Mariana Piana

Chemical composition and antioxidant activity of the essential oil of Tabernaemontana catharinensis A. DC. leaves

The essential oils obtained by hydrodistillation from the leaves of Tabernaemontana catharinensis had their composition analysed by GC–MS. A total of 18 substances were identified, consisting of a complex mixture of sesquiterpenes (83.52%), monoterpenes (5.46%) and triterpenes (4.56%). The main components in the oil were β-caryophyllene (56.87%), α-cadinol (12.52%), 8S,13-cedran-diol (5.41%), α-terpineol (3.99%), β-eudesmol (2.54%), caryophyllene oxide (2.51%) and ethyl iso-allocholate (2.03%) along with β-cubebene, γ-cadinene, cubenol, 1,8-cineol, o-cymene, curcumenol, spathulenol, friedeline and β-sitosterol as minor constituents. An antioxidant property was tested with the oil obtained by means of 1,1-diphenyl-2-picrylhydrazyl assay; the oil presented interesting radical scavenging activity. To the best of our knowledge, this is the first study of the composition and antioxidant activity of essential oil from the T. catharinensis collected from Brazil.

Antioxidant Activity and Phytochemical Composition of the Leaves of Solanum guaraniticum A. St.-Hil

Solanum guaraniticum is a shrub belonging to the Solanaceae family popularly known in Brazil as jurubeba or false-jurubeba. The aim of this study was to evaluate the antioxidant activity of crude extract and chloroform, ethyl acetate and n-butanol fractions from its leaves, verifying the ability to remove reactive species and identify and quantify phenolic compounds. The ethyl acetate fraction showed the highest amount of total polyphenols (546.57 ± 2.35 mg gallic acid equivalent/g) and the lowest IC50 (9.11 ± 0.75 µg/mL) by the DPPH method. Furthermore, the chloroform fraction presented the highest content of flavonoids (75.73 ± 0.34 mg rutin equivalents/g), tannins (56.03 ± 0.68 mg catechin equivalents/g) and alkaloids (10.79 ± 0.06 mg/g). This fraction was effective in the scavenging of reactive species by 2′,7′-dichlorofluorescein diacetate assay, in addition to completely reducing protein carbonyl content and reducing lipid peroxidation at basal levels even at low concentrations. Chlorogenic, caffeic and rosmarinic acids were identified and quantified by HPLC/DAD. These results show that S. guaraniticum is rich in phenolic compounds and has potential as an antioxidant.

Antimicrobial activity of Scutia buxifolia against the honeybee pathogen Paenibacillus larvae

The honeybee disease American foulbrood (AFB) is a serious problem since its causative agent (Paenibacillus larvae) has become increasingly resistant to conventional antibiotics. One of the feasible alternative treatments being used for control of this disease are plants extracts. The aim of the present work was to evaluate the effect of crude extract and fractions of Scutia buxifolia against six Paenibacillus species, including P. larvae, and its potential use for the control of AFB. In vitro activity of S. buxifolia samples against Paenibacillus species were evaluated by the disk diffusion and microdilution methods, and the minimal inhibitory concentration (MIC) were also determined. All Paenibacillus species were sensitive to crude extract and fractions of S. buxifolia. The dichloromethane (DC) fraction showed the better MIC (1.56 mg/mL), followed by ethyl acetate (EtAc) (6.25 mg/mL), n-butanol (BuOH) (25 mg/mL) and Crude extract (CE) (50 mg/mL). Toxic effect of S. buxifolia crude extracts and fractions against bees were also evaluated by the spraying application method of the same concentrations of MICs. The samples tested showed no toxic effects for the bees after 15 days of observation. These results are first time described for this species and showed that S. buxifolia presented a important activity against Paenibacillus species and proved to be a natural alternative for the prevention/control of AFB.

