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The effect of nitric oxide on the production of cyclic AMP by a human osteoblast (HOS) cell line stimulated with hydroxyapatite

Sosroseno W, Sugiatno E, Samsudin AR, Ibrahim MF

Biomed Pharmacother, 2008 Jun;62(5):328-32.
PMID: 17988826

The aim of the present study was to determine the effect of nitric oxide (NO) on the production of cyclic AMP (cAMP) by a human osteoblast cell line (HOS cells) stimulated with hydroxyapatite. Cells were cultured on the HA surfaces with or without the presence of NO donors (SNAP and NAP) for 3 days. The effect of adenylyl cyclase inhibitor (SQ22536), NO scavenger (carboxy PTIO) or endothelial nitric oxide synthase (eNOS) inhibitor (L-NIO), was assessed by adding these to the cultures of HA-stimulated HOS cells with or without the presence of SNAP. Furthermore, HOS cells were pre-treated with anti-human integrin alphaV antibody prior to culturing on HA surfaces with or without the presence of SNAP. The levels of cAMP and cGMP were determined from the 3-day culture supernatants. The results showed that the production of cAMP but not cGMP by HA-stimulated HOS cells was augmented by SNAP. SQ22536 and carboxy PTIO suppressed but L-NIO only partially inhibited the production of cAMP by HA-stimulated HOS cells with or without the presence of exogenous NO. Pre-treatment of the cells with anti-human integrin alphaV antibody suppressed the production of cAMP by HA-stimulated HOS cells with or without the presence of NO. Therefore, the results of the present study suggest that NO may up-regulate the production of cAMP, perhaps, by augmenting adenylyl cyclase activity initiated by the binding between HOS cell-derived integrin alphaV and HA surface.

Matched MeSH terms: Nitric Oxide/metabolism*; Nitric Oxide Donors/pharmacology; Nitric Oxide Synthase Type III/antagonists & inhibitors
Nitric oxide production by murine spleen cells stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

Sosroseno W, Herminajeng E, Susilowati H, Budiarti S

Anaerobe, 2002 Dec;8(6):333-9.
PMID: 16887678

The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could induce murine spleen cells to produce nitric oxide (NO). Spleen cells derived from Balb/c mice were stimulated with LPS-A. actinomycetemcomitans or LPS from Escherichia coli for 4 days. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B, and cytokines (IFN-gamma and IL-4) on the production of NO were also assessed. The NO production from the carrageenan-treated spleen cells stimulated with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma was determined. The carrageenan-treated mice were transferred with splenic macrophages and the NO production was assessed from the spleen cells stimulated with LPS-A. actinomycetemcomitans or LPS-A. actinomycetemcomitans and IFN-gamma. The results showed that NO production was detectable in the cultures of spleen cells stimulated with LPS-A. actinomycetemcomitans in a dose-dependent fashion, but was lower than in the cells stimulated with LPS from E. coli. The NO production was blocked by NMMA and polymyxin B. IFN-gamma up-regulated but IL-4 suppressed the production of NO by the spleen cells stimulated with LPS-A. actinomycetemcomitans. The carrageenan-treated spleen cells failed to produce NO after stimulation with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma. Adoptive transfer of splenic macrophages to the carrageenan-treated mice could restore the ability of the spleen cells to produce NO. The results of the present study suggest that LPS-A. actinomycetemcomitans under the regulatory control of cytokines induces murine spleen cells to produce NO and that splenic macrophages are the cellular source of the NO production. Therefore, these results may support the view that NO production by LPS-A. actinomycetemcomitans-stimulated macrophages may play a role in the course of periodontal diseases.

Matched MeSH terms: Nitric Oxide
Nitric oxide production by a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

