Rat Tongue Research Articles

Evaluation of the effect of ozone olive oil and laser photobiomodulation on the tissue repair of traumatic ulcer on the rat tongue

ABSTRACT The objective of this study was to evaluate the effect of ozonized olive oil with or without laser photobiomodulation (LPBM) on the healing process of traumatic ulcers in rat tongues. Sixty male Wistar rats underwent tongue ulceration using a six-mm diameter punch. Animals were divided into four experimental groups: control-G1, LPBM-G2, Ozonized olive oil-G3, and LPBM + Ozonized olive oil-G4. Euthanasia was performed on days three, seven, and 14. Clinical analysis of the wound size and histomorphological evaluation using hematoxylin and eosin and Sirius red staining were conducted to identify edema, inflammatory infiltrates, fibroblastic cellularity, reepithelialization, and collagen characterization. Descriptive and exploratory analyses were performed using R and inferential statistics were calculated using Fisher’s exact tests, with a significance level of 5%. G2 and G3 positively modulated the repair phases clinically (p < 0.05) and histologically, showing reepithelialization, fibroblastic population, and thick collagen fiber deposition from the 3rd day of the experiment. G4 exhibited a significant difference from G1 in the clinical parameters (p < 0.05), but did not demonstrate superiority in histomorphological terms of tissue repair. Isolated use of LPBM and ozonized olive oil improved tissue repair in rat tongues.

Possible Effects of nutmeg oil versus propolis in treatment of chemical induced ulcer on papillae of tongue in albino rats. (Histological and Scanning Electron Microscopic study)

Possible Effects of nutmeg oil versus propolis in treatment of chemical induced ulcer on papillae of tongue in albino rats. (Histological and Scanning Electron Microscopic study)

Locally injected bone marrow-derived mesenchymal stem cells reverts the histopathological changes in the tongue of carbimazole-induced hypothyroidism of male rats

ObjectiveTo decipher the role of locally injected bone marrow mesenchymal stem cells (BM-MSCs) in the tongue of hypothyroid rats. DesignA total 24 male Wister rats were utilized and allocated into 3 groups (n = 8). As for the control group, rats received distilled water via oral gavage. In the hypothyroid group, rats administered carbimazole 5 mg/ 250 g/ day for 6 successive weeks, for hypothyroidism induction. The BM-MSC treated hypothyroid group (BM-MSC group); hypothyroid rats received local injection of 0.5 million BM-MSCs in tongue. Six weeks after BM-MSC injection, tongue samples were processed for Hematoxylin and eosin (H and E) staining, Ki67-immunohistochemistry and histomorphometric analysis. ResultsThe hypothyroid group revealed degenerative alterations in the lingual papillae, and apparent thinning of the inferior lingual epithelium compared to their controls. Tongues of the BM-MSC group depicted restoration of the normal tongue histology. The Ki67 immunoreaction was apparently decreased in the lingual epithelium of hypothyroid group compared to their controls, however the BM-MSC group regained Ki67 immunostaining. ConclusionOur data suggest that administration of BM-MSCs rescued the degenerative changes in the lingual mucosa and one of the possible underlying mechanisms could be the restoration of cellular proliferation in the lingual epithelium.

Mechanism underlying the anti-diabetic potential of bee venom as compared to bone marrow mesenchymal stem cells in the diabetic rat tongue.

