Protective Effect of Ginseng on Salivary Dysfunction Following Radioiodine Therapy in a Mouse Model

Dynamic viscosity of the wall of the lacrimal sac in disorders of the patency of the lacrimal ducts

PURPOSE

To assess the dynamic viscosity of the lacrimal sac wall in patients with various origins of lacrimal duct obstruction.

METHODS

The study was performed in 35 cases: 21 cases with primary nasolacrimal duct obstruction (PANDO) and 14 cases with secondary nasolacrimal duct obstruction after radioiodine therapy (SALDO). The study of biomechanical properties of the lacrimal sac was carried out using a test bench. The principle of the study was to indent the sample at a given speed and record the data obtained from the sensor of the force transmitted to the sample. The area under the curve (AUC) and the peak viscosity were calculated. A qualitative characteristic of the obtained curve was given.

RESULTS

Median AUC in patients with PANDO was 17 × 106 [6 × 106; 19 × 106] N/m2 × s, in patients with SALDO 21 × 106 [13 × 106; 25 × 106] N/m2 × s. Intergroup differences were statistically significant (p = 0,048). The median peak viscosity in PANDO patients was 29 × 106 [25 × 106; 35 × 106] N/m2, in patients with SALDO 32 × 106 [21 × 106; 41 × 106] N/m2. The qualitative characteristics of the obtained curves differed.

CONCLUSION

Biomechanical properties of the lacrimal sac may vary depending on the cause of obliteration of the lacrimal ducts. The integrated dynamic viscosity is significantly higher in SALDO patients due to exposure to radioiodine compared to that in PANDO patients.

[Dacryocystorhinostomy with a counteropening in the treatment of secondary nasolacrimal duct obstruction after radioiodine therapy]

Among secondary forms of nasolacrimal duct obstruction caused by radioactive iodine therapy, its distal forms localized in the area of the Hasner's valve are predominant. In this regard, during dacryocystorhinostomy (DCR) there is a high probability of developing the sump syndrome, for which the anatomical prerequisite is that the lower edge of the DCR ostium is above the level of obstruction. In such cases, we propose to supplement DCR with a counteropening in the area of the Hasner's valve.

PURPOSE

This study analyzes the clinical effectiveness of dacryocystorinostomy with a counteropening.

MATERIAL AND METHODS

The outcomes of 49 surgeries (49 patients) with secondary acquired nasolacrimal duct obstruction due to radioactive iodine therapy were analyzed, including 34 DCR and 15 DCR with a counteropening. The clinical outcomes were analyzed over the longest possible period after surgery. The analysis included the severity of tearing on the Munk scale, the characteristic of the formed ostium on the M. Ali scale and the height of the tear meniscus. Differences were considered significant at a confidence level of 95% (p≤0.05).

RESULTS

Analysis of the results of the performed surgeries showed that DCR was clinically effective in 30 (88%) cases, DCR with a counteropening - in 15 (100%) cases. The differences were not statistically significant in the total sample, but were statistically significant when comparing the results of surgeries in patients with distal obliteration.

CONCLUSION

The developed and clinically tested method of DCR with a counteropening in the area of the Hasner's valve was completely effective in 15 patients with secondary nasolacrimal duct obstruction caused by radioiodine therapy.

The underlying mechanisms and strategies of DNA damage and repair in radiation sialadenitis

Radiation therapy is a critical strategy for the treatment of malignant tumors. X-ray external radiation has been successfully used to treat head and neck cancer. On the other hand, ¹³¹ I internal radiation has been effective in managing differentiated thyroid cancer. However, these therapies cause radiation damage to salivary glands. Radiation sialadenitis is the most common complication associated with radiotherapy applied to the head and neck and it severely affects patients' quality of life. Since DNA is the main intracellular target of radiation, and the integrity of the DNA structure is critical to genomic stability and the cellular survival of salivary glands, regulating radiation-induced DNA damage offers great promise in preventing and managing radiation sialadenitis. In this review, we summarize recent progress in DNA damage and repair in irradiated salivary glands.

Cell-derived vesicles from adipose-derived mesenchymal stem cells ameliorate irradiation-induced salivary gland cell damage

Introduction

Salivary gland (SG) damage is commonly caused by aging, irradiation, and some medications, and currently, no damage modifying agent is available. However, cell therapy based on mesenchymal stem cells (MSCs) has been proposed as a therapeutic modality for irradiated SGs. Therefore, we administered cell-derived vesicles (CDVs) of adipose-derived mesenchymal stem cells (ADMSCs) to irradiated SG cells to investigate their radioprotective effects in vitro.

