Rat Parotid Gland Research Articles

Tempol mitigates inflammation, oxidative stress, and histopathological alterations of cadmium-induced parotid gland injury in rats

Cadmium (Cd) is a potent environmental pollutant that causes functional and structural damage to the salivary glands. Tempol (TEM) has powerful antioxidant activity that can potentially preserve organ function. Aims: This study was designed to investigate the protective effects of TEM on Cd-induced toxicity in rat parotid salivary glands. Materials and methods: Twenty-four adult Wistar male rats were randomly assigned to four equal groups: control, TEM (27.5 g/100 ml), Cd (0.6 g/100 ml), and TEM plus Cd (at the same doses). All treatments were dissolved in distilled water and administered subcutaneously four times a week for four weeks. Parotid gland tissues were isolated and subjected to molecular and histo-biochemical assessments. Key findings: TEM exerted a prophylactic effect against Cd-induced toxicity in the parotid glands by controlling inflammation through the downregulation of toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor kappa B/ interleukin-1 beta mRNA expression, upregulation of aquaporin-5 mRNA expression, improvement of the oxidant/antioxidant status in the parotid gland, mitigation of endoplasmic reticulum stress, and repair of the associated histological and ultrastructural abnormalities. Significance: TEM protects against Cd-induced toxicity in the parotid glands of rats, attributable at least in part to its anti-inflammatory and antioxidant properties, as well as its ability to inhibit ER stress and facilitate glandular repair. However, the protective effects of TEM did not reach the levels observed in the control group. TEM could be a promising clinical candidate for protecting the salivary glands, particularly in high-risk groups such as workers exposed to Cd and cigarette smokers.

The effects of radiofrequency electromagnetic radiation emitted by mobile phones on rat parotid gland histology - an experimental study.

The advancement of telecommunication technology and devices promptly transformed mobile phones into indispensable objects in our day-to-day lives, but their biological effects remain unclear. Therefore, this study aimed to investigate the potential histopathological changes induced by mobile phone radiation in the parotid gland and the nearby tissues. Thirty female Rattus Norvegicus rats were divided into three groups: group 1 (exposed for 30 days), group 2 (exposed for 60 days), and control group (non-exposed). Each subject was exposed to mobile phone radiation in the form of a phone call for two hours every day for their subsequent exposure time. The exposure was always directed towards the same side of the face throughout the whole exposure period. At the end of the exposure period, a comprehensive examination was conducted, including inspection of the orofacial structures, tissue sections of the parotid glands, overlying skin, oral mucosa, and cervical lymph nodes, as well as obtaining smears from the oral cavity. To highlight the presence of micronuclei within the exfoliated squamous cells of the oral epithelium, Feulgen stain was performed. The results showed a significant activation of the fibroblasts in the parotid gland septa, in both exposed experimental groups, compared to the control group. We also detected significant cervical lymph node reactive changes, hyperkeratosis of the oral epithelium, and activated fibroblasts in the dermis and oral mucosa lamina propria in both experimental groups. Dermal fibrosis and lamina propria fibrosis were significantly increased in the second experimental group, compared to the control group. Moreover, vascular congestion in the parotid gland, dermal, and lamina propria fibrosis were significantly increased in the second study group compared to the first one. These findings suggest that exposure to mobile phone radiation may lead to pathological changes in the parotid gland and nearby tissues of experimental rats.

Does Radiofrequency Radiation From Mobile Phones Affect the Formation of Parotid Gland Malignancy? An Experimental Study.

