Researchers from the State University of Maringa in Brazil have found that rosemary (Rosmarinus officinalis), pomegranate (Punica granatum), and misty plume bush (Tetradenia riparia) have antibacterial properties, especially against methicillin-resistant Staphylococcus aureus (MRSA). The study, which appeared in the Journal of Herbal Medicine, investigated the efficacy of these plants against planktonic and biofilm cells of S. aureus.
To determine the anti-staphylococcal effect of the plants, the researchers obtained extracts from each and subjected these to a microdilution technique. This determined the minimal inhibitory and bacterial concentrations (MIC and MBC) from each hydroalcoholic extract.
The researchers used a checkerboard method to determine the synergistic reactions between the extracts and penicillin, as well as MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction assay and scanning electron microscopy (SEM) to assess anti-biofilm effects for each.
Based on the results, extracts from rosemary and misty plume bush exhibited significant anti-staphylococcal effects, having MICs in the range of 15.6–125 micrograms per milliliter (mcg/mL).
Pomegranate peel extracts exhibited moderate activity with MICs of 125–250 mcg/mL and MBCs of 500–1,000 mcg/mL.
Researchers also found a synergistic effect when the extracts are used in concert with penicillin.
Rosemary and misty plume bush extracts displayed anti-biofilm effects at 30–250 mcg/mL, and SEM images revealed a significant reduction in biofilm cells.
From the findings, the team concluded that rosemary, pomegranate, and misty plume bush can be used in the development of new therapies against S. aureus.
Journal Reference:
Endo EH, Costa GM, Makimori RY, Ueda-Nakamura T, Nakamura CV, Filho BPD. Anti-biofilm activity of Rosmarinus officinalis, Punica granatum and Tetradenia riparia against methicillin-resistant Staphylococcus aureus (MRSA) and synergic interaction with penicillin. Journal of Herbal Medicine. 2018;14:48–54. DOI: 10.1016/j.hermed.2018.07.001