Activation of specific bitter taste receptors by olive oil phenolics and secoiridoids

A Simple Chiral 1H NMR Method for the Discrimination of (R)- and (S)-Cannabichromene in Complex Natural Mixtures and Their Effects on TRPA1 Activity

In recent years, the enantiomeric ratio of cannabichromene (CBC) within the cannabis plant has attracted significant attention. Cannabichromene is one of the well-known cannabinoids found in cannabis, along with THC (tetrahydrocannabinol) and CBD (cannabidiol). Cannabichromene exists as a scalemic mixture, meaning it has two enantiomers, (S)-cannabichromene and (R)-cannabichromene, with the ratio between these enantiomers varying among different cannabis strains and even within individual plants. This study presents an accurate and robust chiral NMR method for analyzing cannabichromene's enantiomeric ratio, a well-investigated cannabinoid with numerous pharmacological targets. The use of Pirkle's alcohol as the chiral solvating agent (CSA) or, alternatively, the use of (S)-ibuprofen as a chiral derivatizing agent (CDA) facilitated this analysis. Moreover, the chiral NMR method proves to be a user-friendly tool, easily applicable within any NMR facility, and an expanded investigation of cannabichromene chirality may provide insights into the origin, cultivation, treatment, and processing of Cannabis sativa plants. This study also undertakes a pharmacological examination of the (R)- and (S)-cannabichromenes concerning their most extensively studied pharmacological target, the TRPA1 channels, with the two enantiomers showing the same strong agonistic effect as the racemic mixture.

Compositional Changes during Storage of Industrially Produced Olive Oils Co-Milled with Olive Leaves

The possibility of enriching the oil produced from Leccino cultivar olive fruits with phenolic and volatile compounds by adding olive leaves (2.5%) during industrial-scale production were investigated. Furthermore, the influence of the addition of leaves on the oil quality, composition, and oxidative stability during storage for 6 and 12 months was studied. A slight negative impact on the oil quality after processing with leaves was determined. The addition of leaves had no influence on the total saturated, monounsaturated, and polyunsaturated fatty acids in oils, while it influenced increases in total phenolic compounds (+29.55%), total secoiridoids (+29.43%), chlorophylls (+47.59%), and the oil stability index (+18.70%), and their higher values were also determined in the stored oils. The addition of leaves increased C5 volatiles (+10.50%) but decreased C6 volatiles (-10.48%). The intensity of most of the positive sensory characteristics increased in fresh oils obtained with leaves, and the established improvements were also maintained in the stored oils. The extractability of olive paste was positively affected by the addition of olive leaves, which increased the oil yield (+27.17%). The obtained results significantly contribute to the knowledge about the possibilities of enriching olive oils with bioactive compounds.

Bitter Is Better: Wild Greens Used in the Blue Zone of Ikaria, Greece

The current study reports an ethnobotanical field investigation of traditionally gathered and consumed wild greens (Chorta) in one of the five so-called Blue Zones in the world: Ikaria Isle, Greece. Through 31 semi-structured interviews, a total of 56 wild green plants were documented along with their culinary uses, linguistic labels, and locally perceived tastes. Most of the gathered greens were described as bitter and associated with members of Asteraceae and Brassicaceae botanical families (31%), while among the top-quoted wild greens, species belonging to these two plant families accounted for 50% of the wild vegetables, which were consumed mostly cooked. Cross-cultural comparison with foraging in other areas of the central-eastern Mediterranean and the Near East demonstrated a remarkable overlapping of Ikarian greens with Cretan and Sicilian, as well as in the prevalence of bitter-tasting botanical genera. Important differences with other wild greens-related food heritage were found, most notably with the Armenian and Kurdish ones, which do not commonly feature many bitter greens. The proven role of extra-oral bitter taste receptors in the modulation of gastric emptying, glucose absorption and crosstalk with microbiota opens new ways of looking at these differences, in particular with regard to possible health implications. The present study is also an important attempt to preserve and document the bio-cultural gastronomic heritage of Chorta as a quintessential part of the Mediterranean diet. The study recommends that nutritionists, food scientists, and historians, as well as policymakers and practitioners, pay the required attention to traditional rural dietary systems as models of sustainable health.

Oleocanthal - Characterization, production, safety, functionality and in vivo evidences

Oleocanthal, OC, 2-(4-Hydroxyphenyl)ethyl(3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate, is a natural organic compound exclusively found in Olea europaea L. (Oleoaceae), such as extra virgin olive oil (EVOO). Chemically, it is considered a monophenolic secoiridoid, taking part of the validated antioxidants naturally occurring in some plant-based foods. In this review, the aim is to summarize the identity and characteristics of this molecule, where it can be obtained (isolation from the natural source or chemical synthesis), as well as the use as food component. Then, the bioavailability, safety and studies aiming to demonstrate the potential health benefits, including in vitro and in vivo animal and human studies were also discussed.