Objectives: The use of mobile phone is increasing around the world. Although it is beneficial in terms of communication, the electromagnetic radiations emitted by mobile phones may cause undesirable biological effects on the human body. In practical use, the tissue with which mobile phones come into most and are closest is the parotid gland. This study investigated the effects of the 1800 MHz electromagnetic field created by a generator on the parotid gland in rats. Methods: A total of 21 Sprague-Dawley Albino rats were included in the study. The rats were randomly divided into three equal groups. To simulate a mobile phone in conversation mode, the first study group was exposed to an 1800-MHz electromagnetic field for 6 hours a day for 30 days, and the second study group was exposed to an 1800-MHz electromagnetic field for 12 hours a day for 30 days. After 30 days, rats were sacrificed, and histopathological and immunohistochemical methods were used to evaluate the effects on the parotid gland. The total antioxidant level and the total oxidant level were measured biochemically in homogenized parotid tissue. Results: Histopathological results showed an increase in degeneration in rats exposed to electromagnetic fields for 6 and 12 hours a day, and immunohistochemical analysis showed an increase in the apoptotic index in both study groups (P = .001, P < .001). Intranuclear inclusions was observed during histopathological examination performed by electron microscopy. Conclusions: This study observed that the 1800 MHz electromagnetic field caused undesirable adverse histopathological and biochemical effects on the parotid gland of rats. Histopathological and biochemical findings were detected with increasing contact and exposure time. This study will lead to other studies on this topic and contribute to the literature by completing other studies.

Possible Modulatory Role of Quercetin Flavonoid on Monosodium Glutamate-Induced Chronic Toxicity in Parotid Glands of Albino Rats (Histologic and ultrastructural study)

Possible Modulatory Role of Quercetin Flavonoid on Monosodium Glutamate-Induced Chronic Toxicity in Parotid Glands of Albino Rats (Histologic and ultrastructural study)

Histological and immunohistochemical evaluation for the role of bone marrow-derived mesenchymal stem cells to counteract the streptozotocin-induced diabetic changes in the rat parotid gland.

Histological and immunohistochemical evaluation for the role of bone marrow-derived mesenchymal stem cells to counteract the streptozotocin-induced diabetic changes in the rat parotid gland.

Correlation between the expression of the iNOS, caspase-3 and α-SMA genes in the parotid glands of albino rats following the administration of two antihistamines from two different generations.

Several medications, including antihistamines, can alter salivary gland function, causing dry mouth or xerostomia. Antihistamines are commonly used for treating allergic rhinitis. The aim of the present study was to compare and correlate the effects of first-generation vs. second-generation H1-antihistamines on the parotid glands of rats. Twelve adult male albino rats were used; 4 rats served as a control group (group I) and the remaining rats were divided into 2 groups: group II received promethazine hydrochloride; and group III received cetirizine dihydrochloride for 3 weeks. The parotid salivary glands were dissected, and examined histologically and analyzed histomorphometrically for the acinar area percentage. In addition, mRNA gene expression of iNOS, caspase-3 and α-SMA was assessed using quantitative realtime polymerase chain reaction (qRT-PCR). Finally, all the obtained data was statistically analyzed. Histologically, group I showed the typical architecture of the gland. In group II, degenerative changes were noticed, including acinar degeneration and shrinkage with widened connective tissue septa, intracellular vacuolization, and increased inflammatory cell infiltration. In group III, similar histological features were detected as in group II, but to a lesser extent. Histomorphometric results revealed significant differences in the acinar area percentage between various groups. In addition, qRT-PCR results showed a significant increase in iNOS expression in both groups II and III as compared to group I, caspase-3 gene expression was significantly increased in group II, while in group III, it increased non-significantly. Finally, α-SMA gene expression non-significantly decreased in both groups II and III. A significant positive correlation was observed between caspase-3 and iNOS gene expression, while an inverse correlation was noticed between caspase-3 and α-SMA gene expression. The administration of antihistamines resulted in changes in the rat salivary glands, which could be due to the induction of oxidative stress and the resultant apoptotic effect. These changes were suggested to occur mainly through action on muscarinic receptors; yet, action on histamine receptors could not be excluded. However; these effects were less marked with the second-generation antihistamine.