Methods

The artificial CDVs were obtained from ADMSC by tangential flow filtration (TFF) purification and ultracentrifugation. Cultured human SG epithelial cells were exposed to 2, 5 or 15 Gy of 4 MV X-rays produced by a linear accelerator. The effects of ADMSC-CDVs on SG epithelial cells damaged by irradiation were tested by proliferation activity, transepithelial electrical resistance (TEER), and amylase activity.

Results

Exposure to penetrating radiation inhibited the proliferation of SG epithelial cells, but the radiation intensity required to reduce the proliferation of human submandibular gland epithelial cells (hSMGECs) was greater than required for other SG cells. ADMSC-CDVs restored the proliferative ability of SG epithelial cells reduced by irradiation, and the proliferation capacities of irradiated human parotid gland epithelial cells (hPGECs) and human sublingual gland epithelial cells (hSLGECs) were increased by administering ADMSC-CDVs to non-irradiated SG epithelial cells. Furthermore, amylase activity in irradiated hPGECs, hSMGECs, and hSLGECs was lower than in non-irradiated controls. However, amylase ability was restored in all by ADMSC-CDV treatment. Also, TEER was diminished by irradiation in hPGECs, hSMGECs, and hSLGECs and restored by ADMSC-CDV administration.

Conclusion

Overall, our findings demonstrate that ADMSC-CDVs have potent radioprotective effects on irradiated SG cells.

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ADMSC-CDVs restored the proliferation and amylase activity of SG cells damaged by irradiation.

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Reduced TEER in irradiated SG epithelial cells was restored by ADMSC-CDVs.

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ADMSC-CDVs have potent radioprotective effects on irradiated SG cells.

Radioprotective effects and mechanism of HL-003 on radiation-induced salivary gland damage in mice

Ionizing radiation (IR) can cause damage to the structure and function of salivary glands. Our research group independently synthesized the ROS scavenger, HL-003. The aim of this study was to explore the protective effects and underlying mechanisms of HL-003 on radiation-induced salivary gland injury. Salivary flow rate measurement, H&E staining, immunohistochemistry, FRAP, TUNEL, and western blotting were used to evaluate the radioprotective effect on salivary glands. The results showed that HL-003 protected the salivary secretion function by protecting the AQP-5 protein, on the salivary epithelial cell membrane, from IR damage. HL-003 reduced oxidative stress in the salivary gland by regulating the expression of ROS-related proteins NOX4, SOD2, and 8-OHdG. Furthermore, HL-003 downregulated the expression of p-p53, Bax, caspase 3, and caspase 9, and upregulated the expression of Bcl-2, suggesting that it could inhibit the activation of p53 to reduce cell apoptosis. In conclusion, HL-003 is an effective radioprotector that prevents damage of the radiation-induced salivary gland.

The Beneficial Impact of the Black Chokeberry Extract against the Oxidative Stress in the Sublingual Salivary Gland of Rats Intoxicated with Cadmium

Cadmium (Cd) is one of the most harmful xenobiotics to which humans are exposed, mainly by the oral route, throughout life. Preventive strategies are searched as low intoxication with this element, among others due to its prooxidative properties, can be deleterious to health and the exposure to it is continuously increasing. Recently, interest has been paid to plant raw materials with a high antioxidative potential to oppose the prooxidative properties of cadmium, such as black chokeberry (Aronia melanocarpa L. fruit), which is rich in polyphenolic compounds. The study was aimed at assessing whether the chokeberry extract may counteract the prooxidative impact of low-level and moderate repeated intoxication with cadmium on the sublingual salivary gland. The investigation was performed on 96 Wistar rats (females), which were treated with a 0.1% aqueous extract from chokeberries or/and a diet containing 1 or 5 mg Cd/kg for 3 and 10 months, and control animals. The intoxication with cadmium, in a dose- and time-dependent manner, attenuated the enzymatic and nonenzymatic antioxidative potential and increased the concentration of hydrogen peroxide and total oxidative status of the sublingual salivary gland resulting in an occurrence of oxidative stress, enhancement of lipid peroxidation, and oxidative injuries of proteins in this salivary gland. The treatment with the black chokeberry extract during the intoxication with cadmium prevented this xenobiotic-caused oxidative/reductive imbalance and oxidative modifications of proteins and lipids in the salivary gland. The above results allow the conclusion that the consumption of black chokeberry products during intoxication with cadmium can prevent oxidative stress and its consequences in the sublingual salivary gland and thus counteract the unfavourable impact of this xenobiotic on the oral cavity.