Sosroseno W, Barid I, Herminajeng E, Susilowati H

Oral Microbiol. Immunol., 2002 Apr;17(2):72-8.
PMID: 11929552

The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could stimulate a murine macrophage cell line (RAW264.7 cells) to produce nitric oxide (NO). The cells were treated with LPS-A. actinomycetemcomitans or Escherichia coli LPS (LPS-Ec) for 24 h. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B and cytokines (IFN-gamma, TNF-alpha, IL-4 and IL-12) on the production of NO were also determined. The role of protein tyrosine kinase, protein kinase C and microtubulin organization on NO production were assessed by incubating RAW264.7 cells with genistein, bisindolylmaleide and colchicine prior to LPS-A. actinomycetemcomitans stimulation, respectively. NO levels from the culture supernatants were determined by the Griess reaction. The results showed that LPS-A. actinomycetemcomitans stimulated NO production by RAW264.7 cells in a dose-dependent manner, but was slightly less potent than LPS-Ec. NMMA and polymyxin B blocked the production of NO. IFN-gamma and IL-12 potentiated but IL-4 depressed NO production by LPS-A. actinomycetemcomitans-stimulated RAW264.7 cells. TNF-alpha had no effects on NO production. Genistein and bisindolylmalemaide, but not colchicine, reduced the production of NO in a dose-dependent mechanism. The results of the present study suggest that A. actinomycetemcomitans LPS, via the activation of protein tyrosine kinase and protein kinase C and the regulatory control of cytokines, stimulates NO production by murine macrophages.

Matched MeSH terms: Nitric Oxide/antagonists & inhibitors; Nitric Oxide/biosynthesis*
Nitric oxide production by murine spleen cells stimulated with Porphyromonas gingivalis-derived lipopolysaccharide

Sosroseno W

Asian Pac J Allergy Immunol, 2000 Dec;18(4):209-14.
PMID: 11316041

The aim of the present study was to determine whether Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) may stimulate nitric oxide (NO) production by murine spleen cells. Spleen cells derived from Balb/c mice were cultured in the presence of Pg-LPS or LPS from Salmonella Typhosa. The cell were also cultured in the presence of Pg-LPS with or without L-arginine, L-arginine plus NG-monomethyl-L-arginine (NMMA), or IFN-gamma. Furthermore, the plastic non-adherent spleen cells were stimulated with Pg-LPS and L-arginine. The results showed that Pg-LPS failed to stimulate splenic NO production by themselves. Exogenous L-arginine or IFN-gamma up-regulated the NO production of Pg-LPS-stimulated spleen cells, but the stimulatory effects of L-arginine were completely blocked by NMMA. It was also demonstrated that in the presence of Pg-LPS and L-arginine, splenic macrophages were the cellular source of NO. These results suggest, therefore, that P. gingivalis-LPS may induce murine splenic macrophages to produce NO in a L-arginine and an IFN-gamma-dependent mechanism.

Matched MeSH terms: Nitric Oxide/biosynthesis*; Nitric Oxide/metabolism
L-arginine-dependent nitric oxide production of a murine macrophage-like RAW 264.7 cell line stimulated with Porphyromonas gingivalis lipopolysaccharide

Sosroseno W, Herminajeng E, Bird PS, Seymour GJ

Oral Microbiol. Immunol., 2004 Apr;19(2):65-70.
PMID: 14871343

The aim of this study was to determine nitric oxide (NO) production of a murine macrophage cell line (RAW 264.7 cells) when stimulated with Porphyromonas gingivalis lipopolysaccharides (Pg-LPS). RAW 264.7 cells were incubated with i) various concentrations of Pg-LPS or Salmonella typhosa LPS (St-LPS), ii) Pg-LPS with or without L-arginine and/or NG-monomethyl-L-arginine (NMMA), an arginine analog or iii) Pg-LPS and interferon-gamma (IFN-gamma) with or without anti-IFN-gamma antibodies or interleukin-10 (IL-10). Tissue culture supernatants were assayed for NO levels after 24 h in culture. NO was not observed in tissue culture supernatants of RAW 264.7 cells following stimulation with Pg-LPS, but was observed after stimulation with St-LPS. Exogenous L-arginine restored the ability of Pg-LPS to induce NO production; however, the increase in NO levels of cells stimulated with Pg-LPS with exogenous L-arginine was abolished by NMMA. IFN-gamma induced independent NO production by Pg-LPS-stimulated macrophages and this stimulatory effect of IFN-gamma could be completely suppressed by anti-IFN-gamma antibodies and IL-10. These results suggest that Pg-LPS is able to stimulate NO production in the RAW 264.7 macrophage cell model in an L-arginine-dependent mechanism which is itself independent of the action of IFN-gamma.