Anti-HIV drugs lopinavir/ritonavir activate bitter taste receptors

Lopinavir and ritonavir (LPV/r) are the primary anti-human immunodeficiency virus (HIV) drugs recommended by the World Health Organization for treating children aged 3 years and above who are infected with the HIV. These drugs are typically available in liquid formulations to aid in dosing for children who cannot swallow tablets. However, the strong bitter taste associated with these medications can be a significant obstacle to adherence, particularly in young children, and can jeopardize the effectiveness of the treatment. Studies have shown that poor palatability can affect the survival rate of HIV-infected children. Therefore, developing more child-friendly protease inhibitor formulations, particularly those with improved taste, is critical for children with HIV. The molecular mechanism by which lopinavir and ritonavir activate bitter taste receptors, TAS2Rs, is not yet clear. In this study, we utilized a calcium mobilization assay to characterize the activation of bitter taste receptors by lopinavir and ritonavir. We discovered that lopinavir activates TAS2R1 and TAS2R13, while ritonavir activates TAS2R1, TAS2R8, TAS2R13, and TAS2R14. The development of bitter taste blockers that target these receptors with a safe profile would be highly desirable in eliminating the unpleasant bitter taste of these anti-HIV drugs.

Extra Virgin Olive Oil Secoiridoids Modulate the Metabolic Activity of Dacarbazine Pre-Treated and Treatment-Naive Melanoma Cells

Nowadays, many individuals, whether healthy or diagnosed with disease, tend to expose themselves to various easily accessible natural products in hopes of benefiting their health and well-being. Mediterranean populations have traditionally used olive oil not only in nutrition but also in cosmetics, including skincare. In this study, the phenolic profile—composed of twelve compounds altogether, including the secoiridoids oleocanthal (OCAL) and oleacein (OCEIN)—of extra virgin olive oil (EVOO) from autochthonous cultivars from Croatia was determined using ¹H qNMR spectroscopy and HPLC-DAD analysis, and its biological activity was investigated in melanoma cell lines. The EVOO with the highest OCEIN content had the strongest anti-cancer activity in A375 melanoma cells and the least toxic effect on the non-cancerous keratocyte cell line (HaCaT). On the other hand, pure OCAL was shown to be more effective and safer than pure OCEIN. Post-treatment with any of the EVOO phenolic extracts (EVOO-PEs) enhanced the anti-cancer effect of the anti-cancerous drug dacarbazine (DTIC) applied in pre-treatment, while they did not compromise the viability of non-cancerous cells. The metastatic melanoma A375M cell line was almost unresponsive to the EVOO-PEs themselves, as well as to pure OCEIN and OCAL. Our results demonstrate that olive oils and/or their compounds may have a potentially beneficial effect on melanoma treatment. However, their usage can be detrimental or futile, especially in healthy cells, due to inadequately applied concentrations/combinations or the presence of resistant cells.

Improved Oxidative Stability and Sensory Quality of Beef Hamburgers Enriched with a Phenolic Extract from Olive Vegetation Water

This study aims at evaluating the effect of a phenol-rich extract obtained from the concentration and purification of olive mill wastewaters (added at a ratio of 87.5 and 175 mg of phenols/kg meat) on the stability and sensory quality of beef hamburgers packed under modified atmosphere and stored under alternating exposure to fluorescent light at 4 ± 2 °C for 9 days. The hamburgers were sampled at different times (0, 6, and 9 days) and grilled at 200 °C. After 9 days, more than 56% of the added phenols in the raw burgers and more than 20% the grilled ones were retained. The results show that both concentrations of phenolic extract proved to effectively reduce primary and secondary lipid oxidation, as well as cholesterol oxidation products (COPs), during the shelf-life of raw hamburgers. Peroxide value, thiobarbituric acid reactive substances, and total COPs were up to 1.4-, 4.5-, and 8.8-fold lower in phenol-enriched raw hamburgers, respectively, than in the control samples; a similar trend was noted also in phenol-enriched cooked hamburgers (1.3-, 5.7-, and 4-fold lower). The sensory analysis also confirmed the effectiveness of the addition of phenolic extract, resulting in a positive effect on the red color intensity (raw product) and thus reducing browning during storage.