Attenuating Effect of Vitamin E against Silver Nano Particles Toxicity in Submandibular Salivary Glands

Silver nanoparticles (AgNPs) are extensively used in many industries due to their superior antimicrobial properties. However, it is evident from many studies that AgNPs has cytotoxic potential through its effect on excessive formation of reactive oxygen species (ROS). The aim of this study was to examine the toxic effect of AgNPs on the submandibular salivary glands and the attenuating effect of vitamin E, as a natural antioxidant, against this toxicity. Thirty Albino rats were divided into 3 groups (n = 10): control group, AgNPs group receiving 2 mg/kg daily for 28 days, and AgNPs and vitamin E group receiving AgNPs the same as the previous group in addition to vitamin E at a dose of 100 mg/kg. Microscopic, ultrastructural, and cytokeratin immune-reactivity examination of the glands were performed. The AgNPs group showed noticeable degeneration in all structures of the gland as evident in the histological and ultrastructural examination. The AgNPs and vitamin E group revealed an improvement of the glandular elements. A significant increase in cytokeratin immune expression was found after comparison of both groups (p = 0.01). This current study shows that vitamin E has powerful antioxidant properties, which can combat the cytotoxic effect caused by AgNPs. Further studies are deemed necessary to confirm this finding using other immunohistochemical markers, such as myosin and E-cadherin.

THE EFFECT OF NERVE GROWTH FACTOR ON INDICATORS OF THE ANTIOXIDANT SYSTEM IN RAT BRAIN TISSUE

The work was to study the effect of nerve growth factor (NGF) on the parameters of the antioxidant system in the rat brain. From the submandibular salivary glands of male mice, we isolated and purified fractions with nerve growth activity. We study the effect of NGF on the parameters of the antioxidant system – catalase, superoxide dismutase (SOD), and malon dialdehyde (MDA). It was found that the activity of catalase increases at a concentration of NGF of 5 μg, with a further growth of concentration of NGF a decrease in the activity of the enzyme was observed. SOD activity tends to increase at NGF concentrations of 5 and 25 μg. The decrease in the content of MDA is pronounced with the introduction of various concentrations of NGF. Thus, the activity of antioxidant enzymes tends to be restored in the presence of NGF. Neuroprotectors can exhibit therapeutic efficacy of antioxidants in neurodegenerative diseases and ischemic brain damage.

LIPOPOLYSACCHARIDE-INDUCED SYSTEMIC INFLAMMATORY RESPONSE ENHANCES THE DEVELOPMENT OF OXIDATIVE-NITROSATIVE STRESS IN SALIVARY GLANDS OF RATS UNDER ALCOHOL DAMAGE

We addressed the role of lipopolysaccharide (LPS)-induced systemic inflammatory response (SIR) in the development of oxidative-nitrosative stress in the salivary glands of rats under the influence of alcohol. Ethanol (40%) at the dose of 24 mg/kg was administered intraperitoneally (ip) twice per day for 14 days. SIR was induced by ip administration of LPS (Salmonella typhi) at the dose 0.4 mg/kg for 1 week followed by a weekly LPS administration for 7 weeks. We found that long-term administration of ethanol in the back- ground of LPS-induced SIR increased the circulating level of proinflammatory markers (TNFa, IL-6) and C-reactive protein and this increase exceeded the respective values when LPS and alcohol were administered separately. Under these conditions, in submandibular salivary glands, the superoxide anion production by mitochondria respiratory chain was increased by 25.9 and 30.5%, by microsomal monooxygenases and NO synthase by 19.0 and 27,1%, by phagocyte NADPH-oxidase by 29.5 and 30.0%. The activity of inducible NO-synthase increased by 15.5 and 83.6%, the concentration of peroxynitrites of alkali and alkali-earth metals elevated by 32.5 and 58, 3%, and S- nitrosothiols raised by 20.2 and 22.7%. These changes were accompanied by a decrease in α-amylase activity and the aquaporin-5 concentration that impairs water and protein excretion by salivary glands. We conclude that adminis- tration of ethanol in the background of LPS-induced SIR results in more pronounced development of oxidative- nitrosative stress in the submandibular salivary glands and more marked dysfunction compared to separate use of LPS and alcohol.

