Study on Synergistic Activity of Ethanolic Leave Extract of Terminalia chebula in Combination to Azithromycin and Ciprofloxacin against Various Bacterial Strains

Abstract

Aims: To investigate the antibacterial activity of ethanolic extract of Terminalia chebula leaf against Bacillus cereus, Sarcina lutea, Staphylococcus aureus, Bacillus subtilis, Salmonella  paratyphi, Escherichia coli, Vibrio milieus, Shigella dysenteriae, Shigella boydii, Salmonella typhii in comparison to standard antibiotics azithromycin and ciprofloxacin. Study Design: Extraction of T. chebula leaf, susceptibility tests (zone of inhibition) of extract itself as well as with combination of antibiotics. Place and Duration of Study: The leaves of T. chebula were collected from Gazipur, Bangladesh, in October, 2015, and identified by an expert taxonomist. (Hosne Ara, Director, Bangladesh National Herbarium, Mirpur-1, Dhaka, Bangladesh) Antibacterial analysis was done in Department Pharmacy, Southeast University from August to December, 2015. Methodology: Disc diffusion test was done to determine Antibacterial activity to plant extract against the above mentioned microbial species. The leaves of T. chebula were collected, dried at room temperature and extracted with ethanol and evaporated with rotary evaporator. The discs were prepared by incorporating the desired concentration (10 µl) of extract individual and along with the antibiotics. Results: Etahnolic extract of T. chebula leaves has shown highest activity against B. cereus with 20 mm of zone of inhibition. When combined to azithromycin it possessed highest synergistic effect against S. dysenteriae, S. boydii, S. lutea with 29 mm of zone of inhibition. When combined to ciprofloxacin it possessed highest synergistic effect against B. subtilis where the zone of inhibition was 32 mm. Conclusion: This study reveals that T. chebula has antibacterial activity to both Gram positive and Gram negative bacteria. This antibacterial activity is associated with the variety of phytochemicals found in this plant. The review also estimated the combination therapy of leaf extract with antibiotics towards revealing a new formulation of drug dosage form. Further studies should concentrate on the investigations of not only leaf but also the other parts of the plant.