Topical Aloe Vera (Aloe barbadensis Miller) Extract Does Not Accelerate the Oral Wound Healing in Rats.

The effect of topical application of Aloe Vera (Aloe barbadensis Miller) extract was assessed on the healing of rat oral wounds in an in vivo model using 72 male Wistar rats divided into three groups (n = 24): control, placebo and Aloe Vera (0.5% extract hydroalcoholic). Traumatic ulcers were caused in the dorsum of the tongue using a 3-mm punch tool. The Aloe Vera and placebo group received two daily applications. The animals were sacrificed after 1, 5, 10 and 14 days. Clinical analysis (ulcer area and percentage of repair) and histopathological analysis (degree of re-epithelialization and inflammation) were performed. The comparison of the differences between scores based on group and experimental period, both in quantitative and semi-quantitative analyses, was performed using the Kruskal-Wallis test. The significance level was 5%. On day 1, all groups showed predominantly acute inflammatory infiltrate. On day 5, there was partial epithelialization and chronic inflammatory infiltrate. On the days 10 and 14 total repair of ulcers was observed. There was no significant difference between groups in the repair of mouth ulcers. It is concluded that treatment using Aloe Vera as an herbal formulation did not accelerate oral wound healing in rats.

Pharmacological evaluation of a traditional Brazilian medicinal plant, Monteverdia ilicifolia. Part I - Preclinical safety study.

ETHNOPHARMACOLOGICAL RELEVANCE: Monteverdia ilicifolia (Maytenus ilicifolia, Celastraceae), known as "espinheira-santa", has been widely used in Brazil to manage mainly gastrointestinal diseases. This species has been listed in the Brazilian Pharmacopeia and in the National List of Essential Medicines (RENAME). Considering that clinical studies about M. ilicifolia are rare, our group has been performing a broader project designed to evaluate the efficacy of M. ilicifolia capsules in a clinical trial, for this reason, approaches to provide safety to those patients are relevant. AIM OF THE STUDY: We aimed to investigate the potential pharmacokinetic interaction and hepatotoxicity and intestinal toxicity of an aqueous extract of M. ilicifolia and its main phytocompounds, catequin, epicatequin, and quercetin. METHODS AND MATERIALS: Slices of liver and intestine of Wistar rats were incubated with different concentrations of M. ilicifolia extract or isolated compounds (catechin, epicatechin and quercetin). Commercial kits were used to evaluate enzyme activities of CYP2D6 and CYP3A4 isoforms, as well as cell viability (MTT) assay and intracellular enzymes leakage, specifically lactate dehydrogenase (LDH), alkaline phosphatase (AP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) were studied. RESULTS: Incubation with M. ilicifolia extract, catechin, epicatechin and quercetin did not affect significantly any evaluated parameter in intestines. The intracellular enzymes leakages, CYP2D6, LDH and AST, were increased with M. ilicifolia extract and quercetin in liver slices. CONCLUSIONS: Our in vitro findings highlighted, for the first time, the potential hepatotoxicity induced by an aqueous extract of M. ilicifolia, consequently this species and its products should be avoided in liver diseases, supporting that studies of safety must be performed including in the context of traditional medicinal plants.

Neuroinflammation, blood-brain barrier dysfunction, hippocampal atrophy and delayed neurodevelopment: Contributions for a rat model of congenital Zika syndrome.