RESIDUAL PHENOMENA OF THE TRANSFERRED COVID-19 IN THE MAXILLOFACIAL REGION OR ITS COMPLICATIONS

Today, the issues of the incidence of the Covid-19 virus and its complications are extremely relevant. Much attention in the scientific literature is paid to possible complications such as sufferings of the lungs, heart. Along with this, it became known that the coronavirus can affect the brain, nasopharynx, eyes, blood vessels, liver, kidneys and intestines. Interesting data from clinicians and morphologists has been received. Those who have had Covid-19 note the long-term effects of scarring of the lung tissue and kidney failure, inflammation of the heart muscle, arrhythmias, liver damage, cognitive impairment, psychosis, accompanied by a sharp change in mood. Interesting observations from the Department of Systems Biology at George Mason University were seen: 70% of patients who have had Covid-19 rarely observe pathology of internal organs. The purpose of our work was to highlight the complications from the large salivary glands in the patients who suffered from Covid-19. Objects and research methods. Our observations were carried out at the Poltava Center for Salivary Gland Pathology. There were only 17 patients. Three or four weeks ago, they reliably suffered from the disease. The function of the parotid salivary glands was studied using metal catheters, which were introduced into the mouth of the gland ducts for 10 minutes. The cellular composition of the secretion of the parotid glands was investigated according to the method generally accepted in cytology. 8 patients underwent ultrasound examination of salivary glands. Results. The antiviral and symptomatic treatment given to the patients eliminated the leading symptoms of the disease. At the time of completion of treatment, general somatic symptoms were eliminated and they were discharged healthy. 3 patients complained of dryness in the mouth, especially at night and in the morning. 4 patients complained of dry mouth, burning sensation in the eye area. In 5 patients, along with dryness in the mouth and nose, there was a complete lack of sense food taste. 5 patients complained of disorders of appearance. The parotid-masticatory areas were enlarged, we could observe dryness of the mucous membranes of the mouth and eyes. All patients had short-term or long-term headaches. Before the viral disease, none of the patients and their relatives had diseases of the salivary glands. Physical examination in 8 patients did not reveal any facial asymmetry. Palpation revealed slightly enlarged parotid salivary glands, slightly compacted, and slightly painful. The submandibular salivary glands were of normal consistency and were painless. These patients had a moderate amount of oral fluid in the mouth. Saliva of normal viscosity was released from the ducts of the parotid and submandibular glands. With sialometry of the parotid glands, there was a slight drop in secretion to 1.5 + 0.3 ml. Cytological examination of the secretion of the parotid glands determined a small number of cells of the columnar epithelium. Some of these cells had a tendency to necrosis; single squamous epithelial cells were found in the preparation. Conclusions. We evaluated the results of clinical examination data of 17 patients who had a viral Covid-19 infection and they were examined by us. In 3 - 4 weeks after recovery, there were complaints: dryness of the mucous membranes of the mouth, nose, conjunctiva of the eyes, loss food taste, enlargement of the parotid and submandibular salivary glands. It is possible to reliably state that patients have clinical phenomena of sialopathy. The results of additional studies of the secretion of the parotid glands, data of the cytology of their secretion and ultrasound examination confirm the secretory process in the glands of various degrees. The presence of elements of an inflammatory nature in the secret clearly defines the sialectatic process. The presence of headaches in the examined patients determines their probable vascular disorders in the components of the brain. Such changes can indirectly affect the vascular complex of the salivary glands and be the cause of the development of duct contractures and leads to sialadenosis. Perspectives. In order to examine this category of patients, the study of the features of blood circulation in the vessels of the brain and salivary glands should be considered to clarify the pathogenesis of sialadenosis.

