Study of Staining Capability of Alcoholic and Aqueous Hibiscus sabdariffa Extract in Demonstration of Selected Fungal Moulds in Some Selected Tissue Section of Wistar Rat

Introduction: Hibiscus sabdariifa is a natural dye, generally called roselle. Most of Synthetic dye have been established to cause toxicity. The aim of this research was to determine the staining effect of different concentration of Hibiscus sabdariffa extracts at various pH, duration on fungal staining.

Methods: Standard Gomori’s metenaine silver stains as control and Hibiscus sabdariffa extracts (alcoholic and aqueous) were used to stain a fungal (Aspergillus spp) positive lung tissue, using various concentration (5% and 10%) of the extract, with change of pH achieved by treating the extracts with ammonium hydroxide and glacial acetic acid at various duration (30 seconds and 1 hour respectively), each was used for staining Aspergillus spp in tissue section as a primary stain replacing (4% Chromic acid, sodium metabisulphite, Hexamine working silver solution and Sodium thiosulphate).

Results: All extracts after treatment were acidic, the fungi were best demonstrated with Aqueous hibiscus stains (5% untreated, 10% untreated and 5% glacial acetic acid treated) at longer duration, staining the capsule, light to dark-brown in a light-green background when compared with the alcoholic hibiscus stain. Few of the alcoholic hibiscus stains show metachromatic property. The Hibiscus stains stained better at longer duration and the change of pH was indirectly proportional to the staining ability of the hibiscus stains.

Conclusion: The results obtained indicate that hibiscus plant extract have the potential for use in the morphological identification of fungi in formalin-fixed paraffin-embedded tissue section.