Abstract
Tabernaemontana divaricata R.Br. is a medicinal shrub belongs to the family Apocynaceae. The medicinal properties of its leaves and flowers are well known to the traditional medicine. The flowers are useful to cure burning sensation, ophthalmic and dermatopathic diseases. However, the antibacterial effect of its flower is not yet unravelled. Therefore, the present investigation was mainly focused on the antibacterial activity of the flowers of Tabernaemontana divaricata. For validating the taxonomic description of flower, powder microscopic study was also carried out. In the study, different flower extracts were tested against standard bacterial strains by disc diffusion method. Microscopic character of the flower powder was studied by trinocular microscope. The results of the study indicated that only the methanolic extract of the flower was effective to inhibit the growth of Staphylococcus aureus and Escherichia coli. The different flower extracts were ineffective against Pseudomonas aeruginosa, Klebsiella pneumoniae and Serratia marcescens. Powder microscopy revealed that the flower has light fragrant spirally thickened xylem vessels, prismatic crystals of calcium oxalate, trichomes, small starch grains and pollen grains. The study concludes that the flower extract of Tabernaemontana divaricata has significant antibacterial activity against Staphylococcus aureus and Escherichia coli. Therefore, the flower extract in methanol can be taken for the purification of active principle. The various flower characteristics obtained from the powder microscopy can be used as a taxonomic tool for identifying the flower and plant species.
