First clues of Flaveria trinervia (Spreng.) C. Mohr as an adjuvant against bacteria responsible for Pneumonia

In some regions of Mexico, Flaveria trinervia (Spreng.) C. Mohr, also known as “Scotch broom”, is used to treat respiratory diseases, but no scientific studies have been carried out to confirm their possible therapeutic use. For this reason, in this research, the antimicrobial and antioxidant activities were evaluated along with its possible mechanism of action. 16 extracts of flowers, leaves, stems and the whole plant of Flaveria trinervia (Spreng.) C. Mohr were tested using hexane, chloroform, acetone and methanol as extraction solvents. The higher yield and antioxidant activity were obtained when methanol and acetone were used as extraction solvents for the leaves. The antimicrobial activity against microorganisms associated with pneumonia showed that the highest sensitivity was obtained for the two tested strains of S. aureus (50F and ATCC-43300) when acetone was used as extraction solvent (0.57 and 1.53 mg/mL respectively). On the other hand, the sensitivity of the tested Gram-negative microorganisms [A. baumannii (A164) and P. aeruginosa (ATCC-14)] was in the range of 0.36 and 1.9 mg/mL, similar to the positive control. Similar cell membrane damage was observed in all tested microorganisms compared to the control group, especially regarding nucleic acid leakage. These results were confirmed by the increase in penetration of the crystal violet dye and the decrease in microbial density. The results are important considering the greater antimicrobial activity against Gram-positive bacteria.