The Anti-Inflammatory Potential of an Ethanolic Extract from Sarcopoterium spinosum Fruits for Protection and/or Counteraction against Oxidative Stress in Dysfunctional Endothelial Cells.

Plants and plant extracts are a relevant source of bioactive compounds widely employed as functional foods. In the Mediterranean area, the shrub Sarcopoterium spinosum is traditionally used as an herbal medicine for weight loss and a diabetes treatment. Inflammation is a protective mechanism involved in the development of many pathological conditions, including cardiovascular diseases. The present study aimed to investigate in vitro the antioxidant and cytoprotective properties of an ethanolic extract from S. spinosum fruits (SEE) in a cellular model of endothelium dysfunction. Corilagin and quercetin are two polyphenols abundant in SEE and were tested for comparison. The exposure of HECV cells for 24 h to 30 µM hydrogen peroxide (H2O2) lead to an oxidative stress condition. When HECV cells were treated with 10 µg/mL of SEE or single compounds after or before the oxidative insult, the results showed their ability to (i) decrease the reactive oxygen species (ROS) production quantified using fluorometric analysis and the lipid peroxidation measured with a spectrophotometric assay; (ii) rescue both the glutathione reduced to oxidized (GSH/GSSG) ratio and nitric oxide impair and the protein denaturation; and (iii) accelerate the wound repair measured using a T-scratch assay. Taken together, our findings indicate that the ethanolic extract from S. spinosum fruits could be a potential candidate for nutraceutical application.

Polyphenol-enriched extracts of Sarcopoterium spinosum fruits for counteracting lipid accumulation and oxidative stress in an in vitro model of hepatic steatosis.

Sarcopoterium spinosum (L.) Spach is a Rosaceae shrub employed in the folk medicine in the Eastern Mediterranean basin. The previous few studies have focused on the S. spinosum roots, while the fruits have been poorly investigated. The present study aims to assess the biological properties of S. spinosum fruits collected in Lebanon and subjected to ethanolic, water or boiling water extraction. The extracts were compared for the phenol and flavonoid contents, and for the in vitro radical scavenging ability. The ethanolic extract (SEE) was selected and characterized by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) showing a phenolome rich in tannins (ellagitannins), flavonoids (quercetin derivatives), and triterpenes. The biological activity of SEE was tested on a cellular model of moderate steatosis consisting of lipid-loaded hepatic cells treated with increasing concentrations of SEE (1-25 µg/mL), or with corilagin or quercetin as comparison. In steatotic hepatocytes the SEE was able (i) to ameliorate the hepatosteatosis; (ii) to counteract the excess ROS and lipid peroxidation; (iii) to restore the impaired catalase activity. The results indicate that the ethanolic extract from S. spinosum fruits is endowed with relevant antisteatotic and antioxidant activities and might find application as nutraceutical product.

Nuclear and chromatin rearrangement associate to epigenome and gene expression changes in a model of in vitro adipogenesis and hypertrophy.

Hypertrophy of adipocytes represents the main cause of obesity. We investigated in vitro the changes associated with adipocyte differentiation and hypertrophy focusing on the nuclear morphometry and chromatin epigenetic remodelling. The 3 T3-L1 pre-adipocytes were firstly differentiated into mature adipocytes, then cultured with long-chain fatty acids to induce hypertrophy. Confocal and super-resolution stimulation emission depletion (STED) microscopy combined with ELISA assays allowed us to explore nuclear architecture, chromatin distribution and epigenetic modifications. In each condition, we quantified the triglyceride accumulation, the mRNA expression of adipogenesis and dysfunction markers, the release of five pro-inflammatory cytokines. Confocal microscopy revealed larger volume and less elongated shape of the nuclei in both mature and hypertrophic cells respect to pre-adipocytes, and a trend toward reduced chromatin compaction. Compared to mature adipocytes, the hypertrophic phenotype showed larger triglyceride content, increased PPARγ expression reduced IL-1a release, and up-regulation of a pool of genes markers for adipose tissue dysfunction. Moreover, a remodelling of both epigenome and chromatin organization was observed in hypertrophic adipocytes, with an increase in the average fluorescence of H3K9 acetylated domains in parallel with the increase in KAT2A expression, and a global hypomethylation of DNA. These findings making light on the nuclear changes during adipocyte differentiation and hypertrophy might help the strategies for treating obesity and metabolic complications.

Adipocyte-hepatocyte crosstalk in cellular models of obesity: Role of soluble factors.

Hepatic steatosis is often a consequence of obesity. Adipose tissue is an important endocrine regulator of metabolic homeostasis in the body. In obesity, adipocytes become hypertrophic and develop an inflammatory phenotype, altering the panel of secreted adipokines. Moreover, excess fatty acids are, in part, released by adipocytes and delivered to the liver. These multiple pathways of adipose-liver crosstalk contribute to the development and progression of liver disease: TNFα induces hepatocyte dysfunction, excess of circulating fatty acids promotes hepatic steatosis and inflammation, whilst adipokines mediate and exacerbate liver injury. In this study, we investigated in vitro the effects and mechanisms of the crosstalk between adipocytes and hepatocytes, as a function of the different adipocyte status (mature vs hypertrophic) being mediated by soluble factors. We employed the conditioned medium method to test how mature and hypertrophic adipocytes distinctively affect the liver, leading to metabolic dysfunction. The media collected from adipocytes were characterized by high triglyceride content and led to lipid accumulation and fat-dependent dysfunction in hepatocytes. The present findings seem to suggest that, in addition to triglycerides, other soluble mediators, cytokines, are released by mature and hypertrophic adipocytes and influence the metabolic status of liver cells. Understanding the precise factors involved in the pathogenesis and pathophysiology of NAFLD in obesity will provide important insights into the mechanisms responsible for the metabolic complications of obesity, paving the way for new possible approaches.