Effect of cevimeline and different concentration of gum arabic on parotid salivary gland function in methotrexate-induced xerostomia: a comparative study

ObjectiveThis study assessed the effect of cevimeline and different concentrations of gum arabic on the parotid gland of rats being given xerostomia-inducing methotrexate.MethodsOne hundred twenty-five rats were divided into five equal groups of twenty-five each. The rats in Group I received basic diets, while those in Groups II, III, IV, and V received 20 mg/kg MTX as a single intraperitoneal dose on day one. Group III received 10 mg/kg CVM dissolved in saline orally and daily, and the other two groups received a 10% W/V aqueous suspension of GA. Therefore, Group IV received 2 ml/kg suspension orally and daily, while Group V received 3 ml/kg suspension orally and daily. After 9 days, the parotid glands were dissected carefully and prepared for hematoxylin and eosin (H&E) staining as a routine histological stain and caspase-3 and Ki67 immunohistochemical staining. Quantitative data from α-Caspase-3 staining and Ki67 staining were statistically analysed using one-way ANOVA followed by Tukey’s multiple comparisons post hoc test.ResultsRegarding caspase-3 and Ki67 immunohistochemical staining, one-way ANOVA revealed a significant difference among the five groups. For Caspase-3, the highest mean value was for group II (54.21 ± 6.90), and the lowest mean value was for group I (15.75 ± 3.67). The other three groups had mean values of 31.09 ± 5.90, 30.76 ± 5.82, and 20.65 ± 3.47 for groups III, IV, and V, respectively. For Ki67, the highest mean value was for group I (61.70 ± 6.58), and the lowest value was for group II (18.14a ± 5.16). The other three groups had mean values of 34.4 ± 9.27, 48.03 ± 8.40, and 50.63 ± 8.27 for groups III, IV, and V, respectively.ConclusionGA, rather than the normally used drug CVM, had a desirable effect on the salivary glands of patients with xerostomia.

Effect of Propolis on Salivary Glands After Radiotherapy.

To investigate the effects of increasing propolis doses on salivary glands exposed to radiotherapy (RT). Thirty-seven rats were divided into 4 groups: The control group (G0, n: 7), G1 group (n: 10), G2 group (n: 10), and G3 group (n: 10). The rats in the G1 group received 15 Gray (Gy) RT only to the head and neck area. The rats in the G2 and G3 groups received 15 Gy RT for the head and neck area along with 100mg/kg/ml and 200mg/kg/ml of propolis. The parotid, submandibular, and sublingual glands of rats were immunohistochemically stained with aquaporin-1 (AQP-1) and aquaporin-5 (AQP-5). They were also evaluated for malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPO), total antioxidant (TAS), and total oxidant status (TOS). AQP-1 and AQP-5 values were highest in G0 group followed by G3, G2, and G1 groups in decreasing order. The MDA and TOS values were highest in G1 group, which was followed by G2, G3, and G0 groups. The highest GPO, SOD, and TAS values were observed in G0 group followed by G3, G2, and G1 groups in decreasing order. It was found that propolis increased antioxidant products and decreased oxidative products in the salivary glands receiving RT in parallel with the dose increase. Similarly, in the groups receiving propolis, an increase in the immune expression of aquaporin molecules was detected in a dose-dependent manner. Based on these data, it could be stated that propolis has a healing effect on the salivary glands exposed to RT.

The possible protective role of vitamin C on rat parotid gland exposed to mobile phone radiation