The congenital Zika syndrome (CZS) has been characterized as a set of several brain changes, such as reduced brain volume and subcortical calcifications, in addition to cognitive deficits. Microcephaly is one of the possible complications found in newborns exposed to Zika virus (ZIKV) during pregnancy, although it is an impacting clinical sign. This study aimed to investigate the consequences of a model of congenital ZIKV infection by evaluating the histopathology, blood-brain barrier, and neuroinflammation in pup rats 24 h after birth, and neurodevelopment of the offspring. Pregnant rats were inoculated subcutaneously with ZIKV-BR at the dose 1 × 107 plaque-forming unit (PFU mL-1) of ZIKV isolated in Brazil (ZIKV-BR) on gestational day 18 (G18). A set of pups, 24 h after birth, was euthanized. The brain was collected and later evaluated for the histopathology of brain structures through histological analysis. Additionally, analyses of the blood-brain barrier were conducted using western blotting, and neuroinflammation was assessed using ELISA. Another set of animals was evaluated on postnatal days 3, 6, 9, and 12 for neurodevelopment by observing the developmental milestones. Our results revealed hippocampal atrophy in ZIKV animals, in addition to changes in the blood-brain barrier structure and pro-inflammatory cytokines expression increase. Regarding neurodevelopment, a delay in important reflexes during the neonatal period in ZIKV animals was observed. These findings advance the understanding of the pathophysiology of CZS and contribute to enhancing the rat model of CZS.

Proposal of a secure and efficient protocol for a murine oral carcinogenesis model induced by 4-nitroquinoline-1-oxide (4NQO).

An important rat model using the chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) has been described for the study of the process of oral carcinogenesis. This model replicates the gradual progression seen in oral carcinoma patients. However, due to its high level of toxicity, its use in fundamental research is challenging. Here, we propose a secure and efficient modified protocol based on a lower dose of 4NQO concentration as well as an increased water supply and hypercaloric diet, in order to reduce the damage caused to the animals during the process of oral carcinogenesis. Twenty-two male Wistar rats were exposed to 4NQO, evaluated clinically once a week and euthanized at 12 and 20 weeks for histopathological analysis. The protocol involves a staggered dose of 4NQO up to a concentration of 25 ppm, associated with two days of pure water, a 5% glucose solution once a week and a hypercaloric diet. This modified protocol prevents the immediate consequences of the carcinogen. At week 7, all animals displayed clinically evident tongue lesions. From a histological perspective, after 12 weeks of 4NQO exposure, 72.7% of the animals developed epithelial dysplasia and 27.3% developed in situ carcinoma. In the group exposed for 20 weeks, epithelial dysplasia and in situ carcinoma were diagnosed in one case each, whereas invasive carcinoma was diagnosed in 81.8% of the cases. Nonsignificant modification of animal's behavior and weight was observed. This new proposed 4NQO protocol was secure and effective for studying oral carcinogenesis and can be used to conduct lengthy investigations.

BMI-1 expression increases in oral leukoplakias and correlates with cell proliferation.

Oral leukoplakia (OL) is a white lesion of an indeterminate risk not related to any excluded (other) known diseases or disorders that carry no increased risk for cancer. Many biological markers have been used in an attempt to predict malignant transformation; however, no reliable markers have been established so far. Objective To evaluate cell proliferation and immortalization in OL, comparing non-dysplastic (Non-dys OL) and dysplastic OL (Dys OL). Methodology This is a cross-sectional observational study. Paraffin-embedded tissue blocks of 28 specimens of Non-dys OL, 33 of Dys OL, 9 of normal oral mucosa (NOM), 17 of inflammatory hyperplasia (IH), and 19 of oral squamous cell carcinomas (OSCC) were stained for Ki-67 and BMI-1 using immunohistochemistry. Results A gradual increase in BMI-1 and K-i67 expression was found in oral carcinogenesis. The immunolabeling for those markers was higher in OSCC when compared with the other groups (Kruskal-Wallis, p<0.05). Ki-67 expression percentage was higher in OL and in IH when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). Increased expression of BMI-1 was also observed in OL when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). No differences were observed in expression of both markers when non-dysplastic and dysplastic leukoplakias were compared. A significant positive correlation between Ki-67 and BMI-1 was found (Spearman correlation coefficient, R=0.26, p=0.01). High-grade epithelial dysplasia was associated with malignant transformation (Chi-squared, p=0.03). Conclusions These findings indicate that BMI-1 expression increases in early oral carcinogenesis and is possibly associated with the occurrence of dysplastic changes. Furthermore, our findings indicate that both Ki-67 and BMI-1 are directly correlated and play a role in initiation and progression of OSCC.

