Claudio R. Galmarini

Garlic and Onion Attenuates Vascular Inflammation and Oxidative Stress in Fructose-Fed Rats

This study evaluates the antioxidant and the anti-inflammatory properties of garlic (G) and onion (O) in fructose-fed rats (FFR). Thirty-day-old male Wistar rats were assigned to control (C), F (10% fructose in drinking water), F+T (tempol 1 mM as control antioxidant), F+G, and F+O. Aqueous G and O extracts were administered orally in doses of 150 and 400 mg/kg/d respectively, and along with tempol, were given during the last 8 weeks of a 14-week period. At the end of the study, FFR had developed insulin resistance, aortic NADPH oxidase activity, increased SBP, plasma TBARS and vascular cell adhesion molecule-1 (VCAM-1) expression in mesenteric arteries, and a decrease in heart endothelial nitric oxide synthase (eNOS). Garlic and onion administration to F rats reduced oxidative stress, increased eNOS activity, and also attenuated VCAM-1 expression. These results provide new evidence showing the anti-inflammatory and antioxidant effect of these vegetables.

Aqueous garlic extracts prevent oxidative stress and vascular remodeling in an experimental model of metabolic syndrome.

The organosulfur profile and the effect on oxidative stress and vascular remodeling in fructose-fed rats (FFR) were evaluated in Fuego INTA and Morado INTA garlic cultivars. Wistar rats were fed either normal rat chow (control) or the same diet plus 10% fructose in drinking water. During the last 6 weeks of a 12 week period of the corresponding diet, a subgroup of control and FFR received an aqueous extract of Fuego INTA and Morado INTA. Fuego INTA showed higher levels of total thiosulfinates, allicin, and pungency than Morado INTA. FFR showed an increase of systolic blood pressure, aortic NAD(P)H oxidase activity, plasma thiobarbituric acid reactive substances, and vascular remodeling that was significantly reduced after both garlic administrations. The beneficial effect was slightly higher when Fuego INTA was administered. Both aqueous garlic extracts prevent oxidative stress and vascular remodeling in rats with metabolic syndrome, suggesting the existence of slight differences among cultivars.

Variability of solids, organosulfur compounds, pungency and health-enhancing traits in garlic (Allium sativum L.) cultivars belonging to different ecophysiological groups.

Garlic is a vegetable mainly agamically propagated, and it has been dispersed all around the world. Garlic cultivars have been classified in different ecophysiological groups (EG) according to their bulbing requirements. The variability in organosulfur composition (ACSOs), solids content (SC), pungency (PC) and antiplatelet activity (IAA) and the correlation among these traits in garlic clones belonging to three EG was studied. We found variability for ACSOs, SC, PC and IAA between clones belonging to different EG and also among clones belonging to the same EG. Cutivars EG III presented more variability than EG IV for ACSOs, thiosulfinates, allicin and PC, while for SC, EG IV was the most variable. The correlations found suggested that IAA observed was mainly due to organosulfur composition. Finally recommendations about the most suitable cultivars for fresh consumption, pharmaceutical and dehydration industry are made.

Nectar and Flower Traits of Different Onion Male Sterile Lines Related to Pollination Efficiency and Seed Yield of F1 Hybrids

ABSTRACT Honey bees are the main pollinators of onion crops for seed production, but owing to low attractiveness of flowers, pollination is often inadequate. Pollination problems result in low seed yields. This problem is accentuated when male sterile lines (MSL) are used to produce hybrid onion seeds. In this study, the effect of floral attributes and nectar composition on the preference of honey bees of four MSLs and one onion open pollinated cultivar were assessed. The chemical composition of nectar was described through the analysis of sugars, trace elements, volatile organic compounds, and phenol compounds. The samples studied showed qualitative and quantitative differences in the analyzed traits of flowers and nectar among the different lines. Furthermore, field observations showed a great difference on the number of bee visits and seed yield among the onion lines analyzed. For the first time, this study demonstrates that there are marked differences in the chemical composition of nectar and floral morphology between open pollinated and MSLs and also within MSLs. In addition, these differences were correlated with the number of visits and seed yield. Therefore, it would be possible to select indirectly the most promising productive MSL using simple determinations of chemical compounds or floral morphological characters.

Determination of alkaloids in onion nectar by micellar electrokinetic chromatography.

