Effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood

Effect of irinotecan administration on amiloride-sensitive sodium taste responses in mice

Taste alteration is a frequently reported side effect in patients receiving the chemotherapeutic agent, irinotecan. However, the way in which irinotecan causes taste disturbance and the type of taste impairment that is affected remain elusive. Here, we used the two-bottle preference test to characterize behavioral taste responses and employed immunohistochemical analyses to clarify the types and mechanisms of taste alteration induced, in mice, by irinotecan administration. Irinotecan administration resulted in a reduced intake of sodium taste solution but had no effect on sweet taste responses, as determined in the two-bottle preference test. In the presence of amiloride, which inhibits the function of the epithelial sodium channel (ENaC) in the periphery, the intake of sodium taste solution was comparable between the irinotecan-treated and control groups. Immunohistochemical analyses revealed that α-ENaC immunoreactivity detected in taste bud cells decreased slowly after irinotecan administration, and that administration of irinotecan had little effect on the number of cells expressing the cellular proliferation marker, Ki67, within or around taste buds. Our results imply that irinotecan administration may be responsible for altered behavioral sodium taste responses originating from ENaC function in the periphery, while being accompanied by the reduction of α-ENaC expression at the apical membrane of taste receptor cells without disturbing taste cell renewal.

The effect of systemic application of propolis on tongue damage and oral mucositis in rats exposed to radiation

PURPOSE

In this experimental study, the effect of dose-dense systemic application of propolis on oral mucosity, histological changes in papilla, and inflammatory and hypoxic markers in rats exposed to radiation was investigated.

METHODS

Seven rats were in the control and 30 rats in the experimental group. Three experimental groups were formed. In Group 1 RT (15 Gy) was delivered only to the head and neck region. In Group 2, RT (15 Gy) and systemic administration of 100 mg/kg/ml propolis, in Group 3, RT (15 Gy) and systemic administration of 200 mg/kg/ml propolis were applied. Oral mucositis index (OMI) was scored in control and experimental groups. Proinflammatory markers [interleukin-6 (IL-6), myeloperoxidase (MPO), tumor-necrosis factor-α (TNF-α)] hypoxia markers [glucose transporter-1 (GLUT-1), hypoxia-inducible factor 1α (HIF-1α)] were studied histomorphologically.

RESULTS

The significantly highest OMI score was observed in the G1. OMI score was statistically significantly decreased in experimental groups receiving systemic propolis, especially in G3. Proinflammatory markers increased significantly only in the experimental RT group, G1. Serum levels of MPO and TNF-α significantly decreased in the dose-dense systemic propolis arm. The highest levels of hypoxia markers (HIF-1α and GLUT-1) were detected in the RT group, then in G2, G3, and control groups in order of decreasing frequency. However, the difference between the groups did not reach the level of statistical significance.

CONCLUSION

Systemic propolis can be reduced acute mucositis with its anti-inflammatory effect without developing resistance to RT (tumor protection). However, greater number of clinical studies should be designed to arrive at definitive conclusions.

Study of the Possible Alleviated Role of Atorvastatin on Irinotecan-Induced Lingual Mucosal Damage: Histological and Molecular Study

BACKGROUND

Oral mucositis is the most debilitating and troublesome adverse effect of irinotecan (CPT-11) treatment. It adversely affects the patient quality of life. The aim of this work was to study the histological, immunohistochemical, and molecular changes in the oral mucosa by CPT-11 and the possible alleviated role of atorvastatin.

METHODS

Rats were randomly divided into control, CPT-11-treated group, and CPT-11+ atorvastatin-treated group. At the end of the experiment, the anterior two-thirds of the tongue was dissected out and divided into two parts: one part for light microscopic examination and the second for molecular study.

RESULTS

CPT-11-treated group revealed loss of normal mucosal organization, areas of ulceration and inflammation, and loss of architecture of lingual papillae. A significant decrease in immunohistochemical and molecular gene expression of Ki-67 and antiapoptotic Bcl-2 levels was observed. A significant increase in NF-κB immunohistochemical and mRNA gene expression level and a nonsignificant increase in Nrf2 gene expression were detected. Coadministration of atorvastatin showed remarkable improvement in the histopathological picture with a significant increase in Ki-67 and Bcl-2, a significant decrease in NF-κB protein and gene expression, and a significant increase in Nrf2 gene expression.

CONCLUSION

Atorvastatin substantially attenuates CPT-11-induced oral mucositis through the initiation of the antiapoptotic gene, modulation of the inflammatory, and antioxidant gene expression.

Effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood

Irinotecan is one of the most important anti-tumour drugs against a broad spectrum of malignancies, but is known to be associated with possible oral complications. The aim of the present study was to evaluate the effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood using different histological and immunohistochemical methods. Twenty juvenile male albino rats were divided equally into two groups: control and irinotecan-treated group (single injection of 200 mg irinotecan/kg, then kept for four weeks without treatment). The tongue specimens were processed for light microscopy and scanning electron microscopy. The irinotecan-treated group showed statistically significant shortening and thinning of the lingual papillae. There was loss of the normal appearance of the filiform papillae with focal cell loss alternating with areas of hyperkeratosis. Focal separation of the keratin layer, some nuclear changes and vacuolation of some epithelial cells were detected. Dilated congested blood vessels and mild mononuclear cellular infiltration were encountered. Atrophic fungiform papillae with ill-defined taste bud cells were observed. A statistically significant decrease in the pattern of Ki67 immunohistochemical staining reaction was detected in comparision to the control group. Scanning electron microscopy revealed different signs of atrophy of the tongue papillae. Focal areas of desquamation of lingual papillae were observed revealing some filiform papillae with desquamated surface, bisected tips and evident thinning. Some extravasated red blood cells could be detected. Thus irinotecan caused significant morphological and morphometrical alterations of the tongue mucosa in particularly the filiform papillae.