The potential preventive role of a dietary supplement containing hydroxytyrosol in COVID-19: a multi-center study.

OBJECTIVE: COVID-19 is a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged as a global pandemic in 2019. Its main symptoms include fever, cough, fatigue, and, in severe cases, pneumonia, acute respiratory distress syndrome, and organ failure, which can be life-threatening. Various therapies have been proposed for treating COVID-19, among which antiviral drugs and monoclonal antibodies, but natural molecules have gained attention for their potential antiviral properties against various viral infections, including COVID-19. The use of hydroxytyrosol (HT), a polyphenol from the olive tree possessing antioxidant, anti-inflammatory, and anti-viral properties, has been proposed to reduce COVID-19 infection. SUBJECTS AND METHODS: A total of 443 subjects were recruited from four centers, located in Albania, Germany, and Italy (Milan and Trento provinces). The participants were randomly assigned to receive either the dietary supplement containing HT or a placebo for a duration of one month. RESULTS: Analysis of the study data revealed that, among the subjects who tested positive for COVID-19 during the study, 36% belonged to the group that received the dietary supplement containing HT, while 64% belonged to the placebo group. The difference was statistically significant. These findings suggest that the use of a dietary supplement containing HT may have a possible preventive effect against COVID-19 infection. CONCLUSIONS: The study's results indicate that the dietary supplement containing HT shows promise as a possible preventive measure against COVID-19 infection. Large-scale, randomized clinical trials and animal studies could be useful to provide more definitive conclusions on HT's possible potential preventive effects against COVID-19, which could potentially supplement existing therapies and contribute to fighting COVID-19 infection.

Unraveling the Role of Prickly Pear Extract as a Potent Nutraceutical Agent Against Metabolic Syndromes.

Background: Prickly pear (Opuntia) extracts have garnered con-siderable attention in recent years due to their promising medicinal and nutritional properties. This comprehensive review explores the multifaceted potential of prickly pear extracts in mitigating various chronic diseases, including cardiovascular diseases (CVDs), diabetes, obesity, cancer, neuronal diseases, and renal diseases. Methods: This review provides a comprehensive overview of the diverse therapeutic applications of Opuntia extracts in managing chronic diseases. The collective evidence underscores the potential of prickly pear as a valuable natural resource for addressing global health challenges. Further research and clinical investigations are warranted to unlock the full potential of Opuntia in the prevention and treatment of chronic diseases. Results: Studies have suggested that the bioactive compounds within prickly pear may influence glucose metabolism by improving insulin sensitivity, reducing insulin resistance, and modulating gut microbiota composition. These pathways exhibit potential in the reduction of hyperglycemia, which is a fundamental aspect of metabolic syndromes. Opuntia extracts demonstrate also antioxidant, anti-inflammatory capabilities that can contribute to improving health in various conditions. Conclusion: Further research and clinical investigations are warranted to unlock the full potential of Opuntia in the prevention and treatment of chronic diseases.

Study of the effects of Lemna minor extracts on human immune cell populations.

OBJECTIVE: Lemna minor is a plant with a huge repertoire of secondary metabolites. The literature indicates that extracts of Lemna minor have antioxidant, antiradical, immunomodulatory and anti-inflammatory properties. The objective of the present study was to find a suitable technique to extract active compounds from this plant and verify whether these extracts have immunomodulatory activity. MATERIALS AND METHODS: We grew L. minor on a standard medium with Gamborg B5 and vitamins. We extracted compounds from the plant by maceration and decoction. The phytochemical profile of the extracts was characterized by chromatography, spectrophotometry, and spectroscopy. The extracts were tested on cultures of mononuclear cells from four human subjects. These cells were pulsed with carboxyfluorescein succinimidyl ester, grown in triplicate in standard culture medium without (control) and with increasing concentrations of Lemna extracts. Flow cytometry was used to evaluate cell death and proliferation of the total mononuclear cell population and of CD4+, CD8+, B cell and monocyte populations. RESULTS: The Lemna extracts were not cytotoxic and did not cause cell necrosis or apoptosis in immune cells. At low concentrations, they induced very limited proliferation of CD4+ cells within 48 hours. At high concentrations, they induced proliferation of CD8+ cells and B lymphocytes within 48 hours. CONCLUSIONS: Unfortunately, we failed to confirm any immunomodulatory activity of Lemna extracts. Growth and death rates of human immune cells were not significantly affected by adding Lemna extracts to the culture medium.

Effect of a dietary supplement on the reduction of lymphedema-progression in mouse tail-cut model.

OBJECTIVE: The aim of our study was to evaluate in vivo, in a mouse tail model of lymphedema, the effects of a dietary supplement, Garlive®, based on hydroxytyrosol from olive leaves, spermidine from rice seeds, hesperidin from citrus fruits and vitamin A. Hydroxytyrosol has anti-inflammatory, antioxidant and antimicrobial activities and inhibits leukotriene B4 generation; spermidine is able to inhibit the production of pro-inflammatory cytokines and mediators; hesperidin inhibits the secretion of pro-inflammatory cytokines: IFN-γ, IL-2, IL-4, IL-10; vitamin A deficiency was shown to induce inflammation and aggravate existing inflammatory states, whereas supplementation with vitamin A could ameliorate inflammation. MATERIALS AND METHODS: The active compounds were included in tablets: 250 mg of olive leaf extract titrated in 10% hydroxytyrosol, 200 mg of citrus fruits extract titrated in 60% hesperidin, 10 mg of rice (Oryza sativa) seeds extract titrated in 1% spermidine and 0.8 mg of vitamin A. Mice of an inbred group were randomly selected and divided in the control group and drug-treated group. The wound necessary for lymphedema generation was made on the tail of each mice 1 cm below the base of the trunk. RESULTS: After surgical intervention, there was a gradual increase in the circumference of both ends of the wound. The control group showed higher increase of tail volume than the drug-treated group. The differences in tail swelling between the control group and the drug-treated group were significantly different. The peak of swelling was anticipated to the 6th day in the drug-treated group, whereas in the control group the peak was reached later on. CONCLUSIONS: The tested drug prevented the induction of swelling from day 5th of wound creation and decreased the duration of swelling, favoring the wound healing.

Proposal of a food supplement for the management of post-COVID syndrome.

A vast majority of COVID-19 patients experience fatigue, extreme tiredness and symptoms that persist beyond the active phase of the disease. This condition is called post-COVID syndrome. The mechanisms by which the virus causes prolonged illness are still unclear. The aim of this review is to gather information regarding post-COVID syndrome so as to highlight its etiological basis and the nutritional regimes and supplements that can mitigate, alleviate or relieve the associated chronic fatigue, gastrointestinal disorders and continuing inflammatory reactions. Naturally-occurring food supplements, such as acetyl L-carnitine, hydroxytyrosol and vitamins B, C and D hold significant promise in the management of post-COVID syndrome. In this pilot observational study, we evaluated the effect of a food supplement containing hydroxytyrosol, acetyl L-carnitine and vitamins B, C and D in improving perceived fatigue in patients who recovered from COVID-19 but had post-COVID syndrome characterized by chronic fatigue. The results suggest that the food supplement could proceed to clinical trials of its efficacy in aiding the recovery of patients with long COVID.