Evaluation of Antineoplasic Activity of Zingiber Officinale Essential Oil in the Colorectal Region of Wistar Rats

Abstract

Introduction: Aberrant Crypt (AC) and Aberrant Crypt Focus (ACF) are considered pre-neoplasic lesions, ranging from hyperplasia to different degrees of dysplasia in the colon. This work aimed to evaluate and quantify the chemopreventive activity of Zingiber officinale essential oil in the colorectal region of Wistar rats.

Materials and methods: We extracted the essential oil from ginger rhizomes and carried out ACF induction, in rats, with 1.2 Dimethylhydrazine (DMH) at a 20 mg/kg dose. The experimental groups were GI (negative control); GII (positive induction control); GIII (DMH + essential oil); GIV (DMH +5-Florouracil) and GV (essential oil). The histological techniques used were methylene blue, hematoxylin-eosin (HE) dyeing, and immunohistochemistry (IHQ).

Results: The major essential oil compounds were citral (17.25%), δ-citral (10.25%), camphene (9.55%), α-zingiberene (7.57%), nerol (6.37%) and plelandrene (6.83%). For the presence of AC or ACF, we did not observe them in GI and GV, while in GII and GIII, they were observed, in high values, in both regions, but only in the distal region, there was a significant difference between them. For GIV, for both regions, there were significant lower numbers of AC when compared to GIII. As observed, with HE, there were hyperplastic and dysplastic ACF in the proximal and distal portions of the colon. For IHQ analyses, there were positively PCNA antibody marked cells in all experimental groups. Yet, there was no significant correlation of mitotic index among them. Moreover, the results of GIII compared to GIV were very similar.

Conclusion: In this sense, the Zingiber officinale essential oil has good antioxidant potential because it presents a mixture of monoterpene and sesquiterpene compounds. Thus, it is able to develop a chemoprotective effect, as it presented similar results to the standard drug, showing cell proliferation control.

Keywords: Aberrant crypt focus; Colorectal Neoplasms; Essential oil, Chemopreventive effect; Ginger - Zingiber officinale.

Figure 1

Animals Weight Assessment. The graph expresses the body weight in grams of the animals that compose the groups, monitored weekly and, the results presented, represents the average animals’ weight per group per week

Figure 2.

Representative Images of the Study's Histological in Experimental Groups (GII, GIII and GIV). A, Colonic mucosa stained with methylene blue, representing a topographic view of an ACF with seven AC. The AC presents an irregular luminal opening and a thicker epithelial lining compared to normal adjacent crypts (light microscopy - 4x objective). B/C: Colonic mucosa stained with H E representing a topographic view; B, hyperplastic crypts, with abundant glandular formations. The luminal opening of ACF was slightly elevated from the normal mucosa, presenting several elongated crypt layers; C, dysplastic AC (black arrow) presented cells with marked cytoplasmic basophilia; high nucleus-cytoplasm ratio and loss of cell polarity in several degrees, nuclear stratification; and reduction in mucin production

Figure 3.

Colon Photomicrographs Marked with PCNA and Developed with DAB. Crypt cells in the basal region of the crypt (red arrow) and crypt apex in experimental groups (GII, GIII and GIV) (black arrow) with marked expression of PCNA, presence of nuclear stratification and reduced mucin production (*).

Figure 4.

Number of Hyperplasias and Dysplasias Observed after HE Staining in the Proximal and Distal Portions of Each Group. The mean and standard deviation were calculated based on the number of animals in each group. Results were expressed as the mean of the amount observed in the animals of the same group ± standard deviation. * Significance per Tukey test p<0.05