RESUMO
Soluble epoxide hydrolase (sEH) inhibitors have been reported to improve penile erection; therefore, sEH could be useful for management of erectile dysfunction. Methanolic and aqueous extracts of 30 Indian medicinal plants were screened for their sEH inhibition potential. Fifteen extracts showed >50% inhibition when screened at 50 µg/mL in sEH inhibition assay. Methanolic extract of Moringa oleifera Lam. (Moringaceae) seeds (MEMO) was most potent with IC50 1.7 ± 0.1 µg/mL and was selected for in vitro studies on isolated rat corpus cavernosum smooth muscle and in vivo sexual behaviour studies on healthy and diabetic rats. Rats were divided into five groups, each containing six animals and treated orally with either water, vehicle (1% Tween-20), MEMO (45 and 90 mg/kg/day for 21 days), and standard drug, sildenafil (5 mg/kg/day for 7 days). An equal number of female rats were used, and the effect of MEMO and sildenafil was compared with that of vehicle. MEMO significantly relaxed isolated rat corpus cavernosum smooth muscle at 0.1-100 µg/mL in vitro and significantly increased (p < 0.05) sexual activity, intracavernous pressure/mean arterial pressure in normal and diabetic rats. The increase in erectile function of rats by MEMO could be because of its sEH inhibitory activity. Copyright © 2016 John Wiley & Sons, Ltd.
Assuntos
Afrodisíacos/farmacologia , Epóxido Hidrolases/fisiologia , Moringa oleifera , Ereção Peniana/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Epóxido Hidrolases/antagonistas & inibidores , Feminino , Pressão Intracraniana/efeitos dos fármacos , Masculino , RatosRESUMO
OBJECTIVE: Regulation of angiogenesis is critical for many diseases. Specifically, pathological retinal neovascularization, a major cause of blindness, is suppressed with dietary ω3-long-chain polyunsaturated fatty acids (ω3LCPUFAs) through antiangiogenic metabolites of cyclooxygenase and lipoxygenase. Cytochrome P450 epoxygenases (CYP2C8) also metabolize LCPUFAs, producing bioactive epoxides, which are inactivated by soluble epoxide hydrolase (sEH) to transdihydrodiols. The effect of these enzymes and their metabolites on neovascularization is unknown. APPROACH AND RESULTS: The mouse model of oxygen-induced retinopathy was used to investigate retinal neovascularization. We found that CYP2C (localized in wild-type monocytes/macrophages) is upregulated in oxygen-induced retinopathy, whereas sEH is suppressed, resulting in an increased retinal epoxide:diol ratio. With a ω3LCPUFA-enriched diet, retinal neovascularization increases in Tie2-driven human-CYP2C8-overexpressing mice (Tie2-CYP2C8-Tg), associated with increased plasma 19,20-epoxydocosapentaenoic acid and retinal epoxide:diol ratio. 19,20-Epoxydocosapentaenoic acids and the epoxide:diol ratio are decreased with overexpression of sEH (Tie2-sEH-Tg). Overexpression of CYP2C8 or sEH in mice does not change normal retinal vascular development compared with their wild-type littermate controls. The proangiogenic role in retina of CYP2C8 with both ω3LCPUFA and ω6LCPUFA and antiangiogenic role of sEH in ω3LCPUFA metabolism were corroborated in aortic ring assays. CONCLUSIONS: Our results suggest that CYP2C ω3LCPUFA metabolites promote retinal pathological angiogenesis. CYP2C8 is part of a novel lipid metabolic pathway influencing retinal neovascularization.