Diabetes mellitus (DM) is a critical chronic metabolic disease. Several treatment modalities are currently under investigation. Both bee venom (BV) and bone marrow mesenchymal stem cells (BMSCs) can possibly offer an approach for treating type I diabetes. The aim of the present study was to investigate the mechanism underlying the anti-diabetic effect of BV as compared to BMSCs on the tongue mucosa of diabetic rats. A total of 52 male albino rats were used in the current study. The rats were randomly assigned into 4 groups: group 1 (control); group 2 (streptozocin (STZ)); group 3 (BV-treated); and group 4 (BMSC-treated). Diabetes mellitus was induced via an intraperitoneal (IP) injection of STZ in the rats from groups 2, 3 and 4. Following the diagnosis of DM, the rats in group 3 were injected with a daily dose of 0.5 mg/kg of BV, while the rats in group 4 were treated with a single injection of BMSCs. All rats were euthanized after 4 weeks, and their tongues were dissected and divided into halves. The right halves of the tongues were utilized for the histological examination, followed by morphometric analysis. In contrast, the left halves were used to detect the local gene expression of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF). Group 2 revealed marked disruption in the morphology of the fungiform and filiform papillae, and atrophic epithelial changes in both dorsal and ventral surface epithelium as compared to other groups. Group 4 showed a significantly larger number of taste buds, and a higher gene expression of TGF-β1 and VEGF as compared to groups 2 and 3. Additionally, BV and BMSCs effectively increased the thickness of dorsal and ventral surface epithelium as compared to group 2. Treatment with BMSCs was associated with significant improvement in the morphology and number of lingual epithelial cells and taste buds in the tongues of diabetic rats as compared to BV-treated rats, which was due to the local upregulation of TGF-β1 and VEGF gene expression.

Bisphosphonate's effect on the tongue in adult male albino rats and the possible protective role of rutin: light and scanning electron microscopic study.

Alendronate sodium (ALS) is a nitrogen-containing bisphosphonate used for the treatment of different bone disorders. However, its adverse effect on oral soft tissue has been detected. Rutin (RUT) is natural flavonoid with antioxidant and anti-inflammatory properties. This work aimed to investigate the possible effect of ALS on the tongue of adult male albino rats and to evaluate the possible protective role of RUT. Forty adult male albino rats were equally divided into four groups: group I (control), group II (RUT): Received RUT 50 mg/kg, group III (ALS): Received ALS 1 mg/kg, group IV (ALS+RUT): Received ALS and RUT with the same doses as pervious groups. The drugs were given once daily for 5 weeks. Tongue specimens were taken and processed for light and scanning electron microscopic inspection. ALS treated group revealed structural changes in the tongue in the form of decrease in the height of the filiform papillae with blunt ends, marked atrophy in some papillae with areas of focal loss, loss of some epithelial cells, pyknotic nuclei and cytoplasmic vacuoles in some epithelial cells. The lamina propria showed inflammatory cellular infiltration with congested blood vessels. Statistically, there were highly significant decrease in the number of proliferating cell nuclear antigen immunopositive cells, area percentage of Bcl-2 immunoexpression and highly significant increase in the collagen content compared to control group. Administration of RUT with ALS minimizes these changes. RUT protected the rat tongue against the histological and immunohistochemical changes induced by ALS through its antioxidant and anti-inflammatory properties.

One-Step Synthesis of Hydrogel Adhesive with Acid-Responsive Tannin Release for Diabetic Oral Mucosa Defects Healing.

The complex preparation, weak wet tissue adhesion, and limited biological activity of traditional oral wound dressings usually impede their efficient treatment and healing for diabetic oral mucosal defects. To overcome these problems, a novel hydrogel adhesive (named CFT hydrogel) is rapidly constructed using a one-step method based on dual-dynamic covalent cross-linking. Compared with the commercial oral patches, the CFT hydrogel shows superior in vivo (rat tongue) wet tissue adhesion performance. Additionally, the CFT hydrogel exhibits unique acid-responsive properties, thereby facilitating the release of bioactive molecule tannic acid in the acidic diabetic wound microenvironment. And a series of in vitro experiments substantiate the favorable biocompatibility and bioactivity properties (including antibacterial, antioxidative, anti-inflammatory, and angiogenetic effects) exhibited by CFT hydrogel. Moreover, in vivo experiments conducted on a diabetic rat model with oral mucosal defects demonstrate that the CFT hydrogel exhibits significant efficacy in protecting against mucosal wounds, alleviating inflammatory reactions, thereby facilitating the wound-healing process. Taken together, this study provides a promising and comprehensive therapeutic option with great potential for the clinical management of oral mucosa defects in diabetic patients.

