63ª Reunião Anual da SBPC

C. Ciências Biológicas - 6. Farmacologia - 3. Toxicologia

BIOLOGICAL EFFECTS OF A WHITE CINNAMON EXTRACT (Nectandra membranacea): ANALYSIS OF RADIOLABELING OF BLOOD CONSTITUENTS AND OF MORPHOLOGY OF RED BLOOD CELLS FROM THE Wistar RATS.

Silvana Ramos Farias Moreno 1, 2 Jorge José de Carvalho 3 Ana Lúcia Nascimento 3 Emely Kazan Rocha 4 Adriano Arnobio 1 Mario Bernardo-Filho 2, 5

1. Departamento de Patologia, Programa de Pós-Graduação em Ciências Médicas e Unidade de Pesquisa Clínica, UFF, Niterói, RJ. 2. Departamento de Biofísica e Biometria, UERJ, RJ. 3. Departamento de Histologia e Embriologia, UERJ, RJ. 4. Departamento de Biologia Celular e Genética, UERJ, RJ. 5. Instituto Nacional do Câncer, Praça da Cruz Vermelha, Rio de Janeiro, RJ, Brasil.

INTRODUÇÃO:

The ingestion of herbs as food or as medicinal plants has increased worldwide. Unexpected interactions between the use of natural products and orthodox therapeutic treatments are reported. There are numerous species of the Lauraceous plant family; as the Nectandra membranacea (N. Membranacea , white cinnamon). They are frequently found in Brazil and have been used by populations to treat inflammation, hypertension and various other diseases. Red blood cells (RBC) and plasma proteins are labeled with technetium-99m (Tc-99m) and used as radiobiocomplexes. Various factors that can influence the labeling of blood constituents have been described, such as inadequate preparation of reducing agent (stannous ion), the influence of disease and/or the presence of drugs in the patient’s plasma. Some extracts of natural products might alter the labeling efficiency of blood constituents with Tc-99m, as well as the morphology of RBC. The aim of this study was to evaluate the possible in vitro interference of a white cinnamon extract (N. Membranacea) (i) on the labeling of blood cells (BC), (ii) on the labeling process of BC and plasma (P) proteins with technetium-99m (Tc-99m) and (iii) on the morphology of red blood cells (RBC) of Wistar rats.

METODOLOGIA:

Blood samples (0.5mL) obtained from the Wistar rats (n=6) were incubated (60 min), and gently mixed with 0.1mL of Nectandra membranacea extract (100%, 50%, 25%, 12,5%, 6,2%) or with 0.9% NaCl as control. Then, 0.5ml of freshly prepared stannous chloride was added under vacuum conditions and the incubation continued for at least 60 minutes. Then, 0.1ml of Tc-99m as sodium pertechnetate was added. After 10 minutes, these samples were centrifuged (5 min), and plasma (P) and blood cells (BC) were separated. Samples of P and BC were also precipitated with 1ml of trichloroacetic acid (TCA 5 %) and soluble (SF) and insoluble fractions (IF) were separated. The radioactivity in P, BC, IF-P, SF-P, IF-BC and SF-BC were determined in a well gamma counter. After that, the percent of administered radioactivity (%ATI) was calculated and a statistical analysis performed (ANOVA test, Tukey-Kramer test and Dunnet test). The morphometry study was performed with the blood samples. One drop of each sample was smeared onto glass slides (5 slides for each sample) and the May-Grünwald-Giemsa (MGG) method was performed. The morphometry of the RBC images was evaluated using Software Image Pro plus and a statistical analysis (Kruskal-Wallis, post-test Dunns, p<0.05) was carried out.

RESULTADOS:

The results show that the Nectandra membranacea extract does not promote significant alteration of the labeling of BC, IF-P and IF-BC. The qualitative analysis of the shape of RBC (incubated sample with N. membranacea) under light microscopy has shown important qualitative morphological alterations; some blood cells show spikes on their membranes differing from normal RBC, which have a naturally round shape. The results were confirmed by image analysis and the Dunns post-test from the Kruskal-Wallis test, that indicated a significant difference (p<0.05) on the morphometry of the RBC treated with white cinnamon extract when compared with control RBC. Quantitative analysis of the results showed that the cellular shape perimeter/area ratio was altered (P=0.021) in the treated samples, in the 50% concentration from 0.22% to 0.77% and in the 100% concentration from 0.22% to 0.73% when compared with control samples. In the white cinnamon extract are present organic compounds, as the alkaloids, that may have one hydroxyl of alcohol function in their structures with possible similar characteristics to that of the ethanol hydroxyl (alcohol function). This could justify the morphological alterations on RBC morphology.

CONCLUSÃO:

The white cinnamon extract (N. Membranacea) may alter the RBC membrane morphology, but the morphological alterations produced by the extract did not alter the labeling of blood constituents with Tc-99m. Moreover, although our assays were performed with animals, we suggest precaution with the use of extract of white cinnamon (Nectandra membranacea).

Palavras-chave: Nectandra membranacea extract, red blood cell, technetium-99m.