Extratos de morus nigra l. (amora-preta) e bixa orellana l. (urucum) para substituição dos corantes hematoxilina e eosina (HE) na técnica histológica de rotina

Objective: The objective of this study was to evaluate the applicability of the staining by extracts of black mulberry (Morus nigra L.) and urucum (Bixa orellana L.) in order to respectively substitute hematoxylin and eosin staining procedure in the routine histological technique. Methods: Black mulberry fruits and urucum seeds were used in preparation of histological stains according to literature reported methods. The effectiveness of staining was tested on histological sections of encephalon, heart and skin of rats. The sections were submitted to the staining battery with extracts of blackberry or hematoxylin, followed by urucum or eosin staining. The slides were observed through microscope in order to evaluate staining effectiveness. A 0 to 3 scale was determined. The values were statistically analyzed. Results: It was observed a distinct pattern of staining of cell and tissue structures. The cytoplasm presented yellowish coloration by the urucum extract, while the nuclear components were featured with blue pigmentation by the blackberry stain. Color intensity evaluation demonstrates that hematoxylin and urucum combination is similar to hematoxylin and eosin staining. Conclusion: In an unprecedented way, it has been proven that both natural alternative dyes can be used together to perform a double stainig in substitution of the hematoxylin and eosin technique, being considered as interesting alternative for histotechnology.