Will Nigella sativa oil protect parotid glands of rats against cranium gamma irradiation? Histological and immunohistochemical evaluation.

BACKGROUND: Radiation plays an essential role in treating malignancies. Radiation exposure of salivary glands often results in permanent loss of their functions; therefore, their protection against radiation is crucial. Nigella sativa oil (NSO) is a useful antioxidant against free radicals. The purpose of this study was to investigate the radio-protective effect of NSO on oxidative injury of parotid glands of gamma-irradiated rats. METHODS: Twenty-eight male albino rats were divided into four groups (n = 7): Group 1: Neither NSO nor radiation, Group 2: Rats received NSO 400 mg/kg, Group 3: Rats received 15 Gy cranium gamma irradiation & Group 4: Rats received gamma irradiation and NSO. Rats were sacrificed two weeks after the last NSO dose. Histological sections of parotid glands were stained with H&E, Masson's trichrome and anti-TGF-ß antibodies. Area percentage of Masson's trichrome and TGF-ß expression was morphometrically examined. RESULTS: Parotid glands of control and NSO groups revealed normal morphology. Gamma-irradiated glands showed loss of normal acinar architecture and slight acinar shrinkage. NSO treatment of gamma-irradiated glands preserved acinar outline and architecture. Masson's trichrome stained samples revealed trace amounts of collagen fibers in control and NSO groups, and excessive amounts of collagen fibers in gamma-irradiated group, in addition to few collagen fibers for gamma-irradiated glands treated with NSO. Additionally, control and NSO groups showed negative TGF-ß expression. Gamma-irradiated group showed high TGF-ß expression, while NSO treated gamma-irradiated group showed moderate TGF-ß expression. CONCLUSIONS: Gamma-irradiation adversely affected parotid glands, and in contrast, NSO seemed to positively counteract this adverse effect.

Iron overload induced submandibular glands toxicity in gamma irradiated rats with possible mitigation by hesperidin and rutin.

BACKGROUND: Radiation triggers salivary gland damage and excess iron accumulates in tissues induces cell injury. Flavonoids are found in some fruits and are utilized as potent antioxidants and radioprotective agents. This study aimed to evaluate the antioxidant and anti-inflammatory effects of hesperidin and rutin on gamma radiation and iron overload induced submandibular gland (SMG) damage and to evaluate their possible impact on mitigating the alteration in mTOR signaling pathway and angiogenesis. METHODS: Forty-eight adult male Wistar albino rats were randomly assigned to six groups: group C received a standard diet and distilled water; group H received hesperidin at a dose of 100 mg/kg; four times a week for four weeks; group U received rutin at a dose of 50 mg/kg; three times a week for three weeks; group RF received a single dose (5 Gy) of gamma radiation followed by iron at a dose of 100 mg/kg; five times a week for four weeks; group RFH received radiation and iron as group RF and hesperidin as group H; group RFU received radiation and iron as group RF and rutin as group U. SMG specimens from all groups were removed at the end of the experiment; and some were used for biochemical analysis, while others were fixed for histological and immunohistochemical examination. RESULTS: In the RF group, several genes related to antioxidants (Nrf-2 and SOD) and DNA damage (BRCA1) were significantly downregulated, while several genes related to inflammation and angiogenesis (TNFα, IL-1ß and VEGF) and the mTOR signaling pathway (PIK3ca, AKT and mTOR) were significantly upregulated. Acinar cytoplasmic vacuolation, nuclear pyknosis, and interacinar hemorrhage with distinct interacinar spaces were observed as histopathological changes in SMGs. The duct system suffered significant damage, eventually degenerating entirely as the cells were shed into the lumina. VEGF and NF-κB were also significantly overexpressed. Hesperidin and rutin cotreatment generated partial recovery as indicated by significant upregulation of Nrf-2, SOD and BRCA1 and considerable downregulation of TNF-α, IL-1ß, VEGF, PIK3ca, AKT, and mTOR. Although some acini and ducts continued to deteriorate, most of them had a normal appearance. There was a notable decrease in the expression of VEGF and NF-κB. CONCLUSIONS: In γ-irradiated rats with iron overload, the administration of hesperidin and rutin may mitigate salivary gland damage.

The efficacy of using metformin and/or quercetin for amelioration of gamma-irradiation induced tongue toxicity in diabetic rats.

