Search Results (28)

Waterlogging poses a grave abiotic stress that hampers crop productivity and survival due to reduced oxygen availability in the impacted tissues. To adapt to this hypoxic environment, the hypocotyls of melon (Cucumis melo L.) seedlings can produce a profusion of adventitious roots when exposed to waterlogging stress. However, research on the significance of these adventitious roots under waterlogging stress has been limited. The present study aimed to elucidate the critical role of adventitious roots by investigating the physiological, biochemical, and metabolic changes that occur following their removal during waterlogging stress. The removal of adventitious roots compromised the normal growth of melon seedlings, resulting in phenotypic abnormalities such as chlorotic and withered leaves. Our results indicated that the removal of adventitious roots led to significant reductions in total chlorophyll levels by 62.89% and 43.60% compared to the normal control condition and waterlogging stress alone, respectively. Additionally, in the adventitious root removal treatment, higher malondialdehyde (MDA) content, O₂^•− production rate, monodehydroascorbate reductase (MDHAR) activity, alcohol dehydrogenase (ADH) activity, the AsA/DHA ratio, proline content, jasmonic acid (JA) content, and 1-aminocyclopropane-1-carboxylic acid (ACC) content were observed. Specifically, JA levels were significantly enhanced by 180.54% and 52.05%, and ACC levels were significantly increased by 519.23% and 125.16% compared to the control and waterlogging stress conditions, respectively. Through untargeted metabolomic analysis, a total of 447 differentially accumulated metabolites (DAMs) were identified. Notably, jasmonic acid and brassinolide, which are involved in plant hormone signal transduction, along with cyanidin 3-(2G-xylosylrutinoside) classified as flavonoids, (2S,3′S)-α-amino-2-carboxy-5-oxo-1-pyrrolidinebutanoic acid categorized as proline and derivatives, and ligstroside-aglycone and foeniculoside VII annotated as terpenoids, exhibited key roles in the waterlogging response. This research enhances our understanding of the mechanisms underlying the removal of adventitious roots during waterlogging stress, as well as the associated physiological, biochemical, and metabolic changes. These findings provide valuable insights into the crucial role of adventitious roots in melon seedlings subjected to waterlogging stress and may inform strategies for enhancing waterlogging tolerance in breeding practices. Full article

Breast cancer (BC) is the most common malignancy and the second-leading cause of cancer-related mortalities in women. Epidemiological studies suggested the reduced BC incidence in Mediterranean populations due to the daily consumption of diets rich in extra-virgin olive oil (EVOO). EVOO secoiridoid phenolics are widely known for their positive outcomes on multiple cancers, including BC. The current study investigates the suppressive effects of individual and combined EVOO phenolics for BC progression and motility. Screening of a small library of EVOO phenolics at a single dose of 10 µM against the viability of the BC cell lines ZR-75-1 (luminal A) and MDA-MB-231 (triple negative BC, TNBC) identified oleocanthal (OC) and ligstroside aglycone (LA) as the most active hits. Screening of EVOO phenolics for BC cells migration inhibition identified OC, LA, and the EVOO lignans acetoxypinoresinol and pinoresinol as the most active hits. Combination studies of different olive phenolics showed that OC combined with LA had the best synergistic inhibitory effects against the TNBC MDA-MB-231 cells migration. A combination of 5 µM of each of OC and LA potently suppressed the migration and invasion of the MDA-MB-231 cells versus LA and OC individual therapies and vehicle control (VC). Animal studies using the ZR-75-1 BC cells orthotopic xenografting model in female nude mice showed significant tumor progression suppression by the combined OC-LA, 5 mg/kg each, ip, 3X/week treatments compared to individual LA and OC treatments and VC. The BC suppressive effects of the OC-LA combination were associated with the modulation of SMYD2–EZH2–STAT3 signaling pathway. A metastasis–clonogenicity animal study model using female nude mice subjected to tail vein injection of MDA-MB-231-Luc TNBC cells also revealed the effective synergy of the combined OC-LA, 5 mg/kg each, compared to their individual therapies and VC. Thus, EVOO cultivars rich in OC with optimal LA content can be useful nutraceuticals for invasive hormone-dependent BC and TNBC progression and metastasis. Full article

