Chronic Obstructive Pulmonary Disorder (COPD) is characterized by airway inflammation, blockage of airway passages with air trapped inside the lungs reducing lung capacity and elasticity, build-up of scar tissue, and destruction of structures supporting the alveolar sacs.
A cascade of immune responses cause airway inflammation when the lungs are exposed to irritants, allergens, or carcinogens. Neutrophils, CD8+ T lymphocytes, macrophages and B cells, which form the first line of defense in the human body, come into play with the onset of the disease. They release inflammatory mediators such as Tumor Necrosis Factor alpha (TNF alpha), Interleukins (IL), Interferon gamma (INF gamma), C Reactive Protein (CRP), fibrinogens, etc. which cause a series of inflammatory responses, causing damage to the lung tissues. This ultimately leads to limitation of airflow within the lungs, causing breathing problems, chest pain, coughing, wheezing, shortage of breath and associated discomfort.
Studies carried out in the UK and US have recently suggested two novel approaches to reduce chronic inflammation in COPD by easing out the immune response. One of these involve the use of a compound Tanshinone IIA found in red sage — a Chinese medical herb which has had age old applications in treating cardiac disorders, blood circulation and menstrual problems. The other strategy employs the use of nanoparticles embedded in an anti-inflammatory drug, directed towards a particular lymphocyte.
According to a report from February 2014, research groups at the Edinburgh Medical School, Scotland, tested the anti-inflammatory properties of red sage in zebra fish (a common translucent fish often used for research purposes). The fish were genetically modified to have their neutrophils glow green. Now, when fish with their tails injured were treated with Tanshinone IIA (red sage extract), the treatment had a substantial impact in reducing inflammation by driving the neutrophils away from the site or inducing cell death. These findings were published in the journal Science translation Medicine, where the researchers concluded, “The fact that Tanshinone IIA is already used in traditional Chinese medicine makes it likely that future drugs containing this compound wouldn’t be toxic to humans.”
Researchers at the University of Illinois, Chicago have used a nanoparticle coated with the anti-inflammatory compound piceatannol (a metabolic derivative of a compound found in red wine) in treating vascular inflammation induced in laboratory mice. The results showed that neutrophils detached themselves from one another and left the blood vessels. Consequently they were prevented from contributing to the inflammatory cascade of events.
Speaking about the mechanism of action of these nanoparticles, Prof. Asrar B. Malik, the Schweppe Family Distinguished Professor and head of pharmacology in the UIC College of Medicine said in a press release, “It binds to a receptor found only on these activated, sticky neutrophils, and the cell automatically engulfs whatever binds there. Because circulating neutrophils lack these receptors, the system is incredibly precise and targets only those immune cells that are actively contributing to inflammatory disease.” He also added, “Nanoparticles can be used to deliver drugs in a highly targeted, specific fashion to activated immune cells and could be designed to treat a broad range of inflammatory diseases.” The results of this study were published in the latest issue of Nature Nanotechnology.
Another Chinese study published in the February issue of the online journal Lancet Respiratory Medicine suggested the use of antioxidant supplement N-aetylcysteine to reduce exacerbations in chronic COPD patients. (Exacerbations refer to worsening of COPD symptoms leading to changes in the color and consistency of sputum and shortness of breath, often needing immediate hospitalization.) This study was conducted by Nan-Shan Zhong, MD, of China’s First Affiliated Hospital of Guangzhou Medical University, and colleagues, and reported that, “Our findings show that in Chinese patients with moderate-to-severe COPD, long-term use of N-acetylcysteine 600 mg twice daily can prevent exacerbations, especially in disease of moderate severity. Future studies are needed to explore efficacy in patients with mild COPD (GOLD I).”