Therapeutic effect of various ginsenosides on rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is an autoimmune disease which causes disability and threatens the health of humans. Therefore, it is of great significance to seek novel effective drugs for RA. It has been reported that various ginsenoside monomers are able to treat RA. However, it is still unclear which ginsenoside is the most effective and has the potential to be developed into an anti-RA drug.

Methods

The ginsenosides, including Rg1, Rg3, Rg5, Rb1, Rh2 and CK, were evaluated and compared for their therapeutic effect on RA. In in vitro cell studies, methotrexate (MTX) and 0.05% dimethyl sulfoxide (DMSO) was set as a positive control group and a negative control group, respectively. LPS-induced RAW264.7 cells and TNF-α-induced HUVEC cells were cultured with MTX, DMSO and six ginsenosides, respectively. Cell proliferation was analyzed by MTT assay and cell apoptosis was carried out by flow cytometry. CIA mice model was developed to evaluate the therapeutic efficacy of ginsenosides. The analysis of histology, immunohistochemistry, flow cytometry and cytokine detections of the joint tissues were performed to elucidate the action mechanisms of ginsenosides.

Results

All six ginsenosides showed good therapeutic effect on acute arthritis compared with the negative control group, Ginsenoside CK provided the most effective treatment ability. It could significantly inhibit the proliferation and promote the apoptosis of RAW 264.7 and HUVEC cells, and substantially reduce the swelling, redness, functional impairment of joints and the pathological changes of CIA mice. Meanwhile, CK could increase CD8 + T cell to down-regulate the immune response, decrease the number of activated CD4 + T cell and proinflammatory M1-macrophages, thus resulting in the inhibition of the secretion of proinflammatory cytokine such as TNF-α and IL-6.

Conclusion

Ginsenoside CK was proved to be a most potential candidate among the tested ginsenosides for the treatment of RA, with a strong anti-inflammation and immune modulating capabilities.

Keratinocyte Growth Factor-1 Protects Radioiodine-Induced Salivary Gland Dysfunction in Mice

Background: Most patients with thyroid cancer suffer from salivary gland (SG) dysfunctions after radioiodine (RI) therapy. We investigated the effects of keratinocyte growth factor (KGF)-1 on RI-induced SG dysfunction in an animal model. Methods: Six C57BL/6 mice were assigned to each of the following groups: treatment naïve control group, RI group, and RI+KGF-1 group. Body and SG weights, salivary flow rates, salivary lag times and changes in 99mTc pertechnetate uptake and excretion were measured, and histologic changes were noted. Amylase activities and epidermal growth factor (EGF) concentrations in saliva were also measured. In addition, TUNEL assays were performed and apoptosis-related protein expressions were assessed. Results: RI-induced reductions in salivary flow rates and increases in salivary lag times observed in the RI group were not observed in RI+KGF-1 group. Mice in RI group had higher HIF1a levels than controls, but HIF1a levels in RI+KGF-1 group were similar to those in control group. Furthermore, mice in RI+KGF-1 group had more mucin stained acini and decreased periductal fibrosis than mice in RI group, and tissue remodeling of many salivary epithelial cells (AQP5) and endothelial cells (CD31) were observed in RI+KGF-1 group. Amylase activity and expression in saliva were greater in RI+KGF-1 group than in RI group, and fewer apoptotic cells were observed in RI+KGF-1 group. Furthermore, BCLxl (anti-apoptotic) expression was higher, and Bax (pro-apoptotic) expression was lower in RI+KGF-1 group than in RI group. Conclusions: Local delivery of KGF-1 might prevent RI-induced SG damage by reducing apoptosis.

Does Salivary Function Decrease in Proportion to Radioiodine Dose?

OBJECTIVES

This study was conducted to investigate the dose-response characteristics of radioiodine on salivary glands and to investigate the mechanism responsible for radioiodine-induced salivary glands toxicity.

METHODS

Twenty-four mice were divided into six groups: 0, 0.05, 0.10, 0.20, 0.40, and 0.80 mCi/20 g mouse, administered orally. Mortalities were noted 12 months after radioiodine administration. Body weights, gland weights, salivary lag times, flow rates, and changes in ^99m Tc pertechnetate were recorded. Histopathological changes and mRNA expressions were also evaluated, and immunohistochemical analysis and apoptotic assays were performed.

