Citral-Enriched Fraction of Lemon Essential Oil Mitigates LPS-Induced Hepatocyte Injuries.

Lemon essential oil (LEO) is known for its aromatic and healthy properties; however, less consideration is given to the biological properties of the fractions obtained from LEO. This study aims to evaluate the ability of a citral-enriched fraction obtained from LEO (Cfr-LEO) to counteract lipopolysaccharide (LPS)-mediated inflammation, oxidative stress, and epithelial-mesenchymal transition (EMT) in healthy human hepatocytes. Human immortalized hepatocytes (THLE-2 cell line) were pretreated with Cfr-LEO and subsequently exposed to LPS at various time points. We report that the pretreatment with Cfr-LEO counteracts LPS-mediated effects by inhibiting inflammation, oxidative stress, and epithelial-mesenchymal transition in THLE-2. In particular, we found that pretreatment with Cfr-LEO reduced NF-κB activation and the subsequent proinflammatory cytokines release, ROS production, and NRF2 and p53 expression. Furthermore, the pretreatment with Cfr-LEO showed its beneficial effect in counteracting LPS-induced EMT. Taken together, these results support Cfr-LEO application in the nutraceutical research field not only for its organoleptic properties, conferred by citral enrichment, but also for its biological activity. Our study could lay the basis for the development of foods/drinks enriched with Cfr-LEO, aimed at preventing or alleviating chronic conditions associated with liver dysfunction.

Anti-inflammatory properties of an aldehydes-enriched fraction of grapefruit essential oil.

Chronic inflammation is linked to the development of numerous diseases and is accompanied by increased cytokine secretion. Macrophages provide a first line of defense against pathogens that under inflammatory stimuli release pro-inflammatory cytokines. The essential oil (EO) fractions obtained from Citrus spp. rich in different compounds have gained the attention of both researchers and users during the last decades. In particular, grapefruit (Citrus paradisi) peel is rich in phenolics and flavonoids with several health benefits, including anti-inflammatory actions. Additionally, its EO consists of a large number of compounds such as monoterpenes, sesquiterpenes, alcohols, aldehydes, esters, and oxides. Among the methods for encapsulating EOs, spray-drying is the main one. In the present study, we aimed to determine the in vitro anti-inflammatory activity of EO from C. paradisi (grapefruit essential oil [GEO]) (whole and fractions) in a lipopolysaccharide (LPS)-induced inflammation model. Results indicate that Fr-GEO and Fr-GEO_SD exert protective effects against LPS-induced inflammation by decreasing gene expression and levels of pro-inflammatory cytokines as IL-6 and TNF-α. Monoterpenes as the most common components, as well as aldehydes and sesquiterpenes, might be responsible for such effects, although a synergistic action is not excluded. Furthermore, a higher percent of aldehydes is linked to improved olfactory properties. Our findings support the anti-inflammatory effects of selected Fr-GEO with a great potential for the development of new nutraceuticals and/or functional food for the treatment of inflammatory-associated diseases. PRACTICAL APPLICATION: The findings of this study support the anti-inflammatory effects of selected Fr-GEO with a great potential for the development of new nutraceuticals and/or functional food for the treatment of inflammatory-associated diseases.

Preliminary Results of CitraVes™ Effects on Low Density Lipoprotein Cholesterol and Waist Circumference in Healthy Subjects after 12 Weeks: A Pilot Open-Label Study.

Appropriate monitoring and control of modifiable risk factors, such as the level of low-density lipoprotein cholesterol (LDL-C) and other types of dyslipidemia, have an important role in the prevention of cardiovascular diseases (CVD). Recently, various nutraceuticals with lipid-lowering effects have gained attention. In addition to the plant-derived bioactive compounds, recent studies suggested that plant cells are able to release small lipoproteic structures named extracellular vesicles (EVs). The interaction between EVs and mammalian cells could lead to beneficial effects through anti-inflammatory and antioxidant activities. The present study aimed to assess the safety of the new patented plant-based product citraVes™, containing extracellular vesicles (EVs) from Citrus limon (L.) Osbeck juice, and to investigate its ability to modulate different CV risk factors in healthy subjects. A cohort of 20 healthy volunteers was recruited in a prospective open-label study. All participants received the supplement in a spray-dried formulation at a stable dose of 1000 mg/day for 3 months. Anthropometric and hematobiochemical parameters were analyzed at the baseline and after the follow-up period of 1 and 3 months. We observed that the supplement has an effect on two key factors of cardiometabolic risk in healthy subjects. A significant change in waist circumference was found in women after 4 (85.4 [79.9, 91.0] cm, p < 0.005) and 12 (85.0 [80.0, 90.0] cm, p < 0.0005) weeks, when compared to the baseline value (87.6 [81.7, 93.6] cm). No difference was found in men (baseline: 100.3 [95.4, 105.2] cm; 4 weeks: 102.0 [95.7, 108.3] cm; 12 weeks: 100.0 [95.3, 104.7] cm). The level of LDL-C was significantly lower at 12 weeks versus 4 weeks (p = 0.0064). Our study evaluated, for the first time, the effects of a natural product containing plant-derived EVs on modifiable risk factors in healthy volunteers. The results support the use of EV extracts to manage cardiometabolic risk factors successfully.

Biological Properties of a Citral-Enriched Fraction of Citrus limon Essential Oil.

Lemon essential oil (LEO) is a well-known flavoring agent with versatile biological activities. In the present study, we have isolated and characterized four citral-enriched fractions of winter LEO. We reported that in murine and human macrophages the pre-treatment with a mix of these fractions (Cfr-LEO) reduces the expression of the pro-inflammatory cytokines TNF-α, IL-1ß, and IL-6 induced by LPS. In addition, Cfr-LEO counteracts LPS-induced oxidative stress, as shown by the increase in the GSH/GSSG ratio in comparison to cells treated with LPS alone. Overall, the results reported here encourage the application of EO fractions, enriched in citral, in the nutraceutical industry, not only for its organoleptic properties but also for its protective action against inflammation and oxidative stress.