Effect of Black Grape Juice against Heart Damage from Acute Gamma TBI in Rats

The aim of this study was to evaluate the potential positive effect of black grape juice (BGJ) on lipid peroxidation considering Total Body Irradiation (TBI) in Wistar rats. As a potential feasible means of evaluation in situ, blood serum lactate dehydrogenase (LDH) levels were evaluated as a marker for heart damage from acute radiation syndrome (ARS). Twenty rats were divided into four groups, two of them being irradiated by gamma-rays from a Co-60 source. Animals were treated by gavage with 2 mL per day of BGJ or placebo for one week before and 4 days after 6 Gy whole body gamma-irradiation, when they were euthanasiated. LDH on serum and lipid peroxidation on heart tissue were evaluated. High concentration of metabolites from lipid peroxidation in heart, and high LDH level on serum were found only in gamma-irradiated group given placebo, mainly at the first 24 h after radiation. Phytochemical analysis of BGJ was performed by determining total phenolics, flavonoids, and tannins followed by a high-performance liquid chromatography (HPLC/DAD) analysis, which showed resveratrol as the major constituent. Results suggest that BGJ is a good protective candidate compound against heart damage from ARS and its effects suggest its use as a radiomodifier.

Antiinflammatory effects of Viola tricolor gel in a model of sunburn in rats and the gel stability study.

ETHNOPHARMACOLOGICAL RELEVANCE Viola tricolor, popularly known as heartsease has been empirically used in several skin disorders, including burns. AIM OF THE STUDY The objective of this study was investigate the antinociceptive and antiinflammatory effect of a gel containing extract of Viola tricolor flowers on thermal burn induced by UVB irradiation and to perform gel stability study. METHODS The antinociceptive and antiinflammatory effect were evaluated by static and dynamic mechanical allodynia model, paw edema, and neutrophilic cell infiltration. Metabolites compounds were quantified by HPLC. The gel stability study was performed analyzing organoleptical aspects, besides pH, viscosity, and quantification of rutin by HPLC. RESULTS In the results were evidenced changes in threshold in statical and dynamic mechanical allodynia (I(max)=100 ± 10% and 49 ± 10%, respectively), paw edema (I(max)=61 ± 6%), and myeloperoxidase activity (I(max)=89 ± 5%). Such effects may be attributed, in part, to rutin, salicylic and chlorogenic acids, and others compounds found in this species. No important changes were detected in the stability study, in all aspects analyzed in temperature below 25 °C. CONCLUSION These findings suggest that Viola tricolor gel has an antinociceptive and antiinflammatory effect in the ultraviolet-B-induced burn, since maintain the temperature below 25 °C.

Hepatotoxicity Evaluation of Aqueous Extract from Scutia buxifolia

Nowadays there is an increase in the number of people taking herbals worldwide. Scutia buxifolia is used for the treatment of hypertension, but little is known about its action on liver. Thirty-two Wistar rats were divided into four groups: control and groups treated during 30 days with 100, 200 and 400 mg of lyophilized aqueous extract of S. buxifolia (SBSB)/kg of body weight. This study was planned to explore hepatotoxic effect of SBSB, which was assessed by serum transaminases (ALT and AST). Thiobarbituric acid reactive substances (TBARS) levels were determined in liver, along with thiols content (NPSH), catalase (CAT) activity and, superoxide dismutase (SOD) enzymes. Histopathological studies of liver tissue were performed. Flavonoids and phenolics were quantified in SBSB by high performance liquid chromatography with diode array detection (HPLC/DAD). We did not observe alterations on redox status (TBARS, NPSH, CAT and, SOD) in the control and experimental groups. An increase on AST activity was only observed at 200 mg of SBSB, whereas ALT score was not affected by SBSB. Moreover, no morphological alterations were observed on the hepatocytes, matching the analysed biochemical parameters. This way, we conclude that SBSB was not toxic.

Analysis of rutin in the extract and gel of Viola tricolor.

Heartsease, also known as wild pansy (Viola tricolor L.), contains considerable amounts of polyphenols: 109.32 ± 1.29 mg of Gallic acid equivalent/g of extract. This study investigates their phytoconstituents and antioxidant capacity and validates a method for the quantification of rutin in the crude extract of the flowers of V. tricolor and in the extract incorporated in gel. Much better antioxidant capacity was found for the extract [inhibition concentration (IC50) of 16.00 ± 0.78 µg/mL] than the standard ascorbic acid (IC50 of 16.57 ± 0.95 µg/mL); these excellent results may be attributable to the amounts of polyphenols, flavonoids and condensed tannins. The high-performance liquid chromatography method for the quantification of rutin in the extract and gel was linear, sensitive, precise, specific, accurate and robust. This validated method can be used to control the quality of the extract and the gel.

