Radiation induced hepatic lesions and their amelioration by Rosemarinus oficinalis

In the years following the discovery of radioactive, a strong correlation has been observed between exposure to ionizing radiation and the development of cancer. Workers and patients in nuclear medicine tend to be exposed to fractionated high doses of radiation over days, weeks or years. In contrast, survivors of the atomic blasts tend to be exposed to massive external doses of both high and low LET radiations over a matter of seconds with significant secondary fallout effects. Survivors of large scale nuclear accidents such as Chernobyl are exposed to lower doses of radiation over a long period of time, with the exposure involving the whole organism due to the intake of contaminated air, water and food. Public concern is being expressed over the radiation effects on men and environment with the increasing use of atomic energy in medicine, industry and power generation. The present study has been undertaken to rule out the radioprotective capacity of Rosemary plant (Rosemarinus oficinalis) for protection of the individuals exposed to radiation. For this purpose, Swiss albino mice, 6-8 weeks old, were selected from an inbred colony and divided into two groups. Group-I (Experimental) was administered Rosemarinus officinalis extract (ROE), orally at the dose of 1000 mg/kg.b.wt., once daily for 5 consecutive days. Group-ll (Irradiated Control) was given orally double distilled water equivalent to ROE. Half an hr. after the last administration of DDW or ROE on day 5th, both the groups were exposed to 5 Gy of gamma radiation. These mice were nacripsied at various intervals between 12 hrs. to 30 days and their livers were taken out for histopathological study. The variation in the number of normal, binucleated and abnormal hepatocytes in liver was determined in definite area measured with the help of planimeter. Normal hepatocytes were found to be declined in number up to day 5 in both the groups, but later such cells increased by reaching to near normal value at the last autopsy interval (i.e. 30 days), only in experimental group. On contrary, abnormal hepatocytes increased up to day 5 after irradiation. Binucleated hepatocytes showed a biphasic mode of elevation after irradiation, first on day 2 then on day 10 post-treatment in both the groups, but the same was comparatively less marked in experimental group. Several radiation induced hepatic lesions were also visualized in both the groups, but in ROE + radiation treated group, the degree of damage was found to be considerably lesser and the recovery from such lesions was much faster to regain the normal architecture of liver. Hence, the results from the present study suggest that Rosemarinus officinalis leaves extract pretreatment provides protection against radiation-induced histopathological alterations in liver of mammals. (author)