Determining the Presence of 5-Fluorouracil in Hamster Saliva by HPLC / Determinação, por CLAE, da Presença do 5-Fluorouracil em Saliva de Hamsters

Abstract Introduction: Various methods of analysis for the assay of chemotherapeutic agent 5-Fluorouracil (5-FU) in human and animal biological fluids have previously been reported. However, there is no standardization for detecting 5-FU in the hamsters' saliva that received the chemotherapeutic agent. Objective: Considering that the administration of 5-FU in some way changes the morphology and function of the salivary glands, and that the presence of the chemotherapeutic agents in the oral mucosa may lead to some oral complications, the aim of this study was to determine the presence of 5-FU in the hamsters' saliva that received the chemotherapeutic agent, by means of the High Performance Liquid Chromatography technique (HPCL) since this animal model is used in studies of 5-FU induced oral mucositis and glandular hypofunction. Methods: Twelve animals were divided into 4 groups: CP and CPI, in which the animals received pilocarpine (CP) or pilocarpine + isoproterenol (CPI) and the chemotherapy vehicle intraperitoneally; and Groups QP and QPI, in which the animals received the same secretagogues listed above, and the chemotherapeutic agent 5-FU, respectively. After the secretagogue administration, saliva was collected from all the animals for a period of 60 mins. Subsequently, the saliva was frozen at -80 ˚C for later determination of the chemotherapeutic agent by HPLC. After the the chromatograms analysis, and based on the results obtained, it was possible to identify the presence of 5-FU in the saliva samples from hamsters that received the chemotherapeutic agent intraperitonally, by the HPLC technique. (AU)

Resumo Vários métodos de análise para o ensaio do quimioterápico 5-Fluorouracil (5-FU) em fluidos biológicos de humanos e animais, foram previamente relatados. No entanto, não há uma padronização para detecção de 5-FU na saliva de hamsters que receberam o quimioterápico. Considerando que a administração do 5-FU altera de alguma maneira a morfologia e função das glândulas salivares, e que a presença do quimioterápico na mucosa oral pode levar a algumas complicações orais, este trabalho teve como objetivo de determinar a presença de 5-FU na saliva de hamsters que receberam o quimioterápico pela técnica de Cromatografia Líquida de Alta Eficiência (CLAE), uma vez que este modelo animal é usado nos estudos com mucosite oral e hipofunção glandular, induzidas por 5-FU. Doze animais foram divididos em 4 grupos: CP e CPI, onde os animais receberam intraperitonealmente pilocarpina (CP) ou pilocarpina + isoproterenol (CPI) e o veículo do quimioterápico, e os grupos QP e QPI, onde os animais receberam, respectivamente, os mesmos secretagogos listados acima e o quimioterápico 5-FU. Após a administração do secretagogo, foi coletada a saliva de todos os animais, por um período de 60 min. Em seguida, a saliva foi congelada a -80 ˚C para posterior determinação do quimioterápico por CLAE. Após análise dos cromatogramas, e com base nos resultados obtidos, foi possível identificar a presença do 5-FU nas amostras de saliva de hamsters que receberam o quimioterápico via intraperitoneal pela técnica da CLAE. (AU)

Forced degradation studies to identify organic impurities in pharmaceuticals: a Brazilian perspective

Objective: The aim of this study was to highlight and sediment the necessary steps to be followed while conducting forced degradation studies to identify degradation products and to describe the Brazilian and international regulations associated with degradation studies of drugs and drug products. Methods: This review was conducted based on the Brazilian guidance tools as RDC 53/2015, Guide 4 and Question and Answer resource; references used as international guides; and articles in the field of degradation product analyses. Results: Characterization of the impurity profile for a substance, and development of indicative stability methods are essential criteria for compliance with current legislation, and address a legitimate health concern. As this matter falls under the purview of recently published regulation, many doubts remain regarding methods of conducting studies of forced degradation, and development of methods indicative of stability. Analytical conditions predict degradation after exposing them to thermal, humid, acidic, basic, oxidation, photolytic, and metal ion conditions. Conclusions: Although RDC 53/2015 outlines the parameters of degradation, the analytical conditions are not specified, as well as in other international standards. A well-designed forced degradation study is key to obtaining a good stability indicating method with peak purity and mass balance.