BACKGROUND: Diabetes is a common disease that cancer patients may suffer from and may aggravate side effects of radiotherapy. This study aimed to detect whether metformin and/or quercetin will improve gamma-irradiation induced tongue toxicity in diabetic rats. METHODS: 35 male albino rats were divided into five groups; NOR no streptozotocin, no radiation and no treatment was given, DR rats were subjected to streptozotocin then gamma-irradiation, DRM rats were subjected to streptozotocin then gamma-irradiation then metformin, DRQ rats were subjected to streptozotocin then gamma-irradiation then quercetin, DRMQ rats were subjected to streptozotocin then gamma-irradiation then metformin and quercetin. Rats were euthanized 24 h after last treatment dose. Mean blood glucose level was recorded. Tongue specimens were stained with H&E and CD68. Histomorphometric analysis of length, diameter and taste buds of lingual papillae and epithelial, keratin and lamina propria thickness and CD68 positive cells were calculated. RESULTS: Blood glucose level of DRMQ was significantly lower than DR, DRM and DRQ, whereas higher than NOR. Metformin or quercetin partially restored tongue structure, papillae length and diameter and tongue layers thickness. The ameliorative effect was superior when metformin and quercetin were used together. Diabetes and irradiation significantly increased number of CD68 positive macrophages in submucosa and muscles. Metformin or quercetin significantly reduced number of lingual macrophages with more noticeable effect for quercetin. Treatment with metformin and quercetin significantly decreased number of macrophages. CONCLUSIONS: Combined use of metformin and quercetin might help mitigate the harmful effects of radiotherapy and diabetes on lingual tissues.

Vitamin E ameliorates oral mucositis in gamma-irradiated rats (an in vivo study).

BACKGROUND: Radiation therapy is the primary treatment for neck and head cancer patients; however, it causes the development of oral mucositis accompanied by tissue structure destruction and functional alteration. This study was conducted to evaluate the effect of different doses of vitamin E as a treatment for radiationinduced oral mucositis in rat model. METHODS: 35 male albino rats were randomly divided into five groups: control, untreated radiation mucositis (single dose of 20 Gy), treated radiation mucositis; radiation (single dose of 20 Gy) then vitamin E at doses of 300, 360 and 500 mg/Kg for seven days started 24 h after irradiation. Body weight and food intake were evaluated for each rat. The mucositis score was assessed every day. Rats were sacrificed once at the end of the experiment, and tongue specimens were stained with hematoxylin and eosin, anti P53 and anti Ki67 antibodies. RESULTS: Results indicated more food intake and less weight reduction in vitamin E treated groups and the contrary for gamma-irradiated group. Additionally, vitamin E delayed the onset and decreased the severity and duration of mucositis. It also restored the histological structure of lingual tongue papillae. Vitamin E treated groups showed a significant higher Ki67 and lower P53 expression as compared to untreated radiation group. The overall improvement increased as vitamin E dose increased. Finally, the amelioration can be attributed to the decreased apoptosis and increased proliferation of cells. CONCLUSIONS: Vitamin E especially at dose of 500 mg/Kg could be an effective treatment for radiation-induced oral mucositis.

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-1ß and TGF-ß1. Results: Results revealed significant improvement of ulcer healing clinically and histologically in both treatment groups compared to control. Moreover, IL-1ß and TGF-ß1 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-1ß and TGF-ß1 compared to treatment groups. In addition, IL-1ß expression decreased by time but still of high level and TGF-ß1 expression increased then declined. Conclusions: We concluded that gamma radiation-impaired mucosal healing could be related to the over expression of IL-1ß and TGF-ß1. 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-1ß and TGF-ß1. Clinical Trial Registration number is 25A122.

Possible radioprotection of submandibular glands in gamma-irradiated rats using kaempferol: a histopathological and immunohistochemical study.

BACKGROUND AND PURPOSE: Salivary gland damage remains a problem despite advances in radiotherapy schedules for head and neck cancer. Kaempferol, a natural flavonoid, found in several fruits and vegetables, is a good antioxidant. This study was designed to evaluate the possible protective effects of kaempferol on submandibular glands (SMGs) of rats exposed to fractionated gamma irradiation. MATERIALS AND METHODS: Twenty-four male adult Wistar albino rats were included in this study and assigned to three groups (n = 8). Rats in group K received kaempferol orally in five doses at a dose of 10 mg/kg/2 days for 10 days. Meanwhile, rats in group R were subjected to fractionated whole-body gamma irradiation at a dose of 2 Gy/5 days/week for 2 weeks (20 Gy), and the KR group received kaempferol as group K and then was subjected to a fractionated whole-body gamma irradiation as group R. SMG samples were collected on days 1 and 7 after the last radiation session; and processed for histopathological and immunohistochemical investigations. RESULTS: The SMGs of group R showed focal atrophy and degeneration. Acini showed vacuolization and had pyknotic hyperchromatic nuclei. Striated ducts degenerated, shrunken, and were surrounded by empty spaces. The percentage of areas covered by cyclooxygenase-2 (COX-2) significantly increased, whereas the percentage of areas covered by proliferating cell nuclear antigen (PCNA) significantly decreased compared with those in group K. Cotreatment with kaempferol (group KR) partially preserved normal gland architecture where acinar vacuolation and degeneration were almost absent; however, some ducts degenerated. A significant decrease in the percentage of areas covered by COX-2 and a significant increase in the percentage of areas covered by PCNA were observed compared with those in group R. CONCLUSIONS: Kaempferol has a possible radioprotective effect on the SMGs of rats exposed to fractionated gamma irradiation.

