Adriana Passos Oliveira

Chemical composition and antibacterial activity of Brazilian propolis essential oil

The present study aimed at investigating the chemical composition of essential oil extracted from Brazilian propolis and the susceptibility of Staphylococcus aureus, Staphylococcus epidermides, Streptococcus pyogenes and Escherichia coli to this substance. The essential oil was obtained by steam distillation of propolis and examined by gas chromatography/mass spectrometry (GC/MS). In addition, the agar diffusion method using filter paper disks was employed. Antibacterial activity was measured as equivalent diameters of inhibition zones (in millimeters) after incubation at 37o C for 24 hours. From the 26 identified constituents, β-caryophyllene (12.7%), acetophenone (12.3%) and β-farnesene (9.2%) were found to be major components. New components, namely linalool, methyl hydrocinnamate, ethyl hydrocinnamate, α-ylangene, γ-elemene and valencene, are reported for the first time to be present in propolis essential oil. This oil also exhibited antibacterial activity.

Effects of the essential oil obtained from Pilocarpus spicatus Saint-Hilaire (Rutaceae) on the development of Rhodnius prolixus nymphae

Bioassays against fifth-instar nymphae of Rhodnius prolixus were conducted with essential oil of Pilocarpus spicatus extracted by hydrodistillation. The main results may be summarized as follows: (i) high levels of toxicity and paralysis together with discrete moulting inhibition were caused by topical application of either 0.5 µL or 1.0 µL per insect of the crude essential oil; (ii) partial fagoinhibition, high moulting inhibition, prolonged intermoulting period and high number of paralyzed insects, but no toxicity were observed after oral treatment using either 5 µL or 10 µL of Pilocarpus spilcatus essential oil per mL of ingested blood meal. The importance of these results in relation to the relevant biological events in R. prolixus is herein discussed.

Metabolite Profiling of the Leaves of the Brazilian Folk Medicine Sideroxylon obtusifolium

Sideroxylon obtusifolium (Roem. & Schult.) T. D. Penn. (family Sapotaceae) is a tree native to Central and South America. Infusions of the bark and the leaves are used in Brazilian folk medicine as an anti-inflammatory remedy. However, information on the constituents of S. obtusifolium remains scarce, and only common pentacyclic triterpenoids have been previously reported. HPLC-DAD/MS analyses revealed that saponins and flavonoids were the main constituents of the leaves. From the butanol-soluble fraction of an ethanolic extract, a total of four saponins and ten flavonol glycosides were isolated by a combination of chromatographic methods including Sephadex LH-20, MPLC, and HPLC. Their structures were established by acid hydrolysis and spectroscopic methods, mainly MS (n), 1D and 2D NMR experiments. The compounds include the new triterpene glycoside 3-O-( β-D-glucopyranosyl)-protobassic acid 28-O- β-D-apiofuranosyl-(1 → 3)-O-[O- β-D-apiofuranosyl-(1 → 3)- β-D-xylopyranosyl-(1 → 4)]-O- α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester ( 1), as well as the new flavonol glycosides, quercetin-3-O-(O- α-L-rhamnopyranosyl-(1→ 2)-O-[ β-D-glucopyranosyl-(1 → 3)]- β-D-galactopyranoside) ( 6) and kaempferol-3-O-(O- α-L-rhamnopyranosyl-(1 → 2)-O-[ β-D-glucopyranosyl-(1 → 3)]- β-D-galactopyranoside) ( 8). In addition, catechin and a glycerogalactolipid, gingerglycolipid A, were obtained from the ethyl acetate-soluble fraction. The isolated compounds could be used in the future as chemical markers for quality control of this herbal drug.