Growth and microcystin production of a Brazilian Microcystis aeruginosa strain (LTPNA 02) under different nutrient conditions

Cyanobacteria are prokaryotic and photosynthetic organisms, which can produce a wide range of bioactive compounds with different properties; including a variety of toxic compounds, also known as cyanotoxins. In this work, we describe the isolation of seven cyanobacterial strains from two reservoirs in São Paulo State, Brazil. Seven different chemical variants of microcystins (MC-RR, MC-LR, MC-YR, MC-LF, MC-LW, and two demethylated variants, dm-MC-RR and dm-MC-LR) were detected in three of the ten isolated strains. One particular Microcystis aeruginosa strain (LTPNA 02) was chosen to evaluate its growth by cell count, and its toxin production under seven different nutritional regimes. We observed different growth behaviors in the logarithmic growth period for only three experiments (p < 0.05). The total growth analysis identified four experiments as different from the control (p < 0.01). Three microcystin variants (MC-RR, MC-LR and MC-YR) were quantified by liquid chromatography-tandem mass spectrometry. At the experimental end, the toxin content was unchanged when comparing cell growth in ASM-1 (N:P = 1), MLA and BG-11 (N:P = 10) medium. In all other experiments, the lowest microcystin production was observed from cells grown in Bold 3N medium during the exponential growth phase. The highest microcystin content was observed in cultures using BG-11(N:P = 100) medium.

Effects of a cyanobacterial extract containing-anatoxin-a(s) on the cardiac rhythm of Leurolestes circunvagans

This work presents the effects of an anatoxin-a(s)-containing extract on a cockroach semi-isolated heart preparation and the results supporting the extract’s biological activity on acetylcholinesterase (purified from ell). The presence of the toxin in cyanobacterial strains Anabaena spiroides (ITEP-024, ITEP-025 and ITEP-026) isolated from the Tapacurá reservoir in Pernambuco, Brazil, was confirmed by means of liquid chromatography coupled to an ion-trap mass spectrometer. The anticholinesterase activity was assessed biochemically by the Ellman test and was confirmed by measuring the cockroach’s heart rate. The concentration of the extract containing the tested anatoxin-a(s) (antx-a(s)) (10, 16 and 100 μg.μL-1) inhibited the eel acetylcholinesterase (AChE) by more than 90%. The cockroach cardiac frequency increased by a maximum of about 20% within 29 min after the addition of 2.5x10³ μg of extract containing antxa (s).g-1 bw (n=9, p<0.05). Our results strongly indicate that antx-a(s) is capable of exerting biological effects on cockroach, indicating that more research might be conducted to determine its role in the environment, especially on insects.

Antioxidant activity and chemical composition of the non polar fraction of Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira)

Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira) (Gracilariales, Rhodophyta) are seaweeds that occur on the Brazilian coast. Based on their economic and pharmaceutical importance, we investigated the antioxidant activity of the methanolic, ethyl acetate and hexane extracts of both species. The hexane extracts display a high antioxidant activity and comparative analyses indicated G. birdiae as the most active species. Chemical investigation of these fractions showed several carotenoids and fatty acids, as well as cholesterol and sitosterol derivatives. HPLC-DAD analysis of G. birdiae showed violaxanthin (0.04 μg.mg-1 of dry material), antheraxanthin (5.31 μg.mg-1), aloxanthin (0.09 μg.mg-1), zeaxanthin (0.45 μg.mg-1) and β-carotene (0.37 μg.mg-1) as the major carotenoids. G. domingensis showed a similar carotenoid profile, however, with much lower concentration than G. birdiae. Gas chromatography coupled to mass spectrometry was used to determine other nonpolar compounds of these seaweeds. The main compounds detected in both studied species were the fatty acids 16:0; 18:1 Δ9; 20:3 Δ6,9,12, 20:4 Δ5,8,11,14. We found no specificity of compounds in either species. However, G. birdiae, presented higher contents of carotenoids and arachidonic acid than G. domingensis.

