In vitro antimicrobial activity of Luffa operculata.

INTRODUCTION Luffa operculata is probably one of the most popular herbal medicines used in the treatment of rhinitis and rhinosinusitis. However, its specific mechanism of action is still unknown. OBJECTIVE To evaluate in vitro antibacterial activity of L. operculata against three ordinary agents of upper respiratory tract infection: Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes. METHODS Different concentrations of L. operculata alcoholic extract were applied to bacterial broth containing reference and community strains of the three described agents. After a 24-h incubation period, the bacterial culture turbidity was measured. The samples were then inoculated onto Mueller-Hinton and human blood agar plates. Bacterial growth was analyzed after 24- and 48-h incubation period. The test was considered negative when there was no environmental turbidity, confirmed by the absence of bacterial growth into the inoculated plates. Tests were considered positive when either turbidity changes were observed on the bacterial broth or when bacterial growth was detected on inoculated plates. Appropriate statistical analysis of the data was performed. RESULTS L. operculata extracts showed antibacterial activity mainly to S. pyogenes followed by S. pneumoniae and S. aureus. CONCLUSIONS L. operculata extract showed promising antibacterial activity in vitro against the studied agents.