Maria Izabel Florindo Guedes

Determination of synthetic food dyes in commercial soft drinks by TLC and ion-pair HPLC.

Synthetic food colourings were analyzed on commercial carbonated orange and grape soft drinks produced in Ceará State, Brazil. Tartrazine (E102), Amaranth (E123), Sunset Yellow (E110) and Brilliant Blue (E133) were extracted from soft drinks using C18 SPE and identified by thin layer chromatography (TLC), this method was used to confirm the composition of food colouring in soft drinks stated on label. The concentration of food colouring in soft drink was determined by ion-pair high performance liquid chromatography with photodiode array detection. The results obtained with the samples confirm that the identification and quantification methods are recommended for quality control of the synthetic colours in soft drinks, as well as to determine whether the levels and lables complies with the recommendations of food dyes legislation.

Occurrence of natural vertical transmission of dengue-2 and dengue-3 viruses in Aedes aegypti and Aedes albopictus in Fortaleza, Ceará, Brazil.

Background Aedes aegypti and Aedes albopictus perform an important role in the transmission of the dengue virus to human populations, particularly in the tropical and subtropical regions of the world. Despite a lack of understanding in relation to the maintenance of the dengue virus in nature during interepidemic periods, the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus appears to be of significance in relation to the urban scenario of Fortaleza. Methods From March 2007 to July 2009 collections of larvae and pupae of Aedes spp were carried out in 40 neighborhoods of Fortaleza. The collections yielded 3,417 (91%) A. aegypti mosquitoes and 336 (9%) A. albopictus mosquitoes. Only pools containing females, randomly chosen, were submitted to the following tests indirect immunofluorescence (virus isolation), RT-PCR/nested-PCR and nucleotide sequencing at the C-prM junction of the dengue virus genome. Results The tests on pool 34 (35 A. albopictus mosquitoes) revealed with presence of DENV-3, pool 35 (50 A. aegypti mosquitoes) was found to be infected with DENV-2, while pool 49 (41 A. albopictus mosquitoes) revealed the simultaneous presence of DENV-2 and DENV-3. Based on the results obtained, there was a minimum infection rate of 0.5 for A. aegypti and 9.4 for A. albopictus. The fragments of 192 bp and 152 bp related to DENV-3, obtained from pools 34 and 49, was registered in GenBank with the access codes HM130699 and JF261696, respectively. Conclusions This study recorded the first natural evidence of the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus collected in Fortaleza, Ceará State, Brazil, opening a discuss on the epidemiological significance of this mechanism of viral transmission in the local scenario, particularly with respect to the maintenance of these viruses in nature during interepidemic periods.

Analytical MethodsDetermination of synthetic food dyes in commercial soft drinks by TLC and ion-pair HPLC

Synthetic food colourings were analyzed on commercial carbonated orange and grape soft drinks produced in Ceará State, Brazil. Tartrazine (E102), Amaranth (E123), Sunset Yellow (E110) and Brilliant Blue (E133) were extracted from soft drinks using C18 SPE and identified by thin layer chromatography (TLC), this method was used to confirm the composition of food colouring in soft drinks stated on label. The concentration of food colouring in soft drink was determined by ion-pair high performance liquid chromatography with photodiode array detection. The results obtained with the samples confirm that the identification and quantification methods are recommended for quality control of the synthetic colours in soft drinks, as well as to determine whether the levels and lables complies with the recommendations of food dyes legislation.

Chemical composition, antioxidant and antibacterial activities of two Spondias species from Northeastern Brazil

