Anti- Asthmatic and Anti-Allergic Activity of Ficus Religiosa (L.) Leaves

Abstract

Asthma is a complex disorder that displays heterogeneity and variability in its clinical expression both acutely and chronically. This heterogeneity is influenced by multiple factors including age, sex, socioeconomic status, race and/or ethnicity, and gene by environment interactions (Lemanske and Busse, 2010). The prevalence of asthma has rapidly increased over the last few decades to epidemic proportions and there are now an estimated 300 million sufferers worldwide, a total that is expected to rise dramatically over the next 15–20 years (Murdoch and Lloyd, 2010). Herbal medicines remain the major source of health care for the world’s population. The world health organization (WHO) has recognized herbal medicine as an essential building block of primary health care of vast countries like India and China. We have yet to explore fully the vast storehouse of indigenous, tribal or folklore and traditional system of medicine of our country. In spite of advances in modern system of medicine, there are various areas like tropical diseases, herpes, AIDS, cancer, bronchial asthma etc. which might be successfully cured by herbal medicines (Chaudhury, 1994). In recent times, the focus on plant research has been increased all over the world and a large body of evidence has been collected to show immense potential of medicinal plants used in various traditional systems of medicine. More than 13,000 plants have been studied during the last 5 year period in the world (Dahanukar et al., 2000). The genus Ficus (Moraceae) constitute one of the largest genera of angiosperms with more than 800 species of trees, epiphytes and shrubs in the tropical and sub-tropical regions worldwide. It is one of the most diverse plant genera in regard to its growth habit, with both deciduous and evergreen free-standing trees, stranglers, climbers, creepers, small shrubs, lithophytes and rheophytes (Loutfy et al., 2005; Ronsted et al., 2008). Ficus religiosa L. is the most popular member of the genus Ficus (McFarland, 1944; Galil, 1984). The specific epithet “religiosa” and synonym “bodhi tree” alludes to the religious significance attached to this tree (Kala et al., 2006; Sitaramam et al., 2009). Since antiquity, F. religiosa has got mythological, religious and medicinal importance in Indian culture. It is the oldest portrayed tree in India. Atharvaveda (sacred text of Hinduism) links it with the third heaven and discusses its medicinal properties along with Soma and Kustha (holy medicinal herbs). References to F. religiosa are found in several ancient holy texts like, Arthasastra, Puranas, Upanisads, Ramayana, Mahabharata, Bhagavadgita, Buddhistic literature, etc. (Prasad et al., 2006). The preliminary phytochemical screening of Ficus religiosa was carried out. The estimation of the total phenolics and flavonoids content of the different extracts of F. religiosa was also done. The aqueous extract contained the highest amount of phenolics and the methanolic extract contained the highest amount of the flavonoids compared to the aqueous extract. The results for flavonoids content were 118.86 ± 2.91 and 342. 30 ± 2.50 for the aqueous and methanolic extract, respectively. Similarly, the results for phenolics content were 47.22 ± 0.84 and 40.42 ± 1.92 for the aqueous and methanolic extract respectively (Singleton and Rosi, 1965; Baharam et al., 1996). An acute bronchospasm (asphytic reaction) in guinea pigs by exposing to histamine aerosol has been used in the assessment of anti-asthmatic potential of the test compounds by measuring the time taken for the development of pre-convulsion dyspnea (PCD) as an end point (Mitra et al., 1999; Shah and Parmar, 2003). In the present study, a single administration of the Aqueous extract of Ficus religiosa leaves (AEFRL) produced significant effect on the latency to the development of histamine-induced PCD as compared to vehicle control animals, suggesting that the aqueous extracts at the doses employed in the present study are effective to relieve bronchospasm induced by histamine. On the basis of the results obtained in the present study it maybe concluded that Ficus religiosa extract was found to be effective against histamine, as well as acetylcholine induced bronchospasm in guinea pigs. The degranulation of mast cell occurs in response to the immunological stimuli in which antigen antibody reactions are predominant. AEFRL at doses (10-30 μg/mL) significantly protected the mast cells from compound 48/80 induced degranulation in a dose dependent manner.Aqueous extract produced significant spasmolytic activity in isolated ileum against contractions induced by histamine and acetylcholine. This effect is possibly due to the presence of one or more anti-histaminic and anti-cholinergic constituents in the aqueous extract of the drug. The compound 48/80 is one of the most potent mast cell degranulators which cause liberation of mediators of inflammation such as histamine, leukotrienes, PAF and eosinophils etc. These mediators are mainly responsible for development of edema due to immediate hypersensitivity. The aqueous extract of Ficus religiosa leaves used in the present investigations produced dose-dependent protection against pedal edema volume induced by compound 48/80. This effect was similar to ketotifen.