Honey as an alternative fixative for oral tissue: An evaluation of processed and unprocessed honey

Abstract

Background: Fixation is the most imperative step in the practice of diagnostic histopathology, which is intimately linked to 10% formalin. As a result of increasing concerns about the potential carcinogenicity of the formaldehyde, attempt to find safer alternatives is necessary. Honey has been shown to possess antimicrobial, antiviral and antimutagenic properties. Many studies have reported that honey possesses dehydrating and preserving effects also.

Aims and objectives: To study the fixative properties of processed and unprocessed honey in oral tissues followed by comparision with formalin.

Materials and methods: The study group comprised 12 different tissues. Each tissue was cut into 3 segments and were immediately fixed in bottles containing 10% unprocessed honey, 10% processed honey and 10% formalin, respectively, for 24 h at room temperature. After fixation, tissues were processed using the routine standard processing protocol followed by hematoxylin and eosin staining. Data were statistically analyzed using descriptive statistics such as mean, standard deviation and percentage. Kruskal-Wallis test followed by post hoc Dunn's multiple comparisons test and Chi-square test or Fisher's exact test for small sample size. A P < 0.05 was considered as significant. Data analysis was done by using software Minitab v14.0.

Results: When all the stained sections were assessed for the parameters, there was no statistically significant difference between tissues fixed in processed and unprocessed honey compared to formalin (P = 0.004). The tissue morphology and staining adequacy for diagnosis in honey fixed tissue was at par with formalin fixed tissue. Hence, our results suggest that both processed honey and unprocessed honey can be used as a safe alternative for formalin.

Keywords: Formalin substitutes; non-formalin fixatives; processed honey; tissue fixatives; unprocessed honey.

Figure 1

Photomicrograph showing adequacy of nuclear and cytoplasmic staining in epithelial tissue (a) conventional neutral buffered formalin, (b) processed honey and (c) unprocessed honey (H&E stain, ×100)

Figure 2

Photomicrograph showing adequacy of tissue morphology and clarity in salivary gland tissue (a) conventional neutral buffered formalin (H&E stain, ×100), (b) processed honey (H&E stain, ×200) and (c) unprocessed honey (H&E stain, ×200)

Figure 3

Photomicrograph showing adequacy of tissue morphology and clarity in lymphoid tissue (a) conventional neutral buffered formalin, (b) processed honey and (c) unprocessed honey (H&E stain, ×100)

Figure 4

Photomicrograph showing adequacy of tissue morphology and clarity in adipose tissue (a) conventional neutral buffered formalin, (b) processed honey and (c) unprocessed honey (H&E stain, ×100)

Figure 5

Photomicrograph showing artifact shrinkage in epithelial tissue in unprocessed honey (H&E stain, ×100)

Figure 6

Photomicrograph showing artifactual hyalinized connective tissue in unprocessed honey (H&E stain, ×100)