EFFECT OF WATER-SOLUBLE QUERCETIN ON INDICATORS OF OXIDATIVE-NITROSATIVE STRESS IN TISSUES OF SUBMANDIBULAR SALIVARY GLANDS OF RATS UNDER LIPOPOLYSACCHARIDE-INDUCED SYSTEMIC INFLAMMATORY RESPONSE

The aim of this study was to investigate the effect of the water-soluble form of quercetin on the indicators of oxidative-nitrosative stress in the tissues of the submandibular salivary glands (SG) under conditions of lipopolysaccharide-induced systemic inflammatory response (SIR). The study was performed on 30 white Wistar male rats weighing 180-220 g, divided into 3 groups: 1st group included intact animals, 2nd group included animals, subjected to the systemic administration of lipopolysaccharide of Salmonella typhi, 3rd group involved animals, which received water-soluble quercetin complex with polyvinylpyrrolidone (corvitin) in a dosage of 100 mg/kg (10 mg/ g in terms of quercetin) intraperitoneally every 3 days, starting on the 30 day of the experiment with using S. typhi lipopolysaccharide. The latter was administered in a dose of 0.4 μg/kg body weight 3 times during the 1st week, and then once a week for the next 7 weeks. The study has demonstrated that applying quercetin under SIR restrains the production of reactive oxygen species in SG tissues: it reduces unstimulated production of superoxide anion radical and its induced generation with the administration of NADPH (by microsomes and NO-synthase), NADH (by mitochondria), S. typhi lipopolysaccharide (by leukocyte NADPH-oxidase). The administration of quercetin under SIR condition diminishes the signs of nitrosative stress in SG tissues, as evidenced by decrease in inducible NO-synthase activity without significant changes in ornithine decarboxylase activity and the level of coupling of constitutive isoform of NO-synthase, decreased concentration of highly active peroxynitrite, but, however, without significant shift in S-nitrosothiols content.

N-acetylcysteine supplementation did not reverse mitochondrial oxidative stress, apoptosis, and inflammation in the salivary glands of hyperglycemic rats

Background/objectives Previous studies have shown that N-acetylcysteine (NAC) supplementation with the simultaneous inclusion of HFD prevents salivary glands from oxidative stress and mitochondrial dysfunction. In this experiment, we examined if NAC supplementation could reverse the harmful effect of HFD on mitochondrial function, reduce the severity of apoptosis, and the activity of pro-oxidative enzymes in the salivary glands of rats with confirmed hyperglycemia. Subjects/methods Wistar rats were fed the standard or high-fat (HFD) diet for 10 weeks. After 6 weeks of the experiment, HFD rats were diagnosed with hyperglycemia and for the next 4 weeks, the animals were given NAC intragastrically. In the mitochondrial fraction of the parotid (PG) and submandibular salivary glands (SMG), we assessed redox status, inflammation, and apoptosis. Results The inclusion of NAC increased the activity of mitochondrial complexes I and II + III as well as decreased the concentration of interleukin-1β, tumor necrosis factor α, and caspase-3, but only in the parotid glands of rats with hyperglycemia compared to the HFD group. However, N-acetylcysteine supplementation did not reduce the activity of caspase-9 or the Bax/Bcl-2 ratio in PG and SMG mitochondria. In both salivary glands we observed reduced activity of cytochrome c oxidase, NADPH oxidase, and xanthine oxidase, as well as hindered production of ROS and lower ADP/ATP radio, but the levels of these parameters were not comparable to the control group. Conclusions We demonstrated that NAC supplementation restores the glutathione ratio only in the mitochondria of the submandibular salivary glands. The supply of NAC did not significantly affect the other measured parameters. Our results indicate that NAC supplementation provides little protection against free radicals, apoptosis, and inflammation in the salivary gland mitochondria of HFD rats. Stimulated salivary secretion in hyperglycaemic rats supplemented with NAC seems to be closely related to mitochondrial respiratory capacity and appropriate ATP level.

Qualitative ultrastructural analysis of the submandibular salivary glands after administration of khat: in vivo study

Objective Khat (Catha edulis Forssk) plant has been widely chewed for its psychostimulatory effects in the African and Arabian Peninsula, particularly in Yemen. Considering the khat leaves are gradually chewed without swallowing, while its active constituents are extracted into saliva, studying the effect of khat on salivary glands is necessary. This work is an extension of the previously published work that studied the effect of khat extract on the rats' submandibular salivary glands in terms of histological and immunohistochemical evaluations. The current research note aimed to better understand this effect on the ultrastructure of submandibular salivary gland cells by using transmission electron microscope. Results Oral administration of khat extract produced degenerative changes in the secretory and ductal cells of rats' submandibular salivary glands. These changes involved irregular boundaries of variable sized-nuclei, dilated RER, cytoplasmic vacuoles as well as swollen and degenerated mitochondria.