Natural Dyes an alternative to conventional histological staining techniques: Investigating aqueous Avocado seed extract dye

The global concern about the use of eco-friendly and biodegradable materials in tissue staining has borne laudable interest in the use of natural dyes as suitable alternatives to synthetic dyes. Plants like avocados serve as dyeing agents for fabrics, but little is known about their potential as a histological stain. This study focused on investigating the staining properties of the aqueous avocado seed extract on histological sections of the spleen, testis, skin, and pancreas. A total of five fresh avocado seeds were chopped into bits and simmered in water to extract their deep maroon dye. Tissue sections of the spleen, testis, skin, and pancreas of 4 adult Wistar rats aged 12 weeks and weighing 180–250 g were used. They were grouped into four, labeled A to D, with each group containing 4 specimens (1-Spleen, 2-Testis, 3-Skin, and 4-Pancreas). Group A (control) was stained using the Haematoxylin and Eosin technique; group B was stained using Haematoxylin and Avocado seed extract; group C was stained using Avocado seed extract and Eosin, while group D was stained using Avocado seed extract only. Findings revealed blue-black nuclei and pink cytoplasm (group A); blue-black nuclei and brownish but unclear cytoplasm (group B); pinkish cytoplasm with no nuclei seen (group C); brownish cytoplasm with unclear features (group D); only the testis demonstrated remarkable features. This study demonstrated the properties of avocado seed extract as an acid dye capable of staining the cytoplasm, and may have a better inclination towards staining testicular cytoplasm.

Key Words: Avocado Seed, Haematoxylin and Eosin, Natural Dyes, Testicular tissue