Victor Antonio Silva Lima

Fridericia platyphylla, a member of the Bignoniaceae family, is widely recognized as a rich source of flavonoids with significant biopharmacological potential. This study aimed to perform a chemical annotation of its metabolites and to evaluate the antitumor activity of the hydroalcoholic extract from its leaves. The chemical diversity of this specimen was analyzed using liquid chromatography coupled with tandem mass spectrometry and Molecular Networking. Fifteen significant phenolic compounds were annotated, including phenolic acid derivatives, flavonoid glycosides, and flavone aglycones. Furthermore, the antiproliferative activities against human cervical cell lines, adenocarcinoma HPV 18 positive (HeLa) and carcinoma HPV 16 positive (SiHa), in vitro, exhibited distinct inhibitory effects, with IC₅₀ values of 44.78 and 66.97 µg mL⁻¹, respectively. The extract inhibited cell migration and exhibited cytotoxic effects by reducing the viability of HeLa and SiHa cells, suggesting its potential as a therapeutic candidate for cervical cancer. Therefore, given the significant antiproliferative and anti-migratory activity, these results open up prospects for investigating F. platyphylla leaf extract in the development of alternative therapies for cervical cancer.

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.

Infectious and Parasitic Diseases (IPD) remain a challenge for medicine due to several interconnected reasons, such as antimicrobial resistance (AMR). American tegumentary leishmaniasis (ATL) is an overlooked IPD causing persistent skin ulcers that are challenging to heal, resulting in disfiguring scars. Moreover, it has the potential to extend from the skin to the mucous membranes of the nose, mouth, and throat in both humans and various animals. Given the limited effectiveness and AMR of current drugs, the exploration of new substances has emerged as a promising alternative for ATL treatment. Arrabidaea brachypoda (DC). Bureau is a native Brazilian plant rich in dimeric flavonoids, including Brachydin (BRA), which displays antimicrobial activity, but still little has been explored regarding the development of therapeutic formulations. In this work, we present the design of a low-cost liquid formulation based on the use of Pluronic F127 for encapsulation of high BRA concentration (LF-B500). The characterization techniques revealed that BRA-loaded F127 micelles are well-stabilized in an unusual worm-like form. The in vitro cytotoxicity assay demonstrated that LF-B500 was non-toxic to macrophages but efficient in the inactivation of forms of Leishmania amazonensis promastigotes with IC₅₀ of 16.06 µg/mL. The results demonstrated that LF-B500 opened a new perspective on the use of liquid formulation-based natural products for ATL treatment.