Targeted natural Interventions
In addition to the natural therapies listed below, which have been studied in the context of sinusitis, those with acute sinusitis should refer to the Common Cold protocol, since a majority of sinusitis cases arise from complications of the common cold (Puhakka 1998; Han 2011; NIH 2012).
Lactoferrin – Lactoferrin and its active metabolite, lactoferricin, are multifunctional proteins known to possess antibacterial, antifungal, and antiviral activities, as well as immune regulatory and anti-inflammatory actions (Psaltis 2008). Lactoferrin is a component of whey protein that can also be found in high concentrations within mucosal secretions, such as airway mucus, tears, and breast milk (Roxas 2007; Acioglu 2012). Lactoferrin is produced and stored within the cells of the nasal mucosa and is presumed important as a first line of defense against invading pathogens (Acioglu 2012).
Research suggests that lactoferrin may be beneficial for alleviating the symptoms and complications of the common cold for at least 2 reasons. First, it can kill bacteria through the binding of iron molecules that would otherwise be needed for essential bacterial functions (Acioglu 2012; Roxas 2007). Second, lactoferrin exerts an antioxidant effect by preventing the formation of free radicals, thus decreasing nasal tissue oxidative damage (Acioglu 2012).
Studies suggest that decreased levels of lactoferrin may play a role in the development of chronic sinusitis, especially when nasal polyps, asthma, and/or allergies are involved (Zielinska-Blizniewska 2012; Psaltis 2008). Lactoferrin production is reduced in people with sinus conditions compared to healthy subjects. Moreover, lactoferrin levels are particularly low in sinusitis patients with nasal polyps. The low levels of lactoferrin associated with sinusitis are due to both its decreased expression/down-regulation as well as its increased utilization to fight infection (Acioglu 2012).
Vitamin C - Since the human body cannot synthesize vitamin C, it must be acquired from the diet (Hemavathi 2010). Research shows a sufficient daily intake of ascorbic acid is required for the immune system to defend the body against infections (especially viral infections) (Ely 2007).
Evidence suggests that supplementation with 1000 mg daily of vitamin C can decrease the risk of catching a cold (Holt 2010). When given in doses greater than 200 mg daily, vitamin C has been shown to reduce the duration of cold symptoms by 1-4 days (Khalid 2011). Vitamin C markedly improves immune function by enhancing natural killer cell activity, interferons (signaling proteins that boost immune response), macrophages, T-lymphocyte production, cell movement (ie, chemotaxis), and cell-mediated immunity (Heimer 2009; Khalid 2011).
Individuals with sinusitis typically exhibit decreased serum levels of vitamin C (Cho 2009; Unal 2004). Topical vitamin C may be associated with enhanced mucociliary clearance of the paranasal sinuses, through the loosening of thick mucus secretions, and an increase in ciliary beat frequency (Cho 2009; Zhang 2012). Oral vitamin C supplementation also reliably decreases plasma levels of histamine, a known contributor to inflammation and nasal congestion, especially among people with allergy-induced sinusitis (Helms 2006; Naclerio 2010).
Zinc – Zinc is an essential trace element required for a variety of metabolic processes (Classen 2011), including the maintenance of a healthy immune function (Roxas 2007). Unfortunately, zinc deficiency is prevalent throughout developed Western countries (Maggini 2012). Zinc deficiency, which is common among the elderly and the young, is linked to the impairment of many components of the immune response, including T- and B-lymphocyte function, natural killer cell activity, macrophage phagocytosis, and antibody formation (Maggini 2012; Pae 2012; Nriagu 2007). As a result, zinc deficiency is associated with an increased risk of infection (Maggini 2012; Pae 2012). In one study, children with chronic rhinosinusitis exhibited lower levels of antioxidants, including zinc, than healthy control subjects (Unal 2004). Correcting zinc deficiency through supplementation is efficacious for a variety of viral infections (Pae 2012; Nriagu 2007). This may be partly attributable to zinc’s positive effect on the expression of interleukin-2 and interferon-γ, as well as on natural killer and cytotoxic T cells, which help the immune system kill viruses (Sandstead 2010).
Zinc supplementation has long been considered an effective therapy for reducing the duration of the common cold (Roxas 2007; Nriagu 2007). A 2011 study concluded that zinc supplementation significantly reduced both duration and severity of the common cold when administered within 24 hours of the onset of symptoms. This study also revealed that zinc supplementation over 5 months was helpful for preventing infection by common cold viruses (Singh 2011). Likewise, a clinical study involving zinc nasal gel (given within 1-2 days of illness onset) found that zinc was able to reduce the severity and duration of common cold symptoms among healthy adults (Mossad 2003). In a 2012 study, researchers found that the combination of zinc plus vitamin C was more efficacious than placebo at reducing runny nose, and it also appeared to accelerate recovery in common cold patients (Maggini 2012).
N-acetyl cysteine – N-acetyl cysteine (NAC) may reduce the viscosity and improve the clearance of mucus. NAC has antioxidant properties, which can help protect against free radical damage. It may also help restore healthy sinus conditions that have deteriorated due to sinusitis (Clinical Pharmacology 2012).
