Asthma and Plants used for Asthma-An Overview

Asthma is best described as a chronic disease that involves inflammation of the pulmonary airways and bronchial hyperresponsiveness that results in the clinical expression of a lower airway obstruction that usually is reversible. Physiologically, bronchial hyperresponsiveness is documented by decreased bronchial airflow after bronchoprovocation with methacholine or histamine. Other triggers that provoke airway obstruction include cold air, exercise, viral upper respiratory infection, cigarette smoke, and respiratory allergens. Bronchial asthma is a common problem with enormous medical and economics impacts. It is an inflammatory disease of the airways associated with intermittent episodes of bronchospasm. Asthma is not uncommon in the elderly patients. Prevalence of asthma is similar in older and younger adults. Due to rapid industrialization and urbanization, asthma prevalence is predicted to increase more rapidly in the coming years. Despite the availability of a wide range of drugs for the treatment of asthma, the relief offered by them is mainly symptomatic and short lived. Moreover the side effects of these drugs are also quite disturbing. Medicinal Plants have been the highly esteemed source of medicine throughout human history. They are widely used today indicating that they are a growing part of modern, hightech medicine. About 25–30 percent of today's prescription drugs contain chemical moieties derived from plants. The Indian system of medicine i.e Ayurveda alongwith classic texts like Bheshajya Ratnavali has a longstanding tradition that offers a unique insight into comprehensive approach to asthma management through proper care of the respiratory tract. Ayurvedic formulations used in the management of asthma, therefore, judiciously combine herbs to support the physiology of respiration, these herbs apart from exerting bronchial action also possess concomitant properties like antioxidant to support the digestive, cardiac, nerve functions and expectorant as well as just plain soothing herbs. In the present article an attempt has been made to review antiasthmatic medicinal plants with their active chemical constituent and possible mechanism of action.