Context: The leaves of Spondias tuberosa Arr. Cam. (Anacardiaceae) and Spondias mombin L. have been traditionally used for medicinal purposes. Some studies reveal their antibacterial, antimicrobial, and antiviral properties. Objective: Determine the chemical composition, antioxidant, and antimicrobial activities of Spondias species to justify its ethnopharmacological use. Materials and methods: Spondias species extracts were prepared with methanol:water 80:20 and analyzed by silica gel column chromatography and reversed phase liquid chromatography (HPLC). The antioxidant activity was evaluated by scavenging the radicals 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•+) and measuring antimicrobial activity (agar well diffusion method, minimum inhibitory concentration and minimum bactericidal concentrations). Results: The HPLC analysis of Spondias extracts demonstrated the occurrence of high yield of flavonoids. Found in S. mombin were quercetin (2.36 ± 0.01 mg/g) and ellagic acid (41.56 ± 0.01 mg/g) and in S. tuberosa species rutin (53.38 ± 1.71 mg/g), quercetin (24.46 ± 0.87 mg/g), and ellagic acid (169.76 ± 0.17 mg/g). The antibacterial activity of the extracts against the various bacteria strains varied from 8.8 to 20.1 mm. MIC values from 62.5 to 125 µg/mL were satisfactory when compared with other plant products. Medium DPPH scavenging activity IC50 for Spondias extracts varied from 0.042 to 0.558 mg/mL and for ABTS from 0.089 to 0.465 mg/mL. DPPH scavenging activity for constituent ellagic acid IC50 = 0.042 mg/mL and for quercetin IC50 = 0.081 mg/mL. Discussion and conclusion: The chemical study of Spondias leaf extracts showed the occurrence of quercetin, rutin and ellagic acid, substances with relevant antioxidant and antimicrobial activities.

Larvicidal Activity of Tagetes erecta Against Aedes aegypti

Abstract The aim of this study was to evaluate the activity of essential oil from Tagetes erecta against 3rd instars of Aedes aegypti and to determine the amounts of larvicidal thiophenes in all plant tissues. The oil obtained by steam distillation and analyzed by gas chromatography/mass spectrometry showed 14 compounds. The main compounds were piperitone (45.72%), d-limonene (9.67%), and piperitenone (5.89%). The essential oil was active against larvae of Ae. aegypti, with LC50 of 79.78 µg/ml and LC90 of 100.84 µg/ml. The larvicidal thiophene contents were higher in the roots and flowers as demonstrated by high-performance liquid chromatography analysis. Thus, T. erecta constitutes a good source of varied compounds showing larvicidal activity against Ae. aegypti.

Differential responses of ribulose-1,5-bisphosphate carboxylase/oxygenase activities of two Vigna unguiculata cultivars to salt stress

Vita 3 and Vita 5 are two Vigna unguiculata cultivars that differ in their capacities for survival in saline environments; Vita 3 is more tolerant and Vita 5 more sensitive. Both cultivars were submitted to salt stress with 0.1 M NaCl. After 8 days, root and shoot growth from both cultivars was reduced but reduction was more pronounced in Vita 5. Furthermore, leaf area was also reduced in this cultivar. Chlorophyll content and chlorophyll fluorescence parameters were not affected by salt stress, but the specific activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) decreased in Vita 3 and increased in Vita 5. The use of immunological techniques also revealed that the Rubisco content from Vita 3 decreased while that of Vita 5 increased. The discussion of these results is aimed at reaching a better understanding of the differences between these cultivars in relation to salt stress.

[Spatial distribution and breeding site characteristics of Aedes albopictus and Aedes aegypti in Fortaleza, State of Ceará].

INTRODUCTION Since the registration of Aedes albopictus in the municipality of Fortaleza in 2005, it has shown rapid dispersion. A study aiming to identify its occurrence areas, breeding sites and associations with Aedes aegypti and other culicids was carried out during 2008. METHODS Between January and July 2008, samples of immature forms of culicids were gathered from properties located in districts of Fortaleza. Certain features of the breeding sites were highlighted, such as location (indoors or outdoors), presence of covering (protection against impact of sunlight and rain), water turbidity (water clear or not clear), constituent material, volume, height above ground level and simultaneous presence of different species of culicids in the same breeding site. RESULTS Indoor location was an important factor for the breeding sites for Aedes albopictus [PR = 0.52; 95% CI: 0.33-0.81]. On the other hand, water turbidity and reservoir covering were not shown to be differentiators regarding infestation [p > 0.05]. Absence of water turbidity was significant for Aedes aegypti infestation in breeding sites [PR = 1.14; 95% CI: 1.06-1.22]. CONCLUSIONS Absence of one of the species from the breeding sites enhanced the infestation by another species. Breeding sites that had not been infested by Aedes albopictus had a prevalence of infestation by Aedes aegypti that was 2.05 times greater [95% CI: 1.72-2.44]. There was no significant association between volume and height of the breeding sites and infestation by both species. Both species were found to be dispersed throughout the municipality, occupying a wide diversity of breeding sites. However, a slight physical separation could be identified, with higher infestation with Aedes albopictus outdoors.