Nectar is the most important floral reward offered by plants to insects. Minor components such as alkaloid compounds in nectar affect bee foraging, with great influence in seed production. CE is an advantageous tool for the analysis of unexplored samples such as onion nectar due to the limited amounts of samples. Considering the importance of these compounds, a simultaneous determination of nicotine, theophylline, theobromine, caffeine, harmaline, piperine in onion nectar by MEKC‐UV is herein reported. The extraction of alkaloid compounds in nectar was performed by SPE using a homemade miniaturized column (C18). Effects of several important factors affecting extraction efficiency as well as electrophoretic performance were investigated to acquire optimum conditions. Under the proposed conditions, the analytes can be separated within 15 min in a 50 cm effective length capillary (75 μm id) at a separation voltage of 20 kV in 20 mmol/L sodium tretraborate, 100 mmol/L SDS. The amount of sample requirement was reduced up to 2000 times, when compared to traditional methods, reaching limits of detection as low as 0.0153 ng/L. For the first time, this study demonstrates that there are marked qualitative and quantitative differences in nectar alkaloids between open pollinated and male sterile lines (MSLs) and also within MSLs.

Variability in spectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value

Onion pyruvate concentration is used as a predictor of flavor intensity and nutraceutical value. The protocol of Schwimmer and Weston (SW) (1961) is the most widespread methodology for estimating onion pyruvate. Anthon and Barret (AB) (2003) proposed modifications to this procedure. Here, we compared these spectrophotometry-based procedures for pyruvate analysis using a diverse collection of onion cultivars. The SW method always led to over-estimation of pyruvate levels in colored, but not in white onions, by up to 65%. Identification of light-absorbance interfering compounds was performed by spectrophotometry and HPLC analysis. Interference by quercetin and anthocyanins, jointly, accounted for more than 90% of the over-estimation of pyruvate. Pyruvate determinations according to AB significantly reduced absorbance interference from compounds other than pyruvate. This study provides evidence about the mechanistic basis underlying differences between the SW and AB methods for indirect assessment of onion flavor and nutraceutical value.

Towards genetic transformation of local onion varieties

as transfection vectors. Mature embryos from three varieties of ‘Valenciana’ onion, Torrentina, Cobriza INTA and Grano de oro were in vitro cultivated for callus induction. After three to four months an average of 57.4% success for the three varieties was reached. Transformation was carried out with Agl1 or LBA 4404 A.

Dataset on absorption spectra and bulb concentration of phenolic compounds that may interfere with onion pyruvate determinations

We present data on absorption spectra (400–540 nm) and concentration of phenolic compounds quercetin, myricetin, kaempferol, rutin, catechin, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), in yellow, red and white onions. These data are related to the article entitled “Variability in spectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value” (Beretta et al., 2017) [1]. Given the relevance of pyruvate determinations for estimating onion pungency and functional value, it is important to identify compounds that can interfere with pyruvate determinations when using two previously published analytical procedures, namely Schwimmer and Weston (1961) (SW) [2] and Anthon and Barret (2002) (AB) [3], which are based on spectrophotometry and light-absorbance at 420 nm and 515 nm, respectively. The data presented in this article are absorption spectra for 7 onion phenolic compounds in the range 400–540 nm, which include wavelengths used by the two pyruvate analytical methods (Schwimmer and Weston, 1961; Anthon and Barret, 2002) [2,3] that were compared in our reference article (Beretta et al., 2017) [1]. Additionally, bulb content data for these 7 phenolic compounds in onion cultivars and F2 progenies with different bulb color were included to allow further analyses.

Onion Hybrid Seed Production: Relation with Nectar Composition and Flower Traits

Abstract Onion (Allium cepa L.) is one of the main vegetable crops. Pollinators are required for onion seed production, being honeybees the most used. Around the world, two types of onion varieties are grown: open pollinated (OP) and hybrids. Hybrids offer numerous advantages to growers, but usually have lower seed yields than OP cultivars, which in many cases compromise the success of new hybrids. As pollination is critical for seed set, understanding the role of floral rewards and attractants to pollinator species is the key to improve crop seed yield. In this study, the correlation of nectar-analyzed compounds, floral traits, and seed yield under open field conditions in two experimental sites was determined. Nectar composition was described through the analysis of sugars, phenol, and alkaloid compounds. Length and width of the style and tepals of the flowers were measured to describe floral traits. Floral and nectar traits showed differences among the studied lines. For nectar traits, we found a significant influence of the environment where plants were cultivated. Nonetheless, flower traits were not influenced by the experimental sites.The OP and the male-sterile lines (MSLs) showed differences in nectar chemical composition and floral traits. In addition, there were differences between and within MSLs, some of which were correlated with seed yield, bringing the opportunity to select the most productive MSL, using simple determinations of morphological characters like the length of the style or tepals size.