The widespread use of cell phones recently has raised interest in studying the safety of exposure to their electromagnetic waves. This study aimed to evaluate the possible protective role of vitamin C (Vit. C) against the pathological effects produced by the relatively long duration of third-generation mobile phone radiation exposure in the parotid gland of male white albino rats. Also, to detect the expected recovery after 4 weeks of withdrawal by immunohistochemical, histopathological, and biomolecular studies. Forty male adult white albino rats were used in this study, equally divided into 4 groups of 10 rats in each group: Group I served as the sham control group; Group II was exposed to radiation by phone generator (2100 MHz) for 3 hours/day for 5 days/week for 6 weeks; and Group III was exposed to phone radiation similar to Group II and supplemented with Vit. C at a dose of 40 mg/kg for 5 days per week for 6 weeks. Group IV (withdrawal) was exposed to radiation as Group II, then left without intervention for 4 weeks. Histological and immunohistochemical, and the biochemical evaluation of oxidative stress within parotid tissue (malonaldehyde (MDA), superoxide dismutase (SOD), salivary total protein, and amylase activity). qRT-PCR for TGF, MMP2, NFKB, and TNF gene expression was performed in this study. Histological examination of the parotid gland in group II showed many histological changes, such as degenerative changes in the duct system, epithelial lining of the acini, interstitial space which. different collagen fibers and polysaccharides, blood capillaries, and nuclei. Also, alpha smooth muscle actin (α-SMA) and Ki-67 were aggravated. The statistical analysis showed that treating rats with vitamin C improved the parotid glands’ ability to secrete amylase activity and total protein. It also fixed the antioxidant. Inflammatory cytokines TNF, NFKB, and fibrotic marker TGF and MMP2 gene expression were significantly upregulated in the exposed group, which was restored nearly to the control group after Vit C supplementation. Long-term exposure to mobile radiation affected. the. secretory function and the histological structure of the parotid tissues. Vitamin C supplementation ameliorated these pathological effects.

Aquaporin-5 Protein Is Selectively Reduced in Rat Parotid Glands under Conditions of Fasting or a Liquid Diet.

Aquaporin-5 (AQP5) water channel, transmembrane protein 16A (TMEM16A) Ca2+-activated Cl- channel, and Na+-K+-2Cl- cotransporter (NKCC1) are membrane proteins on salivary gland acinar cells that function in watery saliva secretion. We examined their expression changes in rat parotid glands under reduced mastication. Rats were either fed regular chow as a control group, fasted for 48 hr or fed a liquid diet for 48 hr or 1 week to reduce mastication. The parotid glands were then resected to analyze the protein and mRNA levels by immunofluorescence, immunoblotting, and reverse-transcription quantitative PCR (RT-qPCR). AQP5 protein was significantly decreased in both liquid diet groups and the fasting group but its mRNA levels showed no apparent changes compared with the control group. The protein and mRNA levels of TMEM16A and NKCC1 showed no significant changes between any of the groups other than an increase in NKCC1 mRNA in the 1-week liquid diet group. These results suggest that reduced mastication may increase the AQP5 protein degradation, but not that of other membrane proteins necessary for saliva secretion.

Experimental apical periodontitis alters salivary biochemical composition and induces local redox state disturbances in the salivary glands of male rats.

The objective was to evaluate the effects of experimental apical periodontitis on the inflammatory, functional, biochemical, and redox parameters of the parotid and submandibular glands in rats. Twenty 12-week-old male Wistar rats were randomly divided into two groups (n = 10): a control group and apical periodontitis group. After 28days, the saliva was collected for salivary flow rate and biochemistry composition. Both glands were sampled for quantification of the tumor necrosis factor-alpha (TNF-α) and biochemical analyses of redox state. TNF-α concentrations were higher in both salivary glands adjacent to the periapical lesions in animals with apical periodontitis and also compared to the control group. The apical periodontitis group increased the salivary amylase, chloride, potassium, calcium, and phosphate. The total oxidant capacity increased in the parotid gland adjacent to the periapical lesions in the same rat and compared to the control group. Conversely, the total antioxidant capacity of the parotid glands on both sides in the apical periodontitis group was lower than that in the control group. Furthermore, glutathione peroxidase activity increased in the submandibular gland adjacent to the apical periodontitis group compared to the control group. Experimental apical periodontitis alters salivary biochemical composition, in addition to increasing inflammatory marker and inducing local disturbances in the redox state in the parotid and submandibular glands of male rats. Apical periodontitis could exacerbate the decline in oral health by triggering dysfunction in the salivary glands.

