Effect of Paullinia cupana on MCF-7 breast cancer cell response to chemotherapeutic drugs.

Previous studies suggested that certain plants, such as guarana (Paullinia cupana), exert a protective effect against cancer-related fatigue in breast cancer patients undergoing chemotherapy. However, guarana possesses bioactive molecules, such as caffeine and catechin, which may affect the pharmacological properties of antitumor drugs. Therefore, the aim of this study was to evaluate the effects of guarana on breast cancer cell response to 7 chemotherapeutic agents currently used in the treatment of breast cancer. To perform this study, MCF-7 breast cancer cells were cultured under controlled conditions and exposed to 1, 5 and 10 µg/ml guarana concentrations, with and without chemotherapeutics (gemcitabine, vinorelbine, methotrexate, 5-fluorouracil, paclitaxel, doxorubicin and cyclophosphamide). The effect of these treatments on MCF-7 cell viability and proliferation was spectrophotometrically analyzed with the MTT assay. The main results demonstrated an antiproliferative effect of guarana at concentrations of 5 and 10 µg/ml and a significant effect on chemotherapeutic drug action. In general, guarana improved the antiproliferative effect of chemotherapeutic agents, causing a decrease of >40% in cell growth after 72 h of exposure. The results suggested an interaction of guarana with the chemotherapeutic drugs, which requires confirmation by in vivo complementary studies.

Tucumã fruit extracts (Astrocaryum aculeatum Meyer) decrease cytotoxic effects of hydrogen peroxide on human lymphocytes.

This study quantifies the bioactive molecules in and determines the in vitro protective effect of ethanolic extracts isolated from the peel and pulp of tucumã (Astrocaryum aculeatum, Mart.), an Amazonian fruit rich in carotenoids. The cytoprotective effect of tucumã was evaluated in lymphocyte cultures exposed to H2O2 using spectrophotometric, fluorimetric, and immunoassay assays. The results confirmed that tucumã pulp extract is rich in ß-carotene and quercetin, as previously described in the literature. However, high levels of these compounds were also found in tucumã peel extract. The extracts also contained significant amounts rutin, gallic acid, caffeic acid, and chlorogenic acid. Despite quantitative differences in the concentration of these bioactive molecules, both extracts increased the viability of cells exposed to H2O2 in concentrations ranging from 300 to 900 µg/mL. Caspases 1, 3, and 8 decreased significantly in cells concomitantly exposed to H2O2 and these extracts, indicating that tucumã cryoprotection involves apoptosis modulation.

Antimicrobial activity of Amazon Astrocaryum aculeatum extracts and its association to oxidative metabolism.

Several compounds present in fruits as polyphenols are able to kill or inhibit the growth of microorganisms. These proprieties are relevant mainly in tropical areas, as Amazonian region where infectious are highly prevalent. Therefore, this study investigated the antimicrobial activity of tucumã Amazonian fruit against 37 microorganisms. The potential role of oxidative metabolism imbalance was also studied as causal mechanism of antimicrobial activity. The results showed antibacterial effect of pulp and peel tucumã hydro-alcoholic extracts on three Gram-positive bacteria (Enterococcus faecalis, Bacillus cereus, Listeria monocytogenes) and antifungal effect against Candida albicans. The antimicrobial contribution of main chemical compounds (quercetin, rutin, ß-carotene and gallic, caffeic and chlorogenic acids) found in tucumã extracts was also investigated showing an inhibitory effect depending of the organism mainly by quercetin in bacteria and rutin in C. albicans. Analysis of kinetic of DNA releasing in extracellular medium by fluorescence using DNA Pico Green assay(®) and reactive oxygen species production (ROS) showed potential oxidative imbalance contribution on tucumã inhibitory effect. In B. cereus and C. albicans this effect was clear since after 24h the ROS levels were higher when compared to negative control group. In conclusion, tucumã extracts present antimicrobial activity to four microorganisms that have large problems of drug resistance, and the possible mechanism of action of this Amazon fruit is related to REDOX imbalance.

The in vitro genotoxic effect of Tucuma (Astrocaryum aculeatum), an Amazonian fruit rich in carotenoids.

Tucuma (Astrocaryum aculeatum) is an Amazonian fruit that presents high levels of carotenoids and other bioactive compounds such as quercetin. The extracts of tucuma peel and pulp present strong antioxidant activity which illustrate an elevated concentration that causes cytotoxic effects in human peripheral blood mononuclear cells (PBMCs). This study performed additional investigations to analyze the potential genotoxic effects of the tucuma extracts on PBMCs. The genotoxicity was evaluated by DNA fragmentation, Comet assay, and chromosomal instability G-band assays. The acute tucuma extract treatment showed genoprotective effects against DNA denaturation when compared with untreated PBMC cells. However, in the experiments with 24 and 72 h treatments to tucuma treatments, we observed low genotoxicity through a concentration of 100 µg/mL, some genotoxic effects related to intermediary concentrations (100-500 µg/mL), and more pronounced genotoxic effects on higher tucuma extract concentrations. After 24 h of treatment, the reactive oxygen species were similar among treatments and PBMC control groups. However, the caspase-1 activity related to the apoptosis and pyroptosis process increased significantly in higher tucuma concentrations. In summary, tucuma extracts, despite their higher antioxidant content and antioxidant activity, would present PBMCs genotoxic effects that are dependent on concentration and time exposition. These results need to be considered in future in vitro and in vivo studies of tucuma effects.

Morphological basis for the study of the interatrial septum in the human fetus.

OBJECTIVE: To describe morphological features of the interatrial septum in normal fetuses, especially foramen ovale (FO) and septum primum (SP), in order to compare septum primum excursion with foramen ovale diameter. METHODS: Septum primum excursion (SPE) toward the left atrium (LA) and foramen ovale diameter (FOD) were measured in the hearts of ten formaldehyde-fixed human fetuses ranging from 28 to 36 weeks of gestation. Histological sections were obtained from the foramen ovale (FO), septum primum (SP), septum secundum (SS), left atrium (LA), and right atrium (RA). RESULTS: FOD and SPE measurements were the following: FOD 3.1-3.5 mm and SPE 2.8-3.1 mm in three fetuses with presumed gestational age (GA) of 28 weeks; FOD 3.3-3.5 mm, and SP excursion 4.0-5.0 mm in four fetuses with presumed GA of 34 weeks, plus FOD 3.3-4.5 mm and SPE 6.0-9.0 in three fetuses with presumed GA of 36 weeks. Cardiac muscular fibers were identified in both the septum primum and secundum. CONCLUSION: Based on its muscular components, it may be suggested that SP is active in character, influencing blood flow through the FO, SP mobility, and its excursion into the LA.