Characterization of volatile composition of Laurencia dendroidea by gas chromatography-mass spectrometry

In this study we report the characterization of the volatile compounds of Laurencia dendroidea. Solvent extracts (dichloromethane and methanol), hydrodistillation extracts and headspace solid-phase microextraction samples were obtained and analyzed by GC-MS. Forty-six volatile components were identified in L. dendroidea, among them hydrocarbons, alcohols, phenols, aldehydes, ketones, acids, esters and terpenes.

Analyses of photoprotective compounds in red algae from the Brazilian coast

Qualitative and quantitative studies of mycosporine-like amino acids (MAAs) in three species of the genus Gracilaria Greville (G. birdiae, G. domingensis and G. tenuistipitata) were performed. A simple and efficient extraction procedure based on ethanol was described. HPLC, UV and mass spectrometry experiments revealed different profiles between extracts obtained from one species cultivated in the laboratory (G. tenuistipitata) and two species collected in their natural environment (G. birdiae and G. domingensis). The levels detected in the latter two species were approximately 150 times higher than in the species cultivated in vitro. This study revealed that G. birdiae and G. domingensis present a potential source for economical exploration of MAAs.

Effects of heavy metals and light levels on the biosynthesis of carotenoids and fatty acids in the macroalgae Gracilaria tenuistipitata (var. liui Zhang & Xia)

We present here the effect of heavy metals and of different light intensities on the biosynthesis of fatty acids and pigments in the macroalga Gracilaria tenuistipitata (var. liui Zhang & Xia). In order to verify the fatty acid content, gas chromatography with flame ionization detection (GC-FID) was employed. Pigments (major carotenoids and chlorophyl-a) were monitored by liquid chromatography with diode array detection (HPLC-DAD). Cultures of G. tenuistipitata were exposed to cadmium (Cd2+, 200 ppb) and copper (Cu2+, 200 ppb), as well as to different light conditions (low light: 100 µmol.photons.m-2.s-1, or high light: 1000 µmol.photons.m-2.s-1). Cd2+ and Cu2+ increased the saturated and monounsaturated fatty acid content [14:0, 16:0, 18:0, 18:1 (n-7) and 18:1 (n-9)] and all major pigments (violaxanthin, antheraxanthin, lutein, zeaxanthin, chlorophyll-a and β-carotene). Both heavy metals decreased the levels of polyunsaturated fatty acids (PUFA) [18:2 (n-6), 18:3 (n-6), 18:5 (n-4), 20:4 (n-6), 20:5 (n-3), 22:6 (n-3)]. G. tenuistipitata cultures were exposed to high light intensity for five days and no statistically significant differences were observed in the content of fatty acids. On the other hand, the levels of pigments rose markedly for chlorophyll-a and all of the carotenoids studied.

Sesquiterpenes from the essential oil of Laurencia dendroidea (Ceramiales, Rhodophyta): isolation, biological activities and distribution among seaweeds

Two known sesquiterpenes (1R*,2S*,3R*,5S*,8S*,9R*)-2,3,5,9-tetramethyltricyclo[6.3.0.0(1,5)]undecan-2-ol and (1S*,2S*,3S*,5S*,8S*,9S*)-2,3,5,9-tetramethyltricyclo-[6.3.0.0(1,5)]undecan-2-ol were isolated for the first time from the essential oil of the red seaweed Laurencia dendroidea collected in the Brazilian coast. These compounds were not active against eight bacteria strains and the yeast Candida albicans, but showed some antioxidant activity. Both compounds were also found in other seaweed species showing that they are not exclusive taxonomic markers to the genus Laurencia.

Cultivation of algae in photobioreator and obtention of biodiesel

In this work we described the cultivation of Chlorella vulgaris in a photobioreactor to algal biomass production. The dried biomass was used as feedstock for biodiesel production, it presented 26 percent lipids and via sonocatalysis stage of the methodology resulted in 60 percent of fatty acid methyl esters (FAME). The FAME content was confirmed by Gas Chromatography (GC).