Antibacterial Potential and Phytochemical Analysis of Barleria lupulina Lindl. (Aerial Parts) Extracts Against Respiratory Tract Pathogens

Abstract The antibacterial and phytochemical investigation of Barleria lupulina Lindl. aerial parts extracts were examined against common respiratory tract pathogens i.e., Streptococcus pneumoniae (MTCC 655), Staphylococcus aureus (MTCC 1144), Pseudomonas aeruginosa (MTCC 2474), Streptococcus pyogens (MTCC 442), Haemophillus influenzae (MTCC 3826). The plant material was extracted with solvents i.e., petroleum ether (PET), acetone (ACE), methanol (MeOH) and aqueous (H2O) with increasing polarity by Soxhlet apparatus and removed the solvent using vacuum evaporator at 30˚C. Antibacterial activity and minimum inhibitory concentration (MICs) were examined by Agar well diffusion two fold serial dilution method respectively. The maximum inhibition zone was found against S. aureus (17.34±0.78 mm) of methanol extract and minimum against S. pyogens (9.44±0.32 mm). MICs were observed for MeOH extract between 3.12 to 12.5 mg/mL against S. pneumoniae and S. pyogens respectively. Phytochemical examination of plant extracts showed the occurrence of alkaloids, saponins, steroids, flavonoids, glycosides, tannins, resins and phenolic compounds. The antimicrobial activity of the crude extracts of plant represents a significant outcome for the treatment of respiratory tract diseases.