A 2010 study found that NAC is capable of fighting infections, such as those that cause sinusitis, through its ability to break down biofilms. Biofilms are essentially a community of bacteria that adhere to surfaces, including moist mucus membranes. These biofilms are known to produce resistant communities of bacteria and are estimated to be involved in at least 60% of all chronic and/or recurrent infections. NAC has been shown to reduce the adhesion of biofilms to mucus membranes (eg, antibiotics or nasal steroids) (Pintucci 2010).
Vitamin E – Numerous studies have demonstrated that vitamin E may have a positive effect on the human immune system. For instance, elderly patients who took 200 IU of vitamin E daily for 1 year were 20% less likely to catch a cold (Burton 2004). In one study, children with chronic rhinosinusitis were found to have lower serum levels of several antioxidants, including vitamin E, than healthy children (Unal 2004). A 2011 study found that topical vitamin E (in combination with other antioxidant oils) was able to persistently reverse oxidative stress and nasal inflammation, similar to that by viral infections, chronic sinusitis, and allergic disease (Gao 2011). Furthermore, animal studies show that vitamin E may affect the risk and severity of viral respiratory infections (Hemila 2006).
Rosmarinic acid – Rosmarinic acid is an antioxidant compound found in rosemary (Kelsey 2010). In experimental animal models, rosmarinic acid has been shown to reduce allergic inflammatory reactions by decreasing histamine release and inhibiting the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor-alpha (TNF-α) (Oh 2011). This mechanism of action may be significant for individuals suffering from chronic sinusitis caused by allergies.
Bromelain – Bromelain, which is a proteolytic enzyme complex found in pineapple, is frequently used to treat sinusitis because it reduces inflammation and loosens mucus. Specifically, bromelain may inhibit pro-inflammatory prostaglandin biosynthesis and prostaglandin E1 accumulation. This in turn inhibits the release of leukocyte enzymes. Among sinusitis patients, bromelain has been shown to hasten symptom recovery and resolve inflammation better than standard treatment or placebo. Typical oral doses of bromelain are between 500-2000 mg daily (Helms 2006).
Eucalyptus – Cineole is the main ingredient of eucalyptus oil. It has anti-inflammatory and antimicrobial properties, and it also affects ciliary beat frequency (Tesche 2008). Studies have confirmed that cineole can thin, drain, and reduce mucus secretions. In a clinical study involving 152 patients with acute rhinosinusitis, cineole was associated with significant symptom improvement at 4 and 7 days when compared to placebo. The authors concluded that cineole is safe and effective for the treatment of acute rhinosinusitis, and suggested that it be utilized prior to the initiation of antibiotics (Kehrl 2004). In 2008, a similar study was conducted among 150 patients with acute and viral rhinosinusitis. These authors also found that treatment with cineole resulted in reduced symptoms at 4 and 7 days, and concluded that this treatment effect was clinically relevant (Tesche 2008).
Herbal combination formula – A combination of Gentian root, Primula flower, Elder flower, Sorrel herb, and Verbena herb is frequently used in the treatment of acute and chronic rhinosinusitis (Glatthaar-Saalmuller 2011; Rossi 2012). Results from a 2011 laboratory study demonstrated that this formula shows a broad spectrum of antiviral activity against viruses commonly known to cause respiratory infections (Glatthaar-Saalmuller 2011). A more concentrated version of the formula (ie, dry extract) reduced exudate volume and leukocyte numbers in an animal study. It also reduced the expression of cyclooxygenase-2 protein and lowered prostaglandin E2 levels. Therefore, the rationality for using the combination formula to manage sinusitis is partly based on its significant anti-inflammatory effects (Rossi 2012). Since inflammation of the mucosa can often lead to a loss of smell, researchers theorize that this combination of herbs may be useful for this indication as well (Reden 2011).
Xylitol nasal irrigation – Xylitol is a sugar alcohol that appears to enhance the body’s natural defense against bacterial pathogens. An animal model showed that administering xylitol solution simultaneously with a bacterial pathogen reduced the amount of bacteria detectable upon a later examination of the sinuses (Brown 2004). In one trial, 20 subjects with chronic rhinosinusitis were randomized and instructed to rinse their sinuses daily with either a xylitol or saline solution. Fifteen subjects completed the study. Nasal irrigation with the xylitol solution was associated with a significant improvement on a standardized assessment of sinusitis symptoms (Weissman 2011). Another trial designed to assess the effects of xylitol nasal irrigation compared to placebo in the treatment of chronic sinusitis is recruiting participants as of November 2012 (ClinicalTrials.gov NCT00924404).
Black cumin seed oil – Nigella sativa, also known as black cumin, is a flowering plant that grows in Eastern Europe, the Middle East, and Western Asia. The small black seeds of nigella sativa have a rich history of medical use in the Middle East and Asian countries. Modern scientific inquiry has examined the potential benefit of black cumin seeds and the oil derived from them in a variety of contexts ranging from cardiovascular disease to cancer (Shabana 2012; Randhawa 2011; Woo 2012; Butt 2010). Several lines of evidence suggest that black cumin seed oil and some of its active constituents are powerful anti-inflammatory agents and also combat oxidative stress (Inci 2012; Umar 2012; Ammar el 2011). In an animal model of rhinosinusitis, an active constituent derived from black cumin seed was found to be as effective as antibiotic therapy in reducing manifestations of sinusitis such as vascular congestion, inflammation, and epithelial injury in sinus tissue (Cingi 2011).