The health benefits of extra virgin olive oil (EVOO), including improved cardiovascular health and metabolic function, are linked to its phenolic content. This study evaluated how storage duration and packaging affect the phenolic composition and sensory quality of Corbella EVOO. Oils were analyzed at production and after 6 and 12 months of storage in two types of packaging: bag-in-box; stainless steel containers with a nitrogen headspace. UPLC-MS/MS profiling quantified 23 phenolic compounds, predominantly secoiridoids such as oleuropein and ligstroside aglycones. Oleuropein aglycone increased over time, whereas ligstroside aglycone peaked mid-storage before declining, likely converting to oleocanthal. Lignans and flavonoids degraded during storage, although luteolin increased, potentially due to glucoside hydrolysis. Bag-in-box packaging better preserved phenolic content than stainless steel. A sensory analysis corroborated the chemical findings, with oils stored in stainless steel showing greater reductions in pungency and astringency. A Pearson correlation linked bitterness with oleuropein aglycone (r = 0.44) and oleacein (r = 0.66), pungency with oleocanthal (r = 0.81), and astringency with oleacein (r = 0.86) and oleocanthal (r = 0.71). These findings highlight the importance of packaging in preserving the phenolic composition responsible for the sensory qualities of EVOO over time. Full article

Phenolic compounds are important targets in olive breeding due to their health benefits and impact on fruit and oil quality. Fruit phenolic profiling enables efficient screening of large germplasm collections without oil extraction, but environmental variability, especially year-to-year differences, affects their expression. The aim of this study was to assess the genotypic influence on fruit phenolic composition, based on a three-year evaluation of 10 wild olive genotypes and 75 cultivars from an olive core collection. Each genotype was sampled in at least two seasons, with 1 to 3 trees analyzed annually. Variance analysis revealed significant genetic variation among cultivars and notable genotype-by-year interactions for certain phenolics. Broad-sense heritability was generally high for most compounds, although some, such as ligstroside and ligstroside aglycone, showed greater environmental sensitivity. Best linear unbiased predictions (BLUPs) were highly correlated with average relative phenotypic values. Clustering analyses identified strong associations among key phenolic compounds and highlighted distinct metabolic profiles separating wild and cultivated genotypes, reflecting differences in phenolic accumulation patterns. These findings demonstrate the genetic and environmental influences on olive fruit phenolics and provide reliable estimates to support future marker-assisted selection studies aimed at developing useful tools in olive breeding programs. Full article

Near-infrared (NIR) spectroscopy, combined with multivariate calibration techniques such as stepwise decorrelation of variables (SELECT) and ordinary least squares (OLS) regression, was used to develop robust, reduced-spectrum regression models for quantifying key phenolic compound markers in various olive oils. These oils included nine extra virgin olive oil (EVOO) varieties, refined olive oil (ROO) blended with virgin olive oil (VOO) or EVOO, and pomace olive oil, both with and without hydroxytyrosol (HTyr) supplementation. Olive oils were analyzed before and after deep frying. The results show that HTyr ranged from 7.28 mg/kg in Manzanilla (lowest) to 21.43 mg/kg in Royuela (highest). Tyrosol (Tyr) varied from 5.87 mg/kg in Royuela (lowest) to 14.86 mg/kg in Hojiblanca (highest). Similar trends were observed in all phenolic fractions across olive oil cultivars before and after deep-frying. HTyr supplementation significantly increased both HTyr and Tyr levels in non-fried and fried supplemented oils, with HTyr rising from single digits in some controls (around 0 mg/kg) to over 300 mg/kg in most of the supplemented samples. SELECT efficiently reduced redundancy by selecting the most vital wavelengths and thus significantly improved the regression models for key phenolic compounds, including HTyr, Tyr, caffeic acid, decarboxymethyl ligstroside aglycone in dialdehyde form (oleocanthal), decarboxymethyl oleuropein aglycone in dialdehyde form (oleacein), homovanillic acid, pinoresinol, oleuropein aglycone in oxidized aldehyde and hydroxylic form (OAOAH), ligstroside aglycone in oxidized aldehyde and hydroxylic form (LAOAH), and total phenolic content (TPC), achieving correlation coefficients (R) of 0.91–0.98. The SELECT-OLS method generated highly predictive models with minimal complexity, using at most 30 wavelengths out of 700. The number of decorrelated predictors varied, at 12, 14, 15, 30, 30, 21, 30, 30, 30, and 18 for HTyr, Tyr, caffeic acid, oleocanthal, oleacein, homovanillic acid, pinoresinol, OAOAH, LAOAH, and TPC, respectively, demonstrating the adaptability of the SELECT-OLS approach to different spectral patterns. These reliable calibration models enabled online and routine quantification of phenolic compounds in EVOO, VOO, ROO, including both non-fried and fried as well as supplemented and non-supplemented samples. They performed well across eight deep-frying conditions (3–6 h at 170–210 °C). Implementing an NIR instrument with optimized variable selection would simplify spectral analysis and reduce costs. The developed models all demonstrated strong predictive performance, with low leave-one-out mean prediction errors (LOOMPEs) with values of 15.69, 8.47, 3.64, 9.18, 16.71, 3.26, 8.57, 13.56, 56.36, and 82.38 mg/kg for HTyr, Tyr, caffeic acid, oleocanthal, oleacein, homovanillic acid, pinoresinol, OAOAH, LAOAH, and TPC, respectively. These results confirm that NIR spectroscopy combined with SELECT-OLS is a feasible, rapid, non-destructive, and eco-friendly tool for the reliable evaluation and quantification of phenolic content in edible oils. Full article

