Seasonal allergies are not only culprits that keep people from enjoying the bloom of spring or the coolness of fall, but they can be painful and miserable altogether, sometimes even triggering mood disorders. The pollen and mold trigger a rise in proinflammatory leukotrienes and prostanoids in the mucus membranes, and ushers in an army of mast cells and eosinophils. These players begin battle by degranulation and cytokine release, which calls for more reinforcements. Clinically, the host of this battle experiences a runny, itchy nose, sneezing, watery eyes, congestion, fatigue, and sometimes a mild fever.
Nettle Leaf (Urtica dioica)
Nettle, also known as stinging nettle, is commonly known for its efficacy in managing symptoms of seasonal allergies. However, this plant is also surrounded by irony since touching its leaves often results in allergic dermatitis that leaves its victim itching and red. The extract of nettle contains compounds identified as antagonists to the Histamine-1 (H(1)) receptor while also inhibiting mast cell tryptase and preventing the degranulation and release of a host of pro-inflammatory mediators that cause the symptoms of seasonal allergies. Further, nettle extract targets the inflammatory pathways by inhibiting cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and hematopoietic prostaglandin D(2) synthase (HPGDS), all of which are central enzymes in proinflammatory pathways and contribute to prostaglandin production. Clinically, these actions help to decrease allergic rhinitis – one of the most common (and albeit, annoying) symptoms of allergies.
To discover the tangible benefits of nettle extract in managing allergic rhinitis, a randomized, double-blind, placebo- controlled, clinical trial was conducted on 40 patients, assigned either 150mg of Urtica dioica or placebo for one month. Results showed a significant improvement in the severity of allergic rhinitis in both groups; however, those taking nettle had lower eosinophil counts on a nasal smear, compared to placebo. Although this study should be followed up by a more robust study, it suggests nettle can be useful in mitigating the immune responses that trigger common symptoms of seasonal allergies, such as allergic rhinitis.
Guduchi (Tinospora cordifolia)
A less well-known botanical that is immensely useful in managing the symptoms associated with seasonal allergies is Tinospora cordifolia, also known as Guduchi. Commonly used in Ayurvedic medicine, this plant possesses an impressive array of therapeutic properties including anti-diabetic, anti-periodic, anti-spasmodic, anti-inflammatory, anti-arthritic, anti-oxidant, anti-allergic, anti-microbial, anti-osteoporotic, anti-stress, anti-leprotic, anti-malarial, hepatoprotective, immunomodulatory and anti-neoplastic activities. These activities are possible because of the variety of biological compounds including alkaloids, diterpenoid lactones, glycosides, steroids, sesquiterpenoid, phenolics, aliphatic compounds, and polysaccharides.
A highly activated immune response is responsible for most of the symptoms associated with seasonal allergies and many of the compounds found in Guduchi have immunomodulatory effects. More specifically, they have been reported to boost the phagocytic activity of macrophages, influence cytokine production, and activate immune effector cells, enhancing the immune response.
So how does this seemingly amazing botanical function in studies of seasonal allergy symptoms? In a randomized double blind placebo controlled trial, seventy-five patients were given either Tinospora cordifolia or placebo for 8 weeks. In the group receiving Tinospora cordifolia, there was complete relief from sneezing in 83 percent of the patients, nasal discharge in 69 percent, nasal obstruction in 61 percent, and nasal pruritis in 71 percent. In the placebo group, there was only complete relief from sneezing in 21 percent of the patients, nasal discharge in 15.2 percent, nasal obstruction in 17 percent, and nasal pruritis in 12 percent. The significant chasm between these outcomes gives impressive evidence of the usefulness of Tinospora cordifolia in managing symptoms of seasonal allergies.
Unfortunately, for some seasonal allergies seem to linger far longer than the onset of the season. Since the symptoms in seasonal allergies are rooted in the immune system, the health of the microbiome cannot be ignored when considering the balance and robustness of an immune response. Therefore, good quality probiotics and a high-protein/low-sugar diet can also help support a healthy immune response during a particularly challenging season.