Search

Eight Ribes magellanicum collections from three different places in southern Patagonia were compared for content of different groups of phenolics, antioxidant capacity and inhibition of enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The sample with the highest antioxidant capacity was assessed for glutathione (GSH) synthesis stimulation in human gastric adenocarcinoma (AGS) cells. The chemical profile was determined by high performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and the main phenolics were quantified. The samples from Navarino Island and Reserva Nacional Magallanes showed higher content of anthocyanins and caffeoylquinic acid, with better activity towards α-glucosidase and antioxidant capacity. A sample from Omora (Navarino Island), significantly increased intracellular GSH content in AGS cells. Some 70 compounds were identified in the fruit extracts by HPLC-MS/MS. The glucoside and rutinoside from delphinidin and cyanidin and 3-caffeoylquinic acid were the main compounds. Different chemical profiles were found according to the collection places.

Leaf extracts from Chilean bean landraces were assessed for antiplatelet activity using different assays in vitro. Lyophilized MeOH:H2O 7:3 (v/v) and EtOH:H2O 7:3 (v/v) leaf extracts from the Chilean landraces Coscorron, Frutilla, Magnum, Sapito and Tortola were compared for platelet aggregation effect by turbidimetry and flow cytometry. The HPLC-DAD study allowed the identification of caffeoyl malic acid, derivatives of quercetin and kaempferol. The results showed that the EtOH:H2O 7:3 extracts have higher antiplatelet capacity, with better effects for the Frutilla and Sapito landraces (IC50 0.38 ± 0.05 and 0.16 ± 0.08 mg/mL, respectively). The Sapito extract inhibited P-selectin expression, CD63 secretion, and concentration-dependent GPIIb/IIIa activation. The activity was associated with the main phenolics content, including rutin, caffeoyl malic acid and kaempferol 3-O-glucoside. The findings add evidence for the potential of bean leaves as greens, affording naturally occurring compounds with health promoting properties, including inhibition of platelet aggregation in vitro.

Phenolics can decrease the levels of advanced glycation end products (AGEs) from proteins, but their mechanisms in complex mixtures are poorly understood. Leaf extracts and the main phenolics from Chilean bean (Phaseolus vulgaris) landraces were assessed for their capacity to inhibit AGEs and oxidative modifications on bovine serum albumin incubated with glucose. The leaf extracts of six bean landraces decreased AGEs (fluorescent AGEs and carboxymethyl lysine) and oxidative (Kyn, Di-Tyr, protein carbonyls) modifications. Fluorescent AGEs were characterized by time-resolved techniques. The composition of the extracts was determined by HPLC-DAD-Q-TOF-MS/MS, and the main compounds were quantified by HPLC. Correlations between the levels of AGEs or protein carbonyls with the main phenolics suggested synergic effects of caffeoyl malic acid (CMA) and rutin. The synergic effect was evaluated using mixtures of rutin and CMA, showing a strong decrease in fluorescent AGEs and protein carbonylation compared with the pure single compounds, supporting this finding.

The polyphenol-enriched extracts (PEEs) of Chilean currants Ribes magellanicum and R. punctatum were submitted to in vitro gastro-intestinal digestion and their anti-inflammatory activities were assessed using differentiated human Caco-2 (clone C2BBe1) cells stimulated with interleukin 1β (IL-1 β). The inhibitory effect of non-digested and digested PEEs towards human cyclooxygenase 1 (COX-1) and COX-2, and the gene expression of COX-2 and inducible nitric oxide synthase (iNOS) was also evaluated. The digested PEE from R. punctatum decreased the secretion of IL-8, IL-6, and TNF-α; whereas R. magellanicum reduced IL-6 and TNF-α in the Caco-2 cells (p