Organoleptic features allow extra virgin olive oil (EVOO) to be distinguished from other commercial categories and to determine consumer preferences. In this study, we evaluated the influence of the phenolic content on the intensity of two characteristic attributes, namely, bitterness and pungency. The organoleptic analysis was carried out by a panel of trained tasters, who categorized a set of 200 EVOO samples produced in two consecutive crop seasons into three intensity levels (“Delicate”, “Medium”, and “Robust”) according to current regulations. The total phenolic content was correlated with the intensity of both attributes, but a different contribution was identified for individual phenols. For bitterness, aglycone isomers of oleuropein and ligstroside provided over 70% discrimination power (estimated by receiver operating characteristic analysis), while oleocanthal and oleacein were associated with a decrease in bitterness intensity. In addition, the intensity of pungency intensity was related to the content of oleocanthal, oleomissional, and oleokoronal, as they allowed the classification of about 75% of the “Robust” pungency EVOOs. With these premises, it is possible to obtain olive oils with the desired intensity of bitterness and pungency by controlling the factors that influence phenolic metabolism. Full article

Melanoma is among the most abundant malignancies in the US and worldwide. Ligstroside aglycone (LA) is a rare extra-virgin olive oil-derived monophenolic secoiridoid with diverse bioactivities. LA dose–response screening at the NCI 60 cancer cells panel identified the high sensitivity of the Malme-3M cell line, which harbors a BRAF V600E mutation. Daily oral 10 mg/kg LA exhibited potent in vivo antitumor effects against Malme-3M cells xenograft in a nude mouse model by targeting the BRAF signaling pathway. A human Clariom S microarray analysis of the collected Malme- 3M tumors identified 571 dysregulated genes, with the downregulation of pathways critical for melanoma cells growth and survival. A Western blot analysis of the collected animal tumors further validated the downregulation of the mutated BRAF–MAPK axis, as well as the GPD1 and ELOVL6 expression levels. A histopathological analysis of Malme-3M tumor sections showed extensive focal tumor necrosis in treated mice. An immunofluorescence study of tumor sections showed notable reductions in proliferation marker ki67 and the vasculogenesis marker CD31 in treated tumors. These findings promote LA as a potential nutraceutical lead for the control of the BRAF V600E mutant melanoma. Full article

Due to its high sensitivity to numerous variability sources, it is hard to define the typicity of a monovarietal virgin olive oil (VOO) according to its phenolic profile. In this study, we aimed to identify the features of phenolic composition that are persistent and minimally affected by variability sources, making them potential varietal markers. We separately analyzed three databases of monovarietal VOO phenolic compositions, determined by liquid chromatography, from three different cultivars. The first database was produced from the original data of the Bosana cultivar. The other two were obtained through a systematic analysis of scientific literature on Coratina and Frantoio cultivars. Several statistical tools, including coefficient of variability, correlations, and linear regression models, were used to find recurring proportions or ratios unaffected by variability sources suitable to define typical varietal traits. Some proportions between molecules, mostly within the same phenolic class, remain constant. Strong correlations between (i) flavonoids were observed in Bosana and Frantoio VOOs (R² = 0.87 and 0.77, respectively), (ii) oleacein-oleocanthal (Bosana, R² = 0.81) (iii) oleuropein aglycon-ligstroside aglycon (Frantoio, R² = 0.88), and (iv) lignans (Coratina, R² = 0.84). These traits could be useful tools for defining the typicity of monovarietal VOOs. Full article

