chemical synthesis ; chemistry ; pharmacology ; Structure-Activity Relationship ; Ursodeoxycholic Acid ; analogs & derivatives ; pharmacology

To investigate the effect of nitric oxide (NO) on the proliferation of trabecular meshwork (TM) cells, primarily cultured porcine TM cells were exposed to NO donor (SNAP, -nitroso-N-acetyl-D, L-penicillamine) with and without its inhibitor (L-NAME, N (w) -Nitro-L-arginine methyl ester). The proliferation of TM cells was quantified by a rapid colorimetric assay. Acridine orange/Hoechest 33342 staining and flow cytometry with annexin-PI were done. As a result, NO inhibited the proliferation of TM cells significantly in a dose-dependent manner and this inhibitory effect was abolished by L-NAME. Fluorescent microscopy and flow cytometric analysis revealed that NO induced apoptotic cell death. The current results suggest that NO inhibit the proliferation of TM cells and apoptosis may be involved in some degree.
Acridine Orange ; Animals ; Benzimidazoles ; Cell Division/drug effects ; Cell Survival/drug effects ; Cells, Cultured ; Flow Cytometry ; Fluorescent Dyes ; Nitric Oxide/*pharmacology ; Nitric Oxide Donors/pharmacology ; S-Nitroso-N-Acetylpenicillamine/pharmacology ; Swine ; Trabecular Meshwork/*cytology/physiology

The effect of nitric oxide donor sodium nitroprusside (SNP) on resting membrane potential (Em) and potassium currents of the bronchial smooth muscle cells from rats was investigated. All experiments were conducted in conventional whole-cell configuration. The changes of Em and potassium currents after addition of 0.1 mmol/L SNP were measured under the current-clamp mode and the voltage-clamp mode respectively. Results showed that (1) SNP could decrease the Em from -33.8 +/- 7.4 mV to -43.7 +/- 6.7 mV (n = 10, P < 0.01); (2) SNP could increase the Ca(2+)-activated K+ channel peak currents under ramp protocol from 466.9 +/- 180.1 pA to 597.7 +/- 237.6 pA (n = 7, P < 0.01), and the currents under pulse protocol at mV were increased from 544.2 +/- 145.4 pA to 678.1 +/- 206.2 pA (n = 6, P < 0.05); (3) SNP also could increase voltage-gated K+ channel peak currents under ramp protocol from 389.6 +/- 84.1 pA to 526.7 +/- 98.7 pA (n = 7, P < 0.01), the currents under pulse protocol at mV were increased from 275.7 +/- 85.2 pA to 444.3 +/- 128.5 pA (n = 6, P < 0.01). It was concluded that SNP increases the activities of Ca(2+)-activated K+ channels and voltage-gated K+ channels and leads to K+ efflux and hyperpolarization of the cell membrane, resulting in a decrease of the cell excitement.
Animals ; Bronchi ; cytology ; metabolism ; Male ; Membrane Potentials ; Myocytes, Smooth Muscle ; metabolism ; Nitric Oxide ; pharmacology ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Patch-Clamp Techniques ; Potassium Channels ; metabolism ; Potassium Channels, Calcium-Activated ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction

AIMTo search for potential anti-atherosclerosis drugs with vascular relaxation activity, a series of agonists of endothelial targets were designed and synthesized.

METHODSCoupling N-methyl-1,2, 3,6-tetrahydrapyridine ring system with 3,4-dibenzenesulfonyl-1,2,5-oxadiazole-2-oxide through esterification or amidation, a series of arecoline derivatives containing NO donors were designed and synthesised.

RESULTSA novel series of compounds structurally related to arecoline have been prepared, the proposed structures of eighteen new compounds were established by IR, 1H NMR, MS spectroscopy and elemental analysis. The effects of the target compounds on the vasodilation activity were tested in the isolated preparation of mice thoratic aorta.

CONCLUSIONThis preliminary pharmacological tests showed that the candidates have good vasodilation activities and were worthy to be intensively studied.

Animals ; Aorta, Thoracic ; drug effects ; Arecoline ; analogs & derivatives ; chemical synthesis ; pharmacology ; In Vitro Techniques ; Nitric Oxide Donors ; chemistry ; pharmacology ; Rats ; Vasodilation ; drug effects ; Vasodilator Agents ; chemical synthesis ; pharmacology

OBJECTIVETo explore the effect of nitric oxide (NO) on human sperm capacitation and acrosome reaction (AR).

METHODSDifferent concentrations of sodium nitroprusside (SNP) were added to the sperm suspension from 48 healthy fertile men, and the suspension was incubated in 1 x Earle at 37 degrees C for 1 hour. Progesterone was used to induce AR for 15, 30, 45 and 60 min, and then acid phosphatase (ACP) activity in the suspension before and after capacitation and at different time of AR was measured by p-nitrophenyl sodium phosphate assay. In the meantime, sperm motile parameters were assayed by CASA to observe sperm capacitation and AR.

