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.

Prevention of the proliferation of oral pathogens due to prolonged mask use based on α-cyclodextrin and hydroxytyrosol mouthwash.

OBJECTIVE: Face masks help contain the aerosol-mediated transmission of infectious viral particles released from individuals via cough and sneezes. However, the prolonged use of face masks has raised concerns regarding oral hygiene. Here, we present a mouthwash formulation based on α-cyclodextrin and hydroxytyrosol that can maintain healthy oral microbiota. MATERIALS AND METHODS: We isolated and cultured Candida albicans, Staphylococcus aureus, and a mix of Streptococcus sp., Staphylococcus sp. and Neisseria sp. from oral and throat swabs. The microorganisms were cultured in a standard medium with or without the mouthwash. To evaluate the effect of the mouthwash on the oral microbiota, the DNA from the saliva of 3 volunteers that used the mouthwash was extracted. Then, the DNA was amplified using primer pairs specific for bacterial and fungal DNA. Twelve further volunteers were offered to use the mouthwash and a questionnaire was submitted to them to assess the possible beneficial effects of mouthwash on halitosis and other oral disturbances. RESULTS: The bacteria and fungi cultured in media containing the mouthwash showed a growth reduction ranging from 20 to 80%. The PCR amplification of fungal and bacterial DNA extracted from volunteers that used the mouthwash showed a reduction of both bacteria and fungi. Volunteers that used the mouthwash reported a tendency towards a reduction of halitosis, gingival and mouth inflammation, and dry mouth. CONCLUSIONS: The use of a mouthwash containing α-cyclodextrin and hydroxytyrosol is not aggressive against oral mucosa; it is safe and effective to reduce the bacterial and fungal load due to the continuous use of face masks.

Naturally-occurring and cultured bacteriophages in human therapy.

OBJECTIVE: The aim of the study was to show the importance of developing techniques that could exploit the potential of bacteriophages as therapeutics or food supplements. MATERIALS AND METHODS: PubMed database was searched using the following combination of keywords: (bacteriophage) AND (human therapy); (natural bacteriophage) AND (application). RESULTS: The increasing antibiotic resistance of many bacterial strains is making standard antibiotic treatments less effective. Phage therapy provides a non-antibiotic alternative with greater specificity and without harmful effects on the human microbiota. Phages target their specific bacteria, replicate, and then, destroy the host pathogen. Bacteriophages may be administered by several routes, including topical, oral and intravenous. They not only destroy the host pathogen but, in some cases, increase the sensitivity of host bacteria to antibiotics. Various studies have shown that combining phage therapy and antibiotic treatment can be effective against bacterial infections. Clinical trials of phage therapy have shown promising results for various human diseases and conditions. With advances in genetic engineering and molecular techniques, bacteriophages will be able to target a wide range of bacteria. CONCLUSIONS: In the future, phage therapy promises to become an effective therapeutic option for bacterial infections. Since many potentially beneficial bacteriophages can be found in food, supplements containing bacteriophages could be designed to remodel gut microbiota and eliminate pathogenic bacteria. Remodeling of gut microbiota could correct gut dysbiosis. The order of phages known to have these promising activities is Caudovirales, especially the families Siphoviridae and Myoviridae.