Drosophila melanogaster as a model for the study of Malassezia pachydermatis infections.

Malassezia pachydermatis is a yeast that is commonly found in the skin of most animals. Changes in the physical, chemical or immunological processes of the skin may render the host more susceptible to the yeast, which then may cause otitis, dermatitis or, less often, systemic infection. We tested the pathogenicity of M. pachydermatis in wild-type (WT) and Toll-deficient Drosophila melanogaster. Flies were inoculated in the thorax with a needle previously dipped in inoculum concentrations ranging from 103 and 107 yeast cells/mL. After infection, flies were housed at 29 °C and mortality was evaluated daily until day seven. WT flies were resistant to the infection, whereas Toll-deficient flies showed inoculum-dependent mortality rates. Fungal burden, assessed by histopathological analysis and by counting the number of colony-forming units of dead flies, corroborated the results. The D. melanogaster model is a promising minihost model for future large-scale studies of virulence mechanisms and antifungal drug activity in malasseziosis.

Cell proliferation markers at the invasive tumor front of oral squamous cell carcinoma: comparative analysis in relation to clinicopathological parameters of patients.

OBJECTIVES: To evaluate the number of AgNORs per nucleus and the expression of Ki-67 at the tumor invasion front (TIF) in relation to clinical parameters (TNM), TIF classification and the prognosis of oral squamous cell carcinomas in an Uruguayan population. MATERIAL AND METHODS: This study was conducted through a retrospective survey from 2000 to 2010 at the National Institute of Cancer Montevideo, Uruguay and included 40 patients. The samples were obtained from the resection of the tumor and the TIF was defined according with Bryne, et al.5 (1992). Expression of Ki-67 was assessed by the percentage of positive tumor cells and the AgNOR was recorded as the mean AgNOR (mAgNOR) and the percentage of AgNOR per nucleus (pAgNOR). All analyzes were performed by a blinded and calibrated observer. RESULTS: No statistically significant association was observed between immunostaining of Ki-67 and AgNOR with the different types of TIF, regional metastasis and patients prognosis, however it was observed an increase in Ki-67 expression associated with worse patient's clinical staging, although not statistically significant. CONCLUSIONS: Our results suggest that proliferation markers as AgNOR and Ki-67 are not prognostic markers at the tumor invasive front of carcinoma of oral squamous cell.

Ameloblastic neoplasia spectrum: a cross-sectional study of MMPS expression and proliferative activity.

OBJECTIVE: To compare the proliferation and the expression of matrix metalloproteinases (MMPs; MMP-2 and MMP-9) in solid and unicystic ameloblastomas with ameloblastic carcinomas. STUDY DESIGN: Five cases of ameloblastic carcinoma (AC), 18 cases of solid ameloblastoma (SA), and seven of unicystic ameloblastoma (UA) were selected. The immunohistochemical expression of MMPs was assessed by the percentage of positive tumor cells and stained stroma. The mean argyrophilic nucleolar organizer region (AgNOR) and the percentage of cells with more than one AgNOR per nucleus were evaluated. RESULTS: Statistically significant higher mean AgNOR was observed in AC than in SA and UA. MMP-2 was expressed similarly in tumor and stroma among groups. MMP-9 was higher in the stroma of SA than that of UA (P = .0484). CONCLUSIONS: The cell proliferation was related to the greater aggressiveness of AC. High expression of MMP-2 and MMP-9 in all lesions highlighted the importance of these enzymes in the biology of ameloblastic tumors.

Location of injected polymethylmethacrylate microspheres influences the onset of late adverse effects: an experimental and histopathologic study.