In vitro growth-inhibitory effect of Brazilian plants extracts against Paenibacillus larvae and toxicity in bees

American foulbrood (AFB) is a serious worldwide spreading disease in bees caused by Paenibacillus larvae. Plants extracts are known to decrease or inhibit the growth of these bacteria. The purpose of this study was to evaluate the antimicrobial activity of Calendula. officinalis, Cariniana domestica, and Nasturtium officinale extracts against the P. larvae and to evaluate the toxicity of the extracts in bees. In vitro activity against P. larvae of the extracts was evaluated by micro dilution method and the minimal inhibitory concentrations (MICs) were also determined. The concentrations used in the toxicity test were established based on the MIC values and by the spraying application method. The P. larvae was susceptible to the evaluated crude extract of C. officinalis and N. officinale. To C. domestica, only the ethyl acetate (EtAc) fraction and n-butanol (BuOH) fractions had activity against P. larvae. Toxicity analysis in bees showed no toxicity for N. officinale crude extract and for C. domestica BuOH fraction during 15 days of treatment, however, some deaths of bees occurred during the first three days of treatment with C. officinalis and C. domestica EtAc fraction. The results with these species were firstly described and showed that N. officinale crude extract and C. domestica BuOH fraction both presented not toxic effects in the concentration tested by the spraying application method, and can be a useful alternative for treatment or prevention of AFB.

In vitro antimicrobial and antimycobacterial activity and HPLC–DAD screening of phenolics from Chenopodium ambrosioides L.

The main objective of this study was to demonstrate the antimicrobial potential of the crude extract and fractions of Chenopodium ambrosioides L., popularly known as Santa-Maria herb, against microorganisms of clinical interest by the microdilution technique, and also to show the chromatographic profile of the phenolic compounds in the species. The Phytochemical screening revealed the presence of cardiotonic, anthraquinone, alkaloids, tannins and flavonoids. The analysis by HPLC–DAD revealed the presence of rutin in the crude extract (12.5 ± 0.20 mg/g), ethyl acetate (16.5 ± 0.37 mg/g) and n-butanol (8.85 ± 0.11 mg/g), whereas quercetin and chrysin were quantified in chloroform fraction (1.95 ± 0.04 and 1.04 ± 0.01 mg/g), respectively. The most promising results were obtained with the ethyl acetate fraction, which inhibited a greater number of microorganisms and presented the lowest values of MIC against Staphylococcus aureus and Enterococcus faecalis (MIC = 0.42 mg/mL), Pseudomonas aeruginosa (MIC = 34.37 mg/mL), Paenibacillus apiarus (MIC = 4.29 mg/mL) and Paenibacillus thiaminolyticus (MIC = 4.29 mg/mL). Considering mycobacterial inhibition, the best results were obtained by chloroform fraction against M. tuberculosis, M. smegmatis, and M. avium (MIC ranging from 156.25 to 625 μg/mL). This study proves, in part, that the popular use of C. ambrosioides L. can be an effective and sustainable alternative for the prevention and treatment of diseases caused by various infectious agents.

Determination of Phenolic Antioxidants in Amazonian Medicinal Plants by HPLC with Pulsed Amperometric Detection

A wide range of chromatographic methods for the analysis of phenolic compounds in medicinal plants has been published over the years. However, no chromatographic methods with pulsed amperometric detection using a gold electrode have been described to analyze phenolic acids and flavonoids. Moreover, there is a lack of information regarding a modified mobile phase with β-cyclodextrin to determine these compounds in plants by RP-HPLC. For this reason, the present study developed and validated an HPLC–PAD method to determine 12 phenolic compounds in medicinal plants from Amazonia. The isocratic mobile phase was constituted by sodium phosphate 50 m mol L−1, methanol 30% (v/v), and β-cyclodextrin 1 m mol L−1 at pH 2.0. The method demonstrated low detection and quantification limits and robustness. The accuracy ranged from 82–114% for chlorogenic acid and rutin, respectively. Six species of medicinal plants from Amazonia used for medicinal and nutritional purposes were characterized and showed the presence of at least one of the phenolic compounds in the study.