Antihyperlipidemic effect of a Rhamnus alaternus leaf extract in Triton-induced hyperlipidemic rats and human HepG2 cells

Abstract

The Mediterranean buckthorn, Rhamnus alaternus L., is a plant used in traditional medicine in Mediterranean countries. We aimed at characterizing its phenolic compounds and explore potential antihyperlipidemic activity of this plant. The profile of phenolic compounds in R. alaternus leaf crude methanolic extract (CME) and its liquid-liquid extraction-derived fractions were analyzed by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS). Effects of CME on: circulating lipids in rats with Triton WR-1339-induced hyperlipidemia, intracellular lipid accumulation and expression of genes of fatty acid metabolism in human hepatoma HepG2 cells, and adipogenesis in the 3T3-L1 murine adipocyte cell model were assessed. The HPLC/ESI-MS analytical profile revealed a total of fifteen compounds, of which eleven were identified. Oral CME administration decreased blood levels of cholesterol and triacylglycerols in hyperlipidemic rats (by 60% and 70%, respectively, at 200 mg CME/kg). In HepG2 cells, CME exposure dose-dependently decreased intracellular lipids and up-regulated gene expression of carnitine palmitoyltransferase 1 involved in fatty acid oxidation. In the 3T3-L1 model, CME favored preadipocyte proliferation and adipogenesis, pointing to positive effects on adipose tissue expandability. These results suggest novel uses of R. alaternus by showing that its leaves are rich in flavonoids and flavonoid derivatives with an antihyperlipidemic effect in vivo and in hepatic cells.

Signals of diagnostic ions in the product ion spectra of [M − H]− ions of methoxylated flavonoids

“…Some authors have reported no product ion at m / z 193 detected for the [M − H] − ion of rhamnetin . On the other hand, there is one study in which the product ion at m / z 193 has been observed for the [M − H] − ion of rhamnetin, and one study in which the product ion at m / z 192 has been observed for the [M − H] − ion of rhamnetin; perhaps it is a small mistake and it should be 193. Therefore, it seems to be reasonable to assume that the product ion at 193 is really the product ion of the [M − H] − ion of rhamnetin.…”

A Lipophilic Fucoxanthin-Rich Phaeodactylum tricornutum Extract Ameliorates Effects of Diet-Induced Obesity in C57BL/6J Mice

“…On day seven, when more than 95% of the cells showed intracellular lipid accumulation, cells were treated with PTE (100 mg/L), fucoxanthin (5 µM; Sigma-Aldrich, St. Louis, MO, USA) or vehicle (ethanol; 10 µL) for 24 h prior to harvesting. In parallel plates intracellular lipid content was quantified by Oil Red O (ORO) staining, as previously described [32], evidencing no differences between treatments (results not shown). The treatments applied had no cytotoxic effects in 3T3-L1 preadipocytes as assessed by the lactate dehydrogenase release assay (results not shown).…”

Antioxidant, Anti-inflammatory Activities and Polyphenol Profile of Rhamnus prinoides

“…Polyphenols are the main antioxidant components in plants. On the one hand, polyphenols possess strong total reducing power, 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl / 2,2 -azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (DPPH/ABTS + ) free radicals, and nitrite scavenging activities [17]; on the other hand, these compounds could closely be involved in many physiological processes, including but not limited to inflammation, antibiosis, hyperlipidemia, hyperglycemia, and cancer [18][19][20]; for example, polyphenols could inhibit the bioactivities of the vascular endothelial growth factor (VEGF) so as to suppress vascular regeneration [21]. As a matter of fact, however, there are still few reports about the potentials of polyphenols in R. prinoides in Kenya for antioxidants and their related activities.…”