Antieosinophilic activity of various subfractions of leaves of Vitex negundo

Abstract

Aim: The present study was undertaken to isolate and identify active constituent of leaves of Vitex negundo for their actions on bronchial hyperresponsiveness. Materials and Methods: Effects of aqueous subfraction, acetone subfraction, and chloroform sub-fraction on bronchial hyperresponsiveness and serum bicarbonate level were studied using egg-albumin-induced asthma in guinea pigs. The structure of aqueous subfraction of leaves of Vitex negundo was determined by various spectroscopy methods like UV spectroscopy, FT-IR spectroscopy, EI-mass spectroscopy, and H 1 NMR spectroscopy. Results: Animals pretreated with aqueous subfraction of leaves of Vitex negundo showed significantly lesser serum bicarbonate level, when compared with untreated sensitized animals. Animals pretreated with aqueous subfraction showed significant lesser eosinophils count (9.50 ± 1.5044; P < 0.05) when compared with untreated sensitized animals (29.50 ± 2.5074; P < 0.05). Histopathology of lungs in sensitized guinea pig showed infiltration of inflammatory cells like eosinophils and neutrophils which is due to marked inflammation in lungs. Histopathology of lungs in animals pretreated with aqueous subfraction (200 mg/ kg) showed normal airway, blood vessels, and bronchoalveolar space. Conclusion : It can be concluded that aqueous subfraction of leaves of Vitex negundo possesses antieosinophilic activity. It reduces bronchial hyperresponsiveness. As per UV, EI-Mass, FT-IR, and H 1 NMR spectra analysis, the structure of aqueous subfraction is determined as a 5-hydroxy-3,6,7,3',4'-pentamethoxy flavone. It may be useful in the treatment of asthma and various inflammatory, allergic, and immunologic diseases.