Propolis as a Potential Novel Histological Tissue Fixative: A Preliminary Analysis

Background: Fixation of biopsy specimens is a critical step before processing and staining them for histological tissue examination. Formalin is considered the gold standard fixative solution for its attributes. However, it has concerning side effects, such as carcinogenic and potential irritational properties. Owing to its various harmful effects, a safer natural substitute should be explored. In this study, we compared the effectiveness of propolis to 10% formalin and determined its ability as a natural fixative solution. Materials and Methods: Sixty tissue specimens were collected from goats' tongues and immediately placed in (1) 6.6% propolis, (2) 10% natural buffered formalin (positive control), (3) 6.6% propolis followed by 10% formalin, and (4) 0.9% saline (negative control). Tissue samples were fixed at different time points (12, 24, 48, and 72 h) at room temperature, followed by processing and staining. The quality of the microscopic parameters was blindly assessed by two oral and maxillofacial pathologists using a numerical scoring scale. Scores were statistically analyzed. Results: The fixation of tissue samples placed in 6.6% propolis was statistically significantly better than that of samples placed in 10% formalin and 0.9% saline at different time points. Conclusion: Propolis showed promising fixation properties and can be considered a natural alternative to 10% formalin.