Low and high doses of oxandrolone promote pathological cardiac remodeling in young male rats.

Oxandrolone (OXA) used in clinical practice, however, its misuse is frequent, including by adolescents pursuing an aesthetic goal. However, the impacts of noxious doses on the cardiovascular system remain unknown. AIM: To investigate cardiac effects of OXA in low (LD) and high (HD) doses. METHODS: Male Wistar prepubescent rats were separated into 3 experimental groups: control (CON), LD, and HD. Only the CON group received the carrier (carboxymethylcellulose, 0.5%), while the LD and HD groups received, respectively, 2.5 and 37.5 mg/kg/day of OXA via gavage for 4 weeks. The hemodynamic parameters (+dP/dtmax, -dP/dtmin, and Tau) and cardiac autonomic tonus were assessed. Hearts were retrieved for histological analyses and oxidative stress evaluation. Expression levels of calcium-handling proteins were measured by western blot. RESULTS: The OXA treatment changed neither the cardiac contractility nor the cardiac autonomic tonus. However, cardiac hypertrophy, collagen deposition, and increased angiotensin-converting enzyme (ACE) expression were observed in a dose-dependent way. Also, the p-phospholamban (p-PLB)/PLB ratio was observed to decrease and increase, respectively, in the LD and HD groups; the sarcoplasmic/endoplasmic reticulum calcium ATPase 2a (SERCA2a)/PLB ratio being higher in both groups. OXA increased SOD1 expression and decreased catalase expression only in the LD group, and protein oxidation was increased in HD. CONCLUSION: Both doses of OXA could promote pathological cardiac remodeling, probably via increased ACE, and these effects were exacerbated in the HD treatment, but cardiac contractility was not affected regardless of the dose.

Chronic and acute effects of kefir: the role of angiotensin converting enzyme inhibition instead of nitric oxide balance

Probiotic consumption promotes numerous health benefits. The aim of this study is 1) to evaluate the antihypertensive effect of kefir in a hypertension rat model caused by the administration of the nitric oxide synthesis inhibitor, L-NAME, and 2) to evaluate the acute angiotensin converting enzyme (ACE) inhibitory activity of the soluble nonbacterial fraction (SNBF) of kefir. To develop the first aim, male rats were separated into three groups: control group (C) treated with 0.3 mL/100 g of milk; L-NAME group (LN) received 10 mg/kg of said inhibitor; and Kefir group (K) treated with 0.3 mL/100 g of kefir plus L-NAME (10 mg/kg of said inhibitor). The treatments were given by oral gavage twice a day for four weeks. For the second aim"instead additionally, male rats received angiotensin I (in bolus) in three doses (Ang I: 0.03, 3 and 300 µg/kg) and were separated into two groups: a) received captopril (30 mg/kg i.v.) and b)received SNBF of kefir (5 mL/kg i.v.). Blood pressure were evaluated before and after Ang I. After treatment, hemodynamic parameters were evaluated, heart weight was recorded, and body weight gain was calculated. SNBF of kefir did not decrease the blood pressure for L-NAMEtreated animals, and no changes were observed in the cardiac parameters. However, the SNBF of kefir demonstrated acute inhibition of ACE in vivo similar to that of captopril. Thus, our results suggest that kefir may improve human cardiovascular systems by using mechanisms independent of nitric oxide syntheses. Additionally, the renin angiotensin system is probably the most important system involved in kefir effect regarding hypertension.

Phytochemical and in vitro and in vivo biological investigation on the antihypertensive activity of mango leaves (Mangifera indica L.).

AIMS: The aim of this study was to investigate the antihypertensive effect of leaves Mangifera indica L. using in vitro and in vivo assays. METHODOLOGY: The ethanol extract of leaves of M. indica was fractionated to dichloromethanic, n-butyl alcohol and aqueous fractions. The chemical composition of ethanolic extract and dichloromethanic fraction were evaluated by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Antioxidant activity was evaluated in the DPPH scavenging activity assay. Angiotensin-converting enzyme (ACE) inhibitory activity was investigated using in vitro and in vivo assays. The chronic antihypertensive assay was performed in spontaneously hypertensive rats (SHRs) and Wistar rats treated with enalapril (10 mg/kg), dichloromethanic fraction (100 mg/kg; twice a day) or vehicle control for 30 days. The baroreflex sensitivity was evaluated through the use of sodium nitroprusside and phenylephrine. Cardiac hypertrophy was evaluated by morphometric analysis. RESULTS: The dichloromethanic fraction exhibited the highest flavonoid, total phenolic content and high antioxidant activity. Dichloromethanic fraction elicited ACE inhibitory activity in vitro (99 ± 8%) similar to captopril. LC-MS/MS analysis revealed the presence of ferulic acid (48.3 ± 0.04 µg/g) caffeic acid (159.8 ± 0.02 µg/g), gallic acid (142.5 ± 0.03 µg/g), apigenin (11.0 ± 0.01 µg/g) and quercetin (203.3 ± 0.05 µg/g). The chronic antihypertensive effects elicited by dichloromethanic fraction were similar to those of enalapril, and the baroreflex sensitivity was normalized in SHR. Plasma ACE activity and cardiac hypertrophy were comparable with animals treated with enalapril. CONCLUSIONS: Dichloromethanic fraction of M. indica presented an antihypertensive effect, most likely by ACE inhibition, with benefits in baroreflex sensitivity and cardiac hypertrophy. Altogether, the results of the present study suggest that the dichloromethanic fraction of M. indica leaves may have potential as a promoting antihypertensive agent.

Antihypertensive effect of Carica papaya via a reduction in ACE activity and improved baroreflex.

The aims of this study were to evaluate the antihypertensive effects of the standardised methanolic extract of Carica papaya, its angiotensin converting enzyme inhibitory effects in vivo, its effect on the baroreflex and serum angiotensin converting enzyme activity, and its chemical composition. The chemical composition of the methanolic extract of C. papaya was evaluated by liquid chromatography-mass/mass and mass/mass spectrometry. The angiotensin converting enzyme inhibitory effect was evaluated in vivo by Ang I administration. The antihypertensive assay was performed in spontaneously hypertensive rats and Wistar rats that were treated with enalapril (10 mg/kg), the methanolic extract of C. papaya (100 mg/kg; twice a day), or vehicle for 30 days. The baroreflex was evaluated through the use of sodium nitroprusside and phenylephrine. Angiotensin converting enzyme activity was measured by ELISA, and cardiac hypertrophy was evaluated by morphometric analysis. The methanolic extract of C. papaya was standardised in ferulic acid (203.41 ± 0.02 µg/g), caffeic acid (172.60 ± 0.02 µg/g), gallic acid (145.70 ± 0.02 µg/g), and quercetin (47.11 ± 0.03 µg/g). The flavonoids quercetin, rutin, nicotiflorin, clitorin, and manghaslin were identified in a fraction of the extract. The methanolic extract of C. papaya elicited angiotensin converting enzyme inhibitory activity. The antihypertensive effects elicited by the methanolic extract of C. papaya were similar to those of enalapril, and the baroreflex sensitivity was normalised in treated spontaneously hypertensive rats. Plasma angiotensin converting enzyme activity and cardiac hypertrophy were also reduced to levels comparable to the enalapril-treated group. These results may be associated with the chemical composition of the methanolic extract of C. papaya, and are the first step into the development of a new phytotherapic product which could be used in the treatment of hypertension.