Matched MeSH terms: Nitric Oxide/biosynthesis*; Nitric Oxide Synthase/antagonists & inhibitors
Effect of inhibition of inducible nitric oxide synthase (iNOS) on the murine splenic immune response induced by Aggregatibacter (Actinobacillus) actinomycetemcomitans lipopolysaccharide

Sosroseno W, Musa M, Ravichandran M, Ibrahim MF, Bird PS, Seymour GJ

Eur J Oral Sci, 2008 Feb;116(1):31-6.
PMID: 18186729 DOI: 10.1111/j.1600-0722.2007.00501.x

Animal studies suggest that inducible nitric oxide synthase (iNOS) may be associated with destructive periodontal disease. l-N(6)-(1-Iminoethyl)-lysine (L-NIL) has been shown to inhibit iNOS in a selective manner, and hence the aim of the present study was to test the hypothesis that treatment with l-NIL may induce a T-cell helper 1 (Th1)-like immune response by Aggregatibacter (Actinobacillus) actinomycetemcomitans lipopolysaccharide (LPS)-stimulated murine spleen cells in vitro. BALB/c mice were either sham-immunized or immunized with A. actinomycetemcomitans LPS. Spleen cells were stimulated with A. actinomycetemcomitans LPS in the presence or absence of L-NIL. Nitric oxide (NO), iNOS activity, specific IgG subclass antibodies, interferon-gamma (IFN-gamma), and interleukin-4 (IL-4) levels and cell proliferation were determined. The results showed that treatment with L-NIL suppressed both NO production and iNOS activity but enhanced specific IgG2a, IFN-gamma levels, and increased cell proliferation following stimulation with A. actinomycetemcomitans LPS-stimulated cells. The results of the present study suggest that inhibition of iNOS activity by L-NIL may skew the A. actinomycetemcomitans LPS-stimulated murine splenic immune response towards the Th1-like immune profile in vitro.

Matched MeSH terms: Nitric Oxide Synthase Type II/analysis; Nitric Oxide Synthase Type II/antagonists & inhibitors*
Cyclic-AMP-dependent proliferation of a human osteoblast cell line (HOS cells) induced by hydroxyapatite: effect of exogenous nitric oxide

Sosroseno W, Sugiatno E

Acta Biomed, 2008 Aug;79(2):110-6.
PMID: 18788505

BACKGROUND AND AIMS OF THE WORK: Nitric oxide (NO) has been reported to enhance the production of cAMP by hydroxyapatite (HA)-induced a human osteoblast cell line (HOS cells). The aim of the present study was to test the hypothesis that exogenous NO may up-regulate the proliferation of hydroxyapatite (HA)-induced HOS cells via the cyclic-AMP-protein kinase A (PKA) pathway.

Matched MeSH terms: Nitric Oxide/administration & dosage; Nitric Oxide/pharmacology*; Nitric Oxide Donors/metabolism
Effect of exogenous nitric oxide on murine immune response induced by Aggregatibacter actinomycetemcomitans lipopolysaccharide

Sosroseno W, Bird PS, Seymour GJ

J Periodontal Res, 2009 Aug;44(4):529-36.
PMID: 18973550 DOI: 10.1111/j.1600-0765.2008.01157.x

Elevated nitric oxide (NO) has been associated with destructive periodontal disease. The aim of the present study was to test the hypothesis that exogenous NO may inhibit a protective immune response to Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) in a murine model.

Matched MeSH terms: Nitric Oxide/pharmacology*; Nitric Oxide Donors/pharmacology; Nitric Oxide Synthase Type II/analysis; Nitric Oxide Synthase Type II/antagonists & inhibitors
Effect of L-N6-(1-iminoethyl)-lysine, an inducible nitric oxide synthase inhibitor, on murine immune response induced by Actinobacillus actinomycetemcomitans lipopolysaccharide

Sosroseno W, Musa M, Ravichandran M, Fikri Ibrahim M, Bird PS, Seymour GJ

J Periodontal Res, 2007 Apr;42(2):124-30.
PMID: 17305870

Inducible nitric oxide synthase (iNOS) activity is known to regulate the immune response. The present study was carried out to determine the effect of L-N6-(1-iminoethyl)-lysine (L-NIL), an iNOS inhibitor, on the induction of immune response to Actinobacillus actinomycetemcomitans lipopolysaccharide in mice.

