**3.2. Antibacterial activity**

Khan and coworkers [24] used disc diffusion methods to test antibacterial activity of the ethanol extract of *Barringtonia racemosa* roots, its chloroform soluble fraction, and a there from an isolated clerodane diterpenoid (Nasimalun A). The results presented that they all showed potent activity in inhibiting the growth of 19 strains of bacterial with the ethanol extract as the most activity part. A marble cup method was used by Goyal [25] to test the antimicrobial activities of the crude methanolic extract of *Barringtonia asiatica* (leaves, fruits, seeds, stem and root barks) and the fractions (petrol, dichloromethane, ethyl acetate, and butanol) and all the extract exhibited a very good level of broad spectrum antibacterial activity. Baswa [26] evaluated the antibacterial activity of *Pongamia pinnata* seed oil *in vitro* against fourteen strains of pathogenic bacteria. Using the tube dilution technique, it was observed that 57.14 and 21.42% of the pathogens were inhibited at 500 µl/ml, 14.28 and 71.42% at 125 µl/ml, and 28.57 and 7.14% at 250 µl/ml of *Pongamia pinnata* oils. The activity with both the oils was bactericidal and independent of temperature and energy. Most of the pathogens were killed more rapidly at 4°C than 37°C. The activity was mainly due to the inhibition of cell-membrane synthesis in the bacteria.