RESULTSACP activity and sperm motile parameters increased in the 50 approximately 100 nmol/L NO concentration group, showed no significant variation in the 150 approximately 200 nmol/L group, and decreased in the 250 approximately 300 nmol/L group.

CONCLUSIONNO can facilitate sperm capacitation, AR and sperm motile parameters in low concentration and suppress them in high concentration. ACP activity assay of sperm is an objective and reliable method to evaluate sperm capacitation and AR in whole sperm population.

Acid Phosphatase ; metabolism ; Acrosome Reaction ; drug effects ; physiology ; Adult ; Dose-Response Relationship, Drug ; Humans ; Male ; Nitric Oxide ; physiology ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Sperm Capacitation ; drug effects ; physiology ; Sperm Motility ; drug effects ; physiology ; Spermatozoa ; enzymology

The preventive effects of nitroglycerine (NG) on glucocorticoid-induced osteoporosis in growing rats were studied. Three-month-old female Wistar rats were randomly divided into control group (CON), dexamethasone group (DXM), DXM plus a low dose NG group (NG-L), DXM plus a middle dose NG group (NG-M) and DXM plus a high dose NG group (NG-H), 8 rats in each group. The rat model of osteoporosis was developed by intramuscular injection of dexamethasone twice a week. NG 0.2, 0.4 and 1.0 mg/kg was administered by oral gavages to the treatment groups every day for 12 weeks. Rats in CON group and DXM group were treated with normal saline of the same amount. After the treatment, the bone mineral density (BMD) and bone metabolism-associated biochemical markers were determined. Compared with CON group, BMD of lumbar spine and femur in DXM group was decreased significantly (P<0.05 and P<0.01 respectively), blood BGP levels and NO levels reduced (both P<0.01), and TRAP level increased (P<0.05). As compared with DXM group, BMD, serum BGP and NO were increased, and TRAP decreased in NG-L group and NG-M group, but had no significant difference in comparison to CON group. All the markers other than serum NO and TRAP levels had no significant difference between NG-H group and DXM group. It was concluded that low or middle doses of NG could prevent glucocorticoid-induced bone loss in growing rats, but high dose of NG could not. Supplement with NO donor could be considered as a preventive treatment for glucocorticoid-induced osteoporosis in a developing skeleton.
Bone Density/*drug effects ; Dexamethasone ; Nitric Oxide Donors/*therapeutic use ; Nitroglycerin/pharmacology ; Nitroglycerin/*therapeutic use ; Osteoporosis/chemically induced ; Osteoporosis/*prevention & control ; Random Allocation ; Rats, Wistar

Curcumin, an active ingredient of dietary spice used in curry, has been shown to exhibit anti-oxidant, anti-inflammatory and anti-proliferative properties. Using EB directed differentiation protocol of H-9 human embryonic stem (ES) cells; we evaluated the effect of curcumin (0-20 μmol/L) in enhancing such differentiation. Our results using real time PCR, western blotting and immunostaining demonstrated that curcumin significantly increased the gene expression and protein levels of cardiac specific transcription factor NKx2.5, cardiac troponin I, myosin heavy chain, and endothelial nitric oxide synthase during ES cell differentiation. Furthermore, an NO donor enhanced the curcumin-mediated induction of NKx2.5 and other cardiac specific proteins. Incubation of cells with curcumin led to a dose dependent increase in intracellular nitrite to the same extent as giving an authentic NO donor. Functional assay for second messenger(s) cyclic AMP (cAMP) and cyclic GMP (cGMP) revealed that continuous presence of curcumin in differentiated cells induced a decrease in the baseline levels of cAMP but it significantly elevated baseline contents of cGMP. Curcumin addition to a cell free assay significantly suppressed cAMP and cGMP degradation in the extracts while long term treatment of intact cells with curcumin increased the rates of cAMP and cGMP degradation suggesting that this might be due to direct suppression of some cyclic nucleotide-degrading enzyme (phosphodiesterase) by curcumin. These studies demonstrate that polyphenol curcumin may be involved in differentiation of ES cells partly due to manipulation of nitric oxide signaling.
Animals ; Antioxidants ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Curcumin ; pharmacology ; Cyclic GMP ; metabolism ; Embryoid Bodies ; drug effects ; metabolism ; physiology ; Enzyme Activators ; pharmacology ; Gene Expression ; drug effects ; Guanylate Cyclase ; genetics ; metabolism ; Homeobox Protein Nkx-2.5 ; Homeodomain Proteins ; genetics ; metabolism ; Humans ; Mice ; Myosin Heavy Chains ; genetics ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Donors ; pharmacology ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Nitroso Compounds ; pharmacology ; Pyrazoles ; pharmacology ; Pyridines ; pharmacology ; Second Messenger Systems ; Transcription Factors ; genetics ; metabolism ; Troponin ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; metabolism