Effect of Ocimum sanctum, turmeric extract and vitamin E supplementation on the salivary gland and bone marrow of radioiodine exposed mice.

Significant increase in the salivary gland weight was observed after exposure to single therapeutic dose of 3.7 MBq of 131I in mice. Pre-supplementation of antioxidants, O. sanctum leaf extract, turmeric extract and vitamin E for 15 days before 131I exposure demonstrated significant reduction in the salivary gland weight. No major histopathological changes were observed in the salivary gland of experimental animals at 24 h of exposure. Micronuclei index in the bone marrow of polychromatic (PCEs) and normochromatic erythrocytes (NCEs) remained unchanged in all the experimental groups. However, PCE/NCE ratio in the bone marrow decreased significantly in all the 131I exposed animals irrespective of antioxidant supplementation status. The normalization of salivary gland weight by antioxidant pre-supplementation in radioiodine exposed mice is suggestive of the possible ameliorating effect of antioxidants on the salivary gland weight recommending further detailed studies regarding the functional aspect of the salivary gland in higher animals.

Evaluation of the radioprotective effect of turmeric extract and vitamin E in mice exposed to therapeutic dose of radioiodine.

The aim of this study was to evaluate the radioprotective effect of turmeric extract (40 mg/kg body weight) and vitamin E (α- tocopherol acetate, 400 IU/kg body weight) supplementation on lipid peroxidation, reduced glutathione and antioxidant defense enzymes in various organs like liver, kidney and salivary glands at 24 h in adult Swiss mice. (131)Iodine exposure significantly increased lipid peroxidation in kidney and salivary glands in comparison to control animals. Pre supplementation with turmeric extract for 15 days showed significant lowering of lipid peroxidation in kidney. On the other hand vitamin E pre supplementation showed marked reduction in lipid peroxidation in salivary glands. Reduced glutathione levels decreased significantly in liver after radiation exposure. However, pre supplementation with turmeric extract and vitamin E did not improve glutathione levels in liver. In conclusion, we have observed differential radioprotective effect of turmeric extract and vitamin E in kidney and salivary glands. However, Vitamin E seems to offer better radioprotection for salivary glands which is known to be the major site of cellular destruction after radioiodine therapy in patients.

Chromosomal aberration analysis in chronically exposed radiation workers.

We performed a chromosomal aberration analysis on blood samples of 15 radiation workers by scoring dicentric aberrations. These workers were chronically exposed to cumulative doses of approximately 500 mSv over a period of two to three decades. The biological doses estimated using the linear coefficient of the in vitro dose/response curve based on dicentric frequency varied from 0 to 259 mGy, even though all the radiation workers had received approximately the same physical dose--i.e., 500 mSv. In all cases of chronic exposure, the estimated biological doses were found to be lower than the measured physical doses. The measured physical doses were corrected by applying the biphasic decay pattern of lymphocytes and also taking into consideration the time course of accumulation of doses in each individual. The corrected physical doses thus obtained were then compared with the estimated biological doses, and a reasonably good correlation was found between these two sets of values. However, on the whole, the corrected physical doses were found to be smaller than the estimated biological doses in most of the cases. This observation suggests that the kinetics of turnover of lymphocytes in conditions of chronic exposure may be slower than estimated so far in various studies involving exposures to high doses, wherein the estimation of life span of lymphocytes was carried out in patients undergoing radiotherapy.