Maria da Conceição Torrado Truiti

In vitro antibacterial activity of a 7-O-beta-D-glucopyranosyl-nutanocoumarin from Chaptalia nutans (Asteraceae)

Ethanolic crude extracts from the roots of Chaptalia nutans, traditionally used in Brazilian folk medicine, were screened against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by using the disk diffusion test technique. S. aureus with 14 mm inhibition zone was considered susceptible. E. coli and P. aeruginosa without such a zone were considered resistant. As a result of this finding, the ethanolic crude extract was fractionated on silica gel column chromatography into five fractions. The ethyl acetate fraction was active against S. aureus and Bacillus subtilis. Further column chromatography separation of the ethyl acetate fraction afforded 30 fractions, which were assayed against S. aureus. Fractions 16 and 17 showed inhibition zones with S. aureus, indicating the presence of active compounds, and were subjected to purification by repeated preparative thin layer chromatography. The pure compound 7-O-beta-D-glucopyranosyl-nutanocoumarin inhibited B. subtilis and S. aureus at concentrations of 62.5 g/ml and 125 g/ml, respectively. The antibacterial property of C. nutans appears to have justified its use for the treatment of wounds, which are contaminated through bacterial infections.

Screening of Five Brazilian Plants for Anti-inflammatory and Antimicrobial Activities

Abstract Ethanol extracts from the leaves of Cayaponia podantha. Cogn. (Cucurbitaceae), Nectandra falcifolia. (Nees) Castiglioni (Lauraceae), and Paullinia elegans. Cambess. (Sapindaceae), as well as from the aerial parts of Helicteres gardneriana. St. Hil. & Naud. (Sterculiaceae) and Melochia arenosa. Benth. (Sterculiaceae), all naturally occurring species in the Brazilian part of the Upper Paraná River and all belonging to genera used in folk medicine, were screened for anti-inflammatory activity using the carrageenan-induced pleurisy model in rats, and for antimicrobial activity using a broth microdilution assay against Staphylococcus aureus., Bacillus subtilis., Escherichia coli., Pseudomonas aeruginosa., Candida albicans., C. krusei., C. parapsilosis., and C. tropicalis.. In the analysis of anti-inflammatory activity, a 500 mg/kg body weight dose of the extracts of C. podantha., N. falcifolia., P. elegans., and H. gardneriana., administered orally (by gavage), reduced the volume of the inflammatory exudates in rats induced by intrapleural injection. H. gardneriana. also inhibited migration of leukocytes to the lesion site. Crude extract of M. arenosa. was ineffective on the intensity of the inflammatory response. Regarding antimicrobial activity, the best results were obtained with N. falcifolia. and M. arenosa. against the Gram-positive bacteria tested. N. falcifolia. was active against B. subtilis. with a minimum inhibitory concentration (MIC) of 39 µg/ml and a minimum bactericidal concentration (MBC) of 75 µg/ml and M. arenosa. with MIC of 625 µg/ml against B. subtilis. and MIC and MBC of 625 µg/ml against S. aureus.. The results obtained demonstrate the importance of pharmacological studies with neotropical plants, and further research into the specific components responsible for the observed bioactivities is under way.

Three 5-methylcoumarins from Chaptalia nutans

One new 5-methylcoumarin, along with its two new isomeric glucosides were isolated from the roots of Chaptalia nutans.

Antileishmanial and antioxidant potential of fractions and isolated compounds from Nectandra cuspidata

Abstract The effects on the viability of promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and citotoxicity in J774.A1 macrophages of ethanolic extract, fractions and isolated compounds that were obtained from the leaves of Nectandra cuspidata were determined. The total phenolics content (TP) and antioxidant activity were assessed using different assays. The ethyl acetate fraction (EAF) had the best antiproliferative activity (amastigote IC50: 4.42 ± 0.60 μg/mL, promastigote IC50: 33.33 ± 0.78) and presented no cytotoxicity at the highest concentration tested (1000 μg/mL). The EAF also had the greatest antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (DPPH IC50 6.54 ± 0.10 μg/mL, ABTS 4.75 ± 0.11 mmol ET/g; FRAP 2.37 ± 0.03 mmol ET/g; ORAC = 33.52 ± 1.99 mmol ET/g; TP 387.11 ± 0.25 mg GAE/g). Vitexin, epicatechin and isovitexin isolated from EAF contribute to both activities.