Matched MeSH terms: Nitric Oxide/blood; Nitric Oxide Synthase Type II/antagonists & inhibitors*; Nitric Oxide Synthase Type II/blood; Nitric Oxide Synthase Type II/metabolism
Fulltext Rutin Modulates MAPK Pathway Differently from Quercetin in Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy

Siti HN, Jalil J, Asmadi AY, Kamisah Y

Int J Mol Sci, 2021 May 11;22(10).
PMID: 34064664 DOI: 10.3390/ijms22105063

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.

Matched MeSH terms: Nitric Oxide/metabolism
Effects of citrus leaf extract on aortic vascular reactivity in hypertensive rats fed repeatedly heated vegetable oil

Siti HN, Kamisah Y, Mohamed S, Jaarin K

Appl Physiol Nutr Metab, 2019 04;44(4):373-380.
PMID: 30216735 DOI: 10.1139/apnm-2018-0175

The prolonged intake of diet containing repeatedly heated vegetable oil can cause hypertension in the long run.
In this study, the effects of citrus leaf extract (CLE) supplementation on vascular reactivity, plasma nitrite, and aortic structure in hypertensive rats were investigated by the consumption of repeatedly heated vegetable oil [corrected]. Male Sprague Dawley rats (n = 56) were divided into 7 groups corresponding to the respective diets. For 16 weeks, 1 group was given standard rat chow (control) while other groups were given diets containing 15% w/w of palm oil, fresh palm oil (FPO), palm oil heated 5 times (5HPO), and palm oil heated 10 times (10HPO), with or without the incorporation of 0.15% w/w CLE (FPO+CLE, 5HPO+CLE, or 10HPO+CLE). Plasma nitrite levels were measured before and at 16 weeks of treatment. After 16 weeks, the rats were sacrificed and aortae were harvested for measuring vascular reactivity and for microscopic study. CLE supplementation had significantly reduced the loss of plasma nitrite and attenuated the vasoconstriction response to phenylephrine in the 5HPO group but not in the 10HPO group. However, CLE had no significant effect on the vasorelaxation response to acetylcholine and sodium nitroprusside. The elastic lamellae of tunica media in 5HPO, 10HPO, and 10HPO+CLE groups appeared disorganised and disrupted. Obtained findings suggested that CLE was able to enhance nitric oxide bioavailability that might dampen the vasoconstriction effect of phenylephrine.

Matched MeSH terms: Nitric Oxide/metabolism
Fulltext Paclitaxel Inhibits Expression of Neuronal Nitric Oxide Synthase and Prevents Mitochondrial Dysfunction in Spinal Ventral Horn in Rats After C7 Spinal Root Avulsion

Sim SK, Tan YC, Tee JH, Yusoff AA, Abdullah JM

Turk Neurosurg, 2015;25(4):617-24.
PMID: 26242340 DOI: 10.5137/1019-5149.JTN.14035-15.1

This study evaluated the neuroprotective effect of intrathecally infused paclitaxel in the prevention of motoneuron death and mitochondrial dysfunction following brachial plexus avulsion injury.

Matched MeSH terms: Nitric Oxide Synthase Type I/antagonists & inhibitors*; Nitric Oxide Synthase Type I/biosynthesis*
Associations between Aging and Vitamin D Status with Whole-Body Nitric Oxide Production and Markers of Endothelial Function

Siervo M, Hussin AM, Calella P, Ashor A, Shannon OM, Mendes I, et al.

