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Herbal teas are used in South Africa as digestives to lower glycaemia and for other indications. However, the chemical composition of the infusions and their effect on enzymes related to metabolic syndrome is poorly known. The composition of infusions and methanol extracts of B. saligna (Scrophulariaceae), Lippia javanica, L. scaberrima, and Phyla dulcis (Verbenaceae) was assessed and the effect of the infusions and extract was determined towards α-glucosidase, α-amylase, and pancreatic lipase. The commercial herbal products were extracted separately with MeOH or hot water to obtain the extract/infusion for comparative studies. Total phenolic, total flavonoid and antioxidant capacity were assessed. The fingerprints of the MeOH extracts and infusions were compared by HPLD-DAD. The extract constituents were tentatively identified by HPLC-MS/MS and NMR analyses. From the extracts/infusions, 57 compounds were identified, including iridoids, phenylpropanoid glycosides, flavonoids, and caffeic acid derivatives, among others. The MeOH extracts and infusions showed strong inhibition towards α-glucosidase with IC50 in the range of 0.13–0.84 µg/mL for the phenolic-enriched infusion extract (PEI) and 0.47–0.50 µg/mL for the MeOH extracts, respectively. The P. dulcis PEI showed higher inhibition towards α-glucosidase, and the MeOH extract of L. scaberrima was better than the PEI. At 100 µg/mL, the PEI from the four herbal teas reduces the activity of α-amylase by 23.03–28.61%, with L. javanica as the most active tea. Three of the species are high in phenylpropanoid glycosides, while P. dulcis contains rosmarinic acid. Some 26 compounds were identified in the infusion from B. saligna, 28 from L. scaberrima, and 21 from P. dulcis. Four of them are common in all the teas, namely decaffeoylverbascoside, verbascoside, isoverbascoside, and tuberonic acid hexoside. Ten compounds occur in two of the teas and seventeen, fifteen, and eleven compounds were detected only in B. saligna, L. scaberrima, and P. dulcis, respectively. Most of the compounds are reported for the first time from the crude drug infusions. The results give some support for the traditional use of herbal teas as digestives and/or indications for diabetes. The chemical fingerprints set the basis for quality control of the crude drugs, based on the main constituents and differential compounds occurring in the samples.

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.

Olive oil consumption has increased in the last two decades and consequently, its wastes have increased, which generates a tremendous environmental impact. Among the by-products are the olive mill leaves, which are easier and inexpensive to treat than other olive by-products. However, little research has been done on their chemical composition and potential bioactivity. Hence, in this study, olive mill leaves were used to obtain Oleuropein-Enriched Extracts (OLEU-EE) using Conventional Extraction, Ultrasound-Assisted Extraction, and Homogenization-Assisted Extraction. These three techniques were evaluated using a Factorial Design to determine the parameters to obtain an OLEU-EE with high contents of Total Phenolic Compounds (TPC), Antioxidant Activity (AA), and Oleuropein concentration (OLEU). From the results, the Homogenizer-Assisted Extraction (HAE) technique was selected at 18,000 rpm, solid:liquid ratio 1:10, and 30 s of homogenization with 70% ethanol, due to its high TPC (5,196 mg GA/100 g), AA (57,867 μmol of TE/100 g), and OLEU (4,345 mg of OLEU/100 g). In addition, the antiglycating effect of OLEU-EE on the levels of (1) fluorescent Advanced Glycation End Products (AGEs) were IC50 of 0.1899 and 0.1697 mg/mL for 1λEXC 325/λEM 440 and 2λEXC 389/λEM 443, respectively; (2) protein oxidative damage markers such as dityrosine (DiTyr), N-formylkynurenine (N-formyl Kyn), and kynurenine (Kyn) were IC50 of 0.1852, 0.2044, and 0.1720 mg/mL, respectively. In conclusion, OLEU-EE from olive mill leaves has different capacities to inhibit AGEs evidenced by the IC50 of fluorescent AGEs and protein oxidation products, together with the scavenging free radical evidenced by the concentration of Trolox Equivalent. Therefore, OLEU-EE could be potential functional ingredients that prevent oxidative damage caused by free radicals and AGEs accumulation.

