Vasorelaxant Activity of Salvia hispanica L.: Involvement of the Nitric Oxide Pathway in Its Pharmacological Mechanism.

Salvia hispanica L., commonly known as chía, and its seeds have been used since ancient times to prepare different beverages. Due to its nutritional content, it is considered a dietary ingredient and has been reported with many health benefits. Chia seed components are helpful in cardiovascular disease (CVD) by reducing blood pressure, platelet aggregation, cholesterol, and oxidation. Still, its vasodilator effects on the vascular system were not reported yet. The hexanic (HESh), dichloromethanic (DESh), and methanolic (MESh) extracts obtained from chía seeds were evaluated on an aortic ring ex-vivo experimental model. The vasorelaxant efficacy and mechanism of action were determined. Also, phytochemical data was obtained through 13C NMR-based dereplication. The MESh extract showed the highest efficacy (Emax = 87%), and its effect was partially endothelium-dependent. The mechanism of action was determined experimentally, and the vasorelaxant curves were modified in the presence of L-NAME, ODQ, and potassium channel blockers. MESh caused a relaxing effect on KCl 80 mM-induced contraction and was less potent than nifedipine. The CaCl2-induced contraction was significantly decreased compared with the control curve. Phytochemical analysis of MESh suggests the presence of mannitol, previously reported as a vasodilator on aortic rings. Our findings suggest NO-cGMP pathway participation as a vasodilator mechanism of action of S. hispanica seeds; this effect can be attributed, in part, to the mannitol presence. S. hispanica could be used in future research focused on antihypertensive therapies.

Development and Optimization of a High Sensitivity LC-MS/MS Method for the Determination of Hesperidin and Naringenin in Rat Plasma: Pharmacokinetic Approach.

The purpose of this study was to develop, optimize, and fully validate a high-sensitivity methodology using UHPLC-MS/MS to simultaneously quantify hesperidin and naringenin in microsamples (100 µL) of murine plasma after intragastric administration of single pure flavonoids and a mixture. The optimization process allowed for high sensitivity with detection limits of approximately picogram order using an electrospray ionization (ESI) source in negative mode and an experiment based on multiple reaction monitoring (MRM). The validation parameters showed excellent linearity and detection limits, with a precision of less than 8% and a recovery of over 90%. This methodology was applied to compare the pharmacokinetic parameters for the administration of hesperidin and naringenin in individual form or in the form of a mixture. The results showed an absence of significant effects (p > 0.05) for Tmax and Cmax; however, the AUC presented significant differences (p < 0.05) for both flavonoids when administered as a mixture, showing an improved absorption ratio for both flavonoids.

Toxicological Screening of Four Bioactive Citroflavonoids: In Vitro, In Vivo, and In Silico Approaches.

Many studies describe different pharmacological effects of flavonoids on experimental animals and humans. Nevertheless, few ones are confirming the safety of these compounds for therapeutic purposes. This study aimed to investigate the preclinical safety of naringenin, naringin, hesperidin, and quercetin by in vivo, in vitro, and in silico approaches. For this, an MTT-based cytotoxicity assay in VERO and MDCK cell lines was performed. In addition, acute toxicity was evaluated on Wistar rats by OECD Guidelines for the Testing of Chemicals (Test No. 423: Acute Oral Toxicity-Class Method). Furthermore, we used the ACD/Tox Suite to predict toxicological parameters such as hERG channel blockade, CYP450 inhibition, and acute toxicity in animals. The results showed that quercetin was slightly more cytotoxic on cell lines (IC50 of 219.44 ± 7.22 mM and 465.41 ± 7.44 mM, respectively) than the other citroflavonoids. All flavonoids exhibited an LD50 value > 2000 mg/kg, which classifies them as low-risk substances as OECD guidelines established. Similarly, predicted LD50 was LD50 > 300 to 2000 mg/kg for all flavonoids as acute toxicity assay estimated. Data suggests that all these flavonoids did not show significant toxicological effects, and they were classified as low-risk, useful substances for drug development.

Comparative fingerprint analyses of extracts from the root bark of wild Hippocratea excelsa and "Cancerina" by high-performance liquid chromatography.

A simple high-performance liquid chromatography method was developed for the identification and comparison of quinone-methide triterpenes in wild Hippocratea excelsa and "cancerina" to establish the chromatographic profile of these compounds in root bark. The essential chromatographic conditions for this method are based on a gradient system with a reversed-phase column (C18 ) using proportions of water, methanol, and tetrahydrofuran as mobile phases to correctly separate the signals at 254 and 420 nm and compare the signals to those reported in the literature. The chromatograms exhibit good resolution and precision. Statistical analysis showed that the chromatographic profiles of wild H. excelsa and cancerina do not exhibit significant differences (p≥0.05) in their area proportions or relative retention times. The method developed in this study is suitable for the identification of the major chemotaxonomic markers of the Celastraceae family and can be used for quality control of this herbal root bark, which has uses today in Mexican folk medicine.

IMMUNOSUPPRESIVE EFFECTS OF THE METHANOLIC EXTRACT OF CHRYSOPHYLLUM CAINITO LEAVES ON MACROPHAGE FUNCTIONS.

BACKGROUND: The aim of this work was to evaluate the immunomodulatory effect of the methanol extract (MeOH) from Chrysophyllum cainito leaves on the MΦs functions. MATERIAL AND METHODS: Peritoneal murine MΦs isolated from Balb/c mice were treated with the MeOH extract and stimulated with LPS. The effect on the phagocytosis was evaluated by flow cytometry assay. The nitric oxide (NO) and hydrogen peroxide (H2O2) production was measured by the Griess reagent and phenol red reaction, respectively. Levels of IL-6 and TNF-α was measured using an ELISA kit. Viability of MΦs and Vero cells was determined by the MTT method. RESULTS: The MeOH extract of C. cainito leaves inhibited significantly the phagocytosis, and decreased IL-6 and TNF-α production as well as NO and H2O2 released by the MΦs, in a concentration-dependent manner. In addition, MeOH extract of C. cainito showed low cytotoxicity effect against the cells. CONCLUSION: These results suggest that MeOH extract of C. cainito leaves has an immunosuppressive effect on murine MΦs, without effects on cell viability. GC-MS chromatogram analysis of MeOH extract showed that lupeol acetate and alpha-amyrin acetate are the principal compounds.