J Nutr, 2024 Feb;154(2):469-478.
PMID: 38048992 DOI: 10.1016/j.tjnut.2023.12.002

BACKGROUND: Aging and vitamin D deficiency have been associated with reduced nitric oxide (NO) synthesis and impaired endothelial function (EF) but the evidence in humans remains weak.
OBJECTIVES: Two independent cross-sectional studies were designed to evaluate the association between age, sex, and plasma vitamin D concentrations with physiological and biochemical biomarkers of NO synthesis and EF in young and older healthy participants (Study 1) and in overweight and obese postmenopausal females (Study 2).
METHODS: In Study 1, 40 young (20-49 y) and older (50-75 y) males and females (10 participants per age and sex group) were included. Resting blood pressure and ear-to-finger peripheral pulse wave velocity (PWV) were measured. A stable-isotopic method was used to determine whole-body NO production. Plasma 25-hydroxyvitamin D (25(OH)D), nitrate, nitrite, and asymmetric dimethylarginine (ADMA) concentrations were determined. In Study 2, 80 older overweight and obese females (age 61.2 ± 6.2 y, body mass index 29.5 ± 4.4 kg/m2) were recruited. Postocclusion reactive hyperemia (PORH) and peripheral PWV were measured. Plasma concentrations of 25(OH)D, nitrate, cyclic guanosine monophosphate, 3-nitrotyrosine (3-NT), endothelin-1, vascular endothelial growth factor, and ADMA were determined.
RESULTS: In Study 1, whole-body NO production was significantly greater in young compared with older participants (0.61 ± 0.30 μmol·h-1·kg-1 compared with 0.39 ± 0.10 μmol·h-1·kg-1, P = 0.01) but there was no evidence of a sex difference (P = 0.81). Plasma 25(OH)D concentration was not associated with PWV (r = 0.18, P = 0.28) or whole-body NO production (r = -0.20, P = 0.22). Plasma ADMA concentration was associated positively with age (r = 0.35, P = 0.03) and negatively with whole-body NO production (r = -0.33, P = 0.04). In Study 2, age was associated with lower PORH (r = -0.28, P = 0.02) and greater ADMA concentrations (r = 0.22, P = 0.04). Plasma 25(OH)D concentration was inversely associated with 3-NT concentrations (r = -0.31, P = 0.004).
CONCLUSIONS: Older age was associated with lower whole-body NO production. Plasma vitamin D concentrations were not associated with NO production or markers of EF but showed a weak, significant correlation with oxidative stress in postmenopausal overweight females.

Matched MeSH terms: Nitric Oxide*
Fulltext α -Mangostin from Cratoxylum arborescens (Vahl) Blume Demonstrates Anti-Ulcerogenic Property: A Mechanistic Study

Sidahmed HM, Abdelwahab SI, Mohan S, Abdulla MA, Mohamed Elhassan Taha M, Hashim NM, et al.

Evid Based Complement Alternat Med, 2013;2013:450840.
PMID: 23634169 DOI: 10.1155/2013/450840

Cratoxylum arborescens (Vahl) Blume is an Asian herbal medicine with versatile ethnobiological properties including treatment of gastric ulcer. This study evaluated the antiulcerogenic mechanism(s) of α -mangostin (AM) in a rat model of ulcer. AM is a prenylated xanthone derived through biologically guided fractionation of C. arborescens. Rats were orally pretreated with AM and subsequently exposed to acute gastric lesions induced by ethanol. Following treatment, ulcer index, gastric juice acidity, mucus content, histological and immunohistochemical analyses, glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), and nonprotein sulfhydryl groups (NP-SH) were evaluated. The anti-Helicobacter pylori, cyclooxygenase-2 (COX-2) inhibitory effect, and antioxidant activity of AM were also investigated in vitro. AM (10 and 30 mg/kg) inhibited significantly (P < 0.05) ethanol-induced gastric lesions by 66.04% and 74.39 %, respectively. The compound induces the expression of Hsp70, restores GSH levels, decreases lipid peroxidation, and inhibits COX-2 activity. The minimum inhibitory concentration (MIC) of AM showed an effective in vitro anti-H. pylori activity. The efficacy of the AM was accomplished safely without presenting any toxicological parameters. The results of the present study indicate that the antioxidant properties and the potent anti-H. pylori, in addition to activation of Hsp70 protein, may contribute to the gastroprotective activity of α -mangostin.

Matched MeSH terms: Nitric Oxide
Fulltext Current Concepts in the Biochemical Mechanisms of Glaucomatous Neurodegeneration

Shoeb Ahmad S, Abdul Ghani S, Hemalata Rajagopal T

J Curr Glaucoma Pract, 2013 May-Aug;7(2):49-53.
PMID: 26997782 DOI: 10.5005/jp-journals-10008-1137

Glaucoma is now regarded as a neurodegenerative disorder. A number of theories including the mechanical and vascular models have been used to explain the pathogenesis of glaucoma. However, there is now increasing evidence of biochemical molecules which may play a part in it's causation. These biochemical mechanisms include the role of excitatory aminoacids, caspases, protein kinases, oxygen free radicals, nitric oxide, TNF-alpha, neurotrophins and metalloproteins. This paper reviews these new developments which form the biochemical basis of glaucomatous neural degeneration. How to cite this article: Ahmad SS, Ghani SA, Rajagopal TH. Current Concepts in the Biochemical Mechanisms of Glaucomatous Neurodegeneration. J Current Glau Prac 2013;7(2):49-53.