Microhardness and Ultrastructure of Demineralized Gamma-Irradiated Human Enamel after Diode Laser (980 nm) and Fluoride Surface Treatment

Abstract Quality of life drastically diminished after radiotherapy due to radiation induced oral complications. Fluoride was found to be helpful in decreasing the incidence of radiation caries; however it has not led to elimination of dental caries. Thus, new techniques containing low fluoride concentration or not containing fluoride at all, as laser irradiation, have been studied to prevent the beginning or progression of caries. So the purpose of this study is to investigate the effect of laser surface treatment with or without fluoride on microhardness and ultrastructure of demineralized gamma irradiated enamel; Thirty enamel slabs were allocated into three groups (n=10): G slabs were subjected to gamma irradiation only; GL slabs were subjected to gamma irradiation followed by diode laser and GFL slabs were subjected to gamma irradiation followed by fluoride then diode laser. Slabs were then exposed to demineralizing solution for 72 hours. Examination of slabs was performed using vickers microhardness test and scanning electron microscope; The lowest microhardness was recorded in group G, while inGL and GFL groups it significantly increased. Scanning electron microscope revealed a pronounced loss of central prism core and retention of prism peripheries in group G. Confluence of prismatic and interprismatic structures in GL slabs and irregular rough surface with prismatic boundaries conservation in GFL slabs were detected. Applying laser improved the microhardness and counteracted the adverse effect of gamma radiation. Adding fluoride before laser irradiation had a marked effect on microhardness..

Therapeutic effect of Aloe vera and silver nanoparticles on acid-induced oral ulcer in gamma-irradiated mice.

Radiation combined injury, a life-threatening condition, has higher mortality than simple radiation injury. The aim of the present study was to analyze the efficiency of Aloe vera and silver nanoparticles in improving the healing of ulcerated oral mucosa after irradiation. Thirty male Albino mice were divided into five groups: control, radiation, Aloe vera (AV), silver nanoparticles (NS), and AV+NS. The mice were exposed to whole body 6Gy gamma-radiation. After one hour, 20% acetic acid was injected into the submucosal layer of the lower lip for ulcer induction. The animals received topical treatment with the assigned substances for 5 days. Lip specimens were subjected to hematoxylin and eosin and anti alpha-smooth muscle actin immunohistochemical staining. Results demonstrated occurance of ulcer three days post irradiation in all groups except in the AV+NS group where only epithelial detachment was developed. After seven days, data revealed persistent ulcer in radiation group, and almost normal epithelium in the AV+NS group. A significant reduction of epithelial thickness was detected in all groups at the third day as compared to control. At the seventh day, only the AV+NS group restored the epithelial thickness. Area percent of alpha-smooth muscle actin expression was significantly decreased in radiation group at the third day followed by significant increase at the seventh day. However, all treatment groups showed significant increase in alpha-smooth muscle actin at the third day, which decreased to normal level at the seventh day. Our study demonstrated the efficiency of Aloe vera and silver nanoparticles in enhancing ulcer healing after irradiation.

Therapeutic effect of Aloe vera and silver nanoparticles on acid-induced oral ulcer in gamma-irradiated mice

Abstract Radiation combined injury, a life-threatening condition, has higher mortality than simple radiation injury. The aim of the present study was to analyze the efficiency of Aloe vera and silver nanoparticles in improving the healing of ulcerated oral mucosa after irradiation. Thirty male Albino mice were divided into five groups: control, radiation, Aloe vera (AV), silver nanoparticles (NS), and AV+NS. The mice were exposed to whole body 6Gy gamma-radiation. After one hour, 20% acetic acid was injected into the submucosal layer of the lower lip for ulcer induction. The animals received topical treatment with the assigned substances for 5 days. Lip specimens were subjected to hematoxylin and eosin and anti alpha-smooth muscle actin immunohistochemical staining. Results demonstrated occurance of ulcer three days post irradiation in all groups except in the AV+NS group where only epithelial detachment was developed. After seven days, data revealed persistent ulcer in radiation group, and almost normal epithelium in the AV+NS group. A significant reduction of epithelial thickness was detected in all groups at the third day as compared to control. At the seventh day, only the AV+NS group restored the epithelial thickness. Area percent of alpha-smooth muscle actin expression was significantly decreased in radiation group at the third day followed by significant increase at the seventh day. However, all treatment groups showed significant increase in alpha-smooth muscle actin at the third day, which decreased to normal level at the seventh day. Our study demonstrated the efficiency of Aloe vera and silver nanoparticles in enhancing ulcer healing after irradiation.