a b s t r a c tThis study evaluated the cytotoxicity activity of the essential oils of Tagetes erecta L., Asteraceae (TE-OE), Tetradenia riparia (Hochst.) Codd, Lamiaceae (TR-OE), Bidens sulphurea (Cav.) Sch. Bip., Asteraceae (BS-OE), and Foeniculum vulgare Mill., Apiaceae (FV-OE), traditionally used in folk medicine, against the tumor cell lines murine melanoma (B16F10), human colon carcinoma (HT29), human breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), human hepatocellular liver carcinoma (HepG2), and human glioblastoma (MO59J, U343, and U251). Normal hamster lung fibroblasts (V79 cells) were included as control. The cells were treated with essential oil concentrations ranging from 3.12 to 400 g/ml for 24 h. The cytotoxic activity was evaluated using the XTT assay; results were expressed as IC 50 , and the selectivity index was calculated. The results were compared with those achieved for classic chemotherapeutic agents. TE-OE was the most promising among the evaluated oils: it afforded the lowest IC 50 values for B16F10 cells (7.47 ± 1.08 g/ml) and HT29 cells (6.93 ± 0.77 g/ml), as well as selectivity indices of 2.61 and 2.81, respectively. The major BS-EO, FV-EO and TE-EO chemical constituents were identified by gas chromatography mass spectrometry as being (E)-caryophyllene (10.5%), germacrene D (35.0%) and 2,6-di-tert-butyl-4-methylphenol (43.0%) (BS-EO); limonene (21.3%) and (E)-anethole (70.2%) (FV-EO); limonene (10.4%), dihydrotagetone (11.8%), ␣-terpinolene (18.1%) and (E)-ocimenone (13.0%) (TE-EO); and fenchone (6.1%), dronabinol (11.0%), aromadendrene oxide (14.7%) and (E,E)-farnesol (15.0%) (TR-EO). 2,6-di-tert-butyl-4-methylphenol (43.0%), (E)-anethole (70.2%) and ␣-terpinolene (18.1%), respectively. These results suggest that TE-OE may be used to treat cancer without affecting normal cells.

Bacterial cellulose (BC) and silk fibroin (SF) are natural biopolymers successfully applied in tissue engineering and biomedical fields. In this work nanocomposites based on BC and SF were prepared and characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). In addition, the investigation of cytocompatibility was done by MTT, XTT and Trypan Blue dye technique. Cellular adhesion and proliferation were detected additionally. The evaluation of genotoxicity was realized by micronucleus assay. In vitro tests showed that the material is non-cytotoxic or genotoxic. SEM images revealed a greater number of cells attached at the BC/SF:50% scaffold surface than the pure BC one, suggesting that the presence of fibroin improved cell attachment. This could be related to the SF amino acid sequence that acts as cell receptors facilitating cell adhesion and growth. Consequently, BC/SF:50% scaffolds configured an excellent option in bioengineering depicting its potential for tissue regeneration and cultivation of cells on nanocomposites.

Natural products are some of the important sources of new anticancer drugs. The Brazilian flora is considered one of the most diverse in the word, although not many large-scale pharmacological and phytochemical studies have been conducted to date. With this in mind, in the present study we evaluated the antiproliferative activity of Solanum lycocarpum fruit glycoalkaloid extract (SL) and its major compounds, solamargine (SM) and solasonine (SS), against different tumor cell lines: murine melanoma (B16F10), human colon carcinoma (HT29), human breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), human hepatocellular liver carcinoma (HepG2) and human glioblastoma (MO59J, U343 and U251). The antiproliferative activity was evaluated using XTT assay and results were expressed as IC50. The most pronounced antiproliferative activity was observed for SM, with IC50 values ranging from 4.58 to 18.23 μg/mL. The lowest IC50 values were observed against HepG2, being 9.60 μg/mL for SL, 4.58 μg/mL for SM and 6.01 μg/mL for SS. Thus, SL, SM and SS demonstrated antiproliferative activity against the tumor cell lines tested, and were most effective against the HepG2 cell line.

Since the beginning of propolis research, several groups have studied its antibacterial, antifungal, and antiviral properties. However, most of these studies have only employed propolis ethanolic extract (PEE) leading to little knowledge about the biological activities of propolis water extract (PWE). Based on this, in a previous study, we demonstrated the anti-inflammatory and immunomodulatory activities of PWE. In order to better understand the equilibrium between effectiveness and toxicity, which is essential for a new medicine, the characteristics of PWE were analyzed. We developed and validated an RP-HPLC method to chemically characterize PWE and PEE and evaluated the in vitro antioxidant/antimicrobial activity for both extracts and the safety of PWE via determining genotoxic potential using in vitro and in vivo mammalian micronucleus assays. We have concluded that the proposed analytical methodology was reliable, and both extracts showed similar chemical composition. The extracts presented antioxidant and antimicrobial effects, while PWE demonstrated higher antioxidant activity and more efficacious for the most of the microorganisms tested than PEE. Finally, PWE was shown to be safe using micronucleus assays.

The chemical composition and the in vitro schistosomicidal effects of the essential oil of Plectranthus neochilus (PN-EO) grown in Southeast Brazil was studied. β-Caryophyllene (1; 28.23%), α-thujene (2; 12.22%), α-pinene (3; 12.63%), β-pinene (4; 6.19%), germacrene D (5; 5.36%), and caryophyllene oxide (6; 5.37%) were the major essential oil constituents. This chemical composition differed from that previously reported for specimens harvested in Africa. Concerning the in vitro schistosomicidal activity against adult Schistosoma mansoni worms, PN-EO was considered to be active, but less effective than the positive control praziquantel (PZQ) in terms of separation of coupled pairs, mortality, decrease in the motor activity, and tegumental alterations. However, PN-EO caused an interesting dose-dependent reduction in the number and the percentage of developed S. mansoni eggs. These results suggest that PN-EO might be very promising for the development of new schistosomicidal agents.