Matched MeSH terms: Nitric Oxide
Tiger's Milk Medicinal Mushroom, Lignosus rhinocerotis (Agaricomycetes) Sclerotium Inhibits Nitric Oxide Production in LPS-Stimulated BV2 Microglia

Seow SL, Naidu M, Sabaratnam V, Vidyadaran S, Wong KH

Int J Med Mushrooms, 2017;19(5):405-418.
PMID: 28845770 DOI: 10.1615/IntJMedMushrooms.v19.i5.30

In Malaysia and China, the sclerotium of Lignosus rhinocerotis is used by local communities and traditional medicine practitioners as a general tonic and remedy to treat a variety of ailments, including inflammation-associated disorders. In this study, 10 samples from different preparations of L. rhinocerotis sclerotium, including a hot aqueous extract (HAE), an ethanol extract (EE), fractions from the HAE and EE, and crude polysaccharides, were tested for their in vitro cytotoxic and nitric oxide (NO) inhibitory activities in lipopolysaccharide (LPS)--stimulated BV2 microglia. Of the 10 samples tested, HAE was the least cytotoxic toward BV2 microglia, with a half-maximal inhibitory concentration of 176.23 ± 2.64 mg/mL at 24 hours of incubation and 20.01 ± 1.69 mg/ mL at 48 hours of incubation. The inhibition of NO production was explored by pretreatment of BV2 microglia with samples at 2 incubation time points (4 and 24 hours) before the stimulation by LPS for 24 hours. After 24 hours of pretreatment, 8 of the 10 samples inhibited NO production by 50% or more, and cytotoxic effects were not observed. Among the 8 active samples, 500 µg/mL of HAE, 250 µg/mL of an n-butanol fraction of the HAE, and 250 µg/mL of an ethyl acetate fraction of HAE showed maximum inhibition of NO production by 88.95%, 86.50%, and 85.93%, respectively. These results suggest that the L. rhinocerotis sclerotium may contain secondary metabolites that have the potential to inhibit NO production.

Matched MeSH terms: Nitric Oxide/metabolism*
Fulltext Antinociceptive Activity of Methanol Extract of Muntingia calabura Leaves and the Mechanisms of Action Involved

Sani MH, Zakaria ZA, Balan T, Teh LK, Salleh MZ

Evid Based Complement Alternat Med, 2012;2012:890361.
PMID: 22611437 DOI: 10.1155/2012/890361

Muntingia calabura L. (family Elaeocarpaceae) has been traditionally used to relieve various pain-related ailments. The present study aimed to determine the antinociceptive activity of methanol extract of M. calabura leaves (MEMC) and to elucidate the possible mechanism of antinociception involved. The in vivo chemicals (acetic acid-induced abdominal constriction and formalin-, capsaicin-, glutamate-, serotonin-induced paw licking test) and thermal (hot plate test) models of nociception were used to evaluate the extract antinociceptive activity. The extract (100, 250, and 500 mg/kg) was administered orally 60 min prior to subjection to the respective test. The results obtained demonstrated that MEMC produced significant (P < 0.05) antinociceptive response in all the chemical- and thermal-induced nociception models, which was reversed after pretreatment with 5 mg/kg naloxone, a non-selective opioid antagonist. Furthermore, pretreatment with L-arginine (a nitric oxide (NO) donor), N(G)-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase (NOS)), methylene blue (MB; an inhibitor of cyclic-guanosine monophosphate (cGMP) pathway), or their combination also caused significant (P < 0.05) change in the intensity of the MEMC antinociception. In conclusion, the MEMC antinociceptive activity involves activation of the peripheral and central mechanisms, and modulation via, partly, the opioid receptors and NO/cGMP pathway.

Matched MeSH terms: Nitric Oxide
Fulltext Positive outcomes of oil palm phenolics on degenerative diseases in animal models

Sambanthamurthi R, Tan Y, Sundram K, Hayes KC, Abeywardena M, Leow SS, et al.

