Endothelium-dependent vascular relaxing effects of different citrus and olive extracts in aorta rings from spontaneously hypertensive rats

Effectiveness of Consumption of a Combination of Citrus Fruit Flavonoids and Olive Leaf Polyphenols to Reduce Oxidation of Low-Density Lipoprotein in Treatment-Naïve Cardiovascular Risk Subjects: A Randomized Double-Blind Controlled Study

The aim of the study was to assess whether oral intake of a nutraceutical product (Citrolive™) could determine changes in low-density lipoprotein (LDL) oxidation and other parameters of lipid metabolism and plasma atherogenic capacity. Citrolive™ is a commercial extract obtained from the combination of citrus fruit flavonoids and olive leaf extracts. Twenty-three untreated subjects (69.6% males, 30.4% females, mean age 41.9 ± 9.4 years) with cardiovascular risk factors and a total cholesterol level >200 mg/dL and LDL cholesterol (LDL-C) > 130 mg/dL participated in a 3-month randomized double-blind controlled study. Participants in the intervention group (71.4% males, 28.6% females, mean age 42.7 ± 9.7 years) consumed Citrolive™ (500 mg, two capsules/day), and controls (66.7% males, 33.3% females, mean age 40.6 ± 9.4 years) received a matched placebo. At 3 months, oxidized LDL (ox-LDL) decreased significantly in the intervention group from 93.8 ± 19.1 U/L to 62.8 ± 28.7 U/L (p < 0.05), whereas the control group increased from 98.2 ± 23.5 U/L to 105.7 ± 21.9 U/L (p = 0.1). Between-group differences were also significant (p < 0.05). Similar findings in the ox-LDL/LDL-C ratio were observed. Serum paraoxonase activity (PON1) increased significantly in the intervention group from 64.5 ± 15.6 U/L to 78.7 ± 28.8 U/L (p < 0.05) but remained unchanged in controls. Consumption of Citrolive™ for 3 months in treatment-naïve subjects with moderate risk of atherosclerosis was associated with a reduction in oxidized LDL-C and LDL-oxidase/LDL-C ratio as compared to controls.

Ethnomedicinal Plants Used for the Treatment of Cardiovascular Diseases by Healers in the Southwestern State of Paraná, Brazil, and Their Validation Based on Scientific Pharmacological Data

Cardiovascular diseases are responsible for high morbidity and mortality rates worldwide. Among treatment options, medicinal plants are frequently used, especially in developing countries, such as Brazil. Despite social development that has been observed in the last decades, the use of medicinal plants is still driven by popular knowledge, especially by healers. The present study sought to identify medicinal species that are used for the treatment of cardiovascular diseases by healers in the microregion of Francisco Beltrão, Paraná, Brazil. The snowball technique was used to select informants, and data were collected through interviews. The research was performed in two stages: (1) a structured interview and (2) the collection and botanical identification of the species that were mentioned by the healers. Medicinal plants were classified into the following categories of cardiovascular agents: hypotensive and antihypertensive agents, lipid-lowering agents, diuretic agents, and cardiotonic agents. To analyze the data, the frequency was determined, Spearman correlations were calculated, and the informant consensus factor (ICF) and use value were obtained. Some characteristics, such as female gender and old age, were associated with knowledge about medicinal plants. Overall, 77 different species and 149 medicinal uses were cited by the healers. With regard to categories of use, the highest number of species was found among lipid-lowering plants, and the highest ICF was found for species that are used as cardiotonics. Moreover, a literature review indicated that among the cited species, several still lack studies that have proven their effects on the cardiovascular system. The traditional use of medicinal plants for the treatment of cardiovascular diseases is broad in the study regions. The present results are important for clarifying popular knowledge in this region and providing a framework for selecting species with potential for the development of new pharmacological studies.

