Comparing the efficacy of coconut oil and xylene as a clearing agent in the histopathology laboratory

Abstract

Background:The commonly used clearing agent, xylene is supposed to be highly toxic and carcinogenic. As previous research studies have shown the effectiveness of different vegetable oils as clearants, this study was designed to evaluate the efficacy of coconut oil.Materials and Methods:Two equal halves of 60 soft tissue specimens were processed simultaneously in xylene and coconut oil as clearing agents. The Xylene-treated specimens (XY-S) and Coconut oil–treated specimens (CO-S) were checked for gross and histological features and comparison was done between the two groups.Results:Significant shrinkage was noted in XY-S compared to that in CO-S. No difference was found in either of the sections when checked for cellular details and staining quality. Morphometrically, there was significant reduction in the mean cell area in XY-S compared to that in CO-S.Conclusion:Coconut oil may be substituted for the highly hazardous xylene as a clearing agent without compromising the quality of histological details.

Replacement of xylene with extra virgin coconut oil in the clearing step of the histological routine

“…According to Chandraker et al (2018) fabrics processed with coconut oil showed lower translucency and lower stiffness when compared to xylol, low translucency was a characteristic of fabrics treated with coconut oil, while the stiffness of the fabrics was similar to fabrics treated with xylol. These difficulties were not reported by Sermadi et al (2014) and Chandraker et al (2018) who used only coconut oil, Rasmussen et al (1992) who tested olive and coconut oil, Digala et al (2017) who tested coconut oil and peanut oil, Swamy et al (2015) who tested pine, carrot, rose and olive oils, Indu et al (2014) xylene, in our study, did not differ from the procedure performed with xylene alone; vegetable oils can be used in routine histology and have great potential as a substitute for xylene in the clearing step (Rasmussen et al, 1992;Indu et al, 2014;Udonkang et al, 2014;Swamy et al, 2015;Digala et al, 2017;Ashitha, 2018;Chandraker et al, 2018;Ravindran et al, 2018;Carreira et al, 2019;Akpulu et al, 2021;Tsamiya et al, 2021).…”

“…There are several reports in the literature of vegetable oils as substitutes for xylol in the histological routine, Rasmussen et al (1992) used olive oil (olive oil) in the clearing step and coconut oil in the impregnation step and did not consider them less suitable for the histological diagnosis when compared to xylene. Udonkang et al (2014) evaluated palm oil as a clarifying agent and found small differences compared to xylene, without compromising tissue quality; Sermadi et al (2014) compared coconut oil with xylene as a clarifying agent and did not show impairment of histological quality; Indu et al (2014) proposed cedar oil as an effective, ecological and safe alternative to xylene as a deparaffinization agent in the histopathological laboratory; Swamy et al (2015) successfully used carrot oil, pine oil, rose oil and olive oil (olive oil) in histological processing, and found that the four oils have a capacity to clear tissues similar to xylene, being economical oils and that do not compromise histological staining; pine oil was superior in its physical and whitening properties; Digala et al (2017) report that the results obtained with coconut oil and peanut oil are better than xylene in the processing of tissues without health risks; Ashitha (2018) used coconut oil and palm oil in the clearing step and found that both oils, with an advantage over coconut oil, have potential as a substitute for xylene; Chandraker et al (2018) reported difficulties replacing xylene with coconut oil, but stated that the histological quality is similar and without risk to health; Ravindran et al (2018) evaluated palm oil and found similarity with xylene, with good histological results, being a product free of toxicity, without risks, non-flammable, biodegradable, economical, easy to handle and readily available, in addition to staining characteristics with hematoxylin staining and eosin (H/E) showed longevity without fading. histological diaphanization processing, given the results obtained in their study; Abreu et al (2019) demonstrated that in the clearing step, the 1:1 solution (xylene and coconut oil) was satisfactory and meets the specificities of the histological routine; Akpulu et al (2021) recommended eucalyptus oil as an effective agent in the dewaxing process without compromising the staining step and Tsamiya et al (2021) stated that olive oil, clove oil, and peanut oil can clear tissues when compared to those clarified with xylene, also considering their reduced cost, availability, beneficial effects on health and safety for the environment.…”

Substituição do xilol por óleo de coco extravirgem na etapa de diafanização da rotina histológica

“…Independentemente da metodologia usada a miscibilidade dos óleos com o xilol e a parafina é grande e não interfere na coloração com H/E (Rasmussen et al, 1992;Premalatha et al, 2013;Sermadi et al, 2014;Swamy et al, 2015;Indu et al, 2016;Ashitha, 2018;Chandraker et al, 2018;Abreu et al, 2019;Sermadi et al 2019;Carreira et al 2019Tsamiya et al 2021Akpulu et al, 2021). Em relação a outras técnicas de tingimento histológico Rasmussen et al (1992) não evidenciaram diferenças nas colorações histoquímica e imuno-histoquímica, fato corroborado por Sermadi et al (2014) que constataram que a coloração com PAS (ácido periódico de Schiff) não é comprometida pelo uso do óleo de coco e nem com azeite (Sermadi et al, 2019).…”

Evaluation of biosafe alternatives as xylene substitutes in hematoxylin and eosin staining procedure: A comparative pilot study

“…used coconut oil as an alternative in tissue processing and found it as an efficient substitute for xylene causing less shrinkage of the tissue. [ 18 ]…”