Br J Nutr, 2011 Dec;106(11):1664-75.
PMID: 21736778 DOI: 10.1017/S0007114511002133

It is well established that plant phenolics elicit various biological activities, with positive effects on health. Palm oil production results in large volumes of aqueous by-products containing phenolics. In the present study, we describe the effects of oil palm phenolics (OPP) on several degenerative conditions using various animal models. OPP reduced blood pressure in a NO-deficient rat model, protected against ischaemia-induced cardiac arrhythmia in rats and reduced plaque formation in rabbits fed an atherogenic diet. In Nile rats, a spontaneous model of the metabolic syndrome and type 2 diabetes, OPP protected against multiple aspects of the syndrome and diabetes progression. In tumour-inoculated mice, OPP protected against cancer progression. Microarray studies on the tumours showed differential transcriptome profiles that suggest anti-tumour molecular mechanisms involved in OPP action. Thus, initial studies suggest that OPP may have potential against several chronic disease outcomes in mammals.

Matched MeSH terms: Nitric Oxide/deficiency
Evaluation of antioxidant and nitric oxide inhibitory activities of selected Malaysian medicinal plants

Saha K, Lajis NH, Israf DA, Hamzah AS, Khozirah S, Khamis S, et al.

J Ethnopharmacol, 2004 Jun;92(2-3):263-7.
PMID: 15138010

Methanol extracts of seven Malaysian medicinal plants were screened for antioxidant and nitric oxide inhibitory activities. Antioxidant activity was measured by using FTC, TBA and DPPH free radical scavenging methods and Griess assay was used for the measurement of nitric oxide inhibition in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated RAW 264.7 cells. All the extracts showed strong antioxidant activity comparable to or higher than that of alpha-tocopherol, BHT and quercetin in FTC and TBA methods. The extracts from Leea indica and Spermacoce articularis showed strong DPPH free radical scavenging activity comparable with quercetin, BHT and Vit C. Spermacoce exilis showed only moderate activity but other species were weak as compared to the standards. In the Griess assay Lasianthus oblongus, Chasalia chartacea, Hedyotis verticillata, Spermacoce articularis and Leea indica showed strong inhibitory activity on nitric oxide production in LPS and IFN-gamma-induced RAW 264.7 cells. Extracts from Psychotria rostrata and Spermacoce exilis also inhibited NO production but this was due to their cytotoxic effects upon cells during culture.

Matched MeSH terms: Nitric Oxide/antagonists & inhibitors*
Reduced expression of prostacyclin synthase and nitric oxide synthase in subcutaneous arteries of type 2 diabetic patients

Safiah Mokhtar S, M Vanhoutte P, W S Leung S, Imran Yusof M, Wan Sulaiman WA, Zaharil Mat Saad A, et al.

Tohoku J. Exp. Med., 2013 11;231(3):217-22.
PMID: 24225501

Diabetic endothelial dysfunction is characterized by impaired endothelium-dependent relaxation. In this study, we measured the expression of endothelial nitric oxide synthase (eNOS), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostacyclin synthase (PGIS), and prostacyclin receptor (IP) in subcutaneous arteries of type-2 diabetic and non-diabetic patients. Subcutaneous arteries were dissected from tissues from seven diabetics (4 males and 3 females) and seven non-diabetics (5 males and 2 females) aged between 18 to 65 years, who underwent lower limb surgical procedures. Diabetics had higher fasting blood glucose compared to non-diabetics, but there were no differences in blood pressure, body mass index and age. Patients were excluded if they had uncontrolled hypertension, previous myocardial infarction, coronary heart disease, renal or hepatic failure and tumor. The relative expression levels of eNOS, COX-1, COX-2, PGIS and IP receptor were determined by Western blotting analysis, normalized with the β-actin level. Increased expression of COX-2 was observed in subcutaneous arteries of diabetics compared to non-diabetics, whereas the expression levels of eNOS and PGIS were significantly lower in diabetics. There were no significant differences in expression levels of COX-1 and IP receptor between the two groups. Immunohistochemical study of subcutaneous arteries showed that the intensities of eNOS and PGIS staining were lower in diabetics, with higher COX-2 staining. In conclusion, type-2 diabetes is associated with higher COX-2 expression, but lower eNOS and PGIS expression in subcutaneous arteries. These alterations may lead to impaired endothelium-dependent vasodilatation, and thus these proteins may be potential targets for protection against the microvascular complications of diabetes.

Matched MeSH terms: Nitric Oxide Synthase Type III/metabolism*

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