Polymethylmethacrylate (PMMA) has been widely used in the correction of wrinkles because of its long-lasting cosmetic improvements. However, side effects and complications may occur, and its clinical appearance on the oral mucosa can be similar to that of inflammatory or neoplastic disease. The aim of this research was to compare the clinical and histopathologic responses to PMMA injected by two different methods. Twenty-two rats received an injection of PMMA using the tunneling technique (gold standard), with subcutaneous deposition of the filler in the face, or a variation of the technique with transcutaneous submucosal deposition of the filler in the cheek. The tissue reaction was analyzed clinically every 24 hours during the first week, then once a week for the following 3 months. Histologic evaluation was based on the local inflammatory response to the filler. No clinical changes were observed during the initial evaluation period (0-14 days). After 14 days, only the submucosal group showed extra-oral enlargement (n=4, 18.2%). Histopathologic analysis revealed nodule formation in four animals (18.2%) in the submucosal group, with no nodules observed in the subcutaneous group. The data obtained in this study demonstrate that the technique used to deliver the filler may influence the risk of adverse reactions.

BMI-1 expression increases in oral leukoplakias and correlates with cell proliferation

Abstract Oral leukoplakia (OL) is a white lesion of an indeterminate risk not related to any excluded (other) known diseases or disorders that carry no increased risk for cancer. Many biological markers have been used in an attempt to predict malignant transformation; however, no reliable markers have been established so far. Objective To evaluate cell proliferation and immortalization in OL, comparing non-dysplastic (Non-dys OL) and dysplastic OL (Dys OL). Methodology This is a cross-sectional observational study. Paraffin-embedded tissue blocks of 28 specimens of Non-dys OL, 33 of Dys OL, 9 of normal oral mucosa (NOM), 17 of inflammatory hyperplasia (IH), and 19 of oral squamous cell carcinomas (OSCC) were stained for Ki-67 and BMI-1 using immunohistochemistry. Results A gradual increase in BMI-1 and K-i67 expression was found in oral carcinogenesis. The immunolabeling for those markers was higher in OSCC when compared with the other groups (Kruskal-Wallis, p<0.05). Ki-67 expression percentage was higher in OL and in IH when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). Increased expression of BMI-1 was also observed in OL when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). No differences were observed in expression of both markers when non-dysplastic and dysplastic leukoplakias were compared. A significant positive correlation between Ki-67 and BMI-1 was found (Spearman correlation coefficient, R=0.26, p=0.01). High-grade epithelial dysplasia was associated with malignant transformation (Chi-squared, p=0.03). Conclusions These findings indicate that BMI-1 expression increases in early oral carcinogenesis and is possibly associated with the occurrence of dysplastic changes. Furthermore, our findings indicate that both Ki-67 and BMI-1 are directly correlated and play a role in initiation and progression of OSCC.

Effects of a mucoadhesive formulation containing Curcuma longa L. on oral wound healing

Introduction: The aim of this study was to investigate the effects of a topical mucoadhesive formulation with Curcuma longa L. extract (MFC) on oral wound healing. Methods: Seventy-two Wistar rats were randomly assigned to 3 groups: Control, Vehicle, and MFC. Traumatic ulcers were made on the dorsum of the tongue with a 3-mm diameter punch. Vehicle and MFC groups received application of the products twice a day, while animals in the control group were cared for in identical conditions but received no product application. Six rats in each group were euthanized at days 3, 5, 10, and 14. Percentage of repair was calculated based on wound area. HE-stained histological sections were obtained for semi-quantitative analysis of re-epithelization and inflammation. Results: Clinical findings revealed that at days 3 and 5, animals from the MFC group exhibited a significantly higher percentage of wound repair. At day 5, animals from this group also demonstrated a significant increase in the degree of re-epithelization and inflammation. Conclusions: MFC is capable of accelerating oral wound repair in an in vivo model by modulating the inflammatory process and stimulating epithelial proliferation. (AU)

Influence of different energy densities of laser phototherapy on oral wound healing.

