ABSTRACT
Damage to the salivary glands is a well known sequela of radiotherapy in humans, while ionizing radiation penetrates the living matter, it gives up its energy by random interactions with atoms and molecules in its way resulting in the formation of reactive ions and free radicals that hits and damage cells and tissue. However, it was found that antioxidants can efficiently scavenge and even neutralize free radicals making them harmless. The present study was performed to evaluate the protective effects of two different antioxidant agents on irradiated rat submandibular salivary glands. Animals were divided into 4 groups. In group I Animals were used as control, in group II rats received fractionated gamma radiation in three sessions for 3 consecutive days. In group III silymarin [Silybum marianum] which is a medicinal plant was orally given one week before radiation, during radiation and one week after radiation. In group IV Ethanolic extract of brassica seeds [Oleracca Var Capitata] one of the cruciferous vegetables was orally administrated also one week before radiation, during radiation and one week post radiation. Histological study revealed that silymarin alleviated the manifestations of radiation injury in the salivary glands acini as compared with the untreated animals and also with those who received the ethanolic extract of brassica seeds. Immunohistochemically we observed a marked redistribution of Alfa smooth muscle actin as well as a reduction of the proliferating rate of acinar cells especially in untreated animals. Morphometric studies correlated well with the structural impairment manifested histologically and immunohistochemically. All used investigation tools confirmed that silymarin antioxidant agent can effectively ameliorate the submandibular salivary gland response to gamma radiation