Employing photoacoustic spectroscopy in the evaluation of the skin permeation profile of emulsion containing antioxidant phenolic-rich extract of Melochia arenosa

Abstract Context: Oxidative stress is an important factor modulating skin alterations. Melochia arenosa Benth. (Malvaceae) is a Brazilian plant with antimicrobial activity and antioxidant potential. Objective: The objective of this study is to develop a topical formulation containing antioxidant phenolic-rich extract of M. arenosa and to evaluate its skin permeation profile. Materials and methods: Response surface methodology was used to maximize the total phenolic (TP) content of the extract and its antioxidant activity was evaluated by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and respiratory burst methods. An emulsion containing 1% optimized extract (OE) was developed and employed photoacoustic spectroscopy (PAS) for the determination of its skin permeation profile. The morphology of the skin was studied in histological sections stained with hematoxylin–eosin. Results and discussion: The optimum conditions predicted for the major extractive efficiency of the phenolics with 100% ethanol led extraction time 101 h and plant:solvent proportion 1:13.5 (w/v). OE presented TP = 724.6 ± 8.2 mg GAE/g extract and scavenging capacity of DPPH (IC50 value = 11.43 ± 0.14 µg/mL) and ABTS radicals (IC50 value = 35.42 ± 0.48 µg/mL). The production of ROS by neutrophils after stimulation with phorbol miristate acetate was lower when the OE was present in the reaction medium, endorsing its high antioxidant capacity. The data obtained by PAS indicated that the OE present in the emulsion has permeated and was distributed in the whole skin. No histopathological alterations were observed in the histological analysis. Conclusion: The formulation developed is a promising tool for skin care and could prevent the damage caused by oxidative stress.

Inhibitory Effect of Helicteres gardneriana Ethanol Extract on Acute Inflammation

The anti-inflammatory effect of an ethanol extract of Helicteres gardneriana (Nees) Castiglioni was assayed in experimental models of pleurisy and microcirculation in situ. Treatment of animals with 500 mg/kg body weight reduced the exudate volume (35% reduction) induced by intrapleural injection of carrageenan and the migration of polymorphonuclear cells into the inflamed pleural cavity of rats (40%). Additionally, rolling and adhesion of leukocytes and the number of leukocytes that migrated toward the perivascular space in response to the carrageenan injection were decreased by the extract (500 mg/kg). These data demonstrate the anti-inflammatory effect of the ethanol extract of Helicteres gardneriana and imply that inhibition of leukocyte-endothelial interactions is important in the extracts mechanism of action.

Photodamage attenuating potential of Nectandra hihua against UVB-induced oxidative stress in L929 fibroblasts

The total phenolic content (TP) and antioxidant activity of the ethanolic extract and fractions that were obtained from the leaves of Nectandra hihua were assessed using different methods. The ethanolic extract (EE) and ethyl acetate fraction (EAF) had the best antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (ABTS+ 2.55 ± 0.06, 3.54 ± 0.03 mmol TE/g; DPPH IC50 10.27 ± 0.05, 9.88 ± 0.02 μg/mL; FRAP 2.17 ± 0.08, 2.38 ± 0.04 mmol TE/g; ORAC 5.16 ± 0.08, 5.35 ± 0.07 mmol TE/g; TP 568.05 ± 18.15, 397.20 ± 17.88 mg GAE/g, respectively). The cytoprotective effect, reactive oxygen species (ROS) and lipid peroxidation inhibitions on L929 fibroblasts irradiated with UVB (600 mJ/cm2) in pre- and post-treatments with EE and EAF were determined. These plant materials demonstrated high ROS scavenging activity and lipid peroxidation inhibition on L929 fibroblasts in both treatments, especially with pre-treatment (EE 38.47 ± 1.95% and EAF 40.20 ± 4.5% inhibition of ROS production, and EE 39.03 ± 3.33% and EAF 41.67 ± 7.6% of lipid peroxidation inhibition), indicating the best cytoprotection with pre-treatment (13.52 ± 1.66% and 13.34 ± 2.61% increases in cell viability). The antioxidant flavonoids quercitrin, avicularin, juglalin, afzelin and astragalin were isolated from EAF. The results obtained indicate that EE and EAF present photodamage attenuating potential against UVB-induced oxidative stress and can be useful as a starting point for developing dermatological products to prevent oxidative skin damage.