Improving endothelial health with food-derived H2S donors: an in vitro study with S-allyl cysteine and with a black-garlic extract enriched in sulfur-containing compounds.

A healthy vascular endothelium plays an essential role in modulating vascular tone by producing and releasing vasoactive factors such as nitric oxide (NO). Endothelial dysfunction (ED), the loss of the endothelium physiological functions, results in the inability to properly regulate vascular tone, leading to hypertension and other cardiovascular risk factors. Alongside NO, the gasotransmitter hydrogen sulfide (H2S) has emerged as a key molecule with vasodilatory and antioxidant activities. Since a reduction in H2S bioavailability is related to ED pathogenesis, natural H2S donors are very attractive. In particular, we focused on the sulfur-containing amino acid S-allyl cysteine (SAC), a bioactive metabolite, of which black garlic is particularly rich, with antioxidant activity and, among others, anti-diabetic and anti-hypertensive properties. In this study, we analyzed the protective effect of SAC against ED by evaluating reactive oxygen species level, H2S release, eNOS phosphorylation, and NO production (by fluorescence imaging and western blot analysis) in Bovine Aortic Endothelial cells (BAE-1). Furthermore, we chemically characterized a Black Garlic Extract (BGE) for its content in SAC and other sulfur-containing amino acids. BGE was used to carry out an analysis on H2S release on BAE-1 cells. Our results show that both SAC and BGE significantly increase H2S release. Moreover, SAC reduces ROS production and enhances eNOS phosphorylation and the consequent NO release in our cellular model. In this scenario, a natural extract enriched in SAC could represent a novel therapeutic approach to prevent the onset of ED-related diseases.

Quali-Quantitative Characterization of Volatile and Non-Volatile Compounds in Protium heptaphyllum (Aubl.) Marchand Resin by GC-MS Validated Method, GC-FID and HPLC-HRMS2.

Protium heptaphyllum (Aubl.) Marchand (PH) trees are endemic to the tropical region of South America, mostly Brazil. Antibacterial, antinociceptive, anti-inflammatory, anxiolytic, antidepressant and anti-hyperlipidemic/anti-hypercholesterolemic effects were reported for its resinous exudate Protiumheptaphyllum resin (PHR). This work aims to provide a qualitative and quantitative consistent chemical profiling of the major constituents of this resin and two extracts enriched in acid (acidic triterpene concentrated extract, ATCE) and neutral triterpenes (α and ß-amyrin concentrated extract, AMCE). GC-MS/GC-FID was used for volatile terpene fraction, a validated GC-MS method was developed for quantification of neutral α and ß-amyrin and HPLC-APCI HRMS2 was used for acidic triterpenes analysis. The chemical investigation reported 29 molecules, including 14 volatile terpenes, 6 neutral triterpenes and 11 acid triterpenes. The most abundant compounds were α-amyrin (251.28 g kg-1, 123.98 g kg-1 and 556.82 g kg-1 in PHR, ATCE and AMCE, respectively), ß-amyrin (172.66 g kg-1, 95.39 g kg-1 and 385.58 g kg-1 in PHR, ATCE and AMCE, respectively), 3-oxo-tirucalla-7,24-dien-21-oic acid (80.64 g kg-1, 157.10 g kg-1 and 15.31 g kg-1 in PHR, ATCE and AMCE, respectively) and 3α-hydroxy-tirucalla-8,24-dien-21-oic acid (77.71 g kg-1, 130.40 g kg-1 and 11.64 g kg-1 in PHR, ATCE and AMCE, respectively). Results showed specific enrichment of acidic and neutral triterpenoids in the two respective extracts.

Bioactive Triterpenes of Protium heptaphyllum Gum Resin Extract Display Cholesterol-Lowering Potential.

Hypercholesterolemia is one of the major causes of cardiovascular disease, the risk of which is further increased if other forms of dyslipidemia occur. Current therapeutic strategies include changes in lifestyle coupled with drug administration. Statins represent the most common therapeutic approach, but they may be insufficient due to the onset of resistance mechanisms and side effects. Consequently, patients with mild hypercholesterolemia prefer the use of food supplements since these are perceived to be safer. Here, we investigate the phytochemical profile and cholesterol-lowering potential of Protium heptaphyllum gum resin extract (PHE). Chemical characterization via HPLC-APCI-HRMS2 and GC-FID/MS identified 13 compounds mainly belonging to ursane, oleanane, and tirucallane groups. Studies on human hepatocytes have revealed how PHE is able to reduce cholesterol production and regulate the expression of proteins involved in its metabolism. (HMGCR, PCSK9, LDLR, FXR, IDOL, and PPAR). Moreover, measuring the inhibitory activity of PHE against HMGR, moderate inhibition was recorded. Finally, molecular docking studies identified acidic tetra- and pentacyclic triterpenoids as the main compounds responsible for this action. In conclusion, our study demonstrates how PHE may be a useful alternative to contrast hypercholesterolemia, highlighting its potential as a sustainable multitarget natural extract for the nutraceutical industry that is rapidly gaining acceptance as a source of health-promoting compounds.