Evaluation of the effectiveness of plant-based formulations on improvement of symptoms and lung function in asthma

Abstract

Asthma is a common inflammatory and chronic respiratory disease characterized by increased responsiveness of bronchial airways to various stimuli such as environmental irritants, allergens, heavy exertions or anxiety (Balch and Stengler, 2011; Murali, Rajasekaran, Krishnarajasekar, Perumal, Nalini et al., 2006). Recent studies showed that the incidences of morbidity and mortality are still not well managed (Haldar et al, 2009). Treatment options that are available for relieving the exacerbation of asthma which is manifested by worsening of symptoms and bronchoconstriction such as prednisone have been associated with serious side effects particularly in children. Therefore, the purpose of this literature review to evaluate the effectiveness of herbal formulations as a complementary or alternative treatment option in the management of asthma and to determine its safety for patients' usage. The research objective of the study was to determine the therapeutic effects of herbal formulations in the management or treatment of asthma in children and/or adults. Hence, the research question outlining the PICO elements was developed to aid the research process. The PICO elements include: patients with asthma including children greater or equal to 5 years or adults of 18-65 years of age, herbal intervention compared to either conventional medicine or placebo or other recognised traditional herbal intervention. Outcomes were evaluated based on the significant improvement of symptoms and/or lung function in asthmatic patients after treatment with herbal intervention. Lung function measurements included forced expiratory volume in 1 second (FEV 1) and/or peak expiratory flow (PEF). The inclusion and exclusion criteria were applied to achieve the desired outcome. Only articles that were randomized controlled trials (RCTs) and satisfied the PICO elements were included. Although, a comprehensive systematic search was carried out, it resulted in just seven RCTs that were selected for the review. The CONSORT checklist for RCTs of herbal medicine interventions was used to evaluate the quality of the RCTs and the effectiveness of the herbal intervention. Based on the results of the review, it is evident that herbal interventions are effective in the treatment of asthma symptoms and improvement of lung function compared to other conventional medicine such as prednisone, salbutamol and theophylline. However, the studies lack on providing full information about the methods of randomization and blinding and them being the main judgemental criteria in the evaluation of trustworthiness does not allow to explore a full potential of the herbal intervention in the practice. Therefore, no recommendation for the use of herbal intervention in the clinical setting can be made at this stage.