Subcutaneous injection of hyaluronic acid leading to emboliom and recanalization process monitored in real time by three-dimensional photoacoustic imaging

This study describes a method for real-time examination of the microvascular system based on the three-dimensional photoacoustic imaging system to prevent arterial complications, especially vascular embolism, during hyaluronic acid (HA) injections. Chicken embryos were used to simulate the superficial blood vessels of human skin, and then the target area was imaged by the photoacoustic imaging system for three-dimensional vascular imaging, and then the syringe and blood vessels were monitored, and the syringe angle and penetration depth were adjusted in time using an injection device to avoid puncturing the arterial vasculature and clogging the blood vessels. HA was then injected into smaller vessels on the dorsum of the tongue in mice and into thicker vessels on the dorsal portion of the tongue in rats to mimic embolization, and the post-operative recovery was reflected by the changes in the pixel dots of the extracted part of the blocked blood vessels, and it was observed that the blood flow in the area of the fine vessels was restored in about 3 days, whereas blood flow in the area of the large vessels was restored in only about 1 h. The method presented in this paper allows precise guidance of injectable filler HA, which has good application prospects in improving the safety of injection micro-plastic surgery and reducing the experience requirements for medical personnel.

Evaluation of the use of chamomile in isolation and in association with laser photobiomodulation in the healing of rats oral mucosa.

Laser photobiomodulation (LPBM) has been shown to be one of the possible modulating agents of inflammation. Similarly, medicinal plants, such as chamomile (Matricaria recutita) are also used with the same purpose. To evaluate tissue repair in the dorsum of the tongue of rats under topical use of chamomile alone and in association with LPBM. Seventy-five male Wistar rats received a standardized wound on the dorsum of the tongue and were allocated into experimental groups: Control (G1), Chamomile Fluid extract (G2), Chamomile Infusion (G3), Laser (G4), Chamomile Infusion + Laser (G5). Euthanasia was done on days 3, 7, and 14 after surgery. Ulcers were evaluated and measured with a caliper. Sections stained with hematoxylin and eosin and Picrosirius Red allowed evaluation of edema, inflammatory infiltrate, cellularity, and re-epithelialization and characterization of total collagen. Histomorphometric analysis of the percentage of total collagen, the distance from the basal layer to the epithelial surface, and the thickness of the stratum corneum were performed. The G2 and G4 groups modulated the exudative and proliferative phases of inflammation, both clinically and histologically. The G3 and G5 groups did not show significant differences in relation to the G1 group in most of the evaluated parameters. Chamomile fluid extract and LPBM alone showed better clinical and histological responses for tissue repair than the association between these therapeutic modalities. There were differences in the parameters of clinical, histological, and histomorphometric patterns between the experimental groups of the present investigation. The LPBM proved to be superior in the performed analysis.

Ameliorating the toxic effect of the immunosuppressive drugs (Tacrolimus) on male Albino rat tongue by mesenchymal stem cells versus platelet rich plasma (histological, immunohistochemical and scanning electron microscopic study

Ameliorating the toxic effect of the immunosuppressive drugs (Tacrolimus) on male Albino rat tongue by mesenchymal stem cells versus platelet rich plasma (histological, immunohistochemical and scanning electron microscopic study

Delineation of the healthy rabbit tongue by immunohistochemistry – A technical note

In the oral cavity the tongue is an important muscular organ that supports the swallowing of food and liquids. It is responsible for the sense of taste, based on the many different taste buds it contains. Research in the field of tongue diseases demands for suitable preclinical models. The healthy rabbit tongue may therefore serve as baseline and reference for the pathological situation. With this consideration, we covered the fixation and histological stainings as well as the immunohistochemical labelling of the healthy rabbit tongue. In this technical note, initial choice of the fixative is discussed, with a comparison of formalin fixation and subsequent paraffin embedding versus cryopreservation. Moreover, we delineate the effect of an antigen retrieval step for formalin fixation by several examples. Finally, we provide ECM markers collagen I, collagen III, fibronectin, α-SMA and elastin staining as well as ki67 for proliferative status and PAR-2 protein expression as a marker for inflammatory status and nociception in tongue sections, mainly from the tongue body. Technically, we found superiority of paraffin sections for collagen I, collagen III, fibronectin, ki67 and α-SMA labelling, for selected detections systems. As for ECM components, the lamina propria was very rich in collagen and fibronectin, while the muscular body of the tongue showed only collagen and fibronectin positive areas between the muscle fibers. Moreover, α-SMA was clearly expressed in the walls of arteries and veins. The inflammatory marker PAR-2 on the other hand was prominently expressed in the salivary glands and to some extent in the walls of the vessels. Particular PAR-2 expression was found in the excretory ducts of the tongue. This technical note has the aim to provide baseline images that can be used to compare the pathological state of the diseased rabbit tongue as well as for inter-species comparison, such as mouse or rat tongue. Finally, it can be used for the comparison with the human situation.