Assuntos
Hidrocarboneto de Aril Hidroxilases/metabolismo , Ácidos Graxos Ômega-3/toxicidade , Macrófagos/enzimologia , Monócitos/enzimologia , Neovascularização Retiniana/induzido quimicamente , Animais , Ácido Araquidônico/metabolismo , Hidrocarboneto de Aril Hidroxilases/genética , Biotransformação , Hipóxia Celular , Citocromo P-450 CYP2C8 , Gorduras na Dieta/farmacocinética , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Epóxido Hidrolases/deficiência , Epóxido Hidrolases/genética , Epóxido Hidrolases/fisiologia , Proteínas do Olho/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/classificação , Ácidos Graxos Ômega-3/farmacocinética , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/farmacocinética , Humanos , Lipoxigenase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oxigênio/toxicidade , Prostaglandina-Endoperóxido Sintases/metabolismo , RNA Mensageiro/biossíntese , Receptor TIE-2/genética , Proteínas Recombinantes de Fusão/metabolismo , Neovascularização Retiniana/prevenção & controleRESUMO
We have shown previously that inhibition of sEH (soluble epoxide hydrolase) increased EETs (epoxyeicosatrienoic acids) levels and reduced renal injury in diabetic mice and these changes were associated with induction of HO (haem oxygenase)-1. The present study determines whether the inhibition of HO negates the renoprotective effect of sEH inhibition in diabetic SHR (spontaneously hypertensive rats). After 6 weeks of induction of diabetes with streptozotocin, SHR were divided into the following groups: untreated, treated with the sEH inhibitor t-AUCB {trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid}, treated with the HO inhibitor SnMP (stannous mesoporphyrin), and treated with both inhibitors for 4 more weeks; non-diabetic SHR served as a control group. Induction of diabetes significantly increased renal sEH expression and decreased the renal EETs/DHETEs (dihydroxyeicosatrienoic acid) ratio without affecting HO-1 activity or expression in SHR. Inhibition of sEH with t-AUCB increased the renal EETs/DHETEs ratio and HO-1 activity in diabetic SHR; however, it did not significantly alter systolic blood pressure. Treatment of diabetic SHR with t-AUCB significantly reduced the elevation in urinary albumin and nephrin excretion, whereas co-administration of the HO inhibitor SnMP with t-AUCB prevented these changes. Immunohistochemical analysis revealed elevations in renal fibrosis as indicated by increased renal TGF-ß (transforming growth factor ß) levels and fibronectin expression in diabetic SHR and these changes were reduced with sEH inhibition. Co-administration of SnMP with t-AUCB prevented its ability to reduce renal fibrosis in diabetic SHR. In addition, SnMP treatment also prevented t-AUCB-induced decreases in renal macrophage infiltration, IL-17 expression and MCP-1 levels in diabetic SHR. These findings suggest that HO-1 induction is involved in the protective effect of sEH inhibition against diabetic renal injury.
Assuntos
Benzoatos/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Epóxido Hidrolases/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/fisiologia , Ureia/análogos & derivados , Actinas/metabolismo , Albuminúria/prevenção & controle , Animais , Benzoatos/antagonistas & inibidores , Benzoatos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Creatinina/urina , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/fisiopatologia , Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/metabolismo , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Epóxido Hidrolases/metabolismo , Epóxido Hidrolases/fisiologia , Heme Oxigenase (Desciclizante)/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/metabolismo , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/fisiologia , Córtex Renal/metabolismo , Masculino , Proteínas de Membrana/urina , Metaloporfirinas/farmacologia , Ratos , Ratos Endogâmicos SHR , Ureia/antagonistas & inibidores , Ureia/farmacologia , Ureia/uso terapêuticoRESUMO
BACKGROUND/AIMS: An epidemic of hepatitis due to germander teas or capsules recently occurred in France. The aim of the present study was to show the hepatotoxicity of germander and determine its mechanism in mice. METHODS: A germander tea lyophilisate and a fraction that isolated and concentrated 10-fold the furano neo-clerodane diterpenoids of the lyophilisate were prepared. RESULTS: (1) Intragastric administration of the lyophilisate (1.25 g/kg) or the furano neo-clerodane diterpenoid fraction (0.125 mg/kg) produced similar midzonal liver cell necrosis at 24 hours in mice. (2) Toxicity was prevented by pretreatment with a single dose of troleandomycin (a specific inhibitor of cytochromes P4503A) and enhanced by pretreatment with dexamethasone or clotrimazole (two inducers of cytochromes P4503A). (3) Toxicity was attenuated by pretreatment with butylated hydroxyanisole or clofibrate (two inducers of microsomal epoxide hydrolase) and markedly increased by phorone-induced glutathione depletion. CONCLUSIONS: We conclude that germander constituents (probably its furano neo-clerodane diterpenoids) are transformed by cytochromes P450 (particularly P4503A) into hepatotoxic metabolites. The metabolites (probably epoxides) are partly inactivated by glutathione and probably epoxide hydrolase.