Antiproliferative Effect of Colonic Fermented Phenolic Compounds from Jaboticaba (Myrciaria trunciflora) Fruit Peel in a 3D Cell Model of Colorectal Cancer.

Jaboticaba is a Brazilian native berry described as a rich source of phenolic compounds (PC) with health promoting effects. PC from jaboticaba peel powder (JPP) have low intestinal bio-accessibility and are catabolized by gut microbiota. However, the biological implication of PC-derived metabolites produced during JPP digestion remains unclear. This study aimed to evaluate the antiproliferative effects of colonic fermented JPP (FJPP) in a 3D model of colorectal cancer (CRC) composed by HT29 spheroids. JPP samples fermented with human feces during 0, 2, 8, 24 or 48 h were incubated (10,000 µg mL-1) with spheroids, and cell viability was assessed after 72 h. Chemometric analyses (cluster and principal component analyses) were used to identify the main compounds responsible for the bioactive effect. The antiproliferative effect of FJPP in the CRC 3D model was increased between 8 h and 24 h of incubation, and this effect was associated with HHDP-digalloylglucose isomer and dihydroxyphenyl-γ-valerolactone. At 48 h of fermentation, the antiproliferative effect of FJPP was negligible, indicating that the presence of urolithins did not improve the bioactivity of JPP. These findings provide relevant knowledge on the role of colonic microbiota fermentation to generate active phenolic metabolites from JPP with positive impact on CRC.

LC-DAD-ESI-MS/MS analysis and cytotoxic and antiproliferative effects of chlorogenic acid derivative rich extract from Nerium oleander L. pink flowers.

Nerium oleander L. is a widely used medicinal plant for pharmaceutical purposes. In this work, an extract of the pink flowers of this plant (FE) was characterized in terms of phenolic composition by LC-DAD-ESI-MS/MS and bioactivity, namely, antioxidant and antiproliferative effects. A total of 20 compounds from different classes, including derivatives of phenolic acids and flavonoid glycosylated derivatives, were identified in FE. Chlorogenic acid was the dominant phenolic compound in the extract (62.28 ± 1.74 µg mg-1 of dry extract). The antioxidant activity was assessed by ORAC assay, and FE showed an ability to reduce peroxyl radicals (ORAC value of 791.26 µmol TEAC per g DE). Additionally, the FE inhibited the proliferation of a colorectal cancer cell line (HT29 cells, EC50 = 11.72 ± 0.02 µg mL-1) and showed no cytotoxicity to confluent Caco-2 cells, a model of human intestinal epithelium. These results provide new information about the phenolic composition of Nerium oleander pink flowers and the bioactivity of the extracts.

Phenolic compounds from Nerium oleander leaves: microwave assisted extraction, characterization, antiproliferative and cytotoxic activities.

A microwave-assisted extraction (MAE) method was used for the extraction of phenolic compounds from Nerium oleander leaves. The influence of variables such as ethanol concentration, microwave power, irradiation time and liquid/solid ratio on polyphenol extraction was modelled using a second-order regression equation based on response surface methodology (RSM). The optimal conditions for MAE were: extraction solvent 35% ethanol concentration, 500 W microwave power, 60 s irradiation time and a solvent/material ratio of 20 mL g-1. Under optimal MAE conditions, the recovery of TPC was 25.752 mg GAE per g dw. 19 compounds have been identified by HPLC-ESI-MS/MS analysis; the main compounds identified were chlorogenic acid, rutin and quinic acid esters, such as caffeoylquinic acids and dicaffeoylquinic acids. Additionally, the optimized extract demonstrated potential to inhibit HT29 colorectal cancer cell growth (EC50 = 2.432 µg mL-1) without presenting cytotoxicity in confluent Caco-2 cells, a model of human intestinal epithelium. These results supply new information about the phenolic composition of Nerium oleander leaves and their antiproliferative effect.

Characterization of phenolic compounds in chia (Salvia hispanica L.) seeds, fiber flour and oil.

The consumption of chia seeds products has increased recently and it has been suggested that the inclusion of this functional food in a daily human diet could contribute to improve consumers' health. However, a better knowledge about the composition of these products is mandatory. In this work, the phenolic compounds from commercial samples of chia seed, fiber flour and oil were extracted using an ultrasound-assisted methodology and were separated and identified by high-performance liquid chromatography coupled to a mass spectrometer. Methanol:water extracts were prepared and submitted to an acidic hydrolysis. Crude and hydrolyzed extracts were analyzed and phenolic compounds found were mainly caffeic acid and danshensu and its derivatives, such as rosmarinic and salvianolic acids. TPC was higher in the hydrolyzed extracts. These results supply new information about the main phenolic compounds presents in chia, which are important dietary sources of natural antioxidants for prevention of diseases caused by oxidative stress.