RESULTS

Survival rates, body weights, gland weights, and flow rates decreased, and lag times increased on increasing radioiodine dose. Animals administered radioiodine showed acinar atrophy, striated duct dilations, and lymphocytic infiltration in glands and irregular destruction of epithelial surfaces of tongue. The uptake and excretion of ^99m Tc pertechnetate were impaired by radioiodine. Immunohistochemical analysis showed that numbers of salivary epithelial, myoepithelial, and endothelial cells decreased and that numbers of ductal cells increased with radioiodine dose. Oxidative stress biomarker levels increased; reactive oxygen species scavenger levels decreased; and numbers of apoptotic cells increased in animals exposed to higher radioiodine doses.

CONCLUSION

These dose-related, long-term effects on salivary gland should be taken into account when determining radioiodine doses.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:2173-2178, 2020.

Fucoidan attenuates radioiodine-induced salivary gland dysfunction in mice

Background

Radioiodine (RI) treatments can destroy the cellular components of salivary glands (SG) and disrupt their function. This study investigated whether fucoidan could attenuate radioiodine-induced SG dysfunction in a mouse model.

Methods

Female C57BL/6 mice (n = 36) were classified into three groups; i) a normal (control) group, ii) an RI-treated group (0.2 mCi/20 g mouse, administered orally), and iii) a fucoidan and RI-treated group. Mice in each group were classified into three subgroups and sacrificed at 2, 4, and 12 weeks after RI treatment. The measurements of salivary flow rates and lag times and histomorphologic examinations were performed, and apoptotic assays were conducted. Changes in salivary ^99mTechnetium (Tc)-pertechnetate parameters using single-photon emission computed tomography were followed.

Results

Salivary flow rates and lag times in the fucoidan group were improved compared to the RI-treated group. Histologic examinations of SGs in the fucoidan group showed mucin-rich parenchymal areas and reduced periductal fibrosis as compared to the RI-treated group. Moreover, compared with the RI-treated group, fucoidan-treated groups showed evidence of cytoprotection, with a greater number of salivary epithelial cells and myoepithelial cells being observed. Fewer apoptotic cells were observed in the fucoidan group as compared to the RI group. The extent of ^99mTc pertechnetate excretion in the fucoidan group was similar to that of the control group.

Conclusion

Our results demonstrate that fucoidan administration before RI treatment could attenuate RI-induced SG damage and provides a possible candidate for preventing SG damage induced by RI.

Phenylephrine Alleviates 131I Radiation Damage in Submandibular Gland Through Maintaining Mitochondrial Homeostasis

PURPOSE

The impairment of the salivary glands is a permanent side effect of ¹³¹I ablation therapy for patients with differentiated thyroid cancer. Effective and safe treatments for protecting the salivary glands against ¹³¹I are currently not available. Mitochondria are susceptible to ionizing radiation, but alterations after ¹³¹I exposure are unknown. Here, we investigated the mechanisms of ¹³¹I damage in submandibular glands (SMGs) and evaluated the cytoprotective effect of phenylephrine (PE) against mitochondrial radiation damage.

METHODS AND MATERIALS

Rats were randomly divided into 4 groups: control, PE alone, ¹³¹I alone, and ¹³¹I with PE pretreatment. The mitochondrial structure of SMGs was observed under transmission electron microscopy. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Cytochrome c, cleaved-caspase 3, SIRT1, NAMPT, and PGC-1α protein levels were determined with Western blot and immunohistochemistry. Levels of mitochondrial membrane potential, nicotinamide adenine dinucleotide (NAD), and adenosine triphosphate (ATP) were measured with relevant kits.

RESULTS

After exposing rat SMGs to ¹³¹I, the mitochondrial membrane structures were destroyed, the mitochondrial membrane potential decreased, the release of cytochrome c increased, and cleaved-caspase 3 and cell apoptosis were activated. Moreover, the expression of SIRT1, NAMPT, and PGC-1α was downregulated, and the levels of NAD and ATP decreased. In contrast, PE alleviated the ¹³¹I-induced mitochondrial damages and upregulated the expression of SIRT1/NAMPT/PGC-1α and the levels of NAD and ATP.

CONCLUSIONS

These findings demonstrate that ¹³¹I impairs the salivary glands via the downregulation of SIRT1/NAMPT/PGC-1α signal pathways, which disturbs mitochondrial homeostasis. PE alleviated the ¹³¹I damage in SMGs at the mitochondrial level, suggesting that PE could be used as a potential radioprotector for patients with differentiated thyroid cancer with radiation sialadenitis.