Assessment of the oxidative potential of Citrus limon, Citrus aurantifolia juice extracts and counterstaining prospects of Hibiscus sabdariffa leaf extract to the conventional periodic acid Schiff’s technique

Abstract

Background: Periodic acid Schiff (PAS) is a widely used histochemical staining technique specifically for the demonstration of carbohydrate molecules in tissues. Citrus limon and Citrus aurantifolia juice are non-toxic juices that are safe for consumption and do not cause any adverse effects when exposed to bodily tissues.
Aim: This study demonstrates the oxidative potential of Citrus limon and Citrus aurantifolia juice as a substitute for periodic acid in the conventional PAS staining technique while also evaluating the counterstaining quality of Hibiscus sabdariffa extract.
Methodology: Histological sections were obtained from archival blocks retrieved from the histopathology service laboratory of Bowen University Teaching Hospital and stained using the conventional Periodic acid Schiff technique while modification in staining protocol was carried out on subsequent slides that were treated with fresh juice extracts of Citrus limon and Citrus aurantifolia and extracts of Hibiscus sabdariffa obtained from its calyces. While the control tissue sections were stained with the conventional PAS technique, other sections of tissues were independently treated by oxidizing with Citrus limon or Citrus aurantifolia juice respectively and continued with Schiff’s reagent while counterstaining with Harris hematoxylin. The other tissue sections were treated with Citrus limon Schiff and Citrus aurantifolia Schiff technique by first oxidizing with Citrus limon juice / Citrus aurantifolia juice, treated with the Schiff’s reagent and followed by counterstaining with Hibiscus sabdariffa extract.
Results: The result showed that the periodic acid Schiff, Citrus limon Schiff and Citrus aurantifolia Schiff-stained liver and kidney sections appear similarly with purple-magenta colour which demonstrates the glycogen and glycoprotein content of the tissues, as well as the blue colouration demonstrating the counterstained nuclei.
Conclusion: This study showed that the substitution of the 1% periodic acid with freshly prepared Citrus limon or Citrus aurantifolia juice and counterstaining with the extract of Hibiscus sabdariffa impacted a staining effect similar to the conventional PAS staining protocol thus suggesting it as a possible substitute that is cost-effective and readily available alternative in the demonstration of carbohydrates in histologic tissue.