The aim of the present prospective study was to evaluate the impact of laser phototherapy (LPT) on the healing of oral ulcers. Different power densities were used on oral wounds in Wistar rats (n=72) randomly divided into three groups: control (0 J/cm2), 4 J/cm2 laser, and 20 J/cm2 laser. Ulcers (3 mm in diameter) were made on the dorsum of the tongue with a punch. Irradiation with an indium-gallium-aluminum-phosphide laser (660 nm; output power: 40 mW; spot size: 0.04 cm2) was performed once a day in close contact with the ulcer for 14 consecutive days. A statistically significant acceleration in healing time was found with wounds treated with 4 J/cm2 LPT. Moreover, striking differences were found in the ulcer area, healing percentage, degree of reepithelialization, and collagen deposition. The most significant changes occurred after 5 days of irradiation. Based on the conditions employed in the present study, LPT is capable of accelerating the oral mucosa wound-healing process. Moreover, faster and more organized reepithelialization and tissue healing of the oral mucosa were achieved with an energy density of 4 J/cm2 in comparison to 20 J/cm2.

Cell proliferation markers at the invasive tumor front of oral squamous cell carcinoma: comparative analysis in relation to clinicopathological parameters of patients

Abstract Objectives To evaluate the number of AgNORs per nucleus and the expression of Ki-67 at the tumor invasion front (TIF) in relation to clinical parameters (TNM), TIF classification and the prognosis of oral squamous cell carcinomas in an Uruguayan population. Material and Methods This study was conducted through a retrospective survey from 2000 to 2010 at the National Institute of Cancer Montevideo, Uruguay and included 40 patients. The samples were obtained from the resection of the tumor and the TIF was defined according with Bryne, et al.5 (1992). Expression of Ki-67 was assessed by the percentage of positive tumor cells and the AgNOR was recorded as the mean AgNOR (mAgNOR) and the percentage of AgNOR per nucleus (pAgNOR). All analyzes were performed by a blinded and calibrated observer. Results No statistically significant association was observed between immunostaining of Ki-67 and AgNOR with the different types of TIF, regional metastasis and patients prognosis, however it was observed an increase in Ki-67 expression associated with worse patient's clinical staging, although not statistically significant. Conclusions Our results suggest that proliferation markers as AgNOR and Ki-67 are not prognostic markers at the tumor invasive front of carcinoma of oral squamous cell.

Cytogenetic abnormalities in exfoliated oral mucosal cells and their association with oral cancer.

OBJECTIVE: To assess cytogenetic abnormalities through quantification of micronuclei, broken eggs, and karyorrhexis, in cells from normal oral mucosa of individuals exposed to carcinogens (alcohol and tobacco) and adjacent to leukoplakias and squamous cell carcinomas. STUDY DESIGN: The sample was composed of 40 subjects aged > 30 years, divided into four groups: control, alcohol/tobacco, leukoplakia, and squamous cell carcinoma. For control and alcohol/tobacco groups, cells were collected from lower lip, tongue border, and floor of the mouth. For leukoplakia and squamous cell carcinoma groups, mucosa contralateral and adjacent to the lesions were analyzed. Cytologic smears were stained with the Feulgen reaction. A blind observer analyzed 1,000 cells per slide to quantify micronuclei, broken eggs, and karyorrhexis. RESULTS: The leukoplakia group showed an increased number of micronuclei compared to controls (p = 0.0016) and the alcohol/tobacco group (p = 0.0048) and also increased broken eggs compared to the alcohol/tobacco group (p = 0.0172). Similarly, the carcinoma group presented more micronuclei compared to controls (p = 0.0462) and more broken eggs compared to the alcohol/tobacco group (p = 0.0104). CONCLUSION: The assessment of cytogenetic abnormalities micronuclei and broken eggs may be useful for monitoring individuals exposed to risk factors for developing oral cancer.