Purification of infectious myonecrosis virus (IMNV) in species of marine shrimp Litopenaeus vannamei in the State of Ceará.

In Brazil, shrimp farming has been developed most intensely in the Northeast Region. Recently, however, exporters have become concerned over the appearance of Infectious Myonecrosis (IMN), the etiological agent of which is a virus called Infectious Myonecrosis Virus (IMNV). Although IMNV has been characterized extensively, purification methods are complicated to reproduce and very expensive. The objective of this study was to purify the IMNV virus using an easy reproductive method and to produce anti-IMNV antibodies to be used in diagnostic methods. Shrimp samples showing symptoms of IMN obtained from two aquaculture farms in Ceará were used for this purpose. IMNV-positive shrimps were macerated in phosphate buffer, pH 7.5, enriched with antioxidants, clarified with chloroform and the supernatant was submitted to differential centrifugation, precipitated using PEG and NaCl and finally loaded on a discontinuous gradient of sucrose. Purified IMNV was submitted to RT-PCR and electrophoresis either in agarose gel or SDS-PAGE, which revealed RNA and protein bands, characteristic of IMNV. IMNV induced humoral immune response in Swiss mice when administered subcutaneously. Anti-IMNV antibodies were identified by ELISA (enzyme-linked immunosorbent assay) and Western blotting methods and produced a response against purified IMNV and the crude extract obtained from the infected shrimp. However, antibodies specific to the crude extract obtained from uninfected shrimp were not detected. This is the first report of IMNV having been purified in Brazil and the first time that specific antibodies against IMNV proteins have been produced. These results suggest that easy methods can be developed to produce specific antiserum for viral diagnosis on a large scale.

Carnauba wax p-methoxycinnamic diesters: Characterisation, antioxidant activity and simulated gastrointestinal digestion followed by in vitro bioaccessibility.

The beneficial biological effects of cinnamic acid derivatives and the lack of studies on the antioxidant activity and bioavailability of cinnamic esters from carnauba wax, diesters were extracted from carnauba wax powder. Their structural, physical and morphological characteristics, antioxidant activity and in vitro bioaccessibility were measured. p-Methoxycinnamic diester (PCO-C) was identified, which has a crystalline, apolar structure and exhibited significant antioxidant activity (107.27 ± 3.92 μM Trolox/g of dry weight) before and after simulated in vitro gastrointestinal digestion and 32.46% bioaccessibility. In human cells, PCO-C (250 μg/mL) inhibited the production of intracellular reactive oxygen species, with an effect similar to that of Trolox (80 μM). Thermogravimetric analysis showed that PCO-C had high thermal stability and high UV absorption between 250 and 350 nm. These results indicate that this compound is promising as an antioxidant for pharmaceutical and food industry applications, such as the development of active packaging and functional foods.

Interpretation of the presence of IgM and IgG antibodies in a rapid test for dengue: analysis of dengue antibody prevalence in Fortaleza City in the 20th year of the epidemic

INTRODUCTION The diagnosis of dengue and the differentiation between primary and secondary infections are important for monitoring the spread of the epidemic and identifying the risk of severe forms of the disease. The detection of immunoglobulin (Ig)M and IgG antibodies is the main technique for the laboratory diagnosis of dengue. The present study assessed the application of a rapid test for dengue concerning detection of new cases, reinfection recognition, and estimation of the epidemic attack rate. METHODS This was a retrospective, cross-sectional, descriptive study on dengue using the Fortaleza Health Municipal Department database. The results from 1,530 tested samples, from 2005-2006, were compared with data from epidemiological studies of dengue outbreaks in 1996, 2003, and 2010. RESULTS The rapid test confirmed 52% recent infections in the tested patients with clinical suspicion of dengue: 40% detected using IgM and 12% of new cases using IgG in the non-reactive IgM results. The positive IgM plus negative IgG (IgM+ plus IgG-) results showed that 38% of those patients had a recent primary dengue infection, while the positive IgG plus either positive or negative IgM (IgG+ plus IgM+/-) results indicated that 62% had dengue for at least a second time (recent secondary infections). This proportion of reinfections permitted us to estimate the attack rate as >62% of the population sample. CONCLUSIONS The rapid test for dengue has enhanced our ability to detect new infections and to characterize them into primary and secondary infections, permitting the estimation of the minimal attack rate for a population during an outbreak.