Alterations in salivary biochemical composition and redox state disruption induced by the anticonvulsant valproic acid in male rat salivary glands

ObjectiveTo investigate the effects of the anticonvulsant valproic acid (VPA) on salivary glands in male rat using biochemical, functional, histomorphometric, and redox state parameters. Materials and methodsTwenty-four male Wistar rats were randomly distributed into three groups (n = 8 per group): Control (0.9% saline solution), VPA100 (100 mg/kg), and VPA400 (400 mg/kg). After 21 consecutive days of treatment with by intragastric gavage. Pilocarpine-induced saliva was collected to determine salivary flow rate, pH, buffering capacity, and biochemical composition. Analyses of histomorphometric parameters and redox balance markers were performed on the parotid and submandibular glands. ResultsSalivary flow rate, pH, buffering capacity, total protein, potassium, sodium, and chloride were similar between groups. However, phosphate and calcium were reduced in VPA400, while amylase was increased in both VPA100 and VPA400. We did not detect significant differences in the areas of acini, ducts, and connective tissue in the salivary glands between the groups. There were no significant changes in the redox status of the submandibular glands. In turn, in the parotid glands we detected reduced total oxidizing capacity and lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARs) and higher uric acid concentration in both the VPA100 and VPA400 groups, and increased superoxide dismutase (SOD) in the VPA400 group. ConclusionChronic treatment with VPA modified the salivary biochemical composition and caused disruption in the redox state of the parotid gland in rats.

Effects of liquid diet intake on nerve growth in salivary glands of growing rats.

The growth of parotid glands is inhibited by liquid diet intake during growing period, while that of submandibular glands is not affected. This study examined how liquid diet intake affects nerve growth in the parotid and submandibular glands of growing rats, because nerves are closely involved in the maintenance of salivary gland structure. Male Wistar rats were weaned at 21 days of age. Then, rats were fed a pellet diet and a liquid diet in the control group and experimental group, respectively. At 0, 2, 4, or 8 weeks, they were euthanised by isoflurane overdose, and parotid and submandibular glands were removed. The frozen sections were made and immuno-stained with anti-protein gene product 9.5 (PGP 9.5) antibody (general nerve marker), anti-tyrosine hydroxylase (TH) antibody (sympathetic nerve marker), or anti-neuronal nitric oxide synthase (nNOS) antibody (parasympathetic nerve marker). In control parotid glands, scattered punctate or short linear patterns of PGP 9.5-positive sites were observed at week 0. After 2 weeks, PGP 9.5-positive sites, some of which were arranged in long linear patterns, increased in number. There were some TH-positive sites at week 0. After 2 weeks, there were increasing numbers of TH-positive sites, often in long linear patterns. At week 0, there were very few nNOS-positive sites, and nNOS immunoreactivity increased over time. After week 4, they demonstrated linear patterns. In the experimental parotid glands, there were fewer PGP 9.5- and nNOS-positive sites than in control parotid glands at each time point, although TH immunoreactivity was similar between two groups at each time point. In control submandibular glands, few punctate exhibited PGP 9.5-positive site were observed at week 0. At week 4, PGP 9.5 immunoreaction increased and showed linear patterns. TH-positive sites demonstrated punctate or short linear patterns at week 0, and thereafter TH immunoreactivity increased and were arranged in long linear patterns. There were few nNOS-positive sites at week 0, and they gradually increased after week 4. The immunoreactivities of all antibodies in the experimental submandibular glands were similar to those in the control at each time point. Parasympathetic nerve growth in rat parotid glands was inhibited by liquid diet intake during the growth period, while liquid diet intake did not affect parasympathetic nerve growth nor sympathetic nerve growth in rat submandibular glands.

Radioprotective effects of melatonin and thymoquinone on liver, parotid gland, brain, and testis of rats exposed to total body irradiation.

