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.

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.