Lawsonia inermis Linn (Henna) lyophilized extracts as alternate stains may deter staining efficacy in histology sections

Abstract

Lawsonia inermis is a shrub widely cultivated as an ornamental and hedge plant while the leaves are used in many countries for hair dyeing, fingernails painting and eyebrows coloration. This study hopes to stop the monopolization of haematoxylin stain for histopathology investigations. Therefore, our study aimed at exploring the staining properties of L. inermis (Henna) freeze-dried extracts as an alternate stain. The leaves of L. inermis were dried and pulverized. After which, 2kg was macerated in 10L of cold and hot water respectively, and 7.5L of absolute ethanol for each extraction solvents; filtered and freeze-dried. The pH of the 3 paste-like freeze-dried extracts was determined using a pH meter. Kidney, intestine, tonsil, and lung tissues were cut at 3-5mm and processed using routine histological technique and sectioned at 3-5um with the rotary microtome. Different extracts were prepared by substituting haematoxylin powder in Gills and Weigert haematoxylin and eosin preparatory procedures. Modified versions were used to stain sections from lungs, tonsil, appendix, kidney, and intestine with varying staining procedures at altered timing respectively. Freeze-dried extracts of L. inermis poorly stained histology sections compared to conventional methods in this study while, iron mordant significantly enhanced staining uptake / affinity of L. inermis extract. Freeze-dried extracts of L. inermis is not effective for nuclear staining of tissue sections compared to conventional haematoxylin while alcoholic extract appeared to be a better option amongst the trio extraction methods.