Alzheimer’s disease (AD) is the most common form of dementia and has no cure. Therapeutic strategies focusing on the reduction of oxidative stress, modulation of amyloid-beta (Aβ) toxicity and inhibition of tau protein hyperphosphorylation are warranted to avoid the development and progression of AD. The aim of this study was to screen the crude extracts (CEs) and ethyl-acetate fractions (EAFs) of Guazuma ulmifolia , Limonium brasiliense , Paullinia cupana , Poincianella pluviosa , Stryphnodendron adstringens and Trichilia catigua using preliminary in vitro bioassays (acetylcholinesterase inhibition, antioxidant activity and total polyphenol content) to select extracts/fractions and assess their protective effects against Aβ 25–35 toxicity in SH-SY5Y cells. The effect of the EAF of S . adstringens on mitochondrial membrane potential, lipid peroxidation, superoxide production and mRNA expression of 10 genes related to AD was also evaluated and the electropherogram fingerprints of EAFs were established by capillary electrophoresis. Chemometric tools were used to correlate the in vitro activities of the samples with their potential to be evaluated against AD and to divide extracts/fractions into four clusters. Pretreatment with the EAFs grouped in cluster 1 ( S . adstringens , P . pluviosa and L . brasiliense ) protected SH-SY5Y cells from Aβ 25-35 -induced toxicity. The EAF of S . adstringens at 15.62 μg/mL was able completely to inhibit the mitochondrial depolarization (69%), superoxide production (49%) and Aβ 25-35 -induced lipid peroxidation (35%). With respect to mRNA expression, the EAF of S . adstringens also prevented the MAPT mRNA overexpression (expression ratio of 2.387x) induced by Aβ 25–35 , which may be related to tau protein hyperphosphorylation. This is the first time that the neuroprotective effects of these fractions have been demonstrated and that the electropherogram fingerprints for the EAFs of G . ulmifolia , L . brasiliense , P . cupana , P . pluviosa and S . adstringens have been established. The study expands knowledge of the in vitro protective effects and quality control of the evaluated fractions.

Limonium species represent a source of bioactive compounds that have been widely used in folk medicine. This study aimed to synthesize the anticancer and anti-proliferative potential of Limonium species through a systematic review. Searches were performed in the electronic databases PubMed/MEDLINE, Scopus, and Scielo and via a manual search. In vivo or in vitro studies that evaluated the anticancer or anti-proliferative effect of at least one Limonium species were included. In total, 942 studies were identified, with 33 articles read in full and 17 studies included for qualitative synthesis. Of these, 14 (82.35%) refer to in vitro assays, one (5.88%) was in vivo, and two (11.76%) were designed as in vitro and in vivo assays. Different extracts and isolated compounds from Limonium species were evaluated through cytotoxic analysis against various cancer cells lines (especially hepatocellular carcinoma—HepG2; n = 7, 41.18%). Limonium tetragonum was the most evaluated species. The possible cellular mechanism involved in the anticancer activity of some Limonium species included the inhibition of enzymatic activities and expression of matrix metalloproteinases (MMPs), which suggested anti-metastatic effects, anti-melanogenic activity, cell proliferation inhibition pathways, and antioxidant and immunomodulatory effects. The results reinforce the potential of Limonium species as a source for the discovery and development of new potential cytotoxic and anticancer agents. However, further studies and improvements in experimental designs are needed to better demonstrate the mechanism of action of all of these compounds.

Monteverdia ilicifolia is a Brazilian native plant, traditionally used to treat gastric diseases that are now associated with Helicobacter pylori and are commonly associated with several human diseases. We point out the M. ilicifolia extract as active against H. pylori. The crude extract produced with acetone:water presented the best H. pylori inhibitory activity of all five extracts (MIC 64 µg/mL). The ethyl-acetate fractions from crude extracts produced with ethanol and acetone showed a MIC of 64 µg/mL. Both ethyl-acetate fractions and the crude extract produced with acetone showed an antioxidant capacity of between 14.51 and 19.48 µg/mL in the DPPH assay. In the FRAP assay, two ethyl-acetate fractions (EAF2 and EAF4) presented the antioxidant capacity of 5.40 and 5.15 mM Trolox/g of extract. According to the results obtained from the antioxidant and antibacterial assays, two fractions (EAF2 and nBF5) were analyzed by mass spectrometry and confirmed the presence of monomeric, dimeric, trimeric tannins, and glycosylated flavonoids. Some compounds were tested using bioinformatics to evaluate the best enzyme inhibitors and the molecular interaction between the enzyme and the tested ligands. The presence of these polyphenol compounds could play an important role in antioxidant and inhibitory capacities against H. pylori and can be used to assist in the treatment or prevention of infection by H. pylori.

Periodontal diseases are a global oral health problem affecting almost 10% of the global population. Porphyromonas gingivalis (Pg) is one of the main bacteria involved in initiation and progression of inflammatory processes as a result of the action of the cysteine proteases lysin- and arginine-gingipain. Surelease/polycarbophil microparticles (MLB), containing a lyophilized proanthocyanidin-enriched fraction from the rhizomes of Limonium brasiliense, traditionally named as “baicuru” (EAF), were manufactured. EAF was characterized by UHPLC by the presence of samarangenins A and B (12.10% ± 0.07% and 21.05% ± 0.44%, respectively) and epigallocatechin-3-O-gallate (13.44% ± 0.27%). Physiochemical aspects of MLB were characterized concerning particle size, zeta potential, entrapment efficiency, EAF release, and mucoadhesion. Additionally, influence of the EAF-loaded microparticles were performed concerning potential influence on viability of human buccal KB cell, Pg adhesion to KB cells, gingipain activity and Pg biofilm formation. In general, all MLB tested showed strong adhesion to porcine cheek mucosa (93.1% ± 4.2% in 30 min test), associated with a prolonged release of EAF (up to 16. 5% ± 0.8% in 24 h). Preincubation of KB cells with MLB (25 µg/mL) resulted in up to 93% ± 2% reduced infection rate by Pg. Decreased activity of the Pg-specific virulence factors lysin- and arginine-gingipain proteases by MLB were confirmed. MLB decreased biofilm formation of Pg (97% ± 2% at 60 µg/mL). Results from this study prove the promising activity of MLB containing EAF microparticles as a prophylaxis strategy to prevent recurrence of Pg.