Hibiscus: A different hue in histopathology

Background: Nature is vibrant and has an abundance of colors. The use of natural hues in histopathology could offer an economical and feasible alternative to the routinely used stains in special circumstances. Aim: To evaluate the efficacy of the extract of Hibiscus as a counterstain to hematoxylin. Methodology: Hibiscus calyces were sun dried and powdered. Alcoholic and water extracts were obtained by refluxing the powder with 95% ethanol and distilled water, respectively, for 3 h, and then cooled and filtered. Sections from 12 formalin-fixed paraffin-embedded tissue blocks, including both oral mucosal and skin tissues, were used. Nuclear staining was done with hematoxylin, following which the sections were stained with both alcoholic and aqueous Hibiscus extract for 10 min at room temperature using a dropper. All the slides were coded and were reviewed by three blinded oral pathologists for staining efficiency and intensity. NPar test, Kruskal-Wallis test, and Kappa statistics were done to assess the staining efficiency, intensity, and interobserver reliability for the selected parameters. Results: Statistically significant difference was not seen between Hibiscus extract and the controls, except in relation to staining of the basement membrane. Conclusion: Easily available and economical Hibiscus extract is an attractive alternative to eosin. Further studies involving the addition of mordants to the extract and its use as a special stain has to be explored.