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

The COVID-19 pandemic has led to the search for new molecules with antiviral activity against SARS-CoV-2. The entry of the virus into the cell is one of the main targets for inhibiting SARS-CoV-2 infection. Natural products are an important source of new therapeutic alternatives against diseases. Pseudotyped viruses allow the study of SARS-CoV-2 viral entry inhibitors, and due to their simplicity, they allow the screening of a large number of antiviral candidates in Biosafety Level 2 facilities. We used pseudotyped HIV-1 with the D614G SARS-CoV-2 spike glycoprotein to test its ability to infect ACE2-expressing HEK 293T cells in the presence of diverse natural products, including 21 plant extracts, 7 essential oils, and 13 compounds from plants and fungi. The 50% cytotoxic concentration (CC50) was evaluated using the resazurin method. From these analyses, we determined the inhibitory activity of the extract of Stachytarpheta cayennensis, which had a half-maximal inhibitory concentration (IC50) of 91.65 µg/mL, a CC50 of 693.5 µg/mL, and a selectivity index (SI) of 7.57, indicating its potential use as an inhibitor of SARS-CoV-2 entry. Moreover, our work indicates the usefulness of the pseudotyped-virus system in the screening of SARS-CoV-2 entry inhibitors.

The “Kurugua” (Sicana odorifera) is a native fruit that demonstrates attractive nutritional, coloring, flavoring, and antioxidant properties. The main by-products from the processing and consumption of kurugua fruit are epicarp and seeds. In this work, the properties of the seeds of S. odorifera were evaluated. The nutritional composition of the fruit seeds was determined through AOAC official methods and UHPLC-ESI-MS/MS profiling. The antioxidant activities were determined using in vitro methods, and the acute toxicity and hepatoprotective properties were investigated in Swiss albino mice. Quercetin derivatives and cucurbitacins were the main phytochemicals in the seeds’ methanolic extract and demonstrated some biological activities. GC-MS analysis revealed the essential fatty acids linolenic and linoleic as the main compounds present in seeds oil. The methanolic extract significantly reduced the serum levels of glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) in mice with induced hepatotoxicity (GPT p < 0.05; GOT p < 0.001) at the minor concentration tested (100 mg/kg EMSo). The results suggest that the S. odorifera seeds as by-products show potential use as a source of phytochemicals and in the production of oils with application in food supplements and nutraceuticals. Their integral use could contribute to waste reduction from kurugua fruits processing within the food safety and environmental sustainability framework.

Sicana odorifera is a native fruit of South America large in size. Its dark-colored skin constitutes a useful byproduct for obtaining bioactive molecules because it is rich in polyphenolic compounds, such as anthocyanins. Obtaining appropriate extracts for obtaining anthocyanins can be useful for multiple applications in the food industry or for obtaining phytopharmaceuticals. In this work, the fruit and its peel composition were evaluated, an anthocyanin extraction system was designed and optimized, and the extract obtained was characterized. The peel composition of S. odorifera ripe fruits from the black accession growing in Paraguay was rich in polyphenol compounds and anthocyanins. Ultrasound-assisted extractions of total anthocyanins were studied, and the extraction variables were optimized. First, a screening design was considered to analyze time, pH, liquid–solid ratio, solvent concentration, and temperature. From the screening design, the significant variables were considered in a Box–Behnken design, and a response surface methodology was applied. The resulting total anthocyanin extract was characterized by UPLC-DAD-MS / MS-ESI. The most efficient system for the extraction of anthocyanins from the peel was at 15 min, 20 °C, pH = 6, 60% ethanol, and 80 mL/g of liquid–solid ratio. The highest concentration obtained was 61.908 mg C3G/g peel extract. In the extract, 12 main compounds were tentatively identified, including five anthocyanin derivatives, five flavonol derivatives, and two flavonol aglycones. This study provides information for the obtention of an anthocyanin-based dye from black kurugua peel, possibly useful for future applications as a natural colorant in high-added-value foods due to its antioxidant characteristics.

The crude drug ysypó hû (Adenocalymma marginatum DC., Bignoniaceae) is used traditionally by the Guarani of Eastern Paraguayan as a male sexual enhancer. The aim of the present study was to identify the main constituents of the crude drug and to evaluate the in vitro inhibitory activity towards the enzyme phosphodiesterase-5 (PDE-5). The main compounds were isolated by counter-current chromatography (CCC). The metabolites were identified by spectroscopic and spectrometric means. The chemical profiling of the extracts was assessed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). The crude extract and main isolated compounds were tested for their PDE-5 inhibitory activity using commercial kits. The iridoid theviridoside and 4-hydroxy-1-methylproline were isolated as the main constituent of the crude drug. Four chlortheviridoside hexoside derivatives were detected for the first time as natural products. Chemical profiling by HPLC-MS/MS led to the tentative identification of nine iridoids, six phenolics, and five amino acids. The crude extracts and main compounds were inactive towards PDE-5 at concentrations up to 500 µg/mL. Iridoids and amino acid derivatives were the main compounds occurring in the Paraguayan crude drug. The potential of ysypó hû as a male sexual enhancer cannot be discarded, since other mechanisms may be involved.