The frequency of early frosts has increased in recent years, which are injurious to olive growing, causing losses in the yield and quality of virgin olive oil. In this research, it was studied how the management of agronomic factors mitigates frost damage in Arbequina olives, minimizing the loss of phenols and volatiles in virgin olive oil, at different fruit ripening stages. A Box–Behnken design and multivariate analysis were performed, with three levels of irrigation, potassium fertilization, and foliar copper application (15 treatments). Virgin olive oil was extracted from fresh and frozen olives. Light frost caused a significant decrease in the total phenols and secoiridoid compounds in and the antioxidant capacity of the frost-affected oils, which were perceived as more pungent and had the slight defect of “frostbitten olives”. According to the Box–Behnken design, an 86% reference evapotranspiration (ET₀) or higher with 100 potassium oxide units (UK₂O) and a 100% ET₀ or higher with 250 UK₂O would be required to minimize the effect of light frost on phenols and volatiles. Partial Least Squares Regression–Discriminant Analysis (PLS-DA) differentiated the virgin olive oils according to their ripening stage and fresh and frost conditions. Moreover, PLS-DA positively correlated a 75–100% ET₀ and 0 Uk₂O with the dialdehydic form of the decarboxymethyl ligstroside aglycone (p-HPEA-EDA), the dialdehydic form of the decarboxymethyl oleuropein aglycone (3,4-DHPEA-EDA), the dialdehydic form of the ligstroside aglycone (p-HPEA-EDA-DLA), and with fruity, pungent, and bitter attributes. Precision agronomic management based on the needs of the crop itself would avoid unnecessary stress on olive trees and oil damage. Full article

The effects of the phenolic compounds of extra virgin olive oil (EVOO) on AGS cells have never been studied so far, which is the aim of this study. The profiles of the main phenolic components in EVOOs, mainly secoiridoid compounds derived from the transformation of oleuropein during the olive milling process, were evaluated and compared. Oils of different origins were evaluated aiming at verifying whether chemical differences in the phenolic composition of the dry extracts played a role in the metabolism and in maintaining the cellular redox state of AGS cells. The following key enzymes of some metabolic pathways were studied: lactate dehydrogenase, enolase, pyruvate kinase, glucose 6-phosphate dehydrogenase, citrate synthase, 3-Hydroxyacyl-CoA dehydrogenase and hexokinase. As confirmed through PCA analysis, pretreatments with the dry extracts of EVOOs at different concentrations appeared to be able to counteract the enzymatic activity alterations due to oxidative stress induced by H₂O₂ 1 mM and 2 mM. The studied phytocomplexes showed the ability to protect AGS cells from oxidative damage and the secoiridoid derivatives from both oleuropein and ligstroside contributed to the observed effects. The results suggested that EVOOs with medium to high concentrations of phenols can exert this protection. Full article

Several individual olive oil phenols (OOPs) and their secoiridoid derivatives have been shown to exert anti-proliferative and pro-apoptotic activity in treatments of human cancer cell lines originating from several tissues. This study evaluated the synergistic anti-proliferative/cytotoxic effects of five olive secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycone, ligstroside aglycone and oleomissional) in all possible double combinations and of total phenolic extracts (TPEs) on eleven human cancer cell lines representing eight cell-culture-based cancer models. Individual OOPs were used to treat cells for 72 h in half of their EC₅₀ values for each cell line and their synergistic, additive or antagonistic interactions were evaluated by calculating the coefficient for drug interactions (CDI) for each double combination of OOPs. Olive oil TPEs of determined OOPs’ content, originating from three different harvests of autochthonous olive cultivars in Greece, were evaluated as an attempt to investigate the efficacy of OOPs to reduce cancer cell numbers as part of olive oil consumption. Most combinations of OOPs showed strong synergistic effect (CDIs < 0.9) in their efficacy, whereas TPEs strongly impaired cancer cell viability, better than most individual OOPs tested herein, including the most resistant cancer cell lines evaluated. Full article