This study aimed to investigate thymoquinone (TQ), and melatonin's radioprotective effects on liver, parotid gland, brain, and testis of rats which were exposed to total body irradiation (IR). Thirty adult Wistar rats were randomly divided into four groups that are Group 1 (control group): total body IR only, Group 2: IR-Melatonin (10 mg/kg), Group 3: IR-TQ (10 mg/kg), and Group 4 (sham group): nothing. Total body IR dose was 6 Gy. Tissue samples were taken 90 min after IR. The measurements of malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were performed in all groups. In IR group, GSH-Px and SOD activities significantly decreased whereas MDA levels significantly increased when compared with the sham in all tissues. We recorded a significant decrease in MDA levels in IR-TQ group in liver and parotid gland of rats. Moreover, SOD did not change in IR-TQ group compared with IR only group. Melatonin, a powerful antioxidant, plays role in preventing oxidative stress. We revealed that premedication with TQ significantly inhibited the increase in MDA induced by IR in liver and parotid gland and protected the activities of SOD, an antioxidant enzyme, in all other tissues. It has been revealed that TQ has a potential effect preventing IR-induced damage as much as melatonin.

Assessment of the toxic effects of levetiracetam on biochemical, functional, and redox parameters of salivary glands in male Wistar rats

Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to salivary gland dysfunction. Therefore, the current work investigated the effects of LEV on the biochemical, functional, and redox parameters of the parotid and submandibular glands in rats. For this, male Wistar rats (Rattus norvegicus albinus) were randomly divided into 3 groups (n = 10/group): Control (0.9% saline solution), LEV100 (100 mg/kg), and LEV300 (300 mg/kg). After 21 consecutive days of intragastric gavage treatments, pilocarpine stimulated saliva secretion was collected for salivary biochemical analysis. The extracted salivary glands were utilized for histomorphometry and redox state analyses. Our results showed that LEV300 increased plasma hepatotoxicity markers and reduced salivary amylase activity and the acinar surface area of the parotid gland. Total oxidant capacity and oxidative damage to lipids and proteins were higher in the parotid gland, while total antioxidant capacity and uric acid levels were reduced in the submandibular gland of the LEV100 group compared to Control. On the other hand, total oxidant capacity, oxidative damage to lipids and proteins, total antioxidant capacity, and uric acid levels were lower in both salivary glands of the LEV300 group compared to Control. Superoxide dismutase and glutathione peroxidase activities were lower in the salivary glands of treated animals compared to Control. In conclusion our data suggest that treatment with LEV represents a potentially toxic agent, that contributes to drug-induced salivary gland dysfunction.

Immunohistochemical investigation of nerve distribution in mature parotid and submandibular glands of rats with a liquid diet.

Although feeding with a liquid diet does not affect the growth of rat submandibular glands, it inhibits the growth of rat parotid glands during growth periods. In these growth-inhibited parotid glands, the growth of parasympathetic nerves is also suppressed. Meanwhile, the mature parotid glands of animals maintained on a liquid diet become morphologically and functionally atrophic, however, there is no effect of a liquid diet on mature submandibular glands. The objective of the present study was to clarify whether the nerve distribution in the mature salivary glands of rats was affected by a liquid diet. Seven-week-old male Wistar rats were used in this study. Half of the rats were kept on a pellet diet, and half were kept on a liquid diet, for 3, 7, 14, or 21 days. All rats were euthanised by isoflurane at each endpoint. Then, the parotid and submandibular glands were removed, frozen in liquid nitrogen, cryosectioned, and stained with antibodies against protein gene product 9.5 (PGP 9.5; general nerve marker), tyrosine hydroxylase (TH; sympathetic nerve marker), or neuronal nitric oxide synthase (nNOS; parasympathetic nerve marker). In parotid and submandibular glands of the pellet diet group, PGP 9.5- and TH-like immunoreactivity were seen around acini and ducts, and nNOS-like immunoreactivity was lower than PGP 9.5- and TH-like immunoreactivity. In the parotid glands of the liquid diet group, similar immunoreactivities were seen throughout the experimental period. The distribution of antibody labelling in the submandibular glands of the liquid diet group was similar to that of the pellet diet group and remained unchanged during the experimental period. The present study demonstrated no regressive effects of a liquid diet on the distribution of sympathetic or parasympathetic nerves in mature parotid glands and submandibular glands. This differed from inhibitory effects on the growth of parotid glands seen during growth periods.