PAR2-dependent phosphorylation of TRPV4 at the trigeminal nerve terminals contributes to tongue cancer pain

ObjectiveThis study aimed to clarify the interactions between the tongue and primary afferent fibers in tongue cancer pain. MethodsA pharmacological analysis was conducted to evaluate mechanical hypersensitivity of the tongues of rats with squamous cell carcinoma (SCC). Changes in trigeminal ganglion (TG) neurons projecting to the tongue were analyzed using immunohistochemistry and western blotting. ResultsSCC inoculation of the tongue caused persistent mechanical sensitization and tumor formation. Trypsin expression was significantly upregulated in cancer lesions. Continuous trypsin inhibition or protease-activated receptor 2 (PAR2) antagonism in the tongue significantly inhibited SCC-induced mechanical sensitization. No changes were observed in PAR2 and transient receptor potential vanilloid 4 (TRPV4) levels in the TG or the number of PAR2-and TRPV4-expressing TG neurons after SCC inoculation. In contrast, the relative amount of phosphorylated TRPV4 in the TG was significantly increased after SCC inoculation and abrogated by PAR2 antagonism in the tongue. TRPV4 antagonism in the tongue significantly ameliorated the mechanical sensitization caused by SCC inoculation. ConclusionsOur findings indicate that tumor-derived trypsin sensitizes primary afferent fibers by PAR2 stimulation and subsequent TRPV4 phosphorylation, resulting in severe tongue pain.

Age-related Changes in Rat Tongue

The effects of ageing on the oral mucosa are believed to be relatively small. The purpose of this study was to identify morphological changes observed in rat tongue during ageing in 20-day-old, 3-month-old, 12-month-old, 28-month-old, and 48-month-old rats. Age-related changes in the thickness of the epithelium and lamina propria, the density of the elastic fibres and the number of mast cells were histomorphometrically analyzed. In 20-day-old rats, the stratified squamous epithelium and lamina propria thicknesses were thinnest, whereas with age, epithelial thickness reached its greatest thickness in 48-month-old rats and lamina propria thickness was most noticeable in 12-month-old rats. The arrangement and distribution of elastic fibres were disrupted in the lamina propria with ageing. The density of elastic fibres in lamina propria was lowest in 20-day-old rats, while in 12-month-old rats they reached their highest density, and then decreased sharply again in older rats. The number of mast cells per unit area was lowest in 20-day-old rats, reaching its highest number in 12-month-old rats and remaining high in older animals. In conclusion, with age, there was a moderate positive correlation and a statistically significant increase in tongue epithelial thickness, as well as a significant thickening of the lamina propria and an increase in the number of mast cells. The density of the elastic fibres in lamina propria decreased, but no negative correlation was observed with ageing.

Histomorphometric Analysis of the Healing Capacity of Low-Level Laser on Thermally Induced Tongue Ulcers for Gamma-Irradiated Rats.