Olive oil phenols (OOPs) are associated with the prevention of many human cancers. Some of these have been shown to inhibit cell proliferation and induce apoptosis. However, no systematic comparative study exists for all the investigated compounds under the same conditions, due to difficulties in their isolation or synthesis. Herein are presented innovative methods for large-scale selective extraction of six major secoiridoids from olive oil or leaves enabling their detailed investigation. The cytotoxic/antiproliferative bioactivity of these six compounds was evaluated on sixteen human cancer cell lines originating from eight different tissues. Cell viability with half-maximal effective concentrations (EC₅₀) was evaluated after 72 h treatments. Antiproliferative and pro-apoptotic effects were also assessed for the most bioactive compounds (EC₅₀ ≤ 50 μM). Oleocanthal (1) showed the strongest antiproliferative/cytotoxic activity in most cancer cell lines (EC₅₀: 9–20 μM). The relative effectiveness of the six OOPs was: oleocanthal (1) > oleuropein aglycone (3a,b) > ligstroside aglycone (4a,b) > oleacein (2) > oleomissional (6a,b,c) > oleocanthalic acid (7). This is the first detailed study comparing the bioactivity of six OOPs in such a wide array of cancer cell lines, providing a reference for their relative antiproliferative/cytotoxic effect in the investigated cancers. Full article

The purpose of this study was to evaluate the key quality characteristics of olive oil with a main focus on the biophenolic content, its beneficial effects on health and the contribution of various quality characteristics to its health claims, as well as its influence from various parameters. Samples from different traditional oil-producing regions of Greece were initially examined for the most important quality parameters, such as the percentage of free acidity, the number of peroxides and the spectrophotometric investigation in the ultraviolet. The samples were then tested for their biophenolic content, expressed in milligrams of tyrosol, and its derivatives per 20 g of olive oil using the analytical technique high-performance liquid chromatography (HPLC). Then, the biophenol contents of the analyzed samples were compared based on the presented intensities in terms of the variety and the area of cultivation, the altitude, the type of cultivation, the extraction system in the mill and the time interval from olive harvest to oiling. Finally, according to the results, the content of biophenols in olive oil and its health claims were found to be influenced by the various parameters with which they were compared. Full article

A single phenolic group and even a compound play different roles in the sensory properties and stability of virgin olive oil (VOO), which in turn are strongly influenced by several factors. Understanding the causes of differences in phenolic compound composition and oxidative stability (OS) in VOOs is essential for targeted and timely harvest and processing while maintaining desired oil quality. The phenolic profile and OS of two monocultivar VOOs (Oblica and Leccino) grown in two geographical sites of different altitudes (coastal plain and hilly hinterland) were analyzed throughout the ripening period over two years. Concentration of secoiridoids was 30% higher in the Oblica than in the Leccino VOOs, which in turn had significantly higher values of OS. Both cultivars had more than twice as high concentrations of the two most abundant phenolic compounds, the dialdehyde form of decarboxymethyl oleuropein aglycone and the dialdehyde form of decarboxymethyl ligstroside aglycone, and OS values in a colder growing site of higher altitude. Among the studied monocultivar VOOs, the secoiridoid group did not behave equally during ripening. The hierarchy of different influencing factors was investigated using multivariate statistics and revealed: cultivar > geographical site > harvest period > growing season. In addition, the possibility of traceability of VOO using molecular markers was investigated by establishing SSR profiles of oils of the studied cultivars and comparing them with SSR profiles of leaves. Full article

Campania, due to its pedo-climatic conditions and to its large varietal heritage, is able to produce oils with high typicity, each different from the other. In this study a “minor” autochthonous cultivar of Campania “Oliva Bianca” was analyzed. In autumn 2020, on drupes from trees belonging to the Campania germplasm collection a varietal characterization through physical, chemical and chromatic parameters at the harvest was carried out. Phenolic compounds profile, fatty acids composition and volatile organic compounds have been investigated in the resulting oil. Quality indices, organoleptic and sensory qualities (panel test) were also determined on the oil. Drupe weight was 4.31 g, flesh/pit ratio was 3.68 and the accumulation of oil content at harvest in drupes was 18.63% FW. The drupes showed high anthocyanins content equal to 116.10 mg/kg. In the oil studied, the secoiridoids represented the 82.25% of total phenolic compounds, the concentration of oleic acid was 74.82% and the most present volatile compound was trans-2-hexenal (72.30%). High secoiridoid derivatives concentrations such as oleuropein (85.93 mg/kg) and ligstroside (122.43 mg/kg) aglycones were showed. This study showed a good content of qualitative and quantitative parameters of “Oliva Bianca” oil and drupe, that can have important beneficial effects on human health. Full article