The effects of eugenol on histological, enzymatic, and oxidative parameters in the major salivary glands and pancreas of healthy male Wistar rats

ObjectiveWe evaluated the effects of eugenol on histological, enzymatic, and oxidative parameters in the pancreas, parotid, submandibular, and sublingual glands of healthy male rats. DesignTwenty-four adult Wistar rats were assigned into four groups (n = 6/group). Control rats received 2% Tween-20 (eugenol vehicle), whereas the other animals received 10, 20, and 40 mg kg−1 eugenol through gavage daily for 60 d. Major salivary and pancreatic glands were weighed and preserved fixed for microscopic analysis and frozen for in vitro assays. ResultsEugenol did not alter glands’ weight and serum amylase activity regardless of the concentration. The highest dose of eugenol caused an increase in pancreatic amylase activity and a reduction of lipase activity from serum and pancreas. Eugenol at 40 mg kg−1 diminished the activity of SOD and FRAP in the submandibular gland and CAT and FRAP in the sublingual gland. However, it did not exert any effect on GST regardless of the gland. Additionally, 40 mg kg−1 eugenol increased MDA levels in pancreatic, parotid, and submandibular glands and NO levels in the sublingual. The concentrations of eugenol induced distinct responses in the glands regarding the activity of Na+/K+, Mg2+, and total ATPase activity. They also affected histomorphometrical and histochemistrical parameters in the submandibular gland only. ConclusionsResults indicated that 40 mg kg−1 eugenol altered most of the biochemical and oxidatived parameters of digestive glands. Only submandibular glands presented histological changes after eugenol exposure suggesting potential implications for its function.

Histological and immunohistochemical study on the possible ameliorating effects of antox on the parotid gland of rats with Streptozotocin- Induced Diabetes Mellitus Type 1

Histological and immunohistochemical study on the possible ameliorating effects of antox on the parotid gland of rats with Streptozotocin- Induced Diabetes Mellitus Type 1

The Metabolic Effects of High-fructose Corn Syrup in Dental Tissues and Parotid Glands of Rats and the Therapeutic Effect of Alpha Lipoic Acid

The Metabolic Effects of High-fructose Corn Syrup in Dental Tissues and Parotid Glands of Rats and the Therapeutic Effect of Alpha Lipoic Acid

Histological and biochemical evaluation of the effects of silver nanoparticles (AgNps) versus titanium dioxide nanoparticles (TiO2NPs) on rat parotid gland

ABSTRACT The unlimited use of nanoparticles (NPs) results in toxic impacts on different tissues. The current study aimed to compare the adverse effects of AgNPs and TiO2NPs on the parotid gland of adult male albino rats as regards the histopathological, immunohistochemical, and biochemical changes, exploring the possible underlying mechanisms and the degree of improvement after cessation of administration. Fifty-four adult male albino rats were divided into control group (I), AgNPs-injected group (II), and TiO2NPs-injected group (III). We measured the levels of tumor necrosis factor-alpha (TNF-α) and interleukin (IL-6) in the serum, and levels of MDA and GSH in parotid tissue homogenate. Quantitative real-time polymerase-chain reaction (qRT-PCR) was used to measure the expression levels of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1-α), nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), mouse double minute 2 (MDM2), Caspase-3 Col1a1, and Occludin. Parotid tissue sections were examined by light microscope (Hematoxylin & Eosin and Mallory trichrome stains), electron microscope, and immunohistochemical examination of CD68 and anti-caspase-3 antibodies. Both NPs severely affected the acinar cells and damaged the tight junction between them by enhancing expression of the inflammatory cytokines, inducing oxidative stress, and disturbing the expression levels of the studied genes. They also stimulated fibrosis, acinar cell apoptosis, and inflammatory cells infiltration in parotid tissue. TiO2NPs effects were less severe than AgNPs. Cessation of exposure to both NPs, ameliorated the biochemical and structural findings with more improvement in TiO2NPs withdrawal. In conclusion: AgNPs and TiO2NPs adversely affected the parotid gland, but TiO2NPs were less toxic than AgNPs.