Evaluation of the antimicrobial and antioxidant activity of the leaves of Fridericia Platyphylla species

Bacterial resistance is one of the greatest threats to global health, causing difficulties in controlling infections and increasing costs in health system. The study of plant species antimicrobial activity is of foremost importance. Brazil has a wide plant species variety, offering a vast area for research new molecules to produce drugs. Among these species is Fridericia platyphylla, popularly known as “cervejinha do campo". This research aims to evaluate the antimicrobial and antioxidant activity of the crude extract and dichlorine fraction of Fridericia platyphylla species leaves. The chemical characterization of the raw plant extract was performed using HPLC-PDA, FIA-ESI-IT-MS, and LCMS techniques. The DPPH and ABTS methods were used to evaluate the antioxidant properties. The antimicrobial activity was assessed by determination of the minimum inhibitory concentration (MIC) through microdilution assay. An in vivo model using Tenebrio molitor was employed to evaluate the toxicity. Ten compounds were identified in the crude extract. The crude leaf extract showed the highest antioxidant activity at 250 μg/mL. The antimicrobial assays showed that F. platyphylla crude extract inhibited Staphylococcus aureus ATCC 6538 with a MIC of 64 μg/mL. The dichlorine fraction inhibited the same bacteria at a MIC of 16 μg/mL. Enterococcus faecalis ATCC 51299 and Pseudomonas aeruginosa ATCC 27856 were inhibited with MIC of 1024 μg/mL and 512 μg/mL. The results emphasize the crude extract and dichlorine fraction of F. platyphylla leaves potential as an alternative to prevent and combat infections and as a source of raw material in producing drugs and natural products.