Publications by authors named "Robson J Oliveira Junior"

is a virulent Gram-negative bacterial genus mainly found in the intestines of poultry. The indiscriminate use of traditional antibiotics has led to drug resistance in these pathogens, necessitating the development of more efficient and less toxic therapies. Despite their complex biologically active structures, the clinical applications of essential oils (EOs) remain limited.

View Article and Find Full Text PDF

Rhenium complexes show great promise as anticancer drug candidates. Specifically, compounds with a Re(CO)(NN)(py) core in their architecture have shown cytotoxicity equal to or greater than that of well-established anticancer drugs based on platinum or organic molecules. This study aimed to evaluate how the strength of the interaction between rhenium(I) tricarbonyl complexes fac-[Re(CO)(NN)(py)], NN = 1,10-phenanthroline (phen), dipyrido[3,2-f:2',3'-h]quinoxaline (dpq) or dipyrido[3,2-a:2'3'-c]phenazine (dppz) and biomolecules (protein, lipid and DNA) impacted the corresponding cytotoxic effect in cells.

View Article and Find Full Text PDF

Pesticides are considered one of the main causes of the population decline of reptiles worldwide, with freshwater turtles being particularly susceptible to aquatic contamination. In this context, we investigated the potential mutagenic, hepatotoxic, and neurotoxic effects in neonates of Podocnemis expansa exposed to substrate contaminated with different concentrations of glyphosate and/or fipronil during embryonic development. Eggs collected from the natural environment were artificially incubated in sand moistened with pure water, water added with glyphosate Atar 48® at concentrations of 65 and 6500 μg/L (groups G1 and G2, respectively), water added with fipronil Regent® 800WG at 4 and 400 μg/L (groups F1 and F2, respectively) and, water added with the combination of 65 μg/L glyphosate and 4 μg/L fipronil or with 6500 μg/L glyphosate and 400 μg/L fipronil (groups GF1 and GF2, respectively).

View Article and Find Full Text PDF

Prostate Cancer (PCa) is the second leading cause of cancer-related deaths among men worldwide. The treatment of advanced cases is based on chemotherapy, which lacks specificity and efficacy, due to severe side effects and resistance to the traditional drugs. Copper complexes have shown antitumoral efficacy and low toxicity, being considered a promising class of metal-based drugs for the treatment of malignant neoplasms.

View Article and Find Full Text PDF

The thin line between efficacy and toxicity has challenged cancer therapy. As copper is an essential micronutrient and is important to tumor biology, Cu complexes emerged as an alternative to chemotherapy; however, its biological properties need to be better understood. Thus, we report in vitro the antitumor effects of two Cu complexes named [Cu(4-fh)(phen)(ClO)] (complex 1) and [Cu(4-nh)(phen)(ClO)]·HO (complex 2), in which 4-fh = 4-fluorophenoxyacetic acid hydrazide; 4-nh = 4-nitrobenzoic hydrazide and phen = 1,10-phenanthroline.

View Article and Find Full Text PDF

Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted.

View Article and Find Full Text PDF

Recently, a high number of copper derivatives has been evaluated as DNA-targeting metallodrugs, due to the lower toxicity and its potential to cleave DNA. Several strategies have been testing to develop metal compounds effective against tumour cells. In this work, the ternary copper (doxycycline)-(1,10-phenanthroline) complex [Cu(dox)(phen)] was especially designed as an antitumoral drug, previously showing high cytotoxicity and DNA cleavage activity.

View Article and Find Full Text PDF

Invasive species are increasingly replacing native species, especially in anthropogenically transformed or polluted habitats. This opens the possibility to use invasive species as indicator taxa for the biological assessment of pollution. Integrated biological assessment, however, additionally relies on the application of multiple approaches to quantify physiological or cytogenetic responses to pollution within the same focal species.

View Article and Find Full Text PDF

Water quality has declined globally due to increased contamination of aquatic ecosystems. The use of fish genotoxicity biomarkers may improve and complement parameters for environmental risk assessment. The aim of this study was to assess the genotoxicity of samples collected from streams of the Jordão River, a tributary of the Paranaíba River, Brazil with different levels of metal contamination, utilizing a native fish species to determine the sensitivity and viability of implementing a useful, reliable technique for routine biomonitoring programs.

View Article and Find Full Text PDF

This work reports the biological evaluation of a copper complex of the type [Cu(O-O)(N-N)ClO], in which O-O = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbta) and N-N = 1,10-phenanthroline (phen), whose generic name is CBP-01. The cytotoxic effect of CBP-01 was evaluated by resazurin assay and cell proliferation was determined by MTT assay. DNA fragmentation was analyzed by gel electrophoresis.

View Article and Find Full Text PDF

Herein we evaluated the genotoxic effects of BnSP-6, a Lys-49 phospholipase A (PLA) from Bothrops pauloensis, on breast cancer cells. BnSP-6 was able to induce a higher cytotoxic and genotoxic activity in MDA-MB-231 cells, when compared to MCF10A (a non-tumorigenic breast cell line), suggesting that this protein presented a possible preference for cancer cells. BnSP-6 inhibited MDA-MB-231 proliferation at 24, 48 and 72 h.

View Article and Find Full Text PDF

The present study assessed the protective effect of aspirin against carcinogenicity induced by mitomycin C (MMC) by the test for detection of warts/epithelial tumor clones in Drosophila melanogaster. Larvae were treated with different concentrations of aspirin alone (10, 20 or 40 mg/mL) or aspirin in association with MMC. MMC and ultrapure water were employed as the positive and negative control, respectively.

View Article and Find Full Text PDF

Background: Tumor initiation presents a complex and unstable genomic landscape; one of the earliest hallmark events of cancer, and its progression is probably based on selection mechanisms under specific environments that lead to functional tumor cell speciation. We hypothesized that viable tumor phenotypes possess common and highly stable karyotypes and their proliferation is facilitated by an attuned high telomerase activity. Very few investigations have focused on the evolution of common chromosomal rearrangements associated to molecular events that result in functional phenotypes during tumor development.

View Article and Find Full Text PDF

Trachylobane-360 (ent-7α-acetoxytrachyloban-18-oic acid) was isolated from Xylopia langsdorffiana. Studies have shown that it has weak cytotoxic activity against tumor and non-tumor cells. This study investigated the in vitro and in vivo antitumor effects of trachylobane-360, as well as its cytotoxicity in mouse erythrocytes.

View Article and Find Full Text PDF

The major aim to the present study was to determine the effects of neuwiedase, a metalloproteinase isolated from Bothrops neuwiedi snake venom, on invasion and replication of Toxoplasma gondii in human fibroblasts in vitro. Neuwiedase treatment was done on host cells previously infected with T. gondii or on parasite before fibroblast infection.

View Article and Find Full Text PDF