Objective: This study aimed to assess the efficacy of low-level laser therapy (LLLT) for treating thermal tongue ulcers in gamma-irradiated rats. Background: Postradiotherapeutic trauma may cause cell death, tissue damage, organ dysfunction, and loss of hematological components. Materials and methods: Thermal ulcers were induced on the dorsal surfaces of tongues of gamma-irradiated rats (15 Gy). Rats were divided into three groups, group 1 received no treatment, group 2 was subjected to a single dose of diode laser 807 nm with energy density 4 J/cm2, and group 3 was subjected to the same dose of LLLT but fractionated into three sessions at days 1, 3, and 5 after ulcers induction. Ulcers were assessed clinically for their areas and healing percentage. Specimens were examined for the quality of ulcer closure and expression of IL-1β and TGF-β1. Results: Results revealed significant improvement of ulcer healing clinically and histologically in both treatment groups compared to control. Moreover, IL-1β and TGF-β1 expression in both treatment groups was high at the earlier stage of healing then declined by time to reach a normal level. However, untreated group showed higher expression of IL-1β and TGF-β1 compared to treatment groups. In addition, IL-1β expression decreased by time but still of high level and TGF-β1 expression increased then declined. Conclusions: We concluded that gamma radiation-impaired mucosal healing could be related to the over expression of IL-1β and TGF-β1. LLLT, whether one session or fractionated, could be an effective treatment for postradiotherapeutic ulcers. The healing power of LLLT might be due to modulation of IL-1β and TGF-β1. Clinical Trial Registration number is 25A122.

Direct optogenetic activation of upper airway muscles in an acute model of upper airway hypotonia mimicking sleep onset.

Obstructive sleep apnea (OSA), where the upper airway collapses repeatedly during sleep due to inadequate dilator muscle tone, is challenging to treat as current therapies are poorly tolerated or have variable and unpredictable efficacy. We propose a novel, optogenetics-based therapy, that stimulates upper airway dilator muscle contractions in response to light. To determine the feasibility of a novel optogenetics-based OSA therapy, we developed a rodent model of human sleep-related upper airway muscle atonia. Using this model, we evaluated intralingual delivery of candidate optogenetic constructs, notably a muscle-targeted approach that will likely have a favorable safety profile. rAAV serotype 9 viral vectors expressing a channelrhodopsin-2 variant, driven by a muscle-specific or nonspecific promoter were injected into rat tongues to compare strength and specificity of opsin expression. Light-evoked electromyographic responses were recorded in an acute, rodent model of OSA. Airway dilation was captured with ultrasound. The muscle-specific promoter produced sufficient opsin expression for light stimulation to restore and/or enhance electromyographic signals (linear mixed model, F = 140.0, p < 0.001) and induce visible tongue contraction and airway dilation. The muscle-specific promoter induced stronger (RM-ANOVA, F(1,8) = 10.0, p = 0.013) and more specific opsin expression than the nonspecific promoter in an otherwise equivalent construct. Viral DNA and RNA were robust in the tongue, but low or absent in all other tissues. Significant functional responses to direct optogenetic muscle activation were achieved following muscle-specific promoter-driven rAAV-mediated transduction, providing proof-of-concept for an optogenetic therapy for patients with inadequate dilator muscle activity during sleep.

Age-related sex differences in tongue strength and muscle morphometry in a rat model

ObjectiveTo investigate potential effects of sex on voluntary tongue strength, evoked twitch and tetanic tension, speed of contraction, and muscle fiber cross-sectional area in the muscles of the rat tongue. Additionally, we aimed to determine whether estrous cycle stage impacts any of the dependent variables as a pilot investigation into the use of female rats in a model of tongue exercise and aging. DesignFischer 344-Brown Norway male and female rats in two age groups (16 middle-aged, 16 young-adult) were trained to use a tongue force operandum. Tongue muscle contraction, myosin heavy chain (MyHC) composition, and cross section area of the genioglossus and styloglossus muscles were examined. Vaginal lavage determined estrous cycle stage of the female rats daily. ResultsThe female group had significantly lower evoked twitch and tetanic tension, longer contraction times, and a smaller proportion of MyHC type IIa and MyHC type IIx in the styloglossus muscle. There was no significant sex effect in maximal voluntary tongue force (MVTF) despite a significant weight difference between the male and female groups. There were no significant age or sex effects in the genioglossus. Estrous cycle stage did not have a significant effect on any of the dependent variables. ConclusionsSex and age both have a significant effect on tongue muscle structure and physiology. While the female group showed reduced contraction speed and maximal twitch and tetanic tension relative to the male group, differences in muscle morphology appeared to vary by muscle.

