Eloy Fernández

Evaluation of Antioxidant, Antidiabetic and Anticholinesterase Activities of Smallanthus sonchifolius Landraces and Correlation with Their Phytochemical Profiles

The present study aimed to investigate the phytochemical profile of leaf methanol extracts of fourteen Smallanthus sonchifolius (yacon) landraces and their antioxidant, anticholinesterase and antidiabetic activities that could lead to the finding of more effective agents for the treatment and management of Alzheimer’s disease and diabetes. For this purpose, antioxidant activity was assessed using different tests: ferric reducing ability power (FRAP), 2,2-diphenyl-1-picryl hydrazyl (DPPH), nitric oxide (˙NO) and superoxide (O2˙−) scavenging and lipid peroxidation inhibition assays. Anticholinesterase activity was investigated by quantifying the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, whereas antidiabetic activity was investigated by α-amylase and α-glucosidase inhibition tests. To understand the contribution of metabolites, phytochemical screening was also performed by high performance liquid chromatography-diode array detector (HPLC-DAD) system. Among all, methanol extract of PER09, PER04 and ECU44 landraces exhibited the highest relative antioxidant capacity index (RACI). ECU44 was found to be rich in 4,5-di-O-caffeoylquinic acid (CQA) and 3,5-di-O-CQA and displayed a good α-amylase and α-glucosidase inhibition, showing the lowest IC50 values. Flavonoids, instead, seem to be involved in the AChE and BChE inhibition. The results of this study revealed that the bioactive compound content differences could be determinant for the medicinal properties of this plant especially for antioxidant and antidiabetic activities.

Total phenolic content of yacon (Smallanthus sonchifolius) rhizomes, leaves, and roots affected by genotype

Abstract The content of total polyphenols (TP) in rhizomes, leaves, and tuberous roots of five genotypes of yacon (Smallanthus sonchifolius) from New Zealand, Germany, Ecuador, and Bolivia cultivated on trial field plots of the University of Agriculture in Prague‐Suchdol under field conditions from the 2003 harvest was determined spectrophotometrically by Folin‐Ciocalteau phenol reagent. Obtained results were compared by means of dendrograms according to cluster analyses based on TP and morphological traits. In four genotypes the content of inulin and fructose was also determined. From the obtained results, on the basis of similarity of obtained dendrograms, a very close agreement between TP content in rhizomes and leaves and origin and morphological traits of yacon genotypes was found. Five yacon genotypes were classified into three groups. The genotype from New Zealand with white coloured flesh (NZLw) and genotypes from Ecuador (ECU) and Bolivia (BOL) were distinguished with high TP content in purple coloured rhizomes and leaves; whereas the New Zealand genotype with yellow/orange coloured flesh (NZLy) and the genotype from Germany (DEU) with white coloured rhizomes with purple striations showed lower TP content in rhizomes and leaves. Also, inulin content in genotypes from Ecuador (ECU) and Bolivia (BOL) was higher in comparison to the genotypes from Germany (DEU) and New Zealand (NZLy). Thus, we found that TP and inulin content was dependent on botanical origin, morphological traits and polymorphisms of individual genotypes.

Effect of Lepidium meyenii Walp. on Semen Parameters and Serum Hormone Levels in Healthy Adult Men: A Double-Blind, Randomized, Placebo-Controlled Pilot Study

Background/Aims. Products of Lepidium meyenii Walp. (maca) are touted worldwide as an alimentary supplement to enhance fertility and restore hormonal balance. Enhancing properties of maca on semen parameters in animals were previously reported by various authors, but we present to the best of our knowledge the first double-blind, randomized, placebo-controlled pilot trial in men. The aim of this study was to evaluate the effects of maca on semen parameters and serum hormone levels in healthy adult men. Methods. A group of 20 volunteers aged 20–40 years was supplied by milled hypocotyl of maca or placebo (1.75 g/day) for 12 weeks. Negative controls of semen were compared to the samples after 6 and 12 weeks of maca administration; negative blood controls were compared to the samples after 12 weeks of treatment. Results. Sperm concentration and motility showed rising trends compared to placebo even though levels of hormones did not change significantly after 12 weeks of trial. Conclusion. Our results indicate that maca possesses fertility enhancing properties in men. As long as men prefer to use alimentary supplement to enhance fertility rather than prescribed medication or any medical intervention, it is worth continuing to assess its possible benefits.