Effect of a Combination of Citrus Flavones and Flavanones and Olive Polyphenols for the Reduction of Cardiovascular Disease Risk: An Exploratory Randomized, Double-Blind, Placebo-Controlled Study in Healthy Subjects

A single-center, randomized, double-blind controlled trial was conducted to assess the efficacy of a food supplement based on a combination of grapefruit, bitter orange, and olive extracts administered for eight weeks (n = 51) versus placebo (n = 45) on reduction of cardiovascular risk in healthy volunteers. Study variables included flow-mediated vasodilation (FMD), blood pressure (BP), lipid profile, thrombotic status, oxidative stress biomarkers, inflammation-related biomarkers, anthropometric variables, quality of life, and physical activity. The per-protocol data set was analyzed. In the active product group, there were statistically significant within-group differences at eight weeks as compared with baseline in FMD, systolic and diastolic BP, total cholesterol, LDL-C, LDL-oxidase, oxidized/reduced glutathione ratio, protein carbonyl, and IL-6. Significant between-group differences in these variables were also found. Significant changes in anthropometric variables and quality of life were not observed in the study groups. Changes in the level of physical activity were not recorded. Treatment with the active product was well tolerated. All these findings, taken together, support a beneficial effect of supplementation with a mixture of grapefruit, bitter orange fruits, and olive leaf extracts on underlying mechanisms that may interact each other to decrease the cardiovascular risk in healthy people.

Hetero-Tricyclic Lead Scaffold as Novel PDE5A Inhibitor for Antihypertensive Activity: In Silico Docking Studies

Objective:

To screen the phytochemicals for phosphodiesterase 5A (PDE5A) inhibitory potential and identify lead scaffolds of antihypertensive phytochemicals using in silico docking studies.

Methods:

In this perspective, reported 269 antihypertensive phytochemicals were selected. Sildenafil, a PDE5A inhibitor was used as the standard. In silico docking study was carried out to screen and identify the inhibiting potential of the selected phytochemicals against PDE5A enzyme using vLife MDS 4.4 software.

Results:

Based on docking score, π-stacking, H-bond and ionic interactions, 237 out of 269 molecules were selected which have shown one or more interactions. Protein residue Gln817A was involved in H-boding whereas Val782A, Phe820A and Leu804A were involved in π-stacking interaction with ligand. The selected 237 phytochemicals were structurally diverse, therefore 82 out of 237 molecules with one or more tricycles were filtered out for further analysis. Amongst tricyclic molecules, 14 molecules containing nitrogen heteroatom were selected for lead scaffold identification which finally resulted in three different basic chemical backbones like pyridoindole, tetrahydro-pyridonaphthyridine and dihydro-pyridoquinazoline as lead scaffolds.

Conclusion:

In silico docking studies revealed that nitrogen-containing tetrahydro-pyridonaphthyridine and dihydro-pyridoquinazoline tricyclic lead scaffolds have emerged as novel PDE5A inhibitors for antihypertensive activity. The identified lead scaffolds may provide antihypertensive lead molecules after its optimization.

Vasorelaxant and chemical fingerprint studies of Citrus reticulatae pericarpium extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Citrus reticulatae Pericarpium (Chen pi) was widely used as an important ingredient in the prescription of TCM to treat phlegm fluid retention type hypertension. Since Chen pi is involved in treatment as antihypertensive TCM formula, we have reasonable expectation in believing that it might possess vasorelaxant activity.

AIM OF THE STUDY

This study is designed to investigate the vasorelaxant effect of Chen pi and to study its pharmacology effects.

MATERIALS AND METHODS

The vasorelaxant effect of water extract of Chen pi (CRW) were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. The fingerprint of Chen pi and the extracts were developed with quantification of hesperidin content by HPTLC.

RESULTS

CRW exhibited the strongest vasorelaxant activity. CRW caused the relaxation of the phenylephrine pre-contracted aortic rings in the presence and absence of endothelium as well as in potassium chloride pre-contracted endothelium-intact aortic ring. The incubation of propranolol (β-adrenergic receptor blocker), atropine (muscarinic receptor blocker), Nω-nitro-L-arginine methyl ester (NO synthase inhibitor), ODQ (sGC inhibitor), indomethacin (COX inhibitor), 4-aminopyridine (K_V blocker), barium chloride (K_ir blocker), and glibenclamide (K_ATP blocker) significantly reduced the vasorelaxant effects of CRW. CRW was also found to be active in reducing Ca²⁺ releases from the sarcoplasmic reticulum and suppressing the voltage-operated calcium channels.

CONCLUSION

The vasorelaxant effect of CRW on rat aorta involves NO/sGC, calcium and potassium channels, muscarinic and β-adrenergic receptors.