Dental caries and periodontal disease are the most prevalent of the biofilm-dependent diseases. With numerous side effects on the use of chlorhexidine, the search for new safe therapeutic alternatives for microorganisms involved with these diseases increases every day. This study aimed to evaluate the antimicrobial activity and cytotoxicity of extracts made from the bark of Schinopsis brasiliensis Engl. against five oral microorganisms and analyze their phytochemical and thermal degradation profile. The liquid-liquid partition was performed with hexane, chloroform and ethyl acetate. The identification and quantification of the chemical marker was done. Antimicrobial activity was evaluated based on the minimum inhibitory concentration. The cytotoxicity was analyzed based on the hemolysing potential of the samples. The thermal degradation profile was performed by two different methods. Gallic acid was identified as the main compound of the samples and showed the highest amount in the chloroform fraction. All samples were able to inhibit the growth of the microorganisms tested and showed no cytotoxicity. The ethanol extract absorbs less heat than the fractions. All samples exhibited exothermic peak consistent with degradation of gallic acid. Based on the results, the samples used are potential candidates for use in dental formulations for biofilm control.

Tacinga inamoena (K. Schum.) N.P. Taylor & Stuppy, also known as quipá, is a native cactus of the Caatinga used in traditional medicine to treat urethral infections and inflammation. This study aimed to determine the physicochemical characteristics of vegetal drug obtained from the roots of T. inamoena. Analytical techniques and phytochemical tests were used, such as thermal analysis, qualitative and semiquantitative determination of secondary metabolites and spectroscopy at the infrared region. The powder of the vegetal drug met the parameters established by the Brazilian Pharmacopoeia, except for compressibility, which was low. On the thermogravimetric curve, three events related to the mass loss were verified, which correlate with the vegetal drug quality control and play a part in their standardization. The qualitative screening suggested the presence of alkaloids, flavonoids and terpenes. The infrared spectrum reinforced the presence of hydroxyl, carbonyl, and ether groups. In the semiquantitative screening, a concentration for total polyphenols of 65 mg equivalent to gallic acid g-1 to the crude ethanol extract (CEE) was obtained. On the correlation of flavonoid content to seasonality, a concentration was obtained of 3.3 mg equivalent to quercetin g-1 to the CEE obtained during the drought period and of 10.6 mg equivalent to quercetin g-1 to the CCE obtained during the rainy season. In T. inamoena, the presence of important classes of secondary metabolites, which are associated with the pharmacognostic characterization, aids the authentication and quality control of vegetal drugs of importance in traditional Brazilian medicine.

Abstract Background: PnPa11 and PnPa13 are synthetic peptides derived from Phoneutria nigriventer spider venom, which display antinociceptive and neuroprotective properties. In this work, we evaluated the safety of intravitreal use and the neuroprotective effect of these peptides. Methods: The cytotoxicity and the antiangiogenic activity of these peptides were evaluated by the sulforhodamine-B method and chicken chorioallantoic membrane (CAM) assay, respectively. The in vivo safety was analyzed in Wistar rats that were intravitreally injected with different doses (0.50; 1.25; 2.50; 3.75 and 5.00 µg/mL) of these peptides (right eye, n = 6). The retinal function was assessed by electroretinography exams (ERG), intraocular pressure (IOP), and histological analyzes. In order to investigate the neuroprotective effect, Wistar rats received intravitreal injections (right eye, n = 6) of peptides at 1.25 µg/mL and then were exposed to blue LED light. In addition, the visual function and the retinal microstructure were verified. Results: Cytotoxicity analyses demonstrated that the peptides did not present any toxicity over ARPE-19 (adult retinal pigmented epithelial) cell line and the antiangiogenic study highlighted that the peptides promoted the reduction of blood vessels. The intravitreal injection did not cause major changes, neither induced any irreversible damage. In the retinal degeneration assay, the ERG records demonstrated that the prior treatment with PnPa11 and PnPa13 protected the retina from damage. Morphological analyses confirmed the ERG findings. Immunoblotting analyses revealed that PnPa11 increased Erk1/2, NR2A, and NR2B retinal expression after the light stress model, but did not cause Akt1 activation, while PnPa13 prevented Erk1/2 and Akt1 dephosphorylation. Conclusions: The intraocular administration of these peptides was well tolerated and presented protective activity against retinal degeneration, suggesting the potential use of these peptides as neuroprotectors in the ophthalmological field.