The influence of the quinone antioxidants tert-butylhydroquinone and 2,5-di-tert-butylhydroquinone on the arachidonic acid metabolism in vitro

The aim of the present study was to elucidate the effect of the food additive tert-butylhydroquinone (TBHQ), its metabolite tert-butylbenzoquinone (TBQ), the indirect food additive 2,5-di-tert-butylhydroquinone (DTBHQ) and five other structurally related quinones on the enzymatic activity of cyclooxygenase-1 and -2 (COX-1, -2) and 5-lipoxygenase (5-LO). In a study conducted on purified enzymes TBHQ affected neither COX-1 nor COX-2 activity, but inhibited 5-LO in human neutrophils with an IC50 of 13.5 µM. In contrast, DTBHQ regulated the activity of 5-LO as well as the activity of COX-2 (IC50 = 1.8 and 14.1 for 5-LO and COX-2, respectively). The in silico studies on DTBHQ indicated interactions with the catalytic iron of 5-LO and possible hydrogen bond interactions with His367 or His372. These data suggest that TBHQ and DTBHQ influence arachidonic acid (AA) metabolism in biologically relevant concentrations in vitro and should be further studied for their possible effect on the AA pathway in vivo.

Identification of Smallanthus sonchifolius in herbal tea mixtures by PCR and DART/TOF-MS methods

Žiarovská J., Rajchl A., Fernández E., Prchalová J., Milella L. (2016): Identification of Smallanthus sonchifolius in herbal tea mixtures by PCR and DART/TOF-MS methods. Czech J. Food Sci., 34: 495–502. The identification of yacon, a medicinal plant, in tea mixtures by rapid Polymerase Chain Reaction (PCR) and the Direct Analysis in Real Time coupled with Time-of-Flight Mass Spectrometry (DART/TOF-MS) method were evaluated. Three tea products and a pure yacon tea were analysed using the molecular method PCR, concretely the intraspecific variation of the internal transcribed spacer (ITS) regions of rDNA and the DART method coupled with TOF-MS. The results show the reliability of PCR and restriction cleavage of the ITS as a combined approach to confirm the presence of yacon in herbal tea mixtures. Three fragments of approximately 700, 408, and 235 bp in length are present when yacon is a part of the herbal tea mixture. The Principal Component Analysis (PCA) based on the fingerprints of the complete Total Ion Current (TIC) mass spectra shows sufficient separation of herbal teas with and without yacon leaves. The reported methods are technically rapid and can be used as an effective tool for the purposes of yacon identification or authentication.

In vitro Induced Mitotic Polyploidy in Drosera capensis L.

Abstract The objective of this study was to induce mitotic polyploidization in Drosera capensis. Tetraploid plants of D. capensis were induced successfully by treating leaf segments in vitro with oryzalin solution with four different concentrations (20, 40, 60 or 80 μM) for 12, 24 or 48 hours. Three tetraploid (2n = 4x = 80) plants were obtained in three treatments (20 μM for 48 h, 60 μM for 24 h and 80 μM for 12 h). Tetraploidy was confirmed by flow cytometry. The survival rate of these plants was not significantly influenced by oryzalin concentration or exposure time.

Antioxidant Activity and Phytochemical Characterization of Senecio clivicolus Wedd.

Antioxidant phytochemicals play a key role in oxidative stress control and in the prevention of related disorders, such as premature aging, degenerative diseases, diabetes, and cancer. The aim of this study was to investigate the potential antioxidant activity and the phytochemical profile of Senecio clivicolus Wedd., a perennial shrub, belonging to the Asteraceae family. Despite the wide interest of this family, this specie has not been investigated yet. S. clivicolus aerial parts were extracted with 96% ethanol. Then, the ethanol extract was fractionated by liquid/liquid extraction using an increasing solvents polarity. Total polyphenol and terpenoid contents were measured. Moreover, the antioxidant activity was evaluated by six different complementary in vitro assays. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different tests. The sample showing the highest RACI was subjected to characterization and quantitation of its phenolic composition using LC-MS/MS analysis. The ethyl acetate fraction, investigated by LC-MS/MS analysis, showed 30 compounds, most of them are chlorogenic acid and flavonoid derivatives. To the best of our knowledge, this is the first report about the evaluation of antioxidant activity and phytochemical profile of S. clivicolus, underlying the importance of this species as a source of health-promoting phytochemicals.

DMA thermal analysis of yacon tuberous roots

Abstract Specimens prepared from yacon roots in first two weeks after harvest were tested by dynamic mechanical analysis thermal analysis at temperatures between 30 and 90°C. No differences between different parts of roots were proved. There were indicated some differences in the test parameters that were caused by short time storage of the roots. One source of the differences was loss of water during the roots storage. The measured modulus increased during short time storage. Detailed study of changes of the modulus during the specimen dynamic mechanical analysis test provided information about different development of the storage and loss moduli during the specimen heating. The observed results can be caused by changes in cellular membranes observed earlier during vegetable heating, and by composition changes due to less stable components of yacon like inulin.