Antiproliferative activity in tumor cell lines, antioxidant capacity and total phenolic, flavonoid and tannin contents of Myrciaria floribunda

Myrciaria floribunda (H. West ex Willd.) O. Berg, Myrtaceae, is a native plant species of the Atlantic Rain Forest, from north to south of Brazil. The lyophilized ethyl acetate extract from the leaves of M. floribunda was investigated for its antiproliferative activity in tumor cell lines, antioxidant capacity and its total phenolic, flavonoid and tannin contents. Antiproliferative activity was tested in vitro against seven human cancer cells and against immortalized human skin keratinocytes line (HaCat, no cancer cell). Antioxidant activity was determined using 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbing capacity (ORAC) assays and total phenolic, flavonoid and tannin contents were determined by spectrophotometric techniques. Ethyl acetate extract of M. floribunda exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 69.70 and 172.10 µg/mL. For HaCat cell, TGI value was 213.60 µg/mL. M. floribunda showed a strong antioxidant potential: EC50 of 45.89±0.42 µg/mL and 0.55±0.05 mmol TE/g for DPPH and ORAC, respectively. Total phenolic content was 0.23±0.013g gallic acid equivalents (GAE)/g extract and exhibited 13.10±1.60% of tannins content. The content of flavonoid was 24.08±0.44% expressed as rutin equivalents. These results provide a direction for further researches about the antitumoral potential of M. floribunda.

Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells

Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

Nanotechnology in phytotherapy

Abstract This chapter presents a review on the application of lipid nanocarriers which load natural products, specifically from plants. Currently, phytotherapy is used as a complementary medicine in the treatment of several diseases for its efficiency and lower adverse effects. However, the development step of herbal medicinal products presents challenges, due to the complex herbal drug composition and poor water solubility of its major constituents. Considering the advantages of natural products and lipid nanocarriers, there are many studies showing encapsulation to be a potential therapeutic improvement in such systems. Therefore, this chapter presents the latest applications and advantages of each lipid system as a carrier, as well as methods of obtention and characterization regarding the particularities of natural products. It will provide a systematic review of different approaches and assist the research and development of new products.

Wound healing activity and chemical standardization of Eugenia pruniformis Cambess

Background: Eugenia pruniformis is an endemic species from Brazil. Eugenia genus has flavonoids as one of the remarkable chemical classes which are related to the improvement of the healing process. Aims: To evaluate of wound healing activity of E. pruniformis leaves and to identify and quantify its main flavonoids compounds. Materials And Methods: Wound excision model in rats was used to verify the hydroethanolic and ethyl acetate extracts potential. The animals were divided in four groups of six and the samples were evaluated until the 15° day of treatment. Hydroxyproline dosage and histological staining with hematoxilin-eosin and Sirius Red were used to observe the tissue organization and quantify the collagen deposition, respectively. Chemical compounds of the ethyl acetate extract were identified by chromatographic techniques and mass spectrometry analysis and total flavonoids content was determined by spectrophotometric method. The antioxidant activity was determined by oxygen radical absorbing capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazylhydrate radical photometric (DPPH) assays. Results: The treated group with the ethyl acetate extract showed collagen deposition increase, higher levels of hidroxyproline, better tissue reorganization and complete remodeling of epidermis. Quercetin, kaempferol and hyperoside were identified as main compounds and flavonoids content value was 43% (w/w). The ORAC value of the ethyl acetate extract was 0.81± 0.05 mmol TE/g whereas the concentration to produce 50% reduction of the DPPH was 7.05± 0.09 μg/mL. Conclusion: The data indicate a wound healing and antioxidant activities of E. pruniformis. This study is the first report of flavonoids and wound healing activity of E. pruniformis. Abbreviation used: NC: Negative control, PC: Positive control, CH: Crude hydroethanolic extract, EA: Ethyl acetate extract, TE: Trolox equivalent, mg: Milligram, mM: Millimolar, mL: Milliliter, HPLC-PDA: High performance liquid chromatography with a photodiode array detector, HRESI-MS: High-resolution electrospray ionization mass spectrometry analysis, TLC: Thin layer chromatography, ORAC: Oxygen radical absorbance capacity, w/v: Weight per volume