Scientists at Applied Biological Laboratories Inc. have identified how natural bioactive molecules can effectively relieve cold and flu symptoms by protecting the mucosal barrier function and reducing inflammation during these infections. Together, they call these molecules, which include lysozyme and lactoferrin, the “Mucosal Immune Complex.”
The research, led by Nazlie Sadeghi-Latefi, Ph.D., highlights the importance of supporting mucosal barrier immunity to prevent and treat colds and flu. This work was recently presented at the American Chemical Society Fall 2023 Meeting on August 15, 2023.
Mucosal immunity is the body’s first line of defense against invading pathogens, such as those causing the common cold and influenza. While the mucosal barrier functions primarily as a part of the innate immune response, it provides a crucial bridge to adaptive immunity. Once someone is infected, the mucosal immunity and barrier integrity determine the extent of the infection, and thus the illness severity and duration.
Popular cold & flu remedies may do more harm than good
A previous peer-reviewed study by researchers at Applied Biological Laboratories compared the effects of natural bioactive molecules to those of the most popular over-the-counter cough and cold medications using in vitro respiratory mucosal barrier models. The researchers found that these popular OTC medications damage the mucosal barrier and increase inflammation (the underlying cause of cold symptoms), which they say may translate to possibly worsening symptoms, prolonging infections, and increasing the risk of secondary infections.
Smith Johnston, MD, clinical faculty at the University of Texas Medical Branch, former Medical Officer emeritus for NASA’s Medical Operations Branch, and a member of Applied Biological Laboratories’ scientific advisory board adds that decades of meta-analyses of clinical trials have found inconclusive evidence of safety and effectiveness for many popular over-the-counter common cold and flu medications. Although these medications often claim to provide the indicated symptomatic relief, they have not been shown to effectively reduce the severity and duration of illness better than a placebo. Many of these were approved for over-the-counter (monograph) marketing before the FDA required rigorous clinical trials to approve over-the-counter drugs.
Lysozyme and Lactoferrin strengthen mucosal barrier immunity, block viral entry, and synergize with more specific COX inhibitors
One of the key inflammatory signals in respiratory inflammation and cold symptoms involves prostaglandin generation via COX enzymes. When low doses of plant-based acetylsalicylic acid (aspirin), or other naturally derived COX inhibitors such as aloe vera extract were combined with lysozyme, lactoferrin, and menthol the anti-inflammatory effects through inhibition of COX-mediated inflammation and bradykinin-mediated IL-8 were even greater than with the COX inhibitor alone. Thus, this combination of natural bioactive molecules has powerful synergistic effects for relieving cold and flu symptoms.
Unlike common OTC cold & flu remedies, which do not focus on inflammation at all, and which may damage the mucosal barrier, specific concentrations of natural bioactive ingredients like lactoferrin and lysozyme did not damage the mucosal barriers but strengthened it according to the previously mentioned peer-reviewed study. According to numerous other peer-reviewed studies, lactoferrin and lysozyme activate local innate immune cells, such as macrophages and dendritic cells, and may also bind to viruses, preventing them from docking and infecting respiratory epithelial cells.
Clinical trial confirms the synergistic benefits of natural bioactive molecules with low-dose aspirin in treating cold & flu symptoms
To confirm their findings and test their formulations clinically, researchers at Applied Biological Laboratories conducted a randomized, double-blind placebo-controlled multi-center study. Relief of sore throat, a measure of upper respiratory inflammation was assessed as the primary endpoint and reduction of other common cold symptoms such as nasal discharge and congestion, sneezing, sore/scratchy throat, cough, headache, malaise, and fever/chills, as assessed by the modified Jackson scores were measured as secondary endpoints. The trial assessed 179 participants who were randomly assigned to either placebo or one of three treatment groups each containing the mucosal immune complex and a mix of other anti-inflammatory ingredients.
By the second day of the study, the treatment groups had a significant reduction of up to 4.59 points in modified Jackson scores, whereas the placebo group did not demonstrate any improvement in any category of Jackson scores. The researchers conclude that formulas containing the mucosal immune complex are an effective treatment for alleviating cold and flu symptoms, including nasal congestion, discharge, sneezing, sore throat, cough, headache, malaise, and fever/chills.
Implications and Impact
The potential implications of these results are significant, given the vast number of people affected by the common cold and flu every season. Every year, an average household shops for over-the-counter medications 26 times a year, spending an average of $338. To date, few studies have evaluated the impact of these medications on mucosal barrier integrity, which can affect symptom severity and susceptibility to secondary infections. In addition, clinical evidence that demonstrates the safety and effectiveness of cold and flu remedies has been scarce, even in FDA-approved medications.
Meeting: American Chemical Society Fall 2023 Meeting