The Potential Protective Effect of Curcumin Nanoparticles on Radiated Tongue of Male Albino Rats (Histological and Immunohistochemical Study)

The Potential Protective Effect of Curcumin Nanoparticles on Radiated Tongue of Male Albino Rats (Histological and Immunohistochemical Study)

Influence of Nanocurcumin and Photodynamic Therapy Using Nanocurcumin in Treatment of Rat Tongue Oral Squamous Cell Carcinoma Through Histological Examination and Gene Expression of BCL2 and Caspase-3.

Oral squamous cell carcinoma (OSCC) is the sixth most common mouth cancer in the world. The aim of the present study is comparing the effects of using Nanocurcumin, and photodynamic therapy (PDT), alone or together in treatment of OSCC in rats. Forty Wister male rats were divided into Control (group 1), 650 nm diode Laser only (group 2), Nanocurcumin alone (group 3), and PDT with a combination of laser with Nanocurcumin (group 4). Then, OSCC in the tongue induced by dimethylbenz anthracene (DMBA). The treatments were evaluated clinically, histopathologically, and immunohistochemically through BCL2 and Caspase-3 genes expression. Positive control with OSCC displayed significant weight loss, while PDT group gained more than nanocurcumin treated groups as well as laser groups comparing with control positive group. The histological examination of the tongue in PDT group showed improvement. In laser group, there were partial loss of surface epithelium with various ulcers and dysplasia and partial improvement by this type of treatment. The tongue in the positive control group showed ulcer in the dorsum surface with inflammatory cells, hyperplasia of the mucosa membrane around the ulcer (acanthosis) with increase of dentition, vacuolar degeneration of prickle cell layer and increase mitotic activity of basal cell layer together with dermal proliferation. Under the condition of the present study, PDT using nanocurcumin photosensitizer was effective in the treatment of OSCC regarding clinical, histological and gene expression of BCL2 and Caspase-3.

Normal and pathological ultrastructure of mucous membrane epithelium of the tongue of white rats

The aim of the research was to study the nature of the structural and functional features of the epithelium of the oral mucosa and the tongue of laboratory animals as a result of exposure to broadband red light. As a result of morphological and electron microscopic analysis of the structural changes of the oral mucosa of rats after exposure to broadband red light was revealed the absence of severe, irreversible changes in the epithelium, submucous layer and its components, the weak severity and reversibility of circulatory disorders in tissues. The data obtained allow to recommend the method of photokeratoscope for wider use in practice when treating patients with the burning mouth syndrome.

Evaluation of the effect of Matricaria recutita monotherapy or in combination with photodynamic therapy on tissue repair in the dorsum of the tongue of rats*

Evaluation of the effect of Matricaria recutita monotherapy or in combination with photodynamic therapy on tissue repair in the dorsum of the tongue of rats*

Betamethasone-loaded dissolvable microneedle patch for oral ulcer treatment

Oral inflammatory disease (OID) is among the most common oral lesions, affecting people’s quality of life and even leading to oral cancer. Oral ulcers are the most common OID. However, the pain and fear caused by the localized injection of hormones hinder the clinical treatment of oral ulcers. To address this problem, soluble hyaluronic acid (HA) microneedle patches (BSP-BDP@HAMN) containing betamethasone 21-phosphate sodium (BSP) and betamethasone 17,21-dipropionate (BDP) were fabricated for potential application in oral ulcers. BSP-BDP@HAMNs had the sufficient mechanical strength to penetrate the rat tongue abdomen mucosa with an insertion depth of approximately 207 ± 3 µm. The rapidly solubilized HA microneedle carrier released BSP and BDP into the ulcer base within 3 min of entering the mucosa. Cellular assays have shown that BDP@HAMNs have wound healing-promoting and anti-inflammatory effects. Compared with topical injections and creams, BSP-BDP@HAMNs not only penetrated the ulcer surface painlessly but also worked deep in the ulcer for a long time. In conclusion, the proposed BSP-BDP@HAMN patch can improve the comfort and efficacy of oral ulcer treatment, thus providing a new prospect for oral ulcer treatment.