Can Lactoferrin, a Natural Mammalian Milk Protein, Assist in the Battle against COVID-19?

Is there sufficient evidence to support the health benefits of including donkey milk in the diet?

Donkey milk has attracted attention due to its distinctive nutritional composition and potential health advantages, particularly because of its whey protein content, which includes lysozyme, α-lactalbumin, lactoferrin, and β-lactoglobulin and vitamin C, among other components. These elements contribute to immunoregulatory, antimicrobial, antioxidant, and anti-inflammatory properties, positioning donkey milk as a possible therapeutic option. In addition, due to the low levels of caseins, the casein-to-whey protein ratio, and the β-lactoglobulin content in donkey milk, it presents an optimal alternative for infant formula for individuals with cow's milk allergies. Moreover, research into donkey milk's potential for cancer prevention, diabetes management, and as a treatment for various diseases is ongoing, thanks to its bioactive peptides and components. Nevertheless, challenges such as its low production yield and the not fully understood mechanisms behind its potential therapeutic role necessitate more thorough investigation. This review consolidates the existing knowledge on the therapeutic possibilities of donkey milk, emphasizing its importance for human health and the need for more detailed studies to confirm its health benefits.

Lactoferrin Supplementation in Preventing and Protecting from SARS-CoV-2 Infection: Is There Any Role in General and Special Populations? An Updated Review of Literature

At the beginning of the pandemic, SARS-CoV-2 infection represented a great medical burden worldwide, as targeted and effective therapeutic options were lacking. This resulted in the revival of existing molecules and the increasing popularity of over-the-counter nutritional supplements. Among the latter, lactoferrin has been investigated as an adjuvant in COVID-19 therapy with conflicting results, mainly depending on different study designs. Considering that lactoferrin is one of the main components of human breast milk with anti-microbial and anti-inflammatory activity, it is conceivable that such bioactive molecule could be effective in supporting anti-SARS-CoV-2 infection therapy, especially in infants and pregnant women, two subpopulations that have been poorly evaluated in the existing clinical trials. This narrative review is intended to offer insight into the existing literature on lactoferrin's biological functions and protective effects against COVID-19, with a special focus on pregnant women and their infants.

Assessment of Supplementation with Different Biomolecules in the Prevention and Treatment of COVID-19

Consequences of the disease produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to an urgent search for preventive and therapeutic strategies. Besides drug treatments, proposals have been made for supplementation with biomolecules possessing immunomodulatory and antioxidant properties. The objective of this study was to review published evidence on the clinical usefulness of supplementation with vitamin D, antioxidant vitamins (vitamin A, vitamin E, and vitamin C), melatonin, lactoferrin and natural products found in food (curcumin, luteolin, ginger, allicin, magnesium and zinc) as supplements in SARS-CoV-2 infection. In general, supplementation of conventional treatments with these biomolecules has been found to improve the clinical symptoms and severity of the coronavirus disease (COVID-19), with some indications of a preventive effect. In conclusion, these compounds may assist in preventing and/or improving the symptoms of COVID-19. Nevertheless, only limited evidence is available, and findings have been inconsistent. Further investigations are needed to verify the therapeutic potential of these supplements.

Persisting Gastrointestinal Symptoms in Children with SARS-CoV-2: Temporal Evolution over 18 Months and Possible Role of Lactoferrin

BACKGROUND AND AIM

Persisting gastrointestinal symptoms are reported to be relatively common in children with long COVID; however, their detailed characterization and long-term outcomes have not yet been described.

METHODS

We performed a retrospective study aiming to investigate the temporal evolution of gastrointestinal symptoms in children with SARS-CoV-2, from acute infection to 18-months follow-up. To further investigate possible therapeutic strategies, we evaluated the role of lactoferrin in improving gastrointestinal symptoms in these children, compared with those not treated.

RESULTS

A total of 1224 patients (47.7% females) were included. Of these participants, 246 (19.8%) were vaccinated and 143 (11.5%) presented with comorbidities. A total of 175 patients (14.1%) presented gastrointestinal symptoms during acute infection, 54 (4.4%) at three months, 23 (1.9%) at six months, 6 (3.3%) at twelve months, and 2 (2.3%) at eighteen months follow-up. At six months follow-up, children who were treated with 3 months oral lactoferrin had less persisting symptoms compared to those who did not receive lactoferrin, although this difference was not statistically significant (three patients (25%) in the lactoferrin group vs. fourteen patients (33.3%) not treated, p = 0.73), probably due to the low number of patients with persisting GI symptoms.

CONCLUSIONS

GI symptoms are relatively common during acute SARS-CoV-2 infection in children, and a non-negligible proportion of these children reported persisting symptoms for up to 12-18 months after the acute infection. In addition, we found a trend even if statistically nonsignificant toward faster improvement of persisting gastrointestinal symptoms in children with long COVID treated with lactoferrin. Despite the limitations relating to the present study's design, given the significant burden of gastrointestinal symptoms in children with long COVID, our findings provide the basis to perform a prospective, placebo-controlled study.

Bovine Lactoferrin-Loaded Plasmonic Magnetoliposomes for Antifungal Therapeutic Applications

Bovine lactoferrin (bLf) is a milk-derived protein that exhibits potent broad-spectrum antifungal activity against multiple fungi. bLf is susceptible to degradation, while some of its properties depend on the tertiary structure. So, the encapsulation of bLf in stimuli-responsive therapeutic formulations provides an added value to enhance its biological activities. Plasmonic magnetoliposomes (PMLs) arise as promising nanocarriers for dual hyperthermia (magneto-photothermia) and local chemotherapy, since the combination of magnetic and gold nanoparticles (NPs) in a single nanosystem (multifunctional liposomes) enables the targeting and controlled release of loaded drugs. In this work, plasmonic magnetoliposomes (PMLs) containing manganese ferrite nanoparticles (28 nm size) and gold nanoparticles (5-7.5 nm size), functionalized with 11-mercaptoundecanoic acid or octadecanethiol, were prepared and loaded with bLf. The NPs' optical, magnetic and structural properties were measured via UV/vis/NIR absorption spectroscopy, SQUID and TEM, respectively. The Specific Absorption Rate (SAR) was calculated to assess the capabilities for magnetic and photothermal hyperthermia. Finally, the antifungal potential of bLf-loaded PMLs and their mechanism of internalization were assessed in Saccharomyces cerevisiae by counting the colony forming units and using fluorescence microscopy. The results demonstrate that PMLs are mainly internalized through an energy- and temperature-dependent endocytic process, though the contribution of a diffusion component cannot be discarded. Most notably, only bLf-loaded plasmonic magnetoliposomes display cytotoxicity with an efficiency similar to free bLf, attesting their promising potential for bLf delivery in the context of antifungal therapeutic interventions.

Liposomal Lactoferrin Exerts Antiviral Activity against HCoV-229E and SARS-CoV-2 Pseudoviruses In Vitro

A limited number of effective therapies are currently available to treat human coronavirus SARS-CoV-2 and other human coronaviruses, which are responsible for nearly a third of global cases of the common cold. The possibility of new emerging coronaviruses demands powerful new antiviral strategies. Lactoferrin is a well-known protein that possesses anti-inflammatory and immunomodulatory activities, and it has previously shown antiviral activity against several viruses, including SARS-CoV-2. To increase this antiviral activity, here we present bovine liposomal lactoferrin. Liposomal encapsulation of the compound was proven to increase permeability, bioavailability, and time release. In the present work, we compare the antiviral activity of free and liposomal bovine lactoferrin against HCoV229E and SARS-CoV-2 in vitro and in human primary bronchial epithelial cells, and we demonstrated that the liposomal form